Revised Priority List of Hazardous Substances That Will Be the Subject of Toxicological Profiles

DEPARTMENT OF HEALTH AND HUMAN SERVICES

Agency for Toxic Substances and Disease Registry

[ATSDR-78]

Revised Priority List of Hazardous Substances That Will Be the

Subject of Toxicological Profiles

AGENCY: Agency for Toxic Substances and Disease Registry (ATSDR),

Public Health Service (PHS), Department of Health and Human Services

(HHS).

ACTION: Notice.

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SUMMARY: The Comprehensive Environmental Response, Compensation, and

Liability Act (CERCLA or Superfund), as amended by the Superfund

Amendments and Reauthorization Act (SARA), requires that ATSDR and the

Environmental Protection Agency (EPA) annually revise the Priority List

of Hazardous Substances to include additional substances most commonly

found at facilities on the CERCLA National Priorities List (NPL). This

announcement provides notice that the agencies have developed and are

making available a revised CERCLA Priority List of 275 Hazardous

Substances, based on the most recent information available to ATSDR and

EPA. This revised priority list includes newly listed substances which

have been determined to pose the most significant potential threat to

human health at or around NPL hazardous waste sites. Each substance on

the priority list is a candidate to become the subject of a

toxicological profile prepared by ATSDR and subsequent identification

of priority data needs.

ADDRESSES: Requests for a copy of the revised Priority List of

Hazardous Substances, a copy of the ``Supplemental Document for the

1993 Revised Priority List of Hazardous Substances'', or comments on

this notice should bear the docket control number ATSDR-78, and should

be submitted to: ATSDR, Division of Toxicology, Quality Assurance

Branch, Mail Stop E-29, 1600 Clifton Rd., NE., Atlanta, GA 30333.

This is an informational notice only, and comments are not being

solicited at this time. However, comments will be placed in a publicly

accessible docket; therefore, please do not submit confidential

business information.

Electronic Availability: The 1993 Revised Priority List is

available as an electronic file on The Federal Bulletin Board the day

of publication in the Federal Register. By modem dial 202-512-1387 or

call 202-512-1530 for disks or paper copies. This file is available in

Wordperfect 5.1, Dbase III, and ASCII.

FOR FURTHER INFORMATION CONTACT: Quality Assurance Branch, Division of

Toxicology, ATSDR, Atlanta, GA 30333, telephone (404) 639-6308.

SUPPLEMENTARY INFORMATION: CERCLA establishes certain requirements for

ATSDR and EPA with regard to hazardous substances which are most

commonly found at facilities on the CERCLA NPL. Section 104(i)(2) of

CERCLA, as amended (42 U.S.C. 9604(i)(2)), requires that the two

agencies prepare a list, in order of priority, of at least 100

hazardous substances that are most commonly found at facilities on the

NPL and which, in their sole discretion, are determined to pose the

most significant potential threat to human health (see 52 FR 12866,

April 17, 1987). CERCLA also requires the agencies to revise the

priority list to include 100 or more additional hazardous substances

(see 53 FR 41280, October 20, 1988), and to include at least 25

additional hazardous substances in each of the three successive years

following the 1988 revision (see 54 FR 43619, October 26, 1989; 55 FR

42067, October 17, 1990; 56 FR 52166, October 17, 1991). CERCLA also

requires that ATSDR and EPA shall, not less often than once every year

thereafter, revise the list to include additional hazardous substances

which are determined to pose the most significant potential threat to

human health. Each substance on the CERCLA priority list of hazardous

substances is a candidate to become the subject of a toxicological

profile prepared by ATSDR and the subsequent identification of priority

data needs.

The previous priority lists of hazardous substances were based on

the most comprehensive and relevant information available when the

lists were developed. More comprehensive sources of information on the

frequency of occurrence and the potential for human exposure of

substances at NPL sites became available for use in the 1991 priority

list with the development of ATSDR's HazDat database; additional

information from HazDat has become available for this year's listing

activity. In the initial listing activities (1987-1990), new substances

were added to the end of the list, without a comparative reranking. A

notice announcing the intention of ATSDR and EPA to revise and rerank

the priority list of hazardous substances was published on June 27,

1991 (56 FR 29485). In this year's listing activity, as in the previous

two years, new candidate substances (substances found at three or more

NPL sites) were assigned a toxicity/environmental score (TES) using the

EPA Reportable Quantity methodology, and were added to the pool of

substances previously considered for the annual list. All substances

were then evaluated together for consideration on the priority list.

The approach used to generate the 1991 revised priority list was

summarized in the ``Revised Priority List of Hazardous Substances'' (56

FR 52166, October 17, 1991). Using the same approach, and the same

algorithm this year, over 700 candidate substances have been ranked to

create the current list of 275 substances.

The additional information used in this year's listing activity was

entered into ATSDR's HazDat database since the development of the 1992

Priority List of Hazardous Substances. As with other site-specific

information used in the listing activity, this information has been

collected from ATSDR Public Health Assessments and from site file data

packages used in the development of Public Health Assessments. The new

information includes more recent NPL frequency of occurrence data,

additional concentration data, and more information on exposure or

potential exposure to substances present at NPL sites.

At this time the list includes 275 substances which ATSDR and EPA

have determined to pose the most significant potential threat to human

health based on the criteria of CERCLA section 104(i)(2) (42 U.S.C.

9604(i)(2)). All candidate substances have been analyzed and ranked

with the current algorithm, and may become the subject of toxicological

profiles in the future.

The addition of approximately 12,800 contaminant data records (for

air, water and soil) to the HazDat database since October 1992 has

allowed the agencies to better assess the potential for human exposure

to substances at NPL hazardous waste sites. With this additional data,

10 new candidate substances have been added to the list, and 13

substances under consideration last year have moved onto the list.

Accordingly, 23 substances have been replaced on the list of the 275

substances. These changes in the order of substances appearing on the

CERCLA priority list of hazardous substances will be reflected in the

program activities which rely on the list for future direction. For

example, Dicofol moved up significantly (to number 107) on the 1993

list when compared to last year's list. As a result it will be included

in the pool of substances that may become the subject of new

toxicological profiles in the next fiscal year. Similarly, alpha-

Endosulfan (number 33) moved well into the range of those substances to

be considered for the development of updated toxicological profiles

(CERCLA also requires ATSDR to evaluate new information on profiled

substances for potential revision every three years). These changes

reflect the dynamic nature of scientific data on substances present at

NPL (and other) hazardous waste sites.

This annual evaluation activity and announcement of a revised

priority list of hazardous substances fulfills the conditions of CERCLA

section 104(i), as amended, which requires ATSDR and EPA to revise the

list yearly to include additional hazardous substances. The agencies

intend to revise the list of hazardous substances annually thereafter

to reflect changes and improvements in data collection and

availability. Additional information on the methodology used in the

development of the CERCLA Priority List of Hazardous Substances can be

found in the Federal Register notices mentioned above.

Administrative Record

ATSDR and EPA are establishing a single administrative record

entitled ATSDR-78 for materials pertaining to this notice. All

materials received as a result of this notice will be included in the

public file which is available for inspection from 8 a.m. to 4:30 p.m.,

Monday through Friday, except Federal legal holidays, at the Agency for

Toxic Substances and Disease Registry, #4 Executive Park Drive, Suite

2400, Atlanta, Georgia.

Dated: February 18, 1994.

Walter R. Dowdle,

Deputy Administrator, Agency for Toxic Substances and Disease Registry.

[FR Doc. 94-4446 Filed 2-25-94; 8:45 am]

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