Persistent Bioaccumulative Toxic (PBT) Chemicals; Lowering of Reporting Thresholds for Certain PBT Chemicals; Addition of Certain PBT Chemicals; Community Right-to-Know Toxic Chemical Reporting

Federal RegisterOct 29, 1999

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SUMMARY: EPA is lowering the reporting thresholds for certain

persistent bioaccumulative toxic (PBT) chemicals that are subject to

reporting under section 313 of the Emergency Planning and Community

Right-to-Know Act of 1986 (EPCRA) and section 6607 of the Pollution

Prevention Act of 1990 (PPA). EPA is also adding a category of dioxin

and dioxin-like compounds to the EPCRA section 313 list of toxic

chemicals and establishing a 0.1 gram reporting threshold for the

category. In addition, EPA is adding certain other PBT chemicals to the

EPCRA section 313 list of toxic chemicals and establishing lower

reporting thresholds for these chemicals. EPA is removing the fume or

dust qualifier from vanadium and adding all forms of vanadium with the

exception of vanadium when contained in alloys. EPA is also adding

vanadium compounds to the EPCRA section 313 list of toxic chemicals.

However, EPA is not lowering the reporting thresholds for either

vanadium or vanadium compounds. EPA is taking these actions pursuant to

its authority under EPCRA section 313(f)(2) to revise reporting

thresholds and pursuant to its authority to add chemicals and chemical

categories that meet the EPCRA section 313(d)(2) toxicity criteria. The

additions of these chemicals are based on their carcinogenicity or

other chronic human health effects and/or their significant adverse

effects on the environment. Today's actions also include modifications

to certain reporting exemptions and requirements for those toxic

chemicals that are subject to the lower reporting thresholds. This

document also announces the effective date of Sec. 372.27 of the Code

of Federal Regulations, which contained information collection

requirements and which was originally published in the Federal Register

on November 30, 1994.

DATES: 40 CFR 372.27 became effective on March 17, 1995, when the

Office of Management and Budget approved its information collection

requirements. This rule shall take effect on December 31, 1999. For

purposes of EPCRA section 313(d)(4), the chemical additions shall be

considered made as of November 30, 1999, and shall apply for the

reporting year beginning January 1, 2000.

FOR FURTHER INFORMATION CONTACT: For technical information on this

final rule contact: Daniel R. Bushman, Petitions Coordinator,

Environmental Protection Agency, Mail Code 7408, 401 M St., SW.,

Washington, DC 20460; telephone number 202-260-3882, e-mail address:

[email protected]. For general information on EPCRA section 313,

contact the Emergency Planning and Community Right-to-Know Hotline,

Environmental Protection Agency, Mail Code 5101, 401 M St., SW.,

Washington, DC 20460, Toll free: 1-800-535-0202, in Virginia and

Alaska: 703-412-9877 or Toll free TDD: 1-800-553-7672.

SUPPLEMENTARY INFORMATION:

I. General Information

A. Does this Action Apply to Me?

You may be affected by this action if you manufacture, process, or

otherwise use aldrin, chlordane, dioxin and certain dioxin-like

compounds, heptachlor, hexachlorobenzene, isodrin, mercury, mercury

compounds, methoxychlor, octachlorostyrene, pendimethalin,

pentachlorobenzene, polychlorinated biphenyls, certain polycyclic

aromatic compounds, tetrabromobisphenol A, toxaphene, trifluralin, and

vanadium (except alloys) or vanadium compounds. See Table 1 in Unit

V.C. for a more detailed listing. Potentially affected categories and

entities may include, but are not limited to:

------------------------------------------------------------------------

Examples of Potentially Affected

Category Entities

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Industry SIC major group codes 10 (except

1011, 1081, and 1094), 12 (except

1241), or 20 through 39; industry

codes 4911 (limited to facilities

that combust coal and/or oil for

the purpose of generating power for

distribution in commerce); 4931

(limited to facilities that combust

coal and/or oil for the purpose of

generating power for distribution

in commerce); or 4939 (limited to

facilities that combust coal and/or

oil for the purpose of generating

power for distribution in

commerce); or 4953 (limited to

facilities regulated under the

Resource Conservation and Recovery

Act, subtitle C, 42 U.S.C. section

6921 et seq.), or 5169, or 5171, or

7389 (limited to facilities

primarily engaged in solvent

recovery services on a contract or

fee basis)

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Federal Government Federal facilities

------------------------------------------------------------------------

This table is not intended to be exhaustive, but rather provides a

guide for readers regarding entities likely to be affected by this

action. Other types of entities not listed in the table could also be

affected. To determine whether your facility would be affected by this

action, you should carefully examine the applicability criteria in part

372, subpart B of Title 40 of the Code of Federal Regulations. If you

have questions regarding the applicability of this action to a

particular entity, consult the person listed in the ``FOR FURTHER

INFORMATION CONTACT'' section.

B. How Can I Get Additional Information or Copies of this Document or

category

------------------------------------------------------------------------

Polychlorinated biphenyl (PCBs) 1336-36-3 10

------------------------------------------------------------------------

Tetrabromobisphenol A 79-94-7 100

------------------------------------------------------------------------

Toxaphene 8001-35-2 10

------------------------------------------------------------------------

Trifluralin 1582-09-8 100

------------------------------------------------------------------------

Mercury 7439-97-6 10

------------------------------------------------------------------------

[[Page 58672]]

Mercury compounds NA 10

------------------------------------------------------------------------

EPA is deferring its decision for two chemicals and one chemical

category. Specifically, EPA is deferring a determination on dicofol

while the Agency continues to review the available persistence data.

EPA is also deferring its decision on cobalt and cobalt compounds

because it needs to further investigate the bioaccumulative potential

of these chemicals.

C. What Thresholds Has EPA Established for PBT chemicals?

EPA is finalizing the thresholds it proposed for PBT chemicals in

the January 5, 1999 (64 FR 688) Federal Register. Specifically, EPA is

finalizing two thresholds based on the chemicals' potential to persist

and bioaccumulate in the environment. The two levels include setting

section 313 manufacture, process, and otherwise use thresholds at 100

pounds for PBT chemicals and at 10 pounds for that subset of PBT

chemicals that are highly persistent and highly bioaccumulative. One

exception is the dioxin and dioxin-like compounds category. The dioxin

and dioxin-like compounds category threshold determination required

special consideration because these highly persistent and highly

bioaccumulative compounds are manufactured in extremely small amounts

compared to other section 313 chemicals. In order to capture release

and other waste management data, EPA is setting the threshold for the

dioxin and dioxin-like compound category at 0.1 gram.

D. What Exemptions and Other Reporting Issues is EPA Addressing?

EPA is eliminating the de minimis exemption for the PBT chemicals

included in today's final rule. However, this action will not affect

the applicability of the de minimis exemption to the supplier

notification requirements (40 CFR 372.45(d)(1)). During the inter-

agency review process, it was suggested that EPA consider constructing

an exemption for facilities in SIC code 5171, i.e., Petroleum Bulk

Plants and Terminals. Specifically, it was suggested that EPA exempt

the processing of PBT chemicals in petroleum products. Before EPA can

consider this exemption, EPA must determine that these facilities

process and release and otherwise manage as waste very small aggregate

quantities of PBT chemicals. The Agency is soliciting comments and

information on this suggestion, particularly any information that could

provide a factual basis for such an exemption. Please send your

comments to the person listed in the ``FOR FURTHER INFORMATION

CONTACT'' section within the next 60 days. EPA will evaluate this

suggestion, and provide a response within approximately 180 days.

In today's action, EPA is also excluding all PBT chemicals from

eligibility for the alternate threshold of 1 million pounds and

eliminating for PBT chemicals range reporting for on-site releases and

transfers off-site for further waste management. This will not affect

the applicability of the range reporting of the maximum amount on-site

as required by EPCRA section 313(g). EPA is addressing the alkyl lead

compounds, tetraethyl lead (CAS No. 78-00-2), and tetramethyl lead (CAS

No. 75-74-1), in a separate rulemaking for lead and lead compounds (64

FR 42222, August 3, 1999) (FRL-6081-4). Therefore, EPA is not

finalizing any action with respect to these two lead compounds in

today's action.

EPA proposed to require reporting of all releases and other waste

management quantities greater than \1/10\ of a pound of PBT chemicals

(except dioxin), provided that the accuracy in the underlying data on

which the estimate is based supports this level of precision. Also, EPA

stated that releases and other waste management quantities would

continue to be reported to two significant digits. In addition, EPA

stated that for quantities of 10 pounds or greater, only whole numbers

would be required to be reported. For the category of dioxin and

dioxin-like compounds, which have a proposed reporting threshold of 0.1

gram, EPA proposed that facilities report all releases and other waste

management activities greater than 100 g (i.e., 0.0001 gram).

After reviewing all the comments on this issue, EPA is providing

additional guidance on the level of precision at which facilities

should report their releases and other waste management quantities of

PBT chemicals. Facilities should still report releases and other waste

management quantities greater than 0.1 pound (except dioxins) provided

the accuracy and the underlying data on which the estimate is based

supports this level of precision. Rather than reporting in whole

numbers and to two significant digits, if a facility's release or other

waste management estimates support reporting an amount that is more

precise than whole numbers and two significant digits, then the

facility should report that more precise amount. The Agency believes

that, particularly for PBT chemicals, facilities may be able to

calculate their estimates of releases and other waste management

quantities to \1/10\ of a pound and believes that such guidance is

consistent with the reporting requirements of sections 313(g) and (h).

E. What is the Relationship Between This Rule and the Clean Air Act

Mercury Information Collection Request?

Throughout calendar year 1999, EPA has been using authority under

section 114 of the Clean Air Act to require all coal-fired power plants

over 25 mega watts to submit to EPA the results of analyses of the

mercury content of their coal. A representative sample of these plants,

stratified by type of plant and type of coal burned, have been required

to perform stack testing to determine the amount (and species) of

mercury emitted. The stack testing will allow EPA to develop a set of

emissions factors that can be applied to the mercury in coal analysis

to generate mercury emissions estimates for each coal-fired plant. EPA

does not intend to continue to require plants to submit either the coal

analysis or the stack testing beyond the current requirement. Therefore

for the purpose of reporting mercury releases to the TRI, EPA expects

coal-fired power plants that do not have monitoring or stack test data

for the reporting year to use the emissions factors that EPA will

develop and make available to the public in the summer of 2000.

[[Page 58673]]

VI. Summary of Public Comments and EPA Responses

A. What Comments Did EPA Receive on its Statutory Authority to Add

Chemicals and Lower the Reporting Threshold and What is EPA's Response?

Several commenters assert that EPCRA section 313(f)(2) only grants

EPA the authority to raise the statutory thresholds, but not to lower

them. They agree that the substantial majority test is met ``as a

matter of logical necessity'' when EPA lowers the reporting threshold,

and argue that this makes the ``substantial majority'' test essentially

meaningless when thresholds are lowered. They argue that this

demonstrates that Congress did not intend for EPA to lower reporting

thresholds, only to raise them.

These commenters also rely on the language of other provisions of

EPCRA section 313 to support their argument that Congress did not grant

EPA authority to lower thresholds. They rely on the fact that section

313(f)(2) does not provide that EPA can ``raise or lower'' thresholds,

unlike section 313(d), under which EPA can ``add or delete'' chemicals

from the list, and section 313(b), under which EPA can ``add or

delete'' industry sectors. In addition, the commenters argue that

section 313(f)(2) is analogous to section 313(l), where, despite the

use of the otherwise neutral term ``modify,'' Congress clearly meant

for EPA only to make the reporting requirements less frequent (i.e.,

less stringent). Based on these provisions, they also argue that, where

Congress intended EPA to have the authority to both expand and restrict

reporting, the statute explicitly provides the authority, but where

Congress only intended to authorize EPA to reduce the reporting burden,

it provided a neutral term, and then restricted it. The commenters

argue that in section 313(f)(2), Congress qualified EPA's authority

with a substantial majority restriction that only makes sense if EPA

raises the thresholds.

EPA disagrees with the commenters' interpretations. Section

313(f)(2) clearly authorizes EPA to lower thresholds, as well as to

raise them. The plain language of this provision provides that ``the

Administrator may establish a threshold different from the amount

established by paragraph (1).'' It clearly does not state that the

Administrator may only establish a higher threshold than the amount

established by paragraph (1), which appears to be the commenters'

interpretation. Moreover, in the House debate on the conference report,

Representative Edgar, one of EPCRA's sponsors, noted:

The EPA is authorized to revise these thresholds, but only if

such revised thresholds obtain reporting on a substantial majority

of total releases, especially if such revised thresholds raise the

statutory levels,. . . (A Legislative History of the Superfund

Amendments and Reauthorization Act of 1986, Committee Print, vol. 6,

5315) (emphasis added).

The clear implication of this statement is that Congress intended EPA

to have the authority to lower, as well as to raise, the statutory

thresholds.

The commenters' interpretation that EPA lacks the authority to

lower the thresholds conflicts with Congressional intent in other ways.

During debate on the Conference Report, Representative Edgar noted that

``This act is intended to provide a comprehensive view of toxic

chemical exposure and, hopefully, provide a basis for more sensible and

effective local, State, and national policies.'' Legislative History at

5316. See, also, Legislative History at 5313 and 5338. And yet without

the authority to lower the thresholds, EPA cannot ensure that this

objective is achieved. For example, Congress included PCBs on the

original list of EPCRA section 313 chemicals, thereby indicating an

intent to provide the public with a ``comprehensive view of exposure''

to PCBs; but under the original reporting requirements, EPA only

received 6 reports. Under no interpretation can six reports be

characterized as obtaining ``a comprehensive view of toxic chemical

exposure.'' Legislative History at 5315.

EPA also disagrees with the comment that the Agency's

interpretation has rendered this provision meaningless. This argument

is based on a logical fallacy; a standard need not constrain agency

action to the same degree in all circumstances to be meaningful.

Congress may impose a standard that constrains actions to varying

degrees in different circumstances. In this case, the Congressional

debate on this provision indicates that Congress was most concerned

with the loss of publicly available information that may result from

raising the thresholds. See, e.g., Legislative History at 5315-16. It

is therefore reasonable to assume that Congress chose to impose a

standard that presented a greater constraint on the Agency's ability to

raise thresholds, and therefore created a ceiling beyond which the

Agency was not authorized to modify thresholds.

Further, notwithstanding the fact that under EPA's interpretation

of section 313(f)(2), the Agency can meet the statutory standard

without the need for quantitative support when it lowers the threshold,

EPA does not believe that Congress has granted it unfettered discretion

to establish a different threshold. As discussed at length in Unit

VI.E., Congress provided significant guidance in other provisions of

the statute and the legislative history, to guide the Agency's exercise

of discretion under this provision. Moreover, as noted above, the

substantial majority requirement establishes a ceiling beyond which the

Agency is not authorized to modify thresholds.

EPA also disagrees with the commenters' interpretation of other

provisions of EPCRA section 313. In general, Congress established the

basic framework of right-to-know reporting in EPCRA section 313, and

selectively granted EPA carefully qualified authority to adjust

individual parameters as appropriate. For example, EPA is authorized to

modify the chemicals on the EPCRA section 313 list, the SIC codes and

facilities covered by section 313, the reporting frequency, and the

reporting thresholds, but each grant of authority is constrained to

varying degrees by the standards contained in each respective

provision. As the commenters have correctly noted, where Congress

intended to restrict the Agency's authority to modify the original

requirements, it did so explicitly. For example section 313(l)

specifically limits EPA's authority to modify the reporting frequency:

``. . .but the Administrator may not modify the frequency to be any

more often than annually.'' Similarly Congress included no provision

authorizing any amendments to the generally applicable employee

threshold. It is therefore reasonable to assume that had Congress

intended to only permit EPA to raise the thresholds, they would have

included such an explicit restriction in the provision. Moreover, as

noted earlier in this unit, the little legislative history that exists

on this provision indicates that Congress intended EPA to have the

discretion to both raise and lower the reporting thresholds. Further,

EPA disagrees with the commenters' interpretation that Congress relied

on different statutory construction to indicate its decision not to

grant the Agency authority to decrease reporting thresholds, rather

than relying on an explicit restriction in the plain language of the

statute. EPA is aware of no indication of such Congressional intent in

the legislative history, nor have the commenters cited to any. More to

the point, the commenters' interpretation is clearly refuted by the

inclusion in section 313(l) of an explicit restriction, demonstrating

that where Congress

[[Page 58674]]

intended to restrict EPA's authority, it did so explicitly.

One commenter argues that EPA lacks authority to lower the

thresholds based on a comparison of the language in EPCRA sections 311

and 312 authorizing EPA to revise the section 311 and section 312

thresholds, with the language of section 313(f)(2). The commenter

states that Congress could have used this same broad and simple

language in section 313, and argues that because it did not, but

instead chose to impose the ``substantial majority'' requirement, this

demonstrates that Congress did not intend EPA to have the authority to

lower the thresholds. Instead, the commenter argues, Congress was

concerned with reporting burden when it crafted section 313, and so

declined to grant EPA authority to lower the thresholds.

EPA disagrees. There is no significant difference between the

language in sections 311, 312, and 313 that supports the commenter's

interpretation. Unlike section 313, Congress did not establish

thresholds in sections 311 and 312, but granted the Administrator broad

discretion to determine whether a threshold was even appropriate; at

what level to establish the threshold; and to modify it as appropriate.

The language with which Congress conferred this authority provides that

``the Administrator may establish threshold quantities. . . .'' This is

almost identical to the language of section 313(f)(2), which simply

provides that ``the Administrator may establish a threshold amount for

a toxic chemical different from the amount established by paragraph

(1).'' The commenter's argument turns wholly on the inclusion of the

``substantial majority'' requirement, and as explained above, EPA does

not believe that this standard either precludes EPA from lowering

thresholds or demonstrates Congressional intent to do so.

Several commenters challenged EPA's finding that its alternate

thresholds would capture a substantial majority of total releases,

contending that the Agency had impermissibly relied on an increase in

the number of reports submitted. The commenters assert that EPA is

required to estimate releases at these facilities and determine, on a

percentage basis, whether a ``substantial majority'' of all releases of

each chemical, from all facilities subject to EPCRA section 313, will

be captured. One commenter noted that, even if lowering the threshold

for an EPCRA section 313 chemical results in an increase in the number

of reports on the chemical, this does not necessarily mean that the

additional reports will capture a substantial majority of the total

releases from all facilities subject to EPCRA section 313 reporting. In

order for the lower threshold to meet the statutory test, the threshold

must result in capturing at least two thirds of all releases of the

chemical at covered facilities. The commenter contended that the number

of reports is irrelevant to the percentage of releases captured by the

reports. If a certain chemical were present at only one facility in the

country subject to EPCRA section 313, the submission of one report on

the chemical accounting for at least 66% of the releases from that

facility would satisfy the ``substantial majority'' test. By contrast,

if a lower threshold generated 1,000 new reports on a EPCRA section 313

chemical, the ``substantial majority'' test would not be met if those

reports did not account for at least 66% of the total releases from all

facilities subject to EPCRA section 313. This may be the case, for

example, if a large percentage of releases of the EPCRA section 313

chemical occurred at facilities otherwise subject to EPCRA section 313

that do not meet the threshold for that particular chemical that

triggers the obligation to report the releases.

EPA disagrees with the commenter's interpretation. As noted in the

proposed rule, EPA interprets the language in 313(f)(2), ``facilities

subject to the requirements of [section 313],'' to refer to those

facilities that fall within the category of facilities described by

sections 313(a) and (b). Subsection (a) lays out the general

requirement that ``the owner or operator of facilities subject to the

requirements of this section'' file an EPCRA section 313 report.

Subsection (b) then further defines the facilities subject to the

requirements of this section:

[t]he requirements of this section shall apply to owners and

operators of facilities that have 10 or more full-time employees and

that are in Standard Industrial Classification Codes 20-39, . . .

and that manufactured, processed, or otherwise used a toxic chemical

listed under subsection (c) of this section in excess of the

quantity of that toxic chemical established under subsection (f) of

this section during the calendar year for which a toxic chemical

release form is required under this section.

Thus, to be subject to the requirements, a facility must meet all three

of the requirements laid out in subsection (b). This means that the

class of facilities subject to reporting under section 313 will vary

according to the individual chemical. Moreover, facilities that have

not exceeded a threshold for a particular chemical are not ``subject to

the requirements'' of EPCRA section 313 for that chemical.

To determine whether a particular threshold, either higher or

lower, for an individual chemical meets the substantial majority test,

one would compare the total national aggregate of releases of the

chemical by covered facilities at the existing thresholds with the

estimated total national aggregate of releases at the proposed

alternate threshold, and determine whether a substantial majority of

releases reported under the original thresholds would be reported.

Logically, the universe of facilities subject to the requirements under

a lower threshold will always be either equivalent to, or greater, than

the universe of facilities that are subject to the requirements under

the existing thresholds. Moreover, because facilities subject to the

requirements of section 313 must report ``the annual quantity of the

toxic chemical entering each environmental medium,'' EPA can meet the

substantial majority standard when lowering the thresholds, without the

need for quantitative support; i.e., facilities that report, must

report their releases and other waste management quantities. In this

instance, the number of reports serves as an adequate surrogate for

releases because essentially all releases (and other waste management

quantities) will be reported by facilities subject to the requirements

of this section.

In other words, facilities ``subject to the requirements of this

section'' are those that must file EPCRA section 313 reports. Thus, the

baseline against which the ``substantial majority of total releases''

is measured is the category of facilities that currently submit

reports. Consequently, if quantitative support for its finding were

necessary, EPA would be justified in relying on the number of reports

to make its finding.

By contrast, although it is not clear exactly how the commenters

interpret the phrase ``facilities subject to the requirements of this

section,'' it is clear that they do so without reference to all of the

requirements in subsections (a) and (b). And essentially, any

interpretation that ignores any portion of subsection (b), results in

an interpretation of EPCRA section 313(f)(2) as ``facilities otherwise

or potentially subject to the requirements of this section.'' This is

inconsistent with the plain language of section 313(f)(2). The

commenters can only support their argument that EPA has not met the

``substantial majority'' test by assuming that all facilities,

irrespective of whether they are in a covered SIC code or they exceed

the existing thresholds, are subject to EPCRA section

[[Page 58675]]

313, and that EPA must ensure that it captures a substantial majority

of releases from the universe of those facilities. If this were

correct, the addition of certain SIC codes could be a prerequisite to

lowering thresholds for certain chemicals. Such a requirement is not

currently included in section 313. The commenters have provided no

support in either the statute or legislative history for these

interpretations. Nor have the commenters provided any support for the

interpretation that ``substantial majority'' equates to a particular

percentage, such as 66%.

Finally, EPA notes, as it noted in the proposed rule, that, for

several reasons, it does not believe that it has the necessary

information to develop even reasonably accurate estimates of the

potential releases that would be reported at an average facility at

each of the identified options for a lowered threshold. Specifically,

EPA believes that: (1) Sufficient information is not currently

available for these chemicals, and (2) there is insufficient

information on the numerous processes employed by all the sectors

involved to calculate a comprehensive release estimate for each sector.

While there are some data available, comprehensive data are not

available for all sectors and chemicals. EPA further notes that none of

the commenters provided either any information or methodology to

address this issue, notwithstanding EPA's specific request.

Two commenters rely on excerpts from the debate on the Conference

Report with respect to section 313(f)(2) to argue that EPA is only

authorized to revise the thresholds if EPA presents a convincing

analysis that revisions to the threshold will capture a substantial

majority of the releases while also ensuring that it is not placing

undue burdens on facilities which contribute little to such releases.

The commenters argue that EPA has not satisfied the substantial

majority requirement, and to do so, must conduct a more thorough

assessment of the burden imposed on industry focused on the volume of

releases that will be captured, not the number of reports. Another

commenter compares the legislative history of sections 311 and 312 with

313, and concludes that Congress clearly intended EPA to factor burden

into section 313 threshold questions.

EPA disagrees. Ultimately, EPA must comply with the statutory

language, and section 313(f)(2) does not impose any requirement on the

Agency to rely on the type of analyses described by the commenter. In

addition, the commenters' reliance on the statements made during the

Conference Report debate are misplaced. The commenter only quotes part

of Representative Edgar's statement; the full quotation indicates only

that EPA must present a convincing case, ``based on verifiable,

historical data'' that the statutory thresholds warrant revision. As

discussed below in Unit VI.E., EPA believes it has presented a

convincing case that the thresholds should be lowered for PBT

chemicals. The commenter also failed to include the portion of

Representative Edgar's statement explaining that a convincing case was

particularly necessary if the effect of the modification was to raise

the thresholds. See, Legislative History at 5315.

Nonetheless, as discussed in greater detail in Unit VI.E., EPA

considered the burden that lower thresholds would impose on industry in

selecting the PBT thresholds. EPA believes that the levels it has

adopted will capture significantly more information about PBT chemicals

than current thresholds, but will not be unduly burdensome on industry.

In addition, as discussed in the Response to Comments document (Ref.

69), EPA believes that the number of reports filed is a more accurate

measure of burden than the volume of releases.

A commenter alleges that EPA's interpretation of section 313(f)(2)

contradicts its prior statements regarding threshold changes. The

commenterstates that EPA was clear in the original EPCRA section 313

rulemaking that the statute requires a substantial majority finding

supported by actual data. For example, in the June 1987 proposed rule,

EPA stated: ``The Agency is interested in data that would support the

necessary finding that a modified threshold would still generate

reporting on a substantial majority of total releases, as the statute

requires.'' And in the February 16, 1988 final rule promulgating EPCRA

section 313 requirements, EPA stated

. . .the first few years' data should be evaluated to determine

whether modifications of the threshold would meet the statutory test

of obtaining reporting on a substantial majority of the releases

(i.e., pounds released per year) of each chemical from subject

facilities. EPA may consider changing the reporting thresholds based

on several years of data collection.

The commenter also notes that in neither the proposed nor final rule

establishing EPCRA section 313 requirements did EPA specifically assert

that it had the authority to lower thresholds.

EPA disagrees that its statements in this rulemaking contradict its

prior statements in the 1988 rulemaking. As a preliminary matter, EPA

has never denied that the requirement that a revised threshold obtain

reporting on a substantial majority of total releases applies to any

action lowering the reporting thresholds. Specifically, EPA's

discussion in the 1987 proposed rule was in the context of a response

to proposals from the Small Business Administration (SBA) that the

Agency raise the thresholds to capture only larger facilities. EPA's

statements in the 1988 final rule also need to be evaluated with SBA's

proposals in mind. Moreover, while it is true that the discussion to

which the commenter cited did not distinguish between lowering and

raising the thresholds (it was intended as a response to comments on

both sides of the issue), EPA notes that the majority of the comment

summary focuses on requests to raise the thresholds. Finally, while it

is true that EPA did not specifically assert its authority to lower the

thresholds in either rule, neither did EPA deny that EPCRA section

313(f)(2) grants it this authority. However, it is worth noting that in

the final rule, EPA responded to comments from environmental and public

interest groups requesting that the Agency lower the thresholds, and

that EPA never stated or implied that it lacked the authority to lower

thresholds.

One commenter states that EPA's authority to lower reporting

thresholds is not limitless. The commenter argues that a decision to

lower the thresholds must be tied to the overall purpose of the Act,

namely, to inform the public of potential health risks posed by the

presence of toxic chemicals released to the environment in their

communities. A regulatory decision to capture more reports under EPCRA

section 313 must be based on the need to inform the public of health

risks associated with the releases captured in those reports.

Otherwise, the usefulness of the TRI data base begins to diminish. EPA

needs to demonstrate that the releases of the PBTs at such small

amounts pose a meaningful risk to the public health. Another commenter

asserts that EPA is relying on the purposes of EPCRA to support its

interpretation of section 313(f), and argues that, although section

313(h) does describe intended uses for TRI data, section 313(h) itself

does not describe the purposes or intention of section 313. The

commenter instead relies on several provisions of section 313 and

argues that the purpose and intention of Congress to make information

available to the public was balanced by concerns about the potential

burden of the TRI program. The commenter also states that the uses

[[Page 58676]]

Congress anticipated for TRI data do not outweigh the balance that

Congress intended between generating information and minimizing burden,

and do not grant EPA blanket authority to expand the reporting

requirements.

EPA agrees with the commenter that its authority to lower reporting

thresholds is not limitless, and that its decision to lower the

thresholds must be tied to EPCRA's overall purposes. However, EPA

believes that Congress granted the Agency broad, but not unfettered,

discretion to determine when it is appropriate to lower thresholds, and

to determine the specific thresholds that are appropriate. As discussed

in greater detail in Unit VI.E., EPA believes that its decision to

lower the thresholds, and the thresholds it has chosen, reflect these

principles.

However, EPA generally disagrees with the remainder of the

commenter's conclusions. As discussed in more detail in Unit VI.F., EPA

is not required to base its decisions under EPCRA section 313 on the

need to inform the public of health risks associated with reported

releases and other waste management quantities. And as discussed

elsewhere in this preamble and the Response to Comments document (Ref.

69), EPA believes that the information that will be reported as a

result of this rulemaking will provide useful information to the

public.

In large measure, the issues raised in the second comment closely

relate to the specific thresholds and EPA's rationale for choosing

them, and this issue is discussed in more detail in Unit VI.E. However,

to the extent it relates to EPA's interpretation of section 313(f)(2),

some response is also provided here.

As a preliminary matter, while it is true that EPCRA section 313

does not explicitly identify the purposes of the section, the

Conference Report makes clear that subsection (h) of section 313:

Describes the intended uses of the toxic chemical release forms

required to be submitted by this section and expresses the purposes

of this section. The information collected under this section is

intended to inform the general public and the communities

surrounding covered facilities about releases of toxic chemicals, to

assist in research, to aid in development of regulations,

guidelines, and standards, and for other similar purposes.

(Conference Report at 299).

Contrary to the commenter's assertion, the Agency never indicated

that it was relying on section 313(h) to expand its authority under

section 313(f)(2). Rather, EPA noted that it was relying on the

purposes of section 313 as an additional source of Congressional

direction to guide the Agency's exercise of discretion under this

provision. EPA relied on section 313(h), in part, because the Agency

believes that its implementation of EPCRA generally should be guided by

EPCRA section 313's purposes. In addition, section 313(h) shares

certain elements with the Congressional guidance on section 313(f)(2)

in the legislative history. As discussed in greater detail in Unit

VI.E., EPA has distilled those common elements, and relied on them to

guide its discretion in establishing the specific thresholds under

section 313(f)(2).

EPA also disagrees with the commenter's assertion that the purpose

of EPCRA is to achieve a balance between the public's right to

information about their potential exposures to toxic chemicals and the

reporting burden imposed on industry. EPCRA section 313(f)(2) does not

require EPA to consider burden in establishing revised thresholds.

Although EPA has included the reporting burdens imposed on industry as

one consideration in determining the appropriate thresholds, the Agency

is also mindful that the authors of EPCRA, while sensitive to the

burdens EPCRA section 313 reporting placed on industry, never intended

this consideration to outweigh the public's need for access to

information concerning release and waste management, and thus their

potential exposure to toxic chemicals. See, e.g., Legislative History

at 5315-16 and 5338-39. And with respect to the assertion that the

general purposes of section 313 are to balance the public's right-to-

know about toxic chemical releases and other waste management in their

communities against the reporting burdens EPCRA section 313 imposes,

EPA notes that reporting burden is not included anywhere in section

313(h). Nor does the strong policy directive underlying EPA's overall

implementation of EPCRA section 313 support such an interpretation.

Representative Edgar, one of the bill's primary architects noted:

The heart of the Federal Right-to-Know Program is its reporting

requirements, which are intended to provide a comprehensive picture

of the community's and the Nation's exposure to toxic chemicals. As

the Environmental Protection Agency, the States, and localities

implement this program, they should be guided by several general

principles.

First, Congress recognizes a compelling need for more

information about the Nation's exposure to toxic chemicals. Until

now, the success of such regulatory programs such as the Clean Air

Act, the Resource Conservation and Recovery Act, and the Clean Water

Act has been impossible to measure because no broad-based national

information has been compiled to indicate increases or decreases in

the amounts of toxic pollutants entering our environment. As a

result, the reporting provision in this legislation should be

construed expansively to require the collection of the most

information permitted under the statutory language. Any discretion

to limit the amount of information reported should be exercised only

for compelling reasons. . . . Legislative History at 5313.

Significantly, Representative Edgar did not include reporting burden as

one of the general principles that should guide the Agency's

implementation of EPCRA section 313. Rather, he stated:

This is a new Federal initiative, and I recognize the desire of

some of my colleagues to move ahead cautiously to ensure that

burdens imposed on industry are not excessive. Frankly, my concerns

rest with the families that live in the shadows of these chemical

and manufacturing plants. I have put myself in their shoes and have

fought for a program that looks after their needs. This legislation

gets us well on the path to the full disclosure they deserve. Id at

5316.

Nonetheless, EPA has considered the legislative history on section

313(f)(2), including the excerpts cited by the commenter, and

determined it would be reasonable to include some consideration of the

reporting burdens in selecting its revised thresholds. The degree to

which EPA included burden in its selection of the thresholds

established in this rulemaking is discussed at length in Unit VI.E. and

the Response to Comments document (Ref. 69).

EPA agrees that section 313(h) does not grant EPA unfettered

discretion to expand EPCRA's reporting requirements; as noted in a

previous response, Congress established the basic parameters of the

EPCRA section 313 reporting requirements, and selectively granted EPA

carefully qualified authority to modify certain of them. In this

action, for example, EPA is only affecting the activity thresholds, but

Congress established other limitations that govern whether a facility

is subject to reporting. For example, facilities with fewer than 10

employees are not subject to reporting under subsection 313(b)(1).

B. What Comments Did EPA Receive on Persistence Criteria,

Bioaccumulation Criteria, and Toxicity Criteria, and What Are EPA's

Responses?

1. Comments on EPA's general approach. Several commenters contend

that only chemicals which are globally recognized as persistent

bioaccumulative toxic chemicals should form the foundation of the EPCRA

section 313 PBT chemical list and criteria. The application of the

criteria in this manner is consistent with several existing

international agreements and

[[Page 58677]]

programs, such as the Great Lakes Binational Strategy, the North

American Commission on Environmental Cooperation (NACEC), the United

Nations Economic Commission for Europe's (UNECE) agreement to address

persistent organic pollutants (POPs), and the United Nations

Environmental Programme (UNEP). These programs have prompted widely

accepted numerical values for persistence and bioaccumulation and

defined parameters for assessing toxicity. These criteria have also

been adopted with U.S. support and leadership and the commenters

contend that it is not clear why EPA is now taking a vastly different

approach to identifying PBT criteria in the proposed rule. The

commenters suggest that EPA conform the criteria for PBT chemicals on

EPCRA section 313 with the criteria and chemicals that are part of the

programs being implemented by the NACEC, UNECE, and UNEP. By doing so,

EPA would harmonize the U.S. program with similar international

programs that focus on a narrow set of PBT chemicals.

EPA believes that it would be inappropriate to merely adopt the

criteria and list of chemicals managed under the international programs

cited because the purposes of the TRI program are different than the

purposes of the cited international programs. The TRI was established

by Congress under EPCRA section 313 in response to public demand for

information on toxic chemicals being released in their communities. The

TRI program is national in scope, but a significant part of its

overriding goal is to provide information on releases to local

communities so that they can determine if the releases result in

potential risks. The entire concept of TRI, and indeed other, similar

Pollutant Release and Transfer Registries (PRTRs) since established in

several nations, is founded on the belief that the public has the right

to know about chemical use, release, and other waste management in the

areas in which they live, as well as the hazards associated with these

chemicals. This emphasis is fundamentally different from the global

focus of the UNEP negotiation and its concept of residual risk. It is

EPA's position that the domestic, community-based purposes of EPCRA

section 313 have important implications with regard to the criteria

used to identify toxic chemicals as persistent and/or bioaccumulative,

as well as the methods and models used to evaluate persistence and/or

bioaccumulation.

EPCRA section 313 charges EPA with collecting and disseminating

information on releases, among other waste management data, so that

communities can estimate local exposure and local risks. One intent of

EPCRA section 313 is to provide information to the public so that they

can take an active role in determining what risks resulting from toxic

chemical releases in their community are acceptable. This basic local

empowerment is a cornerstone of the right-to-know program.

EPCRA section 313(h) states that:

The release forms required under this section are intended to

provide information to the Federal, State, and local governments and

the public, including citizens of communities surrounding covered

facilities. The release form shall be available, consistent with

section 11044(a) of this title, to inform persons about releases of

toxic chemicals to the environment; to assist governmental agencies,

researchers, and other persons in the conduct of research and data

gathering; to aid in the development of appropriate regulations,

guidelines, and standards; and for other similar purposes.

EPCRA section 313 establishes an information collection and

dissemination program. EPA interprets EPCRA section 313(g)(2) to

require facilities to use readily available information to prepare each

chemical-specific EPCRA section 313 report. The statute does not

require that the facility conduct additional monitoring or emissions

measurements to determine these quantities. A facility must only use

readily available data or reasonable estimation methods in preparing

the quantitative information it reports.

The purpose of EPCRA section 313 is not to ban the manufacture or

use of a chemical, to restrict releases of the chemical, or to dictate

how it should be used or released. As a result, the burden and control

EPCRA section 313 imposes is significantly less than that imposed by a

statute that controls the manufacture, use, and/or release of a

chemical. The focus of EPCRA section 313 is not equivalent to the focus

of a statute or international agreements in which chemicals are to be

banned, phased-out, or restricted.

In contrast, the international agreements cited by the commenters

are intended to ban, restrict, or phase-out the manufacture, use and/or

release of a limited set of persistent organic pollutants and certain

heavy metals that are highly persistent and highly bioaccumulative.

Descriptions of the purposes of the Protocol on Persistent Organic

Pollutants (POPs); Convention on Long-Range Transboundary Air Pollution

(LRTAP), UNECE, UNEP on POPs, North American Commission for

Environmental Cooperation's Sound Management of Chemicals (NACEC SMOC),

as well as the International Council of Chemical Associations' (ICCA)

position on POPs are presented below. The following quotes clearly

illustrate that the intent of the international agreements is to

narrowly focus on that subset of toxic chemicals which are of regional

(e.g., North America and Europe) or global concern.

UNECE LRTAP

The ultimate objective is to eliminate any discharges, emissions

and losses of POPs. The Protocol bans the production and use of some

products outright (aldrin, chlordane, chlordecone, dieldrin, endrin,

hexabromobiphenyl, mirex and toxaphene). Others are scheduled for

elimination at a later stage (DDT, heptachlor, hexachlorobenzene,

PCBs). Finally, the Protocol severely restricts the use of DDT, HCH

(including lindane) and PCBs. The Protocol includes provisions for

dealing with the wastes of products that will be banned. (The 1998

Aarhus Protocol on Persistent Organic Pollutants (POPs); Convention

on Long-Range Transboundary Air Pollution, United Nations Economic

Commission for Europe (UNECE) at http://www.unece.org/env/lrtap)

(Ref. 54)

UNEP

International action to protect health and the environment

through measures which will reduce and/or eliminate emissions and

discharges of persistent organic pollutants, including the

development of an international legally binding instrument.

(Governing Council Decisions 20/24, 1999; United Nations

Environmental Programme at http://irptc.unep.ch/pops/newlayout/

negotiations.htm) (Ref. 57)

NACEC SMOC

NACEC SMOC has developed action plans for PCBs, DDT, chlordane,

and mercury. The action plans include 1) for PCBs ``work toward the

virtual elimination of PCBs in the environment, which the task force

is interpreting as no measurable release to the environment'', 2)

for DDT ``gradual reduction of DDT use for malaria control'' and

``additional reductions,'' 3) for chlordane ``phase-out of chlordane

use'', and 4) for mercury ``reduce sources of anthropogenic mercury

pollution.'' The longer-term goal of the plan is to reduce the

presence of mercury in the environment to achieve naturally

occurring levels.'' (North American Cooperation for the Sound

Management of Chemicals (June 1998); North American Commission for

Environmental Cooperation at http://www.cec.org/english/profile/

coop/Pollute_f.cfm?format=1) (Ref. 40)

ICCA

ICCA Position: ICCA member associations have demonstrated their

commitment to sound chemicals management, and to the goal of

reducing the potential human health and environmental risks that may

be associated with POPs. Many POPs are already subject to

considerable voluntary risk management by chemical companies, and

the uses of most substances identified as POPs has been discontinued

or extremely limited

[[Page 58678]]

by chemical companies within the countries represented by ICCA

member associations. (International Council of Chemical Associations

(ICCA) Briefing Note on Persistent Organic Pollutants (POPs) (April

21, 1998) at http://www.icca-chem.org/issues.htm) (Ref. 26)

In addition, as directed under EPCRA section 313(h), EPA makes the

TRI data available to various groups, including international

organizations, that, in turn, use the information to decide whether to

ban, restrict, or phase-out chemicals.

For the same reasons, EPA also disagrees that only substances

globally recognized as POPs should provide the basis of persistence

criteria for this rulemaking. POPs are organic chemicals whose

characteristics of persistence in the environment, accumulation in

biological organisms and toxicity make them priority pollutants that

cause significant environmental risks to humans and ecosystems. The

substances or substance categories being considered for implementation

of global controls through the UNEP negotiations (UNEP/GC.18/32, 1995:

aldrin, chlordane, DDT, dieldrin, endrin, heptachlor, mirex, toxaphene,

hexachlorobenzene, PCBs, polychlorinated dibenzo-p-dioxins and furans)

(Refs. 44 and 45) were selected largely because they or their

degradation products pose risks that may occur far from their sites of

initial entry into the environment. The UNEP action is the global

counterpart to similar, regional negotiations, most notably the UNECE

Convention on Long-Range Transboundary Air Pollution (LRTAP) (Ref. 54);

the North American Free Trade Agreement (NAFTA) CEC Initiative on the

Sound Management of Chemicals (Ref. 39); and the bilateral US/Canada

agreement to control discharge or release of POPs in the Great Lakes

basin (Ref. 23). A central theme of the UNEP action, consistent with

its global scope, is the notion of residual risk, meaning specifically

that to be subject to the negotiations, it is not sufficient for a

substance to pose risks within a nation or regionally, rather it must

pose risks to populations and nations distant from release sites.

2. Comments on EPA's individual criteria. The same commenters state

that EPA should use the international criteria being applied by UNEP,

UNECE LRTAP, NACEC SMOC, for persistence, bioaccumulation, and

toxicity. Some of these commenters also include the criteria developed

by CMA (CMA, PTB Policy Implementation Guidance: Product Risk

Management Guidance for PTBs (February 1996)). One commenter includes

the criteria developed by the ICCA for POPs. Another commenter states

that there is no reason to adopt criteria that are significantly more

stringent than those used in other programs. One commenter states that

EPA should consider the degree of toxicity and focus on the most toxic

chemicals. Some commenters state that EPA should couple the persistence

and bioaccumulation criteria to each other. They believe that these

criteria should not be considered independently. The numerical criteria

presented by some of the commenters are provided below:

Table 2.--Numerical Persistence and Bioaccumulation Criteria Suggested by Commenters

--------------------------------------------------------------------------------------------------------------------------------------------------------

Environment Canada

UNEP POPs/CEG Toxic Substances

CMA PTB Policy NACEC SMOC UNECE (LRTAP) POPs FRAMEWORK Management Policy ICCA

(June 1995)

--------------------------------------------------------------------------------------------------------------------------------------------------------

Persistence Half-life = 6 Half-life > = 2 Half-life> 2 Half-life > [2 or Half-life > = 2 Half-life = 6

months in water days air; 6 months water or 6 6] months soil/ days air; 6 months water, 1

or 1 year in soil months water/ months soils/ sediment; or months water/ year soil

soil; or 1 year sediment; or other evidence soil; 1 year sediments, or 5

sediment otherwise that substance is sediment days air

sufficiently sufficiently

persistent to be persistent to be

of concern of concern

--------------------------------------------------------------------------------------------------------------------------------------------------------

Bioaccumulation BAF/BCF > = 5,000 BAF/BCF >= 5,000 BAF/BCF > 5,000 or BCF/BAF > 5,000 or Half-life > 2 BCF > 5,000 or log

or estimation or Log Kow > = 5 Log Kow > 5 or Log Kow> [4 or months water or 6 Log Kow > 5 and

techniques factors such as 5]; evidence that months soils/ g/kg)) but much lower levels in

Aleutian otters (40 g/kg) and southeast Alaska otters (1

g/kg), and attributed the higher levels in the California

otters to extensive DDT use and production in this region from the

1950s to the 1970s. Even UNEP's Criteria Expert Group (CEG), which is

charged with developing criteria and procedures for addition of

substances beyond the original 12 POPs, has highlighted the importance

of ``near-field'' exposures:

In warmer climates exposures may occur closer to the source;

e.g., occupational exposure during use, or local exposure caused by

runoff from use or leaking from stockpiles. Food, such as fish, may

be a major route of intake also in warmer climates [in contrast to

Arctic and sub-Arctic regions] and POPs may accumulate in the food

chain and reach high levels in predatory species in these

conditions. (UNEP/POPS/INC/CEG/1/2: 1998) (Ref. 56)

An additional factor that argues for adopting the more protective

persistence criterion is the need for communities with vulnerable

populations to have access to data on release and other waste

management quantities. Examples of such populations include toddlers

who play in contaminated soil, local farmers who consume their own

produce, and subsistence as well as sport fishers, who often consume

large quantities of what they catch. The relative importance of any of

these pathways depends on the properties of the substance, rates and

media of release and other factors, but ingestion of bioaccumulating

substances may occur by all of these routes. The Organization for

Economic Cooperation and Development (OECD) guidance on the assessment

of indirect human exposure to chemical toxicants is consistent with EPA

policy, and states that in the case of local, site-specific emissions,

one or more of these subgroups may be particularly endangered (Ref.

53).

From a scientific perspective there is no one best persistence

criterion. However, it is simply not accurate to state that there is no

precedent or basis for using a persistence criterion of 2 months. As

outlined in the proposed rule (64 FR 701), similar values have been

proposed by several authorities, including the Ontario, Canada Ministry

of Environment and Energy (MOEE) for its Candidate Substances List for

Bans or Phaseouts (Ref. 36); the Canadian initiative for Accelerated

Reduction/Elimination of Toxics (ARET) (Refs. 1 and 2); the

International Joint Commission's (IJC) Great Lakes Water Quality

Agreement (GLWQA) (Ref. 27); and the UNECE's LRTAP Convention, which

did adopt 2 months as the persistence criterion of record for water

(Ref. 54). In each of these programs the focus was on persistent,

bioaccumulative and toxic substances, and it is noteworthy that all are

national or regional, not global, in scope. Thus, a trend exists in

which authorities with domestic or regional mandates to take action to

reduce risks from indirect exposure to PBT chemicals have recommended

half-life criteria substantially lower than 6 months.

EPA's Office of Water maintains a Listing of Fish and Wildlife

Advisories (LFWA) for the U.S. and territories, which listed 2,299

advisories in 1997 (Ref. 29). U.S. states and territories and Native

American tribes have primary responsibility for issuing advisories for

the general population, which include recommendations to limit or avoid

consumption of certain fish and wildlife from specific water bodies.

The overwhelming majority of the advisories are for well recognized PBT

chemicals (chlordane, mercury, PCBs, etc.), but many less familiar

substances are also represented. The number and content of advisories

in LFWA clearly indicate that toxicologically significant levels of

chemical contaminants, specifically PBT chemicals, are often found in

fish and wildlife that are caught noncommercially and consumed by the

U.S. population. It is generally impossible to determine the exact

source(s) of exposure for the species and locations included in any

given advisory, but it seems highly unlikely that the majority of

listed contaminants in U.S. waters could be derived from non-U.S.

(i.e., geographically distant) sources. The LFWA thus lends further

support to the contention that concern for exposure to PBT chemicals is

not limited to situations where the exposure results primarily from

LRT. It should be noted that the fact that no advisories have been

issued for a particular chemical does not mean that it does not

persist. Not all species of aquatic organisms are tested nor are all

water bodies, in addition, each state determines what it will use as

the level of concern for issuing an advisory.

A series of Toxic Substances Control Act (TSCA) section 5

Premanufacture Notifications (PMNs) submitted to EPA in 1990 also

illustrates that exposure to PBT chemicals is not limited to LRT (Refs.

37 and 38), and also demonstrates: (i) Why EPA believes that the

persistence criterion for bioaccumulating substances in soil, water, or

sediment should be set substantially lower than 6 months; and (ii) that

for purposes of EPCRA section 313, concern for potential exposures to

persistent and bioaccumulative toxics

[[Page 58681]]

must extend beyond the UNEP's 12 widely acknowledged POPs. The

substances in question were alkylated diphenyls for use as solvents,

and for which EPA expected discharge to receiving streams and rivers.

The submitter supplied data on use and disposal, aquatic toxicity, and

biodegradability. The submitted environmental fate data and EPA

estimates of biodegradability based on structural analogs suggested

that half-lifes in water would be well below 6 months, but not

necessarily lower than 2 months. As a result of concerns expressed by

EPA, use was limited to sites where resulting water concentrations

could be limited to 1 microgram per liter (g/L) or less;

concomitantly, the submitter was also informed of EPA's belief that a

potential for long-term risk existed, but that EPA could not quantify

this risk since assessments typically evaluated releases over only 1

year. In 1998, results of monitoring were announced by the State EPA

and revealed that the alkylated biphenyls had been found in fish

fillets and sediment samples from the receiving stream.

One commenter contends that the persistence criteria of half-lifes

of 2 months for water, soil, and sediment and 2 days for air may not be

sufficiently protective (i.e., the criteria may be too high).

EPA disagrees with the comment. EPA believes that it should adopt

criteria that focus on toxic chemicals that will build up in the

environment, while at the same time not limiting the list of persistent

toxic chemicals to only those that are of global concern. As discussed

earlier in this section, EPA believes that 2 months is a reasonable

half-life criterion given the purposes of EPCRA section 313. EPA

believes that application of lower criteria would include so many

substances as to be impractical. Further, given the uncertainties that

often exist regarding physical properties and environmental behavior of

chemicals, caution is especially appropriate for substances with

shorter half-lifes, since they are (all other things being equal) less

likely to build up in the environment than more persistent substances.

EPA believes that the adoption of criteria of half-lifes of 2 months in

water, soil, and sediment and a half-life of 2 days in air allows EPA

to balance the need to provide communities and other data users with

information on toxic chemicals that persist in their environment

without being overly inclusive or restrictive.

One commenter contends that a half-life criterion for air of 2 days

should be considered sufficient in and of itself for designating

substances as persistent.

EPA agrees with the comment. EPA made the following statements in

the proposed rule regarding the 2-day air half-life criterion and its

use in the determination as to whether a chemical was a PBT under EPCRA

section 313:

For the purposes of determining whether a toxic chemical is

persistent in the environment under section 313, EPA used a half-

life criterion of 2 months for water/sediment and soil and a half-

life of 2 days for air. Given the above discussions, EPA believes

that, for purposes of reporting under section 313, these values are

appropriate for determining whether a toxic chemical is persistent

in the environment and will persist long enough in the environment

to bioaccumulate or be transported to remote locations. Under these

criteria, if a toxic chemical meets any one of the media specific

criteria, then it is considered to be persistent. Thus if a toxic

chemical's half-life in water or sediment or soil is equal to or

greater than 2 months or greater than 2 days for air then the toxic

chemical is considered to be persistent for purposes of section 313.

Note that when considering persistence in connection with the

potential for a toxic chemical to bioaccumulate, meeting the air

half-life criteria alone would not be sufficient, since a chemical's

potential to bioaccumulate is usually dependent on it being

persistent in either water, sediment, or soil. In determining

whether the chemicals in this proposal were persistent, EPA did not

rely solely on the persistence in air. (at 64 FR 702)

It is clear from the discussion above that EPA agrees with the

commenter that when considering persistence alone an air half-life of 2

days would be considered sufficient to classify a chemical as

persistent under EPCRA section 313. However, for the reasons explained

above, if a chemical only meets the 2-day air half-life persistence

criteria, EPA does not believe that would be sufficient for classifying

a chemical as a PBT under EPCRA section 313.

Some commenters contend that EPA's two-tiered approach to the

persistence criteria is confusing.

EPA notes that it proposed only one set of persistence criteria for

EPCRA section 313, half-lifes of 2 months or greater in water, soil,

and sediment and 2 days in air. The Agency did not propose to use half-

lifes of 6 months or greater in water, soil, and sediment and 2 days in

air as a second set of persistence criteria for EPCRA section 313.

However, for purposes of setting reporting thresholds in this

rulemaking, the Agency did choose to focus on the subset of PBT

chemicals that have half-lifes of 6 months or greater in water, soil,

or sediment (and BCF/BAFs greater than 5,000) by proposing a 10 pound

reporting threshold.

For the reasons given above, EPA reaffirms its intention to use a

half-life of 2 months as the criterion for persistence in water, soil,

and sediment and a half-life of 2 days as the criterion for air when

characterizing a chemical as persistent for purposes of EPCRA section

313.

b. Bioaccumulation. EPA proposed as bioaccumulation criteria for

the TRI program bioaccumulation/bioconcentration factors of 1,000. As

discussed in Unit VI.B.1., EPA disagrees that it must choose for EPCRA

section 313, bioaccumulation criteria consistent with the international

criteria. Applying these strict criteria to EPCRA section 313 would

result in a very narrow list of chemicals that would focus on only

extremely bioaccumulative chemicals. This is inconsistent with the

purposes of EPCRA section 313 and with EPA's technical judgment. There

is no ``bright line'' that separates what is bioaccumulative from what

is not bioaccumulative. The degree of bioaccumulation is a continuum.

Chemicals with BCFs or BAFs of 1,000 to 5,000 are not non-

bioaccumulative. They are less bioaccumulative than chemicals with BCFs

or BAFs greater than 5,000. The degree of bioaccumulation that should

be used as a criterion is not an absolute scientific determination.

Rather it is a combination of science and policy. As discussed in the

proposed rule and below, organizations have generally used as

bioaccumulation criteria BAFs/BCFs of 1,000 and 5,000. The

determination of which numerical criterion to apply will depend on the

final intent: for example, providing communities with information on

bioaccumulative chemicals that can accumulate in organisms versus

banning the manufacture and use and eliminating releases of a chemical

that has global impacts. For EPCRA section 313 which provides

information on toxic chemicals to communities, researchers, and

governments, the criteria should be in keeping with both the Agency's

scientific judgment and the intent of the statute.

From a scientific perspective there is no one bioaccumulation

criterion. However, it is simply not accurate to state that there is no

precedent or basis for using a bioaccumulation criterion of 1,000. As

noted in the proposed rule, for a number of years EPA scientists and

programs have used a BCF of 1,000 or more to indicate a high level of

concern for bioaccumulation. In addition, this value has been used in

some Canadian projects, many dealing with the Great

[[Page 58682]]

Lakes basin. Also, Germany proposed a BAF/BCF criterion of 1,000 during

negotiation of the LRTAP Protocol. Support for a BAF criterion of 1,000

also comes from the Final Water Quality Guidance for the Great Lakes

System (FWQGGLS) (60 FR 15366, March 23, 1995) (FRL-5173-7). In this

document, EPA stated that bioaccumulation of persistent pollutants is a

serious environmental threat to the Great Lakes Basin Ecosystem and

that chemicals identified as bioaccumulative chemicals of concern

(BCCs) (i.e., with BAF values greater than 1,000) would receive

increased attention and more stringent controls. The final guidance

designated as BCCs those chemicals with human health BAFs greater than

1,000 that were derived from certain field-measured BAFs. One commenter

believed that the BAF criteria used in the FWQGGLS did not provide

support for the use of a BAF of 1,000 since a more strenuous

methodology taking more factors into account was used. However, EPA

believes that this does provide support for the criteria established

for the purposes of EPCRA section 313 because, although the underlying

technical assessments may be more stringent, the bioaccumulation level

of concern is still a BAF of 1,000. Also, as noted by some commenters,

EPA has proposed to use a BCF/BAF of 1,000 to trigger testing under

TSCA section 5(e) (63 FR 53417). Specifically, for chemicals subject to

TSCA section 5 that have a BAF of 1,000 or greater and that meet

certain toxicity and persistence criteria (similar to the EPCRA section

313 persistence criteria) testing would be ``triggered'' by specific

production limits. While the manufacturer of the chemical would be

allowed to commercialize the substance, certain controls could be

stipulated, including specific limits on exposures, releases, or uses.

EPA notes that in the same Federal Register document, the Agency has

proposed that chemicals that have a bioaccumulation factor of 5,000 and

that meet certain toxicity and persistence criteria (e.g., half-life of

6 months or greater in soil) be placed in a ``Ban Pending Testing,''

bin. Chemicals meeting these criteria could be subject to more

stringent control up to a ban on commercial production.

Not only is there precedent for the use a BCF/BAF of 1,000, but EPA

believes that the purposes of the statute argue for the use of the more

expansive criterion. Data on PBT chemicals are the type of information

that will be of particular use to specific communities such as those

that consist of subsistence fishers. Subsistence fishers (as well as

sports fishers) are more highly exposed to PBT chemicals than the

general population. Subsistence fishers consume large quantities of

what they catch. In addition, children are affected by lower doses of

certain PBTs than are adults. Children of both subsistence fishers and

sport fishers will consume larger quantities of lake food and seafood

than children in other communities. As discussed in Unit VI.B.2., EPA's

Office of Water maintains a Listing of Fish and Wildlife Advisories

(LFWA) for the U.S. and its territories, which listed 2,299 advisories

in 1997 (Ref. 29). The overwhelming majority of the advisories are for

well-recognized PBT chemicals (chlordane, mercury, PCBs, etc.), but

many less familiar substances are also represented. The number and

content of advisories in LFWA clearly indicate that toxicologically

significant levels of chemical contaminants, specifically PBTs, are

often found in fish and wildlife that are caught noncommercially and

consumed by the U.S. population. It should be noted that the fact that

no advisories have been issued for a particular chemical does not mean

that the chemical does not bioaccumulate. Not all species of aquatic

organisms are tested nor are all water bodies. In addition, each state

determines what it will use as the level of concern for issuing an

advisory. EPA believes that it would be inconsistent with the intent of

EPCRA section 313 to limit the information on bioaccumulative toxic

chemicals to only information for the most bioaccumulative.

One commenter contends that EPA did not provide scientific

justification for its choice of the bioaccumulation criterion of a BCF/

BAF of 1,000. The commenter states the EPA's discussion of the origin

of the 1,000 BCF/BAF value at a 1976 meeting sponsored by the American

Society of Testing and Materials, and its reaffirmation in 1995 in a

research article by two of the original authors, the use of the value

by scientists in EPA's Office of Research and Development's Duluth

Laboratories, by EPA's Office of Pollution Prevention and Toxics in the

review of chemicals under TSCA sections 4 and 5, by EPA's Office of

Water in the Final Water Quality Guidance for the Great Lakes System,

and the use by other authorities, such as the German government, to

identify chemicals of high concern for bioaccumulation do not provide a

technical basis for choosing a value of 1,000 as a criterion for

bioaccumulation. The commenter contends that a criterion of 5,000 is

scientifically supportable because chemicals with a BCF/BAF of 5,000

have a high potential to biomagnify.

As discussed above, there is no scientifically ``best''

bioaccumulation criterion. The degree of bioaccumulation is a

continuum. A chemical does not bioaccumulate only if it has a BCF that

is 5,000 or greater. A chemical that has a BCF of 1,000 will

bioaccumulate, specifically the chemical will be present in an organism

at a concentration that is 1,000 times greater than its concentration

in the surrounding aqueous environment. Rather the choice of a value

along the bioaccumulation spectrum is based to a large degree on how

the criterion is to be used, e.g., to track chemicals entering a

particular environment, or to restrict the use of chemicals, etc. As

such the choice of a bioaccumulation criterion is a combination of

science and policy.

The commenter did not provide support for the contention that 5,000

was scientifically the ``best'' bioaccumulation criterion.

Specifically, the commenter did not indicate why as a scientific matter

a BCF of 5,000 was preferable to a BCF of, for example 4,000 or a BCF

of 15,500. While the commenter did note that chemicals that have a BCF

of 5,000 tend to have a high potential to biomagnify, the commenter did

not indicate in what way this factored into his determination that a

BCF of 5,000 is the scientifically ``best'' bioaccumulation criterion.

In addition, EPA does not agree that a BAF or BCF of 5,000 indicates

that a chemical will be more likely to biomagnify since

biomagnification is a much more complex process. Biomagnification is

not a separate process from bioaccumulation or bioconcentration, but is

instead a specific example or subset of both. Biomagnification has been

defined as: The result of the processes of bioconcentration and

bioaccumulation by which tissue concentrations of bioaccumulated

chemicals increase as the chemical passes up through two or more

trophic levels (Ref. 43). The difference between bioaccumulation and

biomagnification is that for a chemical to biomagnify its level of

bioaccumulation must increase as it moves up the food chain. The whole

concept of biomagnification can be viewed as controversial (Ref. 9) and

biomagnification has been studied for only a few chemicals. Most

importantly, biomagnification is not required in order to have a

concern for chemicals that bioaccumulate. This is because

bioaccumulation in even one species can have a serious impact on that

species or any other species that feeds on it. For example, if a

chemical only bioaccumulates in fish then the fish will

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be exposed to higher concentrations of the chemical as will anything

that eats the fish. Therefore, EPA believes that there is no reason to

establish biomagnification as a criterion for PBT chemicals since

bioaccumulation is of more than sufficient concern in and of itself.

None of the other commenters who believe that the bioaccumulation

criterion of 1,000 is too expansive suggested that EPA adopt another

value, other than the 5,000 value used in international agreements,

addressed in previous responses in this unit. At most, several

commenters took issue with the fact that the EPCRA section 313

bioaccumulation criterion (BCF/BAF of 1,000) is 5 fold less than the

international bioaccumulation criterion of a BCF/BAF or 5,000. Given

that for each of these programs the focus was on PBT chemicals that are

of global concern, EPA believes that as a matter of public policy, it

is more appropriate for a reporting program to use a more protective

criterion than that used in international agreements that seek to ban

or severely restrict the use and/or release of chemicals.

One commenter believes that EPA should not adopt a bioaccumulation

criterion (BCF/BAF of 1,000) for EPCRA section 313 that is more

stringent than the criterion for a Great Lakes BCCs (a human health BAF

of 1,000). EPA notes that BCCs will receive stringent controls which is

not the case for toxic chemicals identified as bioaccumulative (and

persistent) under EPCRA section 313.

Many commenters supported the proposed bioaccumulation criterion of

a BCF/BAF or 1,000. However, one of these commenters believes that

1,000 should be the criterion only if the BCF or BAF is a measured

value. If the BCF is an estimated value, then the criterion should be

500.

EPA believes that such a two-tiered approach will add confusion.

Further, estimated or predicted BCFs are often based on measured data

and equations that have been found to correlate well with measured

data. In addition, EPA believes that a BCF of 500 is overly expansive.

EPA believes that expanding the criteria to include estimated BCFs of

500 would label so many chemicals as bioaccumulative as to be

impractical. EPA believes that the adoption of the criterion of BCF/BAF

of 1,000 allows EPA to balance the need to provide communities with

information on toxic chemicals that bioaccumulate without being overly

inclusive or restrictive.

Some commenters contend that EPA's two-tiered approach to the

bioaccumulation criteria is confusing. EPA notes that it proposed only

one bioaccumulation criterion for EPCRA section 313, a BCF/BAF of

1,000. The Agency did not propose to use a BCF/BAF of greater 5,000 as

a second bioaccumulation criterion for EPCRA section 313. However, for

purposes of setting reporting thresholds in this rulemaking, the Agency

did choose to focus on the subset of PBT chemicals that have a BCF/BAF

greater than 5,000 (and half-lifes greater than 6 months) by proposing

an even lower reporting threshold.

For the reasons given above, EPA reaffirms its intention to use a

BCF/BAF of 1,000 as the criterion for characterizing a chemical as

bioaccumulative under EPCRA section 313.

c. Toxicity. A number of commenters contend that EPA should set a

separate toxicity criteria for PBT chemicals. EPA disagrees. EPCRA

section 313 provides toxicity criteria at section 313(d)(2) to be used

in adding a chemical to or deleting a chemical from the EPCRA section

313 list of toxic chemicals. These criteria are:

(A) The chemical is known to cause or can reasonably be

anticipated to cause significant adverse acute human health effects

at concentration levels that are reasonably likely to exist beyond

facility site boundaries as a result of continuous, or frequently

recurring, releases.

(B) The chemical is known to cause or can reasonably be

anticipated to cause in humans-

(i) cancer or teratogenic effects, or

(ii) serious or irreversible-

(I) reproductive dysfunctions,

(II) neurological disorders,

(III) heritable genetic mutations, or

(IV) other chronic health effects.

anticipated to cause, because of-

(i) its toxicity,

(ii) its toxicity and persistence in the environment, or

(iii) its toxicity and tendency to bioaccumulate in the

environment, a significant adverse effect on the environment of

sufficient seriousness, in the judgment of the Administrator, to

warrant reporting under this section.

Given that Congress has provided EPA with specific toxicity criteria,

and that listed chemicals are statutorily defined as ``toxic

chemicals,'' the Agency does not believe that additional ``toxicity''

criteria would be appropriate. One reason is that the Agency is

concerned that this would imply that TRI data on the toxic chemicals

that meet the statutory toxicity criteria are of less value than TRI

data that meet both the statutory toxicity criteria and some additional

toxicity criteria that would be developed by EPA. EPA believes that

bifurcating the list with an additional, non-statutory toxicity

criteria would be inconsistent with the intent of Congress. In

addition, it is worth noting that some of the toxicity criteria

presented by the commenters are fundamentally consistent with the

toxicity criteria outlined in the statute. However, EPA notes that some

of the criteria provided by the commenters are risk criteria rather

than hazard criteria. For example, see ICCA Briefing Note on POPs

(April 21, 1998) (Ref. 26). As discussed at length in the final rule

adding 286 chemicals to the EPCRA section 313 list (59 FR 61432), the

EPCRA section 313(d)(2)(B) toxicity criteria (chronic toxicity) are

hazard criteria, not risk criteria. The EPCRA section 313(d)(2)(C)

criteria are primarily hazard based with only a limited exposure

component. To impose additional toxicity criteria for purposes of

defining a PBT or a PT or BT chemical based on risk rather than hazard

would be inconsistent with EPCRA section 313. See, e.g., Legislative

History at 5186. Risk assessment may be appropriate for use under

statutes that control the manufacture, use and/or release of a

chemical. However, EPCRA section 313 is an information collection

provision that is fundamentally different from other environmental

statutes that control or restrict chemical activities. For these

reasons, EPA believes that it is inappropriate to add toxicity

criteria, beyond the criteria provided by Congress at EPCRA section

313(d)(2).

3. Persistence and bioaccumulation consideration under EPCRA

section 313(d)(2)(C)(ii) and (iii). The criteria that EPA has laid out

in this rule for determining if a chemical is a persistent and/or

bioaccumulative chemical are not the same criteria EPA uses when

conducting assessments for listing chemicals pursuant to EPCRA section

313(d)(2)(C)(ii) and (iii). These sections of EPCRA allow EPA to

consider whether a chemical meets the listing criteria based on ``its

toxicity and persistence in the environment'' or ``its toxicity and

tendency to bioaccumulate in the environment.'' Including consideration

of persistence and/or bioaccumulation modifies the way in which EPA

assesses a chemical's toxicity for purposes of listing. EPA interprets

the results of the toxicity data in light of a chemical's persistence

and/or bioaccumulation, and adjusts its concerns for the chemical's

toxicity in accordance with the degree to which a chemical persists or

bioaccumulates. For example, standard aquatic toxicity tests provide

toxicity results in time frames that range from hours to a few weeks.

For aquatic toxicity that results

[[Page 58684]]

from such short exposure times, a chemical with a persistence half-life

of even 2 weeks will result in a greater potential for exposure and

therefore increased concern for the concentration at which toxicity is

expressed. In this case, EPA would be concerned about the chemical's

persistence at levels well below a half-life of 2 months or more.

Because EPA's concern under these provisions is with the

interrelationship between two chemical properties and how that affects

whether the chemical can reasonably be anticipated to cause a

significant adverse effect on the environment, EPA believes that it

needs to be able to consider a broader range of values. By contrast,

the persistence and bioaccumulation criteria established in today's

rulemaking serve a different purpose; they are intended to operate

independent of a chemical's toxicity, to identify a fixed class of

chemicals. EPA has provided this explanation to clarify the different

purposes of the persistence and bioaccumulation criteria established in

this rule, and the use of persistence and bioaccumulation in

assessments pursuant to EPCRA section 313(d)(2)(C)(ii) and (iii).

C. Criteria as they Apply to Metals

Many commenters contend that the persistence criteria proposed by

EPA were developed for organic chemicals and cannot be applied to

metals, or if applied, are not useful in screening for hazard. The

critical parameter in determining risk is bioavailability, not

persistence. This has been recognized by international organizations of

which EPA is a member, so it is unclear why it is now necessary for EPA

to deviate from these policies. Metals are not harmful if they are not

in a bioavailable form. Moreover, metals are natural components of the

earth's crust and many are accumulated by living organisms because they

are essential nutrients. Two of the commenters state that because

persistence is defined as ``the failure of a substance to readily

biodegrade,'' this concept has no relevance for metals.

EPA disagrees. The scientific literature contains many definitions

of persistence which vary in detail, but center on a common theme:

persistence is the ability of a chemical substance to remain in a

particular environment in an unchanged form. This definition makes no

mention whatsoever of any specific processes that may impact a

substance's environmental fate, such as biodegradation. According to

this definition, specific metal compounds may or may not be persistent

depending on the form of the metal and environmental conditions, but

the elemental metal itself obviously meets the definition, and this was

acknowledged in the majority of comments received.

That elemental metals are persistent by definition is widely

accepted. While they may take different oxidation states that can be

interconverted, the elemental metal itself cannot be destroyed. For

example, chromium (VI) may convert to chromium (III). Both are simply

different forms of chromium. All elemental metals therefore meet the 2

months half-life criterion automatically. Given this, it is obviously

false to assert, as did the majority of commenters on this issue, that

EPA's proposed persistence criteria cannot be applied to metals. The

position of many commenters was that in determining whether a metal or

metal compound may actually pose a risk if released to the environment,

bioavailability is much more important than the fact that a substance

meets the formal ``definition'' of persistence. EPA agrees that

bioavailability is important in determining the potential for the metal

to be accumulated in organisms, but parent metals do have the potential

to become available from metal compounds under common environmental

conditions. Availability of the metal ion may be the result of biotic

or abiotic processes. There are a number of environmental factors which

EPA considers in determining the availability of the metal ion. These

include hydrolysis, pH effects on solubility, photolysis, aerobic and

anaerobic transformations, and in vivo transformations. As outlined in

the remainder of this section, it is realistic to expect that, in

general, metals when released into the environment can encounter

conditions in which they are available at levels sufficient to exert

toxicity and bioaccumulate.

EPA also disagrees with the commenters' claims, direct or implied,

that metals released to the environment as a result of human activity

must be of negligible concern because they:

Cannot be converted to bioavailable forms; or even if

initially bioavailable are rapidly sequestered in such a way that

subsequent exposure is impossible; or

If bioavailable, are naturally wholesome and good because

organisms need them to function.

EPA disagrees with this simplistic view. Metals can enter the

environment in bioavailable forms or can be converted in the

environment into bioavailable forms. As shown below, metals and metal

compounds may be available to bioaccumulate under many realistic and

common environmental conditions.

The commenters are correct in stating that metals released to the

environment from anthropogenic sources are affected by prevailing

environmental conditions, meaning broadly the wide variety of physical,

chemical and biological processes that act upon them, and these

collectively determine the form in which the metal ultimately exists.

According to Klein (Ref. 28), interconversion of inorganic metal

compounds can be quite rapid, especially for ionic forms, and as a

result the chemical form in which an elemental metal is released may

not be the predominant form post-release. Generally, the ionic forms of

inorganic metals are the most available. Availability is affected by

many factors and its determination is complex. For metals environmental

conditions can affect their availability. A detailed scientific

discussion of the environmental fate of lead, which is representative

of other metals, and that is illustrative of many of the more important

environmental variables that affect availability is provided in Refs.

14, 28, 30, 50, 66a, 72, and 84. See also the preamble to EPA's recent

proposal to lower the EPCRA section 313 reporting thresholds for lead

and lead compounds (64 FR 42222). The same basic chemical properties

and environmental variables will affect the degree of availability of a

metal in the environment regardless of the specific metal. There is no

metal that is unavailable under all conditions.

EPA recognizes that lead and lead compounds are the subject of an

EPA proposal under EPCRA section 313 (64 FR 42222). The inclusion of

the discussion of the environmental fate of lead and lead compounds

does not predetermine EPA's decision on the appropriate thresholds that

should be set for lead and lead compounds. That determination will be

based on a number of factors, including the bioaccumulation of lead.

Microbial transformations in soil, water, and sediment are often

important in determining the overall fate of metals and metal

compounds, and therefore the potential for formation of bioavailable

forms. Metals known to undergo microbial oxidation/reduction processes

include, antimony, arsenic, iron, mercury, selenium, and tellurium

(Ref. 11). Arsenic microbiology illustrates the importance of

environmental conditions in the interconversion of inorganic forms of

arsenic. Microbial populations in activated sludge can oxidize arsenite

to arsenate under aerobic conditions, but under anaerobic conditions

such as often predominate in sediments, arsenate can be reduced to

arsenite and

[[Page 58685]]

beyond. Both arsenites and arsenates can be available in the

environment (Ref. 11). Microorganisms can reduce mercury in the form of

mercuric chloride to elemental mercury, and are also capable of

producing elemental mercury from organomercurials such as

phenylmercuric acetate and methylmercuric chloride. Although the

reduction of Hg2+ to elemental mercury can be regarded as

decreasing availability, the elemental mercury formed is volatile and

more likely to enter the global atmospheric circulation.

Mercury is perhaps better known for its potential to be

biomethylated by bacteria in the environment (Ref. 11). Mercury has

very high stability constants with organic ligands and can form true

organometallic compounds (Ref. 6). As indicated by Stumm and Morgan

(Ref. 49), metals and metalloids that form stable alkyl compounds are

of special concern because they may be volatile; may accumulate in

cells; and are toxic to the central nervous system of higher organisms.

Methylmercury is highly bioaccumulative and is by far the best studied

example of microbial bioalkylation. However, methylation of arsenic is

also fairly well-characterized, involves the replacement of substituent

oxygen atoms by methyl groups (e.g., arsenate is biomethylated to form

dimethylarsine), and is important in the transfer of arsenic from

sediment to the atmosphere (Ref. 11). Lead, germanium, selenium,

tellurium, tin, and several other metals can also be biomethylated

(Ref. 49).

Many of the commenters noted that certain metals are indeed

micronutrients (e.g., cobalt, copper, and iron), and are accumulated

precisely because they are required for certain cellular functions. It

does not follow, however, that any amount of the same metal is

acceptable or desirable. Accumulation of essential elements is usually

governed by homeostatic mechanisms that control uptake (Ref. 28), but

excessive uptake is possible and can be toxic to an organism. For

example, selenium which is a micronutrient can cause selenosis at doses

as low as 0.023 milligrams per kilogram per day (mg/kg/day). Clinical

signs of selenosis include the characteristic ``garlic odor'' of excess

selenium excretion in the breath and urine, thickened and brittle

nails, hair and nail loss, lowered hemoglobin levels, mottled teeth,

skin lesions, and central nervous system (CNS) abnormalities

(peripheral anesthesia, acroparesthesia, and pain in the extremities)

(Ref. 61). Similarly, copper, which is an essential nutrient, at high

doses can cause vascular injury and hemolytic anemia. It should also be

noted that copper exhibits high acute and chronic toxicity to aquatic

organisms that results in the death of the organism (61 FR 54381,

October 18, 1996) (FRL-5396-9), and inhalation of hexavalent chromium

is known to cause cancer in humans (Ref. 60), even though chromium in

very small oral doses is a micronutrient (Ref. 25). Moreover, the

commenters freely cite Allen (Ref. 4), Chapman (Ref. 18) and other

authors to the effect that metals are accumulated ``deliberately''

depending on the physiological needs of the organism, but it is clear

that this applies only to metals that are essential nutrients. Metals

are generally taken into cells by nutrient metal transport systems, and

these are not sufficiently specific to completely exclude nonessential

metals, some of which may be toxic and/or bioaccumulative. In this

situation nutrient metals can be displaced from their binding sites by

undesirable, toxic metals, which then gain access to the cell interior

with concomitant exclusion of the essential metal (Ref. 49). Toxic

metal ions are then free to react with critical enzymes or otherwise

disrupt cellular functions if they reach certain levels. Often this

toxicity occurs at relatively low doses. For example, inorganic arsenic

is a known human carcinogen and causes chronic toxicity at doses as low

as 0.014 mg/kg/day (Ref. 59). Lead has no known biological function in

humans but is readily absorbed and has been shown to cause various

toxic effects. For example, children can suffer permanent damage from

lead poisoning, resulting in lowered intelligence, learning

disabilities, hearing loss, reduced attention span, and behavioral

abnormalities (Ref. 66).

EPA concludes that under many environmental conditions, metals and

metal compounds may be available to express toxicity and to

bioaccumulate, and that these effects are not necessarily limited to

metals that are not essential nutrients. It is appropriate, therefore,

to be concerned about the potential adverse effects, and one step in

this direction is to more accurately assess emissions from

anthropogenic activities. EPCRA section 313 provides that opportunity.

Precedent for this concern exists at the international level in the

form of a protocol for heavy metals under the UNECE LRTAP, which is

currently being negotiated. The draft protocol expresses concern ``. .

.that emissions of certain heavy metals are transported across national

boundaries and may cause damage to ecosystems. . .and may have harmful

effects on human health. . .,'' and specifically advocates assessing

and controlling emissions caused by human activities (Ref. 54).

Several commenters raised the issue of EPA participation in various

international organizations, claiming that any attempt to apply EPA's

proposed persistence and bioaccumulation criteria and/or assessment

approach to metals would violate the policies of these organizations,

whose positions EPA has previously endorsed. These claims are false

because the commenters either misunderstand or misstate the

aforementioned policies. The main focus of the commenter's attention is

two documents, the OECD's Harmonized Integrated Hazard Classification

System for Human Health and Environmental Effects of Chemical

Substances (Ref. 41), and the North American Agreement on Environmental

Cooperation (NAAEC)'s Process for Identifying Candidate Substances for

Regional Action under the Sound Management of Chemicals Initiative

(Ref. 39). A report from a joint Canada/European Union Technical

Workshop on metals (Ref. 17) was also cited by commenters and reached

similar conclusions.

The OECD document's pronouncements on metals are contained in

paragraphs 22 and 23 of that document. Paragraph 22 reads as follows:

For inorganic compounds and metals, the concept of degradability

as applied to organic compounds has limited or no meaning. Rather

the substance may be transformed by normal environmental processes

to either increase or decrease the bioavailability of the toxic

species. Equally, the use of bioaccumulation data should be treated

with care. Specific guidance will be [but has not yet been] provided

on how these data for such materials may be used in meeting the

requirements of the classification criteria. (Ref. 41)

By ``degradability as applied to organic compounds'' OECD means

molecular degradation, most often by microbial degradation and/or

hydrolysis or other abiotic processes, to progressively simpler organic

chemical structures, leading eventually to inorganic substances like

carbon dioxide and water. But, note, paragraph 22 does not in any way

suggest that metals are not persistent. Moreover, it does not suggest

that OECD hazard classification criteria cannot be applied, only that

``care'' (i.e., professional judgment) is required in the

interpretation of data relative to the classification criteria. In

fact, EPA agrees that bioavailability is important in determining the

potential for the metal to be accumulated in organisms.

[[Page 58686]]

The Agency has analyzed information on the environmental fate of

metals, and, as noted above, asserts its professional judgment that the

parent metals do have the potential to become available from metal

compounds under commonly encountered environmental conditions.

Therefore, the Agency's treatment of metals is consistent with the

OECD's intent.

The same holds with respect to NAAEC's pronouncements under the

SMOC (Ref. 39). The focus of NAAEC/SMOC (Ref. 39) is the development of

North American Regional Action Plans (NARAPs) for substances that pose

significant risk to human health and the environment in all three

member countries (namely, Mexico, Canada, and the United States). To

date, NARAPs have been established for DDT/chlordane, PCBs, and mercury

(note: a metal). NAAEC/SMOC (Ref. 39) acknowledges the persistence of

metals, but highlights the role of expert judgment in assessing

potential bioavailability of metals and metal compounds:

For naturally occurring substances such as metals and minerals,

the Task Force understands that the direct application of the

persistence and bioaccumulation criteria proves very

difficult.....Organometals can behave like other persistent organic

pollutants in their metallic form, and as certain compounds, metals

tend to be infinitely persistent though not necessarily in a form

that is bioavailable, and in some cases, they naturally

bioaccumulate for beneficial purposes in organisms (i.e., essential

elements). Expert judgment is essential for a meaningful evaluation

of these substances.

Further, an earlier section of the document (Ref. 39) states,

It is understood that expert scientific judgment plays a

significant role in acknowledging and addressing the difficulties

posed by quantitative criteria for persistence and bioaccumulation,

particularly in relation to naturally-occurring substances like

metals and minerals where the potential for transformation to

complexes or metallic species which are more or less bioavailable,

are emerging as important considerations.

It is difficult to read into the preceding any intention to exclude

metals and metal compounds from consideration, as many commenters

imply, and more specifically, to declare that these substances have no

potential to pose risk because they are never released in bioavailable

forms; cannot be converted to bioavailable forms under any foreseeable

circumstances, etc. On the contrary, it is clear from the preceding

language as well as the inclusion of mercury among the NARAPs developed

to date that any substance judged to be potentially bioavailable and

that otherwise meets the SMOC criteria, whether organic or inorganic,

should not be excluded as a candidate for action. As outlined above, it

is realistic to expect that, in general, released metals can encounter

conditions in which they are available at levels sufficient to exert

toxicity and bioaccumulate. Therefore, the Agency's treatment of metals

is consistent with international policy under NAAEC/SMOC (Ref. 39).

Finally, EPA reminds commenters that a mechanism already exists to

address concerns for any metal compound for which the data show that

the metal cannot become available. The issue of bioavailability was

addressed previously for EPCRA section 313 chemical assessments through

EPA's policy and guidance concerning petitions to delist individual

members of the metal compound categories listed under EPCRA section 313

(56 FR 23703, May 23, 1991). This policy states that if the metal in a

metal compound cannot become available as a result of biotic or abiotic

processes, then the metal will not be available to express its

toxicity, and by extension, to bioaccumulate. If the intact metal

compound is not toxic and the metal is not available from the metal

compound, then such a chemical is a potential candidate for delisting.

EPA has received fewer than 10 petitions to delete individual metal

compounds because the petitioner contended that the metal portion of

the metal compound would not be available under environmental

conditions or in vivo.

D. Multimedia Modeling

One commenter contends that EPA should clarify how and when

multimedia models will be used in the evaluation of PBT chemicals. EPA

should not use the EQC model or other multimedia models as the sole

determinant of potential risk. If exposure and use information is

available, a detailed technical evaluation based on these data is

preferred over modeling based on hypothetical exposure and loading

scenarios.

The purpose of this rulemaking is to lower reporting thresholds for

certain EPCRA section 313 substances that are being designated as

persistent and bioaccumulative, and to list several additional

substances that meet EPCRA section 313 listing criteria and are also

persistent and bioaccumulative. Although neither quantitative risk nor

exposure assessments have been performed, nor are they required under

EPCRA, designation as a PBT does imply the existence of potential risk.

However, contrary to the comment, EPA has not proposed that multimedia

models be used as the sole factor in determining persistence. As

clearly stated in the proposed rule, EPA intends to use such modeling

``as an additional factor, in conjunction with reaction half-lifes for

individual media, bioaccumulation/bioconcentration factors, etc., in

justifying [the] actions proposed.''

In the proposed rule EPA did explain in a general way (at 64 FR

703) how models would be used in PBT evaluation, and stated that

results of multimedia modeling may be used to override compartment

(medium)-specific degradation half-lifes, but only if all model inputs

are judged sufficiently accurate. This leaves unspecified what specific

value(s) might be used for overall environmental persistence criteria

(expressed either as an overall residence time or overall half-life).

To date no international scientific or regulatory authority has

proposed any such criterion for POPs/PBT chemicals, and the complex

relationship between compartment-specific and overall persistence

criteria is in fact a major topic of current research.

One commenter raises concerns regarding the modification EPA made

to the EQC III model that deleted advective losses and sediment burial.

EPA modified the model to exclude advective losses and sediment

burial because if these processes are included the persistence based on

destruction will be underestimated. In multimedia modeling, advection

can be viewed as the flow into or out of the evaluative environment or

``box.'' These include processes such as downstream flow in surface

waters, dispersion downwind in air, and burial in sediments. The model

considers these non-destructive processes to result in loss from the

evaluative environment in the same way that destruction does. However,

these processes simply result in the transport of a chemical to another

part of the environment downwind or downstream from where it is

released, or its deposition into sediments, but not the destruction of

the chemical.

The persistence of a chemical calculated when the model is run

considering advective losses include non-destructive transport

processes which remove the chemical from the evaluative environment.

For example, the environmental persistence of a chemical released to

water which does not significantly partition to sediments, degrade, or

volatilize will reflect the rate at which the water to which it is

released flows out of the evaluative environment. In this example, the

[[Page 58687]]

relative rate of non-destructive transport out of the evaluative

environment may be more rapid than the processes which result in the

destruction of the chemical. Thus, the persistence calculated by the

model will be less than if advective transport from the evaluative

environment was not considered.

EPA used the model to evaluate persistence based on destruction in

a multimedia environment. This is consistent with EPCRA section 313

persistence criteria in that the criteria are based on destruction, not

transport of the chemical. The Level III (non-equilibrium partitioning,

steady state mass balance) models are preferred for developing

qualitative and quantitative predictions of chemical distribution,

pathways, and relative concentrations (Ref. 16). Level III models can

also be used to assess persistence (Ref. 33). At steady state (level

III) conditions the amount of chemical is unchanging with time and the

input and output rates for a compartment are equal. The overall

residence time of the chemical is the mass of the chemical in the

compartment divided by the input or output rates. This represents the

average time the chemical will reside in the compartment. Output may be

by reactions that result in the destruction of the chemical or by

advective flow (non-destructive) usually in air or water. When the

model is modified to eliminate advective flow, the persistence of a

chemical based on the rates of reactions that result in the destruction

of the chemical can be assessed. Webster et al (Ref. 82) used this

approach in evaluating the environmental persistence of chemicals using

a multimedia fate model and noted that if advective loss is included,

the residence time is reduced and can give a misleading impression of a

short persistence. It was also noted that these advective losses ``. .

.merely relocate the chemical; they do not destroy it.'' EPA also used

a modified version of the EQC level III model as a tool to assist on

the characterization of the persistence of the chemicals subject to

this rule. In this version of the model only irreversible

transformation contributes to net loss of a chemical. In other words,

the model was modified to represent a ``closed box'' in which the

effect of processes that serve only to move the chemical from within

the evaluative environment to outside of it, primarily in air and water

(advective losses) were nullified. Sediment processes responsible for

transport of the chemical from the evaluative environment such as

sediment burial were similarly treated. The intent of this modification

was to make sure that only processes responsible for the destruction of

the chemical were considered in evaluating its persistence in a

multimedia environment. EPA supports the use of level III multimedia

models modified, as described, for their ability to simultaneously

consider reaction rates and partitioning so as to give a reasonable

assessment of the persistence of chemicals in the multimedia

environment.

However, EPA notes that its reliance on the multimedia modeling was

limited. As discussed in the proposed rule (at 64 FR 703) and in Unit

VI.B.2., EPA primarily considered media-specific data and made a case-

by-case determination about the persistence of each chemical.

E. Thresholds

The issue most frequently raised by commenters was the Agency's

choice of thresholds and the factors that EPA considered in lowering

the thresholds. Many commenters contended that EPA should not consider

burden in choosing thresholds. They believe that EPA should set a

threshold of 10 pounds for PBT chemicals and 1 pound for that subset of

PBT chemicals that are both highly persistent and highly

bioaccumulative. Some commenters believe that EPA should set a

threshold of 1 pound for all chemicals that are PBT chemicals. Numerous

commenters believe that the threshold for reporting should be zero.

Other commenters believe that burden should have been a greater

consideration in EPA's choice of reporting thresholds. Many of these

commenters believe that EPA should set thresholds based on some

percentage of releases that would be reported.

EPA disagrees with these commenters. As explained in the proposal,

the Agency considered a number of factors to determine the appropriate

thresholds that should be established for these chemicals. EPA relied

on the language of EPCRA sections 313(f)(2) and (h), and the

legislative history to elicit the following principles to guide its

exercise of discretion in lowering the thresholds, and in selecting the

specific thresholds for PBT chemicals: (1) The purposes of EPCRA

section 313; (2) the ``verifiable, historical data'' that convinces EPA

of the need to lower the thresholds; (3) the chemical properties shared

by the members of the class of toxic chemicals for which EPA is

lowering the thresholds i.e., the degree of persistence and

bioaccumulation; and (4) the reporting burden imposed by revised

thresholds to the extent that such consideration would not deny the

public significant information from a range of covered industry

sectors. Further, EPA believes that in the language of EPCRA section

313, and its legislative history, Congress provided direction on the

appropriate weight to allocate to each of these considerations in

implementing EPCRA section 313(f)(2). These considerations underlay the

entire process by which EPA determined the appropriate thresholds. But,

as noted below, the Agency's choice of revised thresholds was governed,

and ultimately constrained, by EPCRA section 313's overriding purpose,

which is to provide government agencies, researchers, and local

communities, with a comprehensive picture of toxic chemical releases

and potential exposures to humans and ecosystems.

In general, EPA's implementation of EPCRA section 313 is guided by

the statutory purposes described by EPCRA section 313(h), which

provides:

The release forms required under this section are intended to

provide information to the Federal, State, and local governments and

the public, including citizens of communities surrounding covered

facilities. The release form shall be available. . .to inform

persons about releases of toxic chemicals to the environment; to

assist governmental agencies, researchers, and other persons in the

conduct of research and data gathering; to aid in the development of

appropriate regulations, guidelines, and standards; and for other

similar purposes.

In addition to section 313(h), EPA was also guided by several

statements on the principles intended to guide EPA's implementation of

EPCRA section 313 made by Representative Edgar, one of EPCRA section

313's principal architects, during debate on the Conference Report.

See, Legislative History at 5313-16. In the course of his statement,

Representative Edgar also articulated EPCRA section 313's overriding

purpose, which is:

to provide a comprehensive view of toxic chemical exposure and,

hopefully, provide a basis for more sensible and effective local,

State, and national policies. Legislative History at 5316 (emphasis

added).

Based on the existing reporting requirements, the Agency believes

that there are still significant gaps in the picture the TRI data

provides local communities, government agencies, and researchers. One

of the most significant of these gaps is a comprehensive picture of the

releases and potential exposure of PBT chemicals to humans and the

environment. Currently, only a very limited picture of releases and

other waste management of PBT chemicals is available from the TRI data,

in part, as a result of the current thresholds. For

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example, under the current reporting thresholds, in 1997, EPA received

only 29 reports on mercury and mercury compounds, and 6 reports on

PCBs. This does not present a ``comprehensive view of toxic chemical

exposure.'' In addition, information on the releases and other waste

management of PBT chemicals is particularly significant because these

chemicals both persist and bioaccumulate. Individually, each of these

attributes has the potential to pose increased exposures to humans and

the environment. Toxic chemicals possessing both attributes have the

potential to pose significant exposures to humans and ecosystems over a

longer period of time; even small amounts of PBT chemicals that enter

the environment can accumulate to elevated concentrations in the

environment and in organisms, and therefore have a greater potential to

result in adverse effects on human health and the environment.

As a first step in addressing the significant gap of information on

PBT chemical releases and waste management, EPA considered whether to

lower the reporting thresholds for PBT chemicals. EPA then looked to

section 313(f)(2) for further guidance on how to proceed. Since

lowering the thresholds ensures that ``all facilities subject to the

requirements of [section 313]'' will continue to report, the

requirement in section 313(f)(2) that a revised threshold obtain a

``substantial majority of total releases of each chemical at all

facilities subject to the requirements of this section'' can be met

without the need for quantitative support. Consequently, EPA looked to

other sources of Congressional direction in the statute and legislative

history to guide its exercise of discretion in establishing revised

thresholds.

Given that there is no guidance on implementing section 313(f)(2)

in the Conference Report, EPA looked to the debate on the Conference

Report. In this context, Representative Edgar, stated:

It is also important to clarify the intent of Congress in

establishing thresholds for reporting under this section. . . .These

thresholds were designed to obtain reporting on both a substantial

majority of the Nation's toxic chemical releases and to obtain

reporting from a large number of firms. These thresholds reflect

Congress' judgement that such thresholds appropriately balance the

need for information against the burden on facilities required to

provide such information. The EPA is authorized to revise these

thresholds, but only if such revised thresholds continue to obtain

reporting on a substantial majority of total releases. Any

determination by the EPA regarding the ability of revised thresholds

to obtain reporting on a substantial majority of releases,

especially if such revised thresholds raise the statutory levels,

must be based on verifiable, historical data which presents a

convincing case that the statutory levels must be revised.

Legislative History at 5313 (emphasis added).

And during the House debate, Representative Swift noted that any

revised threshold ``should be designed to improve the usefulness of the

reports. It must be structured to obtain reporting on a substantial

majority of the total nationwide releases of the toxic chemical at all

facilities covered by section 313.'' Id. at 5338 (emphasis added).

In determining how to structure its threshold revisions, and

particularly how it would improve the usefulness of the reports, EPA

also consulted EPCRA's purposes, laid out in subsection (h). In this

context, EPA also considered the statements made by Senator Stafford

during debate on the Conference Report:

This section also requires the Administrator to computerize the

data reported on the required forms and to make these data public by

various means. Successful implementation of this requirement is

vital to the basic purpose of the program. The data should be

managed in the computer in such a way as to allow a wide variety of

analyses. For example, it should be possible to retrieve data, not

only about individual facilities, but also aggregate data organized

by type of chemical, type of effect, geographic location, company

name, etc. as well as combinations of these parameters. . . .

Legislative History at 5186 (emphasis added).

Based on this Congressional guidance, EPA reached several

conclusions. First, ample ``verifiable, historical data'' exists to

support EPA's conclusions that PBT chemicals persist for long periods

of time in the environment and bioaccumulate in organisms, including

humans; that this persistence and bioaccumulation can result in higher

exposures to humans and the environment; and that to ``obtain a

substantial majority of the Nation's toxic chemical releases,'' lower

thresholds for PBT chemicals are warranted. For example, PCBs have been

found throughout the Great Lakes in sediments, water, and aquatic

organisms. Multimedia analyses indicate that the majority (80-90%) of

human exposure to chlorinated organic compounds, such as PCBs comes

from the food pathway, a lesser amount (5-10%) from air, and minute

amounts (less than 1%) from water. Most of the data available on human

exposure to PCBs in the Great Lakes come from the analyses of

contaminant levels in drinking water and sport fish. The consumption of

contaminated sport fish and wildlife can significantly increase human

exposure to the Great Lakes critical pollutants, such as PCBs. The

sport fish are exposed to PCBs by consumption of sediments and through

water (Ref. 76). See also Refs. 75 and 77.

Further, EPA strongly believes that increased reporting on PBT

chemicals will improve the usefulness of the data on these chemicals.

There are currently very few reports for some of the PBT chemicals,

such as mercury, mercury compounds and PCBs. The currently available

data provide a distorted picture of potential exposures to humans and

the environment, because at the current thresholds only a fraction of

the releases from facilities otherwise subject to EPCRA section 313 are

reported. This limited reporting results in a significant

underestimation of the releases from the industry sectors covered by

EPCRA section 313. As such, the current data are of limited use for

evaluating the potential exposures to humans and the environment of

toxic chemicals that persist and bioaccumulate. Expanding the picture

of releases, and therefore potential exposures, will increase the

utility of all the TRI data on these chemicals. See, e.g., Economic

Analysis, Chapter 6.4 (Ref. 67).

On these bases, EPA determined that revising the thresholds would

be an important first step in closing the information gap on PBT

chemicals. The Agency then began the process of determining the

appropriate levels at which to establish the revised thresholds. For a

number of technical and policy reasons, EPA chose an approach focused

on two classes of PBT chemicals: (1) Toxic chemicals that meet the

EPCRA section 313 persistence and bioaccumulation criteria discussed in

Unit VI.B., i.e., those toxic chemicals that have half-lifes of 2

months or greater in water/sediment or soil and that have

bioaccumulation or bioconcentration factors of 1,000 and (2) the subset

of PBT chemicals that are highly persistent and highly bioaccumulative,

i.e., those toxic chemicals that have half-lifes of 6 months or greater

in water/sediment or soil and that have bioaccumulation or

bioconcentration factors of 5,000 or greater.

First, for the most persistent and bioaccumulative toxic chemicals

any release will lead to elevated concentrations in the environment and

in organisms. EPA believes that such highly persis

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