# WEDNESDAY, OCTOBER 12, 1977 PART IV

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# COUNCIL ON ENVIRONMENTAL QUALITY

TSCA INTERAGENCY TESTING COMMITTEE
Initial Report totheAdministrator,

Environmental Protection Agency55026 [3125-01]

COUNCIL ON ENVIRONMENTAL QUALITY TSCA INTERAGENCY TESTING

- COMMITTEE InitialReporttotheAdministrator, Environmental Protection Agency As required by section 4(e) of the Toxic Substances Control Act (TSCA), presented herein isthefirstofficial report of the Interagency Testing Committee.TheCommitteehasthestatutory responsibilitytoidentifyandrecommend to theAdministrator ofEPA chemical substanceswhichshouldbetestedtodeterminetheirhazardtohumanhealthor theenvironment.

This reportreflects the consensus of representatives from all eight member agencies: tensubstances andcategories ofsubstances arerecommended ashigh priority for testing and designated for consideration by EPA within twelve months.

Asrequiredby thestatute,theCommittee will continue its review process, reporting to the EPA Administrator withinsixmonthsfromthedateofthis reportsuchadditionalrecommendations NOTICES

astheCommittee findsdesirable during thatperiod.

Dated:October5,1977. WARRENR.MUIR, Chairman TSCAInteragency

TestingCommittee. EXECUTIVE OFFICEOFTEOPRESIDENT, COUNCILONENVIRONmIENTAL QUALiTYr, Washington, D.C., October4,1977. Hon.DOUGLASM.COSTLE, Administrator, Environmental Protection Agency, Washington,D.C.

DEARM

.COSTLE: The encloseddocumentisthefirstofficialreportsubmitted toyoubytheInteragencyTestingCommittee pursuant to Section 4(e) of the Toxic Substances Control Act (TSCA). It reflects the consensus ofrepresentatives from all eight member agencies: thatthetenlistedsubstances andcategories ofsubstances berecommended as high priority for testing under TSCA anddesignatedforconsideration byEPA withintwelvemonths.

The report describes theprocess employed bythe Committee inmaking its recommendations and the rationale for each designation. A supporting dossier foreachdesignationwillbeforwardedto the Office of Toxic Substances In the nextfewweeks.

OnlyaportionofthecompoundsIdentifiedintheJulypreliminary reporthas been considered to date.The firstrevision of our recommendations will be based largely upon further review of those chemicals previously identified. Becausethis isacontinuingprocess,we will,ofcourse,Identify additionalchemicalsfor suchreview asInformationbe- comesavailabletous.

The Committee hasbeen hampered Inits deliberations by the lack ofareadily available and consolidated sourceofdata onthe many chemicals to which man andthe on- vironment are ekposed. Other activities under TSCA, e.g., development of coordinated datasystems,inventoryreporting, and other information collection under Section 8,should beofconsiderable valueinfuture Committeeefforts.,Thereforo, we expectthat a number of additional substances will be listed and integrated inourfuture reports,

We hope our ,analysis and recommendations will be helpful toEPA In its implementation ofthe Toxic Substances Control Act. Sincerely, WARRENR.Mum, Ph.D., Chairman,TSCA Interagency TestingCommittee.

FEDERAL REGISTER, VOL 42, NO. 197-WEDNESDAY, OCTOBER 12, 1977NOTICES

INITIAL REPORT OF THETSCA INTERAGENCY TESTING COMMITTEE TOTE I ADMINISTRATOR, ENVIRONMENTAL PROTECTION AGENCY

October 1, 1977

FEDERAL REGISTER, VOL 42, NO. 197-WEDNESDAY, OCTOBER 12, 1977 55027NOTICES

CONTENTS CommitteeMembership i Acknowledgments ii SUMMARY iii CHAPTER 1. INTRODUCTION 1.1 Background 1 1.2 Committee Establishment and Responsibilities 2 CHAPTER 2. DEVELOPMENT OF HE COMMITTEE'S INITIAL RECOMMENDATIONS 2.1 Selection of the Commitee's Basic Approach 4 2.2 Establishment of the -xttial Listing
-. 7 2.3 Reduction to theMaste= File 7 2.4 Selection of the Preliminary List 8 2.5 Public Comment on the Preliminary List 10 2.6 Selection of Substances for Detailed Review 11 2.7 Considerstion for Listing and Designation 14 2.8 Consideration of Availability of Testing Facilities and Personnel 15 CHAPTER 3. RECOMMENDATIONS OF THE COMMITTEE 3.1 Substances and Categories of Substances Recommended for Testing 17 3.2 Reasons for Recommending Tes.ting of the Substances and Categories 19 3.2.A Alkyl Epoxides 19 3.2.B Alkyl Phthalates 20 -3.2.C Chlorinated Benzenes, Mono- and Di- 21 3.2.D Chlorinated Paraffins, 35-64Z Chlorine 22 3.2.E Chloromethane 23 3.2.F Cresols 24 3.2.G Re.xachloro-1 ,3-Butadiene 25 3.2.H Nitrobenzene 26 3.2.1 Toluene 27 3.2.J Xylenes- 28 APPENDICES APPENDI A DATA SOURCES US=D FOR PREPARATION OF THE INITIAL LIST 29 APPENDIX B -PRODUCTION, RELESE AND EXPOSURE SCORES 32 APPENDIX C ORDERING OF TE CHEMICALS BASED ON 'PRODUCTION, RELEASE, AND EXPOSURE 38 APPENDIX D BIOLOGICAL AND "NVIRONMENTAL SCORES 39

FEDERAL REGISTER, VOL. 42, NO. 197-WEDNESDAY, OCTOBER 12, 1977NOTICES TSCAINTERAGENCY TESTING CONMITEE

Statutory Member Agencies Council on Environmental Quality National Institute ofEnvironmental Health Sciences Warren R. Muir, Member and Committee Chairman Hans L. Falk, Member Warren T. Piver, Alternate Department of Commerce National Institute for Occupational Safety and Health Sidney R. Galler, Member Norbert P. Page, Member 'Bernard Greifer, Alternate Jean G. French, Alternate Environmental Protection Agency National Cancer Institute WilliamM.Upholt,Member JamesM. Sontag, Member
James R. Beall, Alternate National Science Foundation Marvin E. Stephenson, Member

and CommitteeVice Chairman Carter Schuth, Alternate Occupational Safety and Health Administration Grover C.Wrenn,Member JamesM.Vail,Alternate
LiaisonAgencies (non-Voting) Department of Defense Department of Interior SeymourL.Friess Charles R.Walker Food.aniDrugAdministration U.S. ConsumerProduct Safety Commission AllenH- Heim Robert M. Hehir JosephMcLaughlin Committee Staff Secretary: PhyllisD.Tucker

FEDERAL REGISTER, VOL 42, NO. 197-WEDNESDAY, OCTOBER 12, 1977 5502955030

FEDERAL REGISTER, VOL. 42, NO. 197-WEDNESDAY, OCTOBER 12, 1977 NOTICES ACKNOWLEDGHENTS
The Committee wishes to acknowledge the important contributions of themany individuals and groups who have significantly aided us in ourw6rk. These include:

- ClementAssociates, Inc., technical support contractor;

- the National Science Foundation, for funding and managing the technical support contract and the National Cancer Institute and National Institute ofEnvironmental Health Scientes for assist~ng in that funding;
Z- government experts who assisted in the scoring ofbiological activity and test needs, including Laurence Fishbein of the National Center for ToxicologicalResearch, Elizabeth Weisburger of theNational Cancer Institute, and anumber.of experts from the Department of Interior; EPAstaffmembers who assisted the Committee inavariety of activities, and particularly: Donald Barnes, Office of Toxic Substances Joyce Dan,Interim Secretary to the Committee John Lyon, Office of General Counsel JosephMerenda, staff support to EPAmember LamarMiller, interim staff support to EPAmember RalphNorthrop,Jr.., Office of Toxic Substances the numerous experts whoprepared presentations andmaterials for the Committee; and themany individuals and organizationswho submitted comments on the Committee's Preliminary List.

ioNOTICES SUMMARY The Toxic Substances Control.Act (TSCA) established theTSCA Interagency Testing Committee, giving it the continuing responsibility to identify and recommend to theAdministrator of theEnvironmental ProtectionAgency chemical substances and mixtures which shouldbe. tested todetermine theirhazards to humanhealth and the environment. The Committee's initial recommendations are to be published in the Federal Register and transmitted to theEPA Adminitrator withinnine months of the effective date of TSCA. The Committee is to consider additions to its recommendations at least every sixmonths. In meet3=g its charge, the Committee has, with the assistance ofa technical support contractor, carried out amulti-step screening procedure to identify for its detailed review a limited number of substances and categories of substances likely to have priority for testing to determine their effects on human health and the environment. Anumber of substances and categories identified by this process have been reviewed by the Committee, which has given careful consideration to each ofthe eight factors specified in Section 4(e)(1)(A) ofTSCA. The Committee has also considered suchfactors as test programs currently in progress, the current status ofregulatory actionwith respect to asubstance, and the need for test data onall members of certain categories rather than on one ormore individual members of the category. InJuly, 1977, the Committeepublished a Preliminary List of330 substances and categories of substances alongwithabackground document describing themethods used by theCommittee in making those selections. ThePreliminary List included substances and categories selected primarily on thebasis of potential for human exposure and environmental release. Public comments received on thePreliminary Listwere reviewed by the Committee and considered in the development of the Committee's initial recommendations. Subsequently, the chemicals on the Preliminary List and chemicals added -athePreliminary List based on the public comments were furthe- screened by the Committee based primarily on their potential foradverse human and/or environmental effects, but also continuing to co-nidr their exposure potential. Available data on and potential for carninogenic, mutagenic, teratogenic and chronic toxic effects, as welL as their ability to bioaccumulate or cause deleterious environmental effects were considered. Ascoring system which took into accountboth available information and the lack of it for these factorswas used in thisprocess. Using these scoring results and its scientific judgment, the Commmittee further narrowed the listunder consideration to about 80 substances and categories. Aided by informationdossiers preparedby its contractor, theCommittee reviewed about half of these compounds and has selected for inclusion in its initial recommendations to theEPA Administrator four individual substances and six categories of substances. Each is being 1;is

FEDERAL REGISTER, VOL 42, NO. 197-WEDNESDAY, OCTOBER 12, 1977 55031I NOTICES designated by the Committee for consideration by EPAwithin the next 12 months. They are (arranged alphabetically): Substance or Category Alkyl Epoxides
Alkyl Phthalates Chlorinated Benzenes, Mono- and DiChlorinated Paraffins
I Chloromethane

CresOls

Hexachloro-1,3- butadiene Nitrobenzene
Toluene
Xylenes TestingRecommended Carcinogenicity, mutagenicity, teratogenicity, other chronic effects, environmental effects, and epidemiological study Environmental effects Carcinogenicity, mutagenicity, teratogenicity, other chronic effects, environmental effects, and epidemiological study Carcinogenicity, mutagenicity, teratogenicity, other chronic effects, and environmental ,effects 'Carcinogenicity, mutagenicity, teratogenicity, and other chronic effects Carcinogenicity, mutagenic.ty, teratogenicity, other chronic effects, and environmental effects Environmental effects Carcinogenicity, mutagenicity, and environmental effects Carcinogenicity, teratogenicity, other chronic effects, and epidemiologioal study Mutagenicity, teratogenicity, and epidemiological study The Committee's reasons for eachrecommendation and a more detailed definition of each of the categories are presented in Section 3.2. The Committee expects that the precise definition of each category willbe.considered further-by EPA in the course ofdeveloping testing rules. The Committee also recognizes that certainmembers of a categorymay already have been adequately tested for one ormore of the effects for which testing of the category has been recommended. In that case, no further testing for that combination of substance and effect would be needed. Adossier summarizing the information considered by the Committee in selecting each substance or categorywill be forwarded to EPA in the next fewweeks. The Committee will continue its review of the remaLning substances and categories already selected for detailed review,andmay identify and review others, inanticipation of its next report. 

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FEDERAL REGISTER, VOL 42, NO. 197-WEDNESDAY, OCTOBER 12, 1977 55032NOTICES INITIAL REPORT OFTHE TSCA INTERAGENCY TESTING CO ffTTEE TO THE ADMINISTRATOR, ENVIRONMMETAL PROTECTION AGENCY October 1,1977
CHAPTER I. INTRODUCTION 1.1 BACKGROUND Section 4(e) of theToxic Substances Control Act (P.L. 94-469, hereafter referred to as TSCA) established theTSCA Interagency Testing Committee. That Committee has the continuing responsibility to identify and recommend to the Administrator ofthe Environmental Protection Agency chemical substances ormiLtures which should be tested to determine their hazard tohuman health or the environment. The statute provides that the Committee shall make its initial recommendations to EPA by October 1, 1977. To carry out thisresponsibility, the Committee has developed and executed amulti-step screening procedure to identify for its detailed review a number of chemical substances and categories ofchemical substances expected to have ahigh priority for testing based on the criteria set forth in Section 4(e)(1)(A) ofTSCA. The Committee received extensive technical support in this screening, andin the gathering of data on substances and categories selected for detailed review, from Clement Associates, Inc. under a contract with the National Science Foundation. After reviewing the information available to it on each candidate, including public comments submitted in response to the Committee's July, 1977, publication ofa preliminary list of substances under consideration, the Committee has selected the ten substances and categories being recommended to the EPA Administrator in this report. As required by the statute, the Commirree will continue its review process, reporting to theEPA Adm+nstrator within sixmonths from the date of this report such aaddit-nna! recommendations as the Committee finds desirable during -thatperiod. Thisreport documents theprocedures usedby the Committee in selecting those substances and categories nowbeing recommended for testing, and, as required by the statute, provides the Committee's reasons formaking each suchrecommendation. In addition to the material contained in this report, the Committee is nowfinalizing a series of dossiers developed by its technical support contractor which will summarize all of the non-confidential information considered by the Commttee in deciding to recommend each substance or category for testing. These dossiers will be transmitted to theEPAin a fewweeks.



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FEDERAL REGISTER, VOL 42, NO. 197-WEDNESDAY, OCTOBER 12, 1977 5503355034

FEDERAL REGISTER, VOL. 42, NO. 197-WEDNESDAY, OCTOBER 12, 1977 NOTICES 1.2 COMMITTEE ESTABLISHMENT AND RESPONSIBILITIES The Committee, as established by Section 4(e) ofTSCA, has eight members, appointedby the eight Federal agencies identified for membership in Section-4(e)(2)(A)of the Act. Inadditioni anumber of alternateshave beendesignated aspermitted by Section 4(e)(2) (B) (i). The Committee has adopted the name "TSCA Interagency Testing Committee", which is frequently shoftiened in this report to "Committee". As provided by Section 4(e)(2) (B)(iii), it has selected a chairman from among its members. The Committee has also invited several other Federal agencies with programs related to the control of toxic substances, butwhichwere not included in the statutory membership of the Committee, to designate liaison representatives to attend Committeemeetings. Current Committeemembers, alternates,and liaison representatives are identified in the frontispiece. TheComm.ttee's testing priority recommendations are required by Section 4(e) to bepublished in theFederal Register and transmitted to the EPAAdministrator withinnine months of theJanuary 1,1977, effective date of TSCA. At least every sixmonths .thereafter,the Committee isrequired to review its recommendations and make such revisions as are necessary. The Committee's recommendations are to be in the form of alist of chemical substances ormixtures set forth, either indivLdually or in groups, in the order inwhich the Committee determines the EPA Administrator should consider taking action under Section 4(a) in developing and promulgating testing regulations. The Committee is authorized to designate up to 50 of these substances or groups for which theEPA Administratormust within 12months either initiate rulemaking requiring their testing orpublish reasons for not taking such action.
Indeveloping its recommendations, the Committee is directed by Section 4(e)(1)(A)of TSCA to consider, alongwith all other relevant factors: the productionvolume, environmental release, occupational exposure, and non-occupational human exposure to the substance or mixture; the similarity of the substance ormixture in question to others 'knownto presentunreasonable risk of injury to health or the environment; the extent of data on the effects of the substance or mixture in question on health or the environment and the extent to whichadditional testing of the substance ormixturemayproduce data fromwhich effects can reasonablybe determined or predicted; and the reasonably foreseeable availability of facilities and personnel for performing the testingbeing recommended. The Committee is also directedby Section.4(e) to givepriority attention in establishing its list ofrecommendations to substances ormixtures which are known or suspected to cause or contribute to cancer, gene mutations, or birth defects.

2NOTICES The Committee's specific reasons for including each substance or mixturein its recommendations are required to bepublished in the Federal Register and transmitted to theEPAAdministrator along with thepriority list. While Section 4(e)refers to the Committee's recommendations as alist of "chemical substances andmixtures", Section 26(c)(1) authorizes the EPAAdministrator to take actions (including the promulgation of Section 4(a) testing regulations) with respect to categories of chemical substances ormixtures as well. A category is defined in TSCA as a group whose members are similar in molecular structure; in physical, chemical, orbiological properties; in us ; in mode of entrance ihto the humanbody or into the environment; or in any other way, so long as the grquping is notbased solely on itsmembers being "new chemical substances" as defined in theAct. Since the EPA Administrator is authorized to promulgate testing regulations for categories of chemical substances or mixtures, the Committee has concluded that its recommendations to theEPA Administrator may also include categories (or groups) ofchemical substances ormixtures, as well as individual substances and mixtures. This conclusion is consistent with Section 4(e) which states that the Committee's recommendations for testing "shallbe in the form of a list of chemical substances and mixtbres which shall be set forth, either by individual substance ormixture orby'groups of substances or mixtures...." In order tomaintain consistency in this report and in keeping with itsmeaning in TSCA, the term "category" will be used to reflect groupings of substances. "Substance" willbe used to refer to both individual chemicals as well as mixtures.

FEDERAL REGISTER, VOL 42, NO. 197-WEDNESDAY, OCTOBER 12, 1977 5503555036

FEDERAL REGISTER, VOL 42, NO. 197-WEDNESDAY, OCTOBER 12, 1977 NOTICES CHAPTER 2. DEVELOPMENT OF THE COMMITTEE'S INITIAL RECOWMIMATIONS 2.1 SELECTION OF THE COMMITTEE'S BASIC APPROACH Estimates of the number of chemical substances and mixtures subject to TSCA rangefrom tens of thousands to over 100)900;-the-number and identities of these substances andmixtures will not be established until after the completion of the chemical inventory under Section 8(b) of TSCA. Nevertheless, all of these substances andmiJtures, togetherwith others which. may be manufactured in the future, are subject to the promulgation of testing rules under Section 4(a) and are thus within the puziviev of the Interagency Testing Committee.
At the same time, Section 4(e) of TSCA specifies a number of factors which the Committee is to c6nsider in determiningwhether to recommend a substance for testing. Careful consideration of these factors requires the collection and review of a substantial amount of data concerning the production,use, chemical and biological activity,and previous testing of each substance or category of substances under -consideration.
As a result, because of the lack of a comprehensive and readily accessible data base on current chemica\Is, 'thelarge number of potential candidates for the Committee's consideration, and the statutory deadline for the Committee's initial recommendations to EPA, the Committee has had to select for its detailed consideration only a small subset of the possible candidates.
In considering alternative approaches to.selecting a limited number of substances for detailed review, the Committeemet with anumber of experts on chemical data systems and chemical characterization. Several possible approaches were identified. Onewas a nomination approach in which Committeemembers or other experts wouldnominate specific chemicals for consideration. Another was to use structure-activity relationships to identify for review substances chemically similar to others of known hazard. Yet another approach was to focus the Committee's attention on those substances known to havehigh\levels of productionvolume, environmental release, or human exposur.e. After considering these alternatives, the Committee decided to adopt a combined strategy employing features of each. This resulted in a multi-step screening process wherein a relatively large number of substances were considered initially and at each subsequent step a smaller subset was selected for collection of more data and more intensive review.NOTICES T-e basic steps in the process adopted by the Committee, which are illustrated in Figure 1 and are described in more detail in subsequent sections; were as follows:

a. Establishment of an-INITIAL LISTIIIGof about 3,650 substances and categories of substancespreviously identifiedas potentialhazards to humanhealth or the environment, b. Compilation of asmallerMASTERFILE (about1,700 substances and categories) through elimination from the INITIAL LISTING of substances not in commercial production or used predominantly aspesticides, food additives, or drugs,
c. Selection ofa PRELIMINARY LIST of about 330 substances and categories for further consideration based on evaluation of the production volume, environmental release, occupational exposure,and generalhuman exposure levels of the substances in the MASTER iLE, d. Selection of about 80 substances and categories for detailed review based onevaluation of the potential biological activity and need forhealth and ecological effects testing of substances appearing on the PRELIMINARYLIST,

e. Selection of substances and categories recommended for testing after review of preliminary dossiers prepared by the Committee's contractor, public comments on the PRELIMINARY LIST, and other pertinent information available to the Committee from various agencies, f. Documentation of the Committee's reasons for including each substance or category in its list of recommendations and completion of afinal dossier summarizing the information considered by the Committee in reaching its decision.

FEDERAL REGISTER, VOL 42, NO. 197-WEDNESDAY, OCTOBER 12, 1977 5503755038 NOTICES

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Lu U.Carrying out this multi-step process required the collection, review, coding, and analysis of data on a largenumber of chemical substances, aswell as the application of scientific judgment in many areas where adequate data were unavailable. The Committee was supported extensively in these efforts byClement Associates, Inc. under a contract with theNational Science Foundation (Contract No. NSF ENV77- 15417with partial funding by theNIMRS andNCI. Thecontractor employed expert consultants from avariety of disciplines in carrying out its tasks under the contract. In addition, manyU.S. Government agencies made data and expertise of their employees available to the Committee for theseefforts. Several of the steps of the Committee's procedure employed quantitative scoring of the substances under consideration. Members of the Committeeused their professional expertise andjudgment in applying these scores to the decisions at each step. 2.2 ESTABLISHMENT OFTHE INITIALLISTING In order to focus its initialattention on substances likely to requirehealth and/or ecological effects testing, and forwhich sufficient preliminary data were likely to be available to permitmore detailed reviews at later steps, the Committee chose to limit its initial consideration to substances or categories of substances which had already been identified,in previous reviews as being ofconcern because of potential adverse effects onhuman health or the environment or as having large production volumes and apotential for substantial human exposure or environmental release. Nineteen separate source lists ofthis type were identified by the Committee andpooled to produce the INITIAL LISTING of about 3,650 substances, mixtures, and categories. The individual source lists areidentified and described briefly inAppendixA. 2.3 REDUCTION TOTHE MASTERFILE The INITIAL LISTING included anumber of substances having pesticide, food additive, or druguses, all ofwhich are regulated under other Federal statutes and are exempted fromregulation byTSCA. To identify them, theINITIAL LISTING was compared with lists of pesticides prepared by theEPA and lists offood additives and drugs prepared by theFood and DrugAdministration, using Chemical Abstracts Service (CAS) Registry Numbers. This initial purge of substances subject to other statuteswas incomplete, since some entries on source lists didnot include CAS numbers. To compensate for this, a further manual purging was required. Consideration was also given to the fact that a substance used as a pesticide, food additive or drug may also have otheruses that are subject to theauthority of TSCA. Since pesticides, food additives, and drugs are generally produced in limited volumes, substances identified as suchbut having annual production over 10millionpounds were considered likely tohave other uses aswell and were retained on the truncated list for further review of their uses. Substances identified as pesticides, food additives, or drugs but known to the Committee or its contractor to have other uses within thejurisdiction of TSCAwere also retained. 7

FEDERAL REGISTER, VOL 42, NO. 197-WEDNESDAY, OCTOBER 12, 1977 NOTICES 553039The resulting file was reduced further by the elimination of chemicals which were judged not likely to be in commercial production. This was accomplished by comparing the file against EPA's Candidate List of Chemical. Substances, prepared by the Office of Toxic Substances (dated April 1977). Again, thebasis of comparison for this purge was an assigned CAS number. Consequently, this purge did not affect those chemicals on source lists for which no CAS number was given. In an attempt to eliminate-substances' which are not in commercial production, the followifg rule was adopted: any substance not identified by a CAS number which appeared on the NIOSH Registry (Source List 13 ofAppendix A) and onnone of the other source lists was judged not likely to be in commercial production. This decision was based on the fact that the NIOSH Registry lists any substance for which toxic effects have been reported, including research chemicals. A scan of the substances eliminated by the application of this rule' demonstrated its usefulness: few of the purged substances were recognized to be in commercial production. As a result of the purges described above, a MASTER FILE of approximately 1700 substances emerged. 2.4 SELECTION OF THE PRELIMINARY LIST Having developed aMASTER FILE of substances-tobe considered for possible recommendation to EPA for testing, the Committee began to apply the eight factors explicitly identified for its consideration In Section 4(e)(1) (A). While recognizing that there would be advantages to applying all of the first seven factors* simultaneously in evaluating the relative priorities for detailed review of the substances under consideration, the Committee concluded that assembling and evaluating the necessary data for all substances on the MASTER FILEwould not be feasible within the time schedule established by statute, considering the limitations of current chemical information systems and the number of professional judgments which would have to be made. Evaluation of the fifth, sixth, and seventh factors (relating to chemical similarity to substances of known hazar&, existing health and environmental effects data, and need for testing) was anticipated to require more independent review and judgment and to be themore time-consuming portion of the task. Hence, the Committee decided to further reduce the number of substances under consideration before explicitly evaluating those factors which had, to scme extent, alreadybeen reflected in the choice of source lists.

* The eighth factor, the reasonably forseeable availability of facilities and personnel for performing the needed testing, was considered principally by the ComiIttee in terms of the aggregate facilities and personnel needs for carrying out all of the Committee's recommendations. See Section 2.8 for further discussion of this factor.
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FEDERAL REGISTER, VOL 42, NO. 197-WEDNESDAY,'OCTODER 12, 1977 55040 NOT'ICES1NOTICES _Ths_1reduction,_which resulted in the selection of the Lf LIST, was based principally on eva.uac.fotff-the first tour factors identified for the Committee s consideration in Section 4(e)(1)(A) of TSCA. These are: i) quantity of the substance produced annually (ii) amount of the substance released into the environment (iii) number of individuals occupationally exposed and duration of their exposure (xv) extent to which the general population will be exposed. Using a combination of published data and judgment, the Committee's contractor made an attempt to score each substance in theIASTER FILE for these four factors. Appendix B.describes in more detail how scores were assigned to substances. Information on the use oruses of a substance was critical to the assignment of scores for environmental release and general population eaxposure, and scores for those factors could not be assigned if use information could not be found by the contractor. For about 1,000 of the 1,700 substances in the iASTER FILE this was the case; as a result, for only about 700 of the substances was it possible to assign scores. By combining the scores for the four factors, as described inAppendix C, a rank-ordered list of the scored substances was prepared for the Committee's consideration.
In selecting the approximately 330 substances and categories included on the PRELIIARY LIST, the Committee considered all of the scored substances and eliminated from current consideration a number of them which in the Committee's professional judgment were found to be:

a. Currently under stringent regulation or of lower priority for the Committee's purposes because theirhazard is reasonablywell characterized (e.g., vinyl chloride and mercury); b. Essentially inertmaterials (e.g. certain polymers) or substances reasonablywell characterized as having low toxicity (e.g., methane); c. Coveredby testing requirements under food, drug and cosmetic or pesticide legislation (e.g., citric acid); or d. Certain natural products (e.g., asphalt) whose consideration should be deferred pending better characterizatibn for testing purposes. Others of the scored substances were specifically selected by the Committee for inclusion on the PRELIMINARY LIST based onjudgment of members that further review was needed. The remainder of the scored substances were considered for inclusion on thePRELIMARY LISTbased on their relative ranking in the scoring process. 9
FEDERAL REGISTER, VOL 42, NO. 197-WEDNESDAY, OCTOBER 12, 1977 55041NOTICES In addition to the scored substances, the Committee also considered in selecting the PRELIMINARYLIST the unscored substances from the MASTER FILE and a limited number of additional substances recommended by Committeemembers or the Committee's contractor. A number of substances from these sources were included on the PRELIMINARY LIST based on the Committee's knowledge of the substance and its uses or the Committee's professional judgment that the substance should be further evaluated.
In reviewing substances for possible inclusion on the PRELIMINARY LIST, theCommittee also considered the desirability of grouping substances nto categories. In several cases the Committee grouped chemlcally-related substances from theMASTERFILE while in other cases the Committee retained groups which had already appeared in one of the source lists. About 15% of the entries on the PRELIMINARY LIST were categories. 2.5 PUBLIC COMMENT ON I.PRELIMINARY LIST The PRELIMINARY LIST, togetherwith a background document describing its development, was published by the Committee in July, 1977. Notice was published by the Committee in the FederalRegister (42 FR 30531 and 42 FR 40756) announcing the availability of the list and background document and requesting public comment. Comments were specifically requested on:

a. Themethodology used by the Committee in developing the PRELIMINARY LIST; b. Substances not appearing on the PRELIMINARY LIST which commentors might recommend for considerationby the Committee and the commentor's reasons for the recommendation;

c. Substances appearing on the PRELIMINARY LIST, which commentors might recommend that the Committee not consider further and the reasons for that recommendation; and d.-Comments on.the needs for and relative priority of testing of the substances being considered by the Committee.
As an additional aid to ccmmentors and others interested in the Committee's activities, copies of the list of substances comprising theMIASTER FILE and a tabulation of the scores for productionvolume, environmental release, and occupational and general population exposure considered by the Committee in selecting the PRELIMINARY LIST weremade available for public inspection at the headquarters and regional offices of the Environmental Protection Agency. Comments on the PRELIMINARY LIST were received from about 65 industrial firms, trade associations, environmental organizations, government agencies, and individuals. About two-thirds of the

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FEDERAL REGISTER, VOL 42, NO. 197-WEDNESDAY, OCTOBER 12, 1977 55042commentors recommended deletion from the Committee's further consideration of one ormore substances or categories appearing on thePREJ.7 AY LIST, while four commentors recomended additional substances forthe Committee's consideration. About one-fifth of the commentors included comments on themethodology employedby the Committee in developing thePREL1INAPy LIST and about one-third included comments on other issues related to the Committee's activities. Such issues were theuse of categories in the Committee's recommendations to EPA, documentation of the Committee's reasons for its decisions with respect to specific substances, and provision of opportunity for public comment on the Committee's actions. Public comments on the PRELflfINARY LIST have been reviewed by the Committee and considered in the development of the Committee's initial recommelations. Four of the seven additional substances recommended by commentors were added to the PRELIINARY LIST for consideration in selecting substances and categories for detailed review. Because of the large number of comments recommending deletions ofsubstances from theCommittee's consideration and the limited time available under the statutory deadline, pertinent comments were considered on a substance-by-substance or category-by-category basis during the Committee's review ofpreliminary dossiers and consideration of reasons for and against recommending testing. Comments on the Committee's methodology have been reviewed and will be considered in subsequent activities of the Committee. In the Committee's judgment, the recommended changes in methodology would not, if implemented, alter its initial recommendations. Comments dealing withuse of categories, documentationof theCommittee's reasons for actions, and other more general issues were also reviewed and considered in the development of the Committee's recommendations. 2.6 SELECTION OF SUBSTANCES FORDETAILED REVIEW This step of the Committee's procedure extended the scoring of the substances under consideration to factors (v) through (vil) of Section 4(e)(1)(A). These factors are: (v) the extent to which the substance or mixture is closely related to a chemical substance ormixture which is known to present an unreasonable risk ofinjury to health or the environment; (vi) the existence ofdata concerning the effects of the substance ormixture onhealth or the environment; and (viLi) the extent towhich testing of the substance or mixturemay result in the development of dataupon which the effects of the substance or mixture on health or the environment can reasonably be determined or predicted.

11

FEDERAL REGISTER, VOL 42, NO. 197-WEDNESDAY, OCTOBER 12, 1977 NOTICES 5504355044

FEDERAL REGISTER, VOL. 42, NO. 197-WEDNESDAY, OCTOBEk 12, 1977 NOTICES To accomplish this, each substance on the PRELIMINARY LIST was scored -foreach of seven biological activity factors by a number of experts available through the Committee's contract. The factors were: carcinogenicity,mutagenicity, teratogenicity, acute toxicity, other toxic effects such as reproductive effects or organ-specific toxicity, bioaccumulation; and ecological effects. After reviewing a summary of information on thebiological activity of the substance developed by the contractorbased on the open literature, each of the contractor's scorers assigned a score to the substance for the effect(s) forwhich that scorer was responsible. A total of nine scorers was used by the contractor,with two or three scorers separately evaluating each effect inmost cases. Each scorer consideredboth the summary information provided by the contractor and his personalknowledge of the substanceand chemically-related substances inassigning scores. Any substantial discrepancies among individual scorerswere identified, discussed among the scorers, and a consensus reached; in the case ofminor discrepancies in the scores for any factor, the scores of the several scorers were averaged. In addition, three of the effects (carcinogenicity,mutagenicity,and ecological effects) were separately scored by government experts from the National Cancer Institute,National Center for Toxicological Research, andDepartment of Interior,.respectively. These scores were averagedwith those of the contractor's scorers. Scores assigned for the various effects took the form of either a numerical score (generally 0,1,2,or 3)or a letter score (generally x, xx, orxxx). Assignment of anumerical score indicated a judgment that further testing of the substance is not needed for the effect under consideration,while themagnitude of the score indicated the degree to which the effect hadbeen confirmed or .thedose level at which it had been found. Assignment of a letter score, on the other hand, indicated a judgment that further testing should be carried out, with thenumber of "x's"assigned reflectinga judgment as to the level ofnumerical score that might be anticipated after testing. For example, in scoring asubstance for carcinogenicity a score of 3meant that the substance iswell established as acarcinogen inhumans or expermmental animals, while ascore of xxxmeant that the substance is strongly suspected of carcinogenic activitybut has not been adequately tested. In averaging the scores assigned to a substance by the several scorers for agiven factor, nomixing ofnumerical and letter scoreswas permitted. Any discrepancies between scorers in chosing the numerical or letter scalewere discussed among the scorers and resolved. The criteria applied by the scorers in assigning scores for thevarious factors are described in more detail in Appendix D. Categories of substances appearing on thePRELIMINARY LIST werenot generally scored as entities, but rather, scores were assigned separately for each of the example substances listed under the category heading in the list.
12.Using-these-scores, :the.-contractor .provided the Committee a series of listsbfthe substances appearing on thePRELIHINARYLIST ranked according to various criteria. These included separate lists for each factor-ranked by the average score a substance received for that factor.(identifying those substancesjudged most in need for testing for a single effect) and a list rankedby the sum of the letter scores received by a substance for all factors (identifying substances requiring testing for a number of effects). Also tabulated on each list.was an exposure index for each substance whichwas derived from the earlier scoring of production volume, environmental release, and occupational and general population exposure. For thehumanhealth effects factors and total letter score lists the exposure indexused was the sumof the productionvolume, occupational exposure, and general population exposure scores, while for thebioaccumulation and ecological effects factors, the exposure indexwas the sum of the productionvolume and environmental release scores. The Committee also received from its contractor a list ofthose substances evaluated by the scorers whichwere known or might be anticipated to have additional adverse health or environmental effects as aresult of contaminants appearing in the commercial product or degradation products of the substance under consideration. The Committee's selection of substances and categories from the PRELIMINARY LIST to be carried forward for detailed review used the various lists provided by its contractor as guides, but reflected the independent judgments of themembers of the Committee. First, the scores themselves were reviewed, with any major discrepancies between the contractor's scores and those of the government scorers or the judgments of Individual tommitteemembers being considered. Then, the Committee turned to thevarious ranked lists, reviewing in turn the substances rankedmost in need of testing on the sum-of-letter-scores lst or the lists for the individual factors. Each substance appearing in the top 75 to 100 positions on one ormoreof these lists was considered by the Committee and a decisionmade whether to select it for detailed review. Particular attention was paid by the Committee to substances known or suspected to be carcinogens, mutagens, or teratogens, Jnkeeping with the statutory guidance provided the Committee in Section 4(e)(1)(A) of TSCA. This emphasis was reflected not only in the Committee's consideratzon of individual substances and categories, but also in its struc=nring of the review process, since these effectswere scored individually and, in effect, received greater attention than dLd other effect:s scored 3n groups (e.g., other toxic effects or ecologicaleffects). Categories of substances appearing on the PRELfl12TARY LISTwere also revewed, in terms of the scoring of their examplemembers and the Commaztt's judgment as to retaining them. Anumber of decisions to modifyprevious categories or definenew categories weremade by the Commixt-ee during this reviewprocess. In reviewing these lists, more than two-thirds of the individual substances .scoredby the contractorwere explicitly considered by the Committee. Approximately eighty substances and categories were selected by the Committee for the drafting of preliminary dossiers and further detailed review. Of these, about half were individual substances and half categories. 13

FEDERAL REGISTER, VOL 42, NO. 197-WEDNESDAY, OCTOBER 12, 1977 5505 NOTICES55046

FEDERAL REGISTER, VOL 42, NO. 197-WEDNESDAY, OCTOBER 12, 1977 NOTICES 2.7 CONSIDERATION FORLISTING AND DESIGNATION For each of the approximately eighty substances and categories selected for detailed ieview., preliminary dossiers havebeen (or are being) prepared by the Committee's contractor. Within the time period allowed by the statute for development of the Committee's initial recommendations, preliminary dossierswere drafted for about one-half of the substances and categories for detailed review. Consideration of these and otherinformation resulted in the initialrecommendations transmitted by this report. Consideration of the remaining substances and categories already selected for detailed review, and others which may subsequently be selected, will continue andwill be reflected in subsequent recommendations to EPAby the Committee. The preliminary dossiers summarized information obtained from the open literature relating to the identification, relevant chemical and physical properties, production volume, uses, environmental release, and exposure to the substanceunder consideration as wellas information on the nature and findings of previous studies of its human health and environmental effects. Information on the biological activity of other chemically similar substances was also included where available. Preliminary dossiers for categories of substances included these types Of information for specific members of the category, generally the example members identified in thePRELIMARY LIST. Using the information summarized in the preliminary dossier, together with information submitted'n public comments on thePRELIMINARY LIST, information available to the Committee from various Federal agencies, and themembers' individual knowledge, the Committee reviewed each substance or category. Each of the factors specified in Section 4(e)(1)(A), as well as any other relevant factors identified by the Committee on a case-by-case basis, was considered. Inparticular, in considering factor (vi) of Section 4(e) (1)(A), the existence of data concerning the effects of the substance on helath or the environment, the Committee considered test programs currently in progress, as well as dataalready generated. Another factor considered in certain instances was the status of current regulatory action relative to the suostance. In .eachcase where a category of substances was under consideration the appropriate definition of the category and the need for data on allmembers of the category were considered. Where relevant to theparticular type of testing under consideration for a substance or category, factor (viii) of Section 4(e)(1) (A), the availability of test facilities and personnel, was discussed on a case-by-casebasis. In general, however, this factorwas considered in the aggregateafter the Committee's tentative recommendations for all substances and categories had been identified. The Committee's consideration of this factor is discussed further insection 2.8 of this report.

14NOTICES After reviewing and thoroughly discussing the information available to the Committee on the substance or category under consideration, a decision was made regarding whether to recommend the development of test rules by EPAand, if so, for which effects. Subsequently, one or more Committeemembers participated in the drafting of the supporting reasons for each recommendation and these reasons were again reviewed by the Committee. A final decision to recommend the substance or category for testing represents a consensus by the Committee members that suclitesting is needed to evaluate the effects of the substance (or of each individual substance falling within the definition ofa category) on human health and the environment, and that priority attention should be given byEPA to requiring the conduct of such testing. The Committee recognized, of course, that some members of recommended categoriesmay have already been adequately tested for the effects of concern and would not require further testing.
Several substances and categories reviewed by the Committeewere deferred for further consideration because of insufficient information to adequately define the categories or to determine the needs for testing. Assignment of priority order to the substances and categories recommended for testingwas also considered. The Committee concluded that all of the substances and categories being recommended at this time should be given equal priority in EPA's development of test rules. Factors contributing to this decision were the limited number of recommendations being made, the Committee's decision to designate all recommended substances and categories for considerationby EPA within 12 months, and the Committee's understanding of EPA's plans to develop its test rules forvarious effects, e.g., carcinogenicity, rather than for individual substances or categories. The Committee recommends that these substances and categories be included in the first applicable "effects rule". 2.8 CONSIDERATION OF AVAILABILITY OF TESTIG FACILITIES AD PERSONNEL
One of the criteria listed in Section 4(e)(1)(A), that the Committee was required to consider, is the reasonably foreseeable availability of facil-rZties and personnel for performing the testing it recommends. The Cmmttee reviewed the results of recent surveys of toxicology testi:& capabilities conducted by the Society of Toxicology (SOT) and the DE Commttee to Coordinate Toxicology and Related Programs (CT=)- While the SOT surveyed general toxicology testing capabifes, the COTEP specifically assessed inhalation test caoab-i'7-4ties. The Committee also reviewed the capabilities and plans ci the National Center forToxicological Research (ITCTR), the possibl impact of theFDA's Good Laboratory Practices, and the logist-ic and practical considerations for carcinogenicity, mutagenicity, and reproductive effects testing. It also was briefed on ecological test capabilities and needs in that area.

FEDERAL REGISTER, VOL 42, NO. 197-WEDNESDAY, OCTOBER 12, 1977 55047NOTICES Based upon these reviews, the Committee has concluded that there are sufficient toxicology testing capabilities in the U.S. to carry out the health effects testing recommendedby the Committee in this report.
A more difficult area to assess was that of environmental or ecological testing. Capabilities for acute studies are probably adequate, but the National capability for conducting long-term tests of chemical pollution on the envLronmentwill be less certain until the test standards and protocols are defined through the rulemaking process. The Committee feels, however, that the testLng burden likely to result from recommendations in this report is reasonable.

FEDERAL REGISTER, VOL 42, NO. 197-WEDNESDAY, OCTOBER 12, 1977 55048NOTICES CHAPTER 3. REC01NENDATIONS OF THE C0I.MITTEE 3.1 SUBSTANCES AND CATEGORIES OF SUBSTANCES RECOMEMMDED FOR TESTMIG As described in Chapter 2 of this report, the Committee has, with the assistance of a technical support contractor, carried out a multI-step screening procedure to identify for its detailed review a limited number of substances and categories of substances likely to hav; priority for testing to determine their effects on human health and the environment. A number of substances and categories identified by this process have been review'ed by the Committee, which has given careful consideration to each of the eight factors specified in Section4(e)(1)(A) of TSCA. The Committeehas also considered such other factors as it judged relevant on a case-by-casebasis. Such additional factors have included test programs currently in progress, the current status of regulatory action with respect to a substance, and the need for testdata on allmembers of certain categories rather than on one ormore individual members of the category. The eighth factor specified in Section 4(e)(1)(A) for the Committee's consideration, the reasonably foreseeable availability of facilities andpersonnel for performing the recommended testing, has (as described in Section 2.8 of this report)been consideredby the Committeewithrespect to the aggregate requirements of all of the testing recommendations made here, as well as for each individual testing recommendation. In the Committee's judgment there are, or can bemade available within the next few years, adequate facilities and' personnel for conducting the testing now being recommended by the Committee. Furthermore, any specific limitations of facilities or personnel which cannot now be identified by the Committee would be expected to be short-term in nature and can be taken into accountby EPA in establishing the time periods for submission of the test data under Section 4(b)(1). In selecting substances and categories for inclusion in its initial recommendations, the Committee has also given priority attention to substances known or suspected to cause cancer, gene mutations, or birthdefects. Based o its consideration of the factors identified in Section 4(e)(1)(A) and all other relevant factors identified by the Committee, andus-in all of the information available to it, including the knowledge and professional judgment of its members, it is the consensus of the TSCA Interagency Testing Committee that the ten substances and categories of substances listed in the accompanying table should be given priority consideration by the Administrator of the Euvironmental Protection Agency for the promulgation of regulations under Section 4(a) requiring the conduct of the types of testing specified. Each of these substances and categories is designated by the Committee for consideration by EPAwithin thenext 12months.

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FEDERAL 'REGISTER, VOL 42, NO. 197-WEDNESDAY, OCTOBER 12, 1977 5504955050

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In selecting categories of substances for inclusion in its recommendations, the Committee recognizes that somemembers of a category- may have alreadybeen adequately tested for one or more of the effects listed; in such cases no additional testing would be required. The Committee also recognizes that the precisedefinition of each category will have to be considered and decided byEPA in developing its test rules. The Committee's reasons for including each substance or category of substances on its list of recommendations, which are requiredby Section 4(e)(1)(B) to be submitted with the Committee's recommendations, are presented in the following section. In addition, the Committee will forward to EPA in the next fewweeks adossier on

- each substance or category included on the Committee's list of recommendations. These dossiers will summarize the information pertaining to each substance or categorywhichwas considered by the Committee inmaking its decision to recommend testing.

3.2 REASONS FOR RECOMMENDING TESTING OF THE SUBSTANCES Af41 CATEGORIES The ten substances and categories which the Committee has designated for consideration by the EPAAdministrator for development of test rules within twelvemonths are listedbelow with the Committee's reasons for recommending them. 3.2.A ALKYL EPOXIDES TESTINGRECOMMENDATIONS: Carcinogenicity Matagenicity Te-atogenicity O=er Chronic Effects

n _r-vronmental Effects Epidemiology CATEC-O IDENTIFICATION: This category includes all noncyclic aliphatic hydrocarbons with one ormore epoxy functional groups. REASONS FORRECOMMENDATIONS: Production, Release and Exposure: Although these compounds are generally used as industrial intermediates, several alkyl epoxides are produced in very large quantities (e.g., ethylene oxide at over 4 billion pounds per year). The vast amounts produced thus raise concernsprimarily with respect to workplace exposure. The reactivity of these compounds is such that environmental persistence is not anticipated; however, their reaction products maybe of significance. 19

FEDERAL REGISTER, VOL 42, NO. 197-WEDNESDAY, OCTOBER 12, 1977 NOTICES 5505155052

FEDERAL REGISTER, VOL 42, NO. 197-WEDNESDAY, OCTOBER 12, 1977 NOTICES EFFECTS OF CONCERN: The epoxy structure is a relatively reactive functional group which is believed to be the source of the carcinogenic andmutagenic activitywhich is well characterized for several members reviewed (particularly the diepoxides). Thus, while somemembers of the group appear to be relatively well characterized as potentialmutagens and/or carcinogens, these results and the presence of the epoxy functional group raise the need for testing other compounds in this group for these and other effects. Carcinogenicity: Diepoxides are demonstrated carcinogens in animal studies. Ethylene oxideproved inactivewhilepropyleneoxide showed carcinogenic activity in mice. Other alkyl'epoxides are less well tested. Because of thealkylatingproperties of these compounds itis recommended that alkyl epoxides be tested for carcinogenic potential. Mutagenicity ofmostmembers of this group tested provides further concern forcarcinogenic potential. Mutagenicity: Becausemost mebbers ofthis group whichhave been tested proved to bemutagenic; othermembers of this group should be tested for this effect. TeratogenicLty: In general, these compounds have not been adequately tested for teratogenicity but shouldbe, considering the reactivity of the epoxy group toward biologicalmaterials. Other Chronic Effects: Because of the reactivity of epoxides with biological materials, they should be tested for specific chronic organ effects and behavioral changes. Environment Effects: While the persistence of these compounds as epoxides is not great, concern is expressed for reactionproducts. In view of this possibility, the fate of epoxides in the environment shouldbe determined through testing. Epidemiology: Because of the large scaleproduction of several of these compounds, andbecause of the strong toxicological evidence of possible carcinogenic and mutagenic effects, the Ccmmittee recommends that retrospective epidemiologic studies be required for two or threeof the highest exposure compounds when suitable cohorts can be identified.

3.2.B ALKYL PHTHXLATES TESTING RECOMMNDATIONS: Environmental Effects CATEGORY IDENTIFICATION: This category consists of all high production (e.g., 10 million lbs/yr or greater) alkyl esters of 1,2-benzenedicarboxylic acid (orthophthalicacid).

20REASONSFORRECOMMENDATIONS: Production, Release, andExposure: Many Of these compounds are produced in large volume, some of them over one hundred millionpounds per year. Their use as plasticizers in,a wide variety of products results in large volumes of alkyl phthalats reaching the aquatic environment either as wastes from formulating plants or fromuse and disposal of end products. Effects of Concern: Environmental Effects: Many of the alkyl phthalares are quite stable, breaking down only slowly tomonophthalates orphthalic acid. There has been a great deal ofinformation published on their environmental fate and toxicity to aquatic organisms. Some are known to have considerable toxicity to fresh water fish. In view of the largevolume in which they can be expected to reach the aquatic environment and persist and accumulate in aquatic organisms, it is important to have data on the toxicity to aquatic organisms of all high production alkyl phthalates. Each such compound should be tested for chronic toxicity to typical aquatic organisms, especially fish. Effects on reproduction (or population) should be included in this testing.

3.2.C CHLORINATED BENZENES, MONO-AND DITESTING RECOMMENDATIONS: Carcinogenicity Mutagenicity Teratogenicity Other Chronic Effects Environmental Effects Epidemiology
CATEGORY IDENTIFICATION: This category consists of four close:ly-related chemical substances: monochlorobenzene (CAS No. 108-9G-7), and ortho-, meta-, and paradichlorobenzene (CAS Nos. 95-50-1, 541-73-1, and 106-46-7). REASONS -OR RECOMMENDATIONS: Product=on,Release and Exposure: The chlorobenzenes areproduced in large qantities, monochlorobenzene over 300million pounds/year and ortho- and pata-dichlorobenzene approximately 50 million pounds each. These chemicals are widely used in industrial processes, as solvents, and inmany consumer products. Therefore, the exposure and potential for hazard is great, particularly in light of their high release rate and anticipated persistence in the environment.

21

FEDERAL REGISTER, VOL 42, NO. 197-WEDNESDAY, OCTOBER 12, 1977 NOTICES 50355054 -

FEDERAL REGISTER, VOL 42, NO. 197-WEDNESDAY, OCTOBER 12, 1977 NOTICES Effects of Concern: Carcinogenicity: One very limited animal study suggested the induction of sarcomas following subcutaneous injections of para-dichlorobenzene. A possible association of several cases of leukemia withhuman exposure, to mixtures of ortho- and. para-dichlorobenzenes has also been reported. These studies, as well asother animal toxicity experiments, do not provide sufficient data on which to assess thercarcinogenic potential of members of this class. Mutagenicity: While a study has demonstrated backmutations inyeast exposed to ortho-dichlorobenzene, the data are inadequate to assess the potentialmutagenichazard. Additional testing is needed in view of the widespread release and exposure. The other chemicals inthis class should also be tested formutagenicity. Teratogenicity: While teratogenic effects are suspected for certain higher chlorobenzenes, themono- and dichlorobenzenes have not been adquately tested. Other Chronic Effects: Liver, kidney, respiratory and neurological effects have been observed with high level exposures. Effects at lower levels cannot be characterized from existing data. Chronic studies should be undertaken. Environmental Effects: The environmental fate of these compounds shouldbe determined. Evidence exists for environmental pollution and bioaccumulation in aquatic life. The effects are unknown. Studies should be initiated to assess the impact of these chemicals on terrestrial and aquatic systems. Epidemiology: A possible linkhas beenmade between exposure to ortho- and para-dichlorobenzene and leukemia. 'urther efforts to evaluate chronic effects should bemade by the identification and evaluation of specific populations who are or have been exposed to either ortho- or paradichlorobenzene.

3.2.D CHLORINATED PARAFFINS, 35-64%CHLORINE TESTING RECOMMENDATIONSr Carcinogenicity Mutagenicity Teratogenicity Other Chronic Effects Environmental Effects CATEGORY IDENTIFICATION: This category is comprised of a series of mixtures of chlorination products ofmaterials known commercially as paraffin oils or paraffin waxes; those-having a chlorine content of 35% through 64% byweight are included.

22REASONS FOR.RECOMMENDATIONS: Production,Release, and Exposure: The 1972 annual production of chlorinated paraffins was about 80 million pounds. Theuse ofthese materials in awide variety ofhousehold and paint products, as well as adhesives and flame retardants, results in an estimated release rate of about 50 million pounds per year. Effects of Concern: HumanHealthEffects: A chronic study in mice showed evidence of degenerative changes in the liver and spleen; no data are available on the carcinogenicity, mutagenicity, teratogenicity, or other chronic effects ofthesemixtures. The Committeerecommends that commercial products in this category be tested for such effects. Environmental Effects: The occurrence ofresidues of chlorinated paraffins in fish indicates theneed for critical assessment of the biological significance of this contamination of the aquatic environment. The persistence, environmental fate, and chronic effects on aquatic organisms of the chlorinated paraffins should be determined by appropriate testing.

3.2.E CHLOROMETHANE TESTING RECOMMENDATIONS: Carcinogenicity

utagencity Teratogenicity Other Chronic Effects SUBSTANCE IDENTIFICATION: CASNo. 74-87-3

PAONS FOR RECOMMENDATIONS: Produrtion, Release, andExposure: The 1974 U.S. production of chlorcmethane was over 350million pounds, most of this being used as a syntaeitic intermediate. However, it is estimated that about 5Z of the aal production (over 15million pounds per year) is released inta the environment. NIOSH estimates that thenumber ofworkers exposea to chloromethane numbers about 31,000. Effects-ofConcern: Carcinogenicity: To date, chloromethane has not been the subject of a carcinogenicity study, although it is structurally related to chloroform, carbon tetrachloride, and iodomethane, all ofwhichhave been reported as being carcinogenic. Moreover, chloromethane has recently beenreported as exhibiting mutagenic properties in the Salmonellamutagenic test withmicrosomal activation.

23

FEDERAL REGISTER, VOL 42, NO. 197-WEDNESDAY, OCTOBER 12, 1977 NOTICES 55055NOTICES Mutagenicity: The initial positive results in the Salmonella mutagenic test withmicrosomal activation should be supplemented with test data regarding chromosomal abberrations. Teratogenicity: The absence of data in this area, coupled with known toxic effects, calls for the initiation of studies to determine the extent of the potential hazard to the reproductive system and the fetus. Other Chronic Effects: Exposure to dhloromethane has been implicated in damage to the central nervous sytem, liver, kidneys, bone marrow and cardiovascular systems. Effects on these systems should be examined in chronic toxicity tests.

3.2.F CRESOLS TESTING RECOMMENDATIONS: Carcinogenicity blutagenicity Teratogenicity Other Chronic Effects Environmental Effects CATEGORY IDENTIFICATION: This category consists of the three isomers of methyl phenol: ortho-cresol (CASNo. 95-48-7), meta-cresol (CASNo. 108-39-4), and para-cresol (CAS No. 106-44-5). REASONS FORRECOMMENDATIONS: Production, Release, and Exposure: Cresols are produced in large quantities, having a combined U.S. production in 1975 of about 90 million pounds. An annual release rate of about 45 million pounds has been estimated. Their wide use as industrial solyents leads to substantial occupational exposure. NIOSH estimates that roughly two millionworkers are exposed to cresols. In addition, cresols are used in many consumer products,resulting in a large general exposure. Effects of Concern: Carcinogenicity: Cresols have not been evaluated for carcinogenicity. Because of widespread exposure and suggestive evidence of mutager.ic effects in certain plants, cresols should be tested for carcinogenicity. Mutagenicity: There is some suggestion of themutagenic potential of cresols in certain plants, but its potential as a humanmutagen has not been assessed. It is, therefore, recommended that further mutagenic studies be conducted.

24

FEDERAL REGISTER, VOL. 42,'NO. 197-WEDNESDAY, OCTOBER 12, 1977 55056NOTICES Teratogenicity: The teratogenicity of the cresols has notbeen assessed, but such testing is needed in viewof the evidence of biological activity of cresols (see Other Chronic Effects, below) and their widespread exposure. Other Chronic Effects: Although toxic effects involving the central nervous system, lungs, kidneys, liver, pancreas, and spleen havebeen observed.following acute exposure to cresol-containingproducts, adequate testing of cresols for chronic effects following prolonged-exposure has notbeen reported and should be conducted. Environmental Effects: There is evidence that creosote oils containing cresols are acutely toxic to fish and taint fish flesh at lowconcentrations. Because of their substantial release into the aquatic environment, cresols should betested for chronic effects on fish and other aquatic organisms.

3.2.G HEXACHLORO-1,3-BUTADIENE
TESTINGRECOMMENDATIONS: Environmental Effects SUBSTANCE IDENTIFICATION: CAS No..87-68-3 REASONS FORRECOMMENDATIONS: Production, Release, and Exposure: Although themostrecent (1974) data available indicate that this compound is no longer commercially manufactured in theU.S., it continues to beproduced as awaste byproduct ofvarious chlorination processes and is also imported into the U.S. for industrial solvent use. The release of hexachlorobutadiene into the environment has notbeen quantified, but there is good evidence ofwidespread distribution in the aquatic environment. Effe-ts of Concern: Environmental Effects: Hexachlorobutadiene's human health effec = are being studied indepth. It is a stable substance which-> -%dely distributed in the aquatic environment and has beenrenorted to bioaccumulate in fish and other aquatic organsms. These factors indicate that hexachlorobutadiene should be tested to determine its fate in aquatic systems and its ef-ects on invertebrates, fish, higher vertebrates, and plant liFe in aquatic systems. Its appearance in some Europe-n agricultural products suggests that its uptake by plants and/or foraging species should alsobe studied.

25.

FEDERAL REGISTER, VOL 42, NO. 197-WEDNESDAY, OCTOBER 12, 1977 550573.2.H NITROBENZENE TESTING RECOMMENDATIONS: Carcinogenicity Mutagenicity Environmental Effects

-SUBSTANCE IDENTIFICATION: CAS No. 98-95-3

REASONS FOR RECONMENDATIONS: Production, Release, and Exposure: U.S.production of nitrobenzene in 1975 was about 400 millidnpounds. Its release to the environment has been estimated to be about 20million pounds annually. Although its predominant use (97 percent of-production) is in closed systems in anilinemanufacture, nitrobenzene is also an industrial sofvent and dye intermediate. General population exposure can arise from environmental release, and from dispersiveuses such asperfume in soap; cleaner for woodwork,wood flooring and paneling; ingredient ofmetal polishes and shoeblacking. Nitrobenzene liquid andvapor penetrate intact skin readily, and the efficiency of vapor absorption by Inhalation is high. Effects of Concern: Carcinogenicity: No information is available on the carcinogenicity of nitrobenzene. Since it is biologically active, producing cellular changes, nitrobenzene shouldbe tested for carcinogenicity. Mutagenicity: Although there is evidence of its biological activity, no mutagenicity pesting has been reported for nitrobenzene. Mutagenicity testing should be performed. Environmental Effects: Nitrobenzene isarelatively persistent substance in the environment. Its lowvolatility, stability to light, and lowwater solubility indicate that bioaccumulation ispossible. Acute effects have been demonstrated in fish. Nitrobenzene inhibits oxygen utilization and hydrogen sulfide production in sewage microorganisms, inhibits growth inyeast, and is toxic to various soil bacteria and microorganisms. Additional data are needed to adequately characterize the persistence and fateof nitrobenzene and its matabolites in the aquatic environment. Testing is needed for such characteristics as well as to determine the effects of chronic exposure to natrobenzene on fish, aquatic invertebrates, aquatic plant life, and waterfowl.

26

FEDERAL REGISTER, VOL 42, NO. 197-WEDNESDAY, OCTOBER 12, 1977 55058 NOTICES3.2.1 TOLUENE TESTINGRECOMMENDATIONS Carcinogenicity Teratogenicity OtherChronic Effects Epidemiology SUBSTANCE. IDENTIFICATION: CAS No. 108-88-3 REASONS -OR RECOMMENDATIONS: Production,Release andExposure: Toluene is produced in large quantities with an annual production rate in excess of 5billion pounds. Because ofits widespread use as a solvent, as well as a multiplicity of other uses, toluene has anunusually high occupational exposure (over1millionworkers). Its presence inmany consumerproducts leads to alarge general exposure. Toluene is currently being substituted formany benzene-uses and has an annual releaserate exceeding 1 billion pounds. Effects of Concern: Carcinogenicity: Previous studies based solely on skin application techniques in animals have demonstrated a carcinogenic potential for toluene. Some of these studies were limited in design and prevented an appropriate appraisal of the carcinogenic hazard of toluene. It is, therefore, recommended that testing be conducted in long-term animal experiments taking into consideration the appropriate route of exposure. Teratogenicity: Information is lacking on the teratogenic hazard of this chemical, thus necessitating the initiation of studies to determine if toluene is teratogenic. Other Chronic Effects: Liver, central nervous system and hematopoietic effects havebeen observed at high level exposures. Efec-ts at lower levels cannot be characterized from existing data. Chronic studies to evaluate the effects ofprolonged exposures are recommended. Ep-d.e_±log : Occupational studies havebeen conducted predominantly on the acute toxic effects of toluene. There is little information on chronic effects in humans from exposure to low levels of toluene over an ext-uded period of time. Because of its long-term use, highhuman exposure, and demonstrated effects in animals, epidemiological studies maybe particularly important in assessing the human health effects of toluene.

27

FEDERAL REGISTER, VOL 42, NO. 197-WEDNESDAY, OCTOBER 12, 1977 55059 NOTICESNOTICES 3.2.J XYLENES TESTING RECOMMENDATIONS: Mutagenicity Teratogenicity Epidemiology CATEGORY IDENTIFICATION: This category consists of the three isomers of dimethyl benzene: ortho-xylene (CAS No. 95-47-6), meta-xylene (AS No. 108-38-3), and para-xylene (CAS No. 106-42-3) REASONS FOR RECOMMENDATIONS: Production, Release, and Exposure: In the aggregate, approximately 8billion pounds of xylenes are produced eachyear. Approximately 900 million pounds arereleased to the environment eachyear. Mixed xylenes wereranked byNIOSH 13th out of approximately 7000 agents in terms of the number of workers exposed. Xylenes are also used in a widevariety of consumer products, resulting in general population exposures. Effects of Concern: Mutagenicity: Mutagenesis tests havenot been reported for any of the xylenes, but should be conducted inview ofwidespread exposure and evidence of toxic effects to several organ systems. Teratogenicity: Xylenes cross the placentalbarrier and, according to two Russian studies, are embryotoxic. Therefore, they should be tested for teratogenicity. Epidemiology: Because of their long-term use, highhuman exposure, and demonstrated effects in animals, epidemiological studies may be particularly important in assessing thehumanhealth effects ofxylenes and should be conducted.

28

FEDERAL REGISTER, VOL 42, NO. 197-WEDNESDAY, OCTOBER 12, 1977 55060NOTICES APPENDIX A DATA SOURCES USED FORPREPARATION OF THEINITIAL LIST 01 Toxic Poliutants in Point SourceWater EffluentDischarge This list of 120 chemicals and categories consists ofAppendicesA and Cof the settlement agreement dated 7 June 1976between the Environmental Defense Fund and EPA. It is apriority list of toxicpollutants subject to regulations through point source effluent limitations CSection 307Ca)) under the Federal Water Pollution Control Act. 02 Scoring of Organic Air Compounds, June 1976, MITRE,MTR-6248 This list of337 chemicals and categories was compiled and documented by MITRE (September 1976) under contract to EPA. The relevant factors in selecting chemicals for the listwere: (1) quantityproduced, (2) potential for atmospheric release, and (3) toxicological effects. 03 Final Report of NSFWorkshop Panel to Select Organic Compounds Hazardous to the Environment, April 1975 This list of 80 chemicals and categories was compiled and documented by Stanford Research Instituteunder contract to the National ScienceFoundation. The list consists ofthose chemicals having the greatest potential for environmental release, selected from the universe ofmanufactured organic chemicals with the highest calculated release rates. 04 Potential Industrial Carcinogens and Mutagens This list of 88 chemicals has been compiled bythe National Center for Toxicological Research. The list is made up of industrial compounds which are potential carcinogens and/or mutagens, and. -oichhave been selected based upon available data concerning activity, use, production, and population at risk. 05 Occupational Carcinogens for Potential Regulatory Action T1 list of 116 chemicals and categories was compiledby OSH4A fr suspected carcinogens. Selection wasbased primarily upon data available through theNIOSHRegistry (SourceList 13). 07 Chemicals Testedor Scheduled forTesting at the Fish-Pesticide Research Laboratory, Department of Interior Thislist consists of 174 toxic chemicals which are suspected of being hazardous to fish and wildlife. 08 Substances with Chronic Effects other thanMutagenicity, Carcinogenicity, or Teratogen'icity; A Subfile of theNIOSH Registry -Asubfile ofthe NIOSHRegistry (Source List 13) 

### Z9
FEDERAL REGISTER, VOL 42, NO. 197-WEDNESDAY, OCTOBER 12, 1977 5506155062

FEDERAL. REGISTER, VOL. 42, NO. 197-WEDNESDAY, OCTOBER' 12, 1977 NOTICES 09 Criteria Documents Prepared or Planned by NIOSH, February 24, 1977 This list of 127 chemicals and categories consists of substances forwhich criteria documents have been orwill be prepared and delivered to the Department of Labor. In selecting these chemicals NIOSHconsidered: a)the number ofworkers exposed, b) known or suspected toxic effects, and c)physical and chemical properties. 10 Suspected Carcinogens; A Subfile of theNIOSH Registry This is alist of 1,900 chemicals and categories whichhave been reported to haveproduced cancer in test animals. The list is included in SourceList 13. 

### 11 SuspectedMutagens; A subfile of theNIOSH Registry This is alist of approximately 100 chemicals and categories which havebeen reported to haveproducedmutagenic effects in test systems. This list is included in SourceList 13. 13 NIOSHRegistry of Toxic Effects of Chemical Substances, 1976 This list of 21,543 chemicals and categories was compiled and documented in the NIOSHRegistry. Only those substances which were on Source Lists 8,10, 11, or 12were included in the INITIAL I LISTING. 17 The'Ecological Impact of Synthetic Organic Compounds on Estuarine Ecosystems, September, 1976, EPA-1600/3-76-075 This list of 9chemicals was compiled aspart of a study of the impact of synthetic organic compounds on estuarine ecosystems. The effects of the 9chemicals and anumber ofpesticides were analyzed and documented in the study. 18 ThresholdLimit Values for Chemical Substances and Physical Agents in the Workroom Environmentwith Intended Changes for 1976, American Conference of Government Industrial Hygienists This list of a pprox~mately 570 chemicals and categories was compiled by theACGR to give Threshold LimitValues for chemical substances andphysical agents intheworkroom environment. 19 National Occupational Hazard Survey (1972-1974) This list of over 7,000 chemicals and-otherhazards has been compiled byNIOSH. Thesehazards are ranked according to the estimatednumber ofworkers exposed. Only the chemicals ranked among the top 500 hazardswere included in the INITIALLISTING. 20 Chemicals Being Tested for Carcinogenicity by the Bioassay Program,DCCP,National Cancer Institute, 1977 This list of 372 chemicals includes those whichhavebeen selected for bioassayby the National Cancer Institute. 30NOTICES 21 EPA/Office ofToxic Substances List ofPriority Toxic Chemicals, 1977 This list of 162 chemicals was compiledby EPA/OTS from theNIOSH list of carcinogens (Source List 10). 22 AStudy of Industrial Dataon Candidate Chemicals for Testing,EPA Contract #68-014109,November, 1976 Thislist of 650 chemicals and categories was compiledby Stanford Research Institute aspart of the contracted effort to produce Source List 03. Production and calculated release data are included. 24 General List of Problem Substances, Environmental Contaminants Committee, Ottawa, Ontario, Canada, 1977 Thislist of 160 chemicals and categories of environmental concern was compiled by the Canadian government. OTHERLISTS USED FORREFERENCE BUT NOT USED AS SOURCE LISTS FOR THEINITIAL LISTING: 06 Survey of Compounds whichhave been Tested for Carcinogenic Activity (Index, 1970-1971), NIH/HEW This list of 3,634 chemicals and categories is a cumulative index by CAS number ofPHS 149 volumes through 1970-1971. 14 Research Project to Gather and Analyze Data and Information on Chemicalsthat Impact Man and the Environment This list of 3,200 chemicals and categories was compiled and documented by Stanford Research Institute under contract tothe National Cancer Institute. The documentation Includes total production and calculated release data for each of the chemicals in nine hazard categories: (1) over-the-counter drugs, (2) -prescription drugs, (3) cosmetics, (4) trade-sales paints, (5) water pollutants, (6) airpollutants, (7) soaps and detergents,

(82) pesticide residues in food, and (9) Intentional food a&citves. 16 OtherPotentialModifiers of the Stratosphere, 1975 T-s list of41 chemicals was compiled by theNational Institute ofEnvironmental Health Sciences from the universe of 275 manufactured chemicals ranked forrelease rate used by Stanford Research Institute in preparing Source List 03. This list identifiespotential.modifiersof the stratosphere and provides related information. 23 EPA/Office ofResearch and Development, Chemical Production A set of production data compiledbyEPA/ORD on approximately 140 chemicals. 31

FKDERAL REGISTER, VOL 42, NO. 197-WEDNESDAY, OCTOBER 12, 1977 5506355064

FEDERAL REGISTER, VOL 42, NO. 197-WEDNESDAY, OCTOBER 12, 1977 NOTICES APPENDIX B PRODUCTION, RELEASE, AND EXPOSURE SCORES

A. The production, environmental release, occupational exposure, and general.population exposure factors described in the text were scored in the following manner: in the following manner: Factor 1: Production Annual production data were collected from a number of sources:

a. Scoring ofOrganic Air Compounds (Source List 02 of Appendix A) b. A Study of Industrial Data on Candidate Chemicals for Testing (Source List 22 of Appendix A)

c. EPA/OR&D Chemical Production (Source List 23 ofAppendix A) d. Synthetic Organic Chemicals, United States Production and Sale, 1975, United States International Trade Comnission

e. Chemical Economics Handbook, 1975 Stanford Research Institute f. Chemical and Engineering News: Vol. 52, No. 51, dated 12/23/74; Vol. 55, No. 18, dated 5/2/77; Vol. 55, No. 24, dated 6/13/77 The Factor 1 score assigned to a chemical was the common logarithm of the highest annual production value (inmillions lbs/yr) found in any of the above sources. If an annual production value was not available for-a chemical in any of these sources, a Factor 1 score of -0.5229 (correspondingto an assumed annual production of 300,000 pounds) was assigned.

3255065 NOTICES Factor 2: QuantityReleased into theEnvironment Thequantity of chemical released into the environment was scored on ascale from 0to 3as follows: Release Rate

30 percent Estimate Based on Uses Mostly dispersiveuses 3to 30 percent Somedispersiveuses .3to 3percent

.3percent Fewdispersive uses; orprimarily industrial chemical with- propensity for leaks Well contained industrial chemical Estimates of release rates for anumber of chemical's are given in Source List 22 ofAppendix A. For those chemicals for which no release rateswere given, an estimatewas made on the basis of the dispersive nature of the chemical's uses as indicated in the above table. An estimatewas alsomade of the chemical's persistence according to the following table:
Score Lifetime Example Infinite (years or greater) Order of 1 year

Order of a few days Hours orless Compounds ofmetals, freons, CC14, N20, SF6, manypolymers Tetrachloroethylene, flame retardants, phthalate esters, silicones

Reactive compounds The sumof the scores of the two subfactors, release quantityand persistence,was taken as an indication of the environmental burdenposedby the chemical. Factor 3: Occupational Exposure The sourceof data on occupational exposure to chemicals was theNational Occupational Hazard Survey (NOHS)conducted by the National Institutefor
33

FEDERAL REGISTER, VOL 42, NO. 197-WEDNESDAY, OCTOBER 12, 1977 Score5506G

FEDERAL REGISTER, VOL 42, NO. 197-WEDNESDAY, OCTOBER 12, 1977 NOTICES Occupational Safety and Health. In this survey, the approximately 7000most common hazards occurring in the working place were rank ordered. To achieve an occupational exposure scorewith a range and direction similar to those of the other factors, the Factor 3score assigned to achemicalwas 3.8451 minus the common logarithm of its rank on the NOHS list. (3.8451.is the logarithm of 7000.) Chemicals which didnot appear on the NOHS list were given a score of zero, equivalent to havingbeen ranked number 7000 on the survey. Factor 4: Extent toWhich the General Population is Exposed Four individual subfactors were scored and then summed tomeasure the generalpopulation exposure. The four subfactorswere scored as followA: SUBFACTOR i Number ofpeople exposed to the chemical (exclusiveof aworkplace environment) Score No. ofPeople Example 3 20X 10 Widelyused household products (e.g., wearing apparel, shoepolish, certain surface coatings, common paints and their solvents, common plastics and their additives, detergents, furnishings and carpets, wood cleaning products, refrigerants, natural gas, nonfood packaging materials, flame proofers) General air, food and water contaminants Automotive products (e.g., gasoline and additives, rubber, surface coatings, plasticizers, flame proofers) Productsused widely in commercial buildings (mostlysameas household, including commercial cleaners, di6infectants) 34NOTICES No. ofPeople Example 2-20 X10

0.2-2 X 10

2 X10 Lesswidely used householdproducts (e.g., unco-mn paints, specialty apparel such as baby wear, hobby uses, arts and crafts, tools) Regional air and water pollutants, farm chemicals (exclusive ofpesticides) Specialtyhobbies (e.g., photography), specialty products Neighborhood airand watetpollutants from local industries Chemical intermediates rarely found outside theworkplace SUBFACTOR 2

Score Frequency of exposure (tothe typical person in ranking number ofpeople exposed under Subfactor 1) Frequency Daily ormore often

Weekly

Monthly

Yearly or less frequently35 Examoless General air, food and water contaminants, household products in regular use, material used inside automobiles, clothing Hobby crafts, householdproductsused intermittently (e.g., certain cleaners), bleaches, gardening products Dry cleaning, certain solvents, housemaintenance (e.g., polishes, certain cleaning agents), automobilemaintenance Application ofhousehold paints, specialty products

FEDERAL REGISTER, VOL 42, NO. 197-WEDNESDAY, OCTOBER 12, 1977 Score 5506755068 SUBFACTOR 3

Score Exposure intensity. This is intended to reflect the total amount ofmaterial that comes into contact with the average or typical person whose exposure has been scored under subfactors 1and 2. Scoring of this factor considered the number of grams of the material thatmakes contact with the average person in the course of one exposure (daily, weekly, monthly oryearly as scored in subfactor2). Thus, for example, a trace pollutant maylead to exposure of a typical person ofthe order ofmicrogramsper day every day; use of a specialty solvent,might lead to exposure of a typical person of the order of grams per day once a year: thesewould be scored 3,0 and 0,3 respectively on subfactors 2and 3. Intensity Examples High (10 ormore grams per exposure)

Medium (10 to 10 gper exposure)

Low (10 to 10 g per exposure)

Very-low (less 10 g per exposure

SUBFACTOR4 Plastics, fabrics, surface coatings, volatile solvents in closed spaces, liquids contacting skin, high concentrationgases Fabric additives, solvents in open spaces or outdoors, dusts, solutes, transitory exposures to vapors or aerosols Lowlevel indoor exposure, volatile substances from home furnishings and building materials (e.g., plasticizers, flame proofers), low volatility solvents, pigments Environmental contaminants (lowlevel air, food, and water contaminants), monomers in polymers Penetrability. This is ameasure of thematerial that comes into contact with aperson (whetherby dermal, inhalation, or ingestion exposure) and that is'expected to be absorbed into thebody (even transitorily) withpotential for interactionwith cells.

FEDERAL REGISTER, VOL. 42, NO. 197-WEDNESDAY, OCTOBER 12, 1977 NOTICESNOTICES Penetrability Examples High (10 to 100% absorption)

Medium (Ito 10% absorption)

Low (0.01 to 1% absorption) Nealegible (less than 0.01% absorption) Organic solvents iu liquid, mist, oraerosol form, vapors and gases if likely to be soluble in body fluids, respirable-sized particles, surface active agents, materials known to have high dermal systemic toxicity Solvents with lowvolatility and/or largermolecules, organic materials in water solution,waxesand polishes, coarsedusts Certain solids,dermal exposure tomost inorganic materials inwater solution Polymers,metals

B. Inmaking the judgments called for inscoring Factors 2and 4above,knowledge of the chemical's useswas necessary. Use information was collected from the following sources: 1. Thd CondensedChemical Dictionary, Ninth Edition,Hawley,VanNostrand Reinhold Company,NewYork, 1977. 2. TheMerck Index,Ninth Edition,Merck and Company, Inc., Rahway,N.J., 1976. 3. Faith, Keyes, and Clark's Industrial Chemicals,Lowenbeim andMoran,Fourth Edition,J.Wiley and Sons, Inc., New York, 1975. 4. ChemicalMarketingReporter, Schnell Publishing Company, Inc., NewYork. 5. Encyclopedia of ChemicalTechnology, Kirk-Othmer, Inter-SciencePublishing Company NewYork, 1972.
37

FEDERAL REGISTER, VOL 42, NO. 197-WEDNSDAY, OCTOBER 12, 1977 Score 5506955070 NOTICES APPENDI= C

ORDERINGTHE CHEMICALS BASED ON PRODUCTION,RELEASE,AND EXPOSURE

A linearweighting schemewas used to rankorder the chemicals. The rank of the jth chemical, r was computed by the formula: 4 fij rj= wi -- , Si

where wi is theweight assigned to the ith factor, f is the ith factor score of the jth chemical, and si is a scaling factor chosen to normalize the assigned scores. The four scaling factors employed were:
s I = log 20,850

- 4.3191; 20,850million lb/yr being the maximum of all Factor 1 chemical production quantities.
s2 - 6; 6being themaximum ofall Factor 2 environmental release scores.

s

3 - 3.8451 - log 3 = 3.3680; third being the h-hestNOHS rank among the scored chemicals. (Ranked first and second on the NOHS list were continuous noise.andmineral oil, the former not being a chemical hazard and the latter not being among thescored chemicals.)
s4 = 12; 12 being the maximumof all Factor 4 general population exposure scores. 1f This choice of se, s., s3, s4 , guaranteed that
. ... !1
for all i and J, and furthermore, that for each i, for at least one chemical J.
38

FEDERAL REGISTER, VOL. 42,-NO. 197--WEDNESDAY, OCTOBER 12, 1977NOTICES APPENDIX D 55071

BIOLOClCAL AND ENVIRONMENTAL SCORES A. The. five human. health effect factors and two environmental effect factors mentioned in the text were scored in the following
. manner:. Factor. 1: Carcinogenicity a.. Numerical Scores Assigned:

. , 3 Established ca~cinogen in humans or in 2 animal species, or in one animal species in well-replicated experiments 2 ~stablished carcinogen in 1 animal species I Insufficient or inadequate experimental data for definite.conclusions, but either (a) no experimental or. structural reason. for suspicion, or (b) good negative mutagenicity tests, or (c) low.biological activity. (Note: some inert.compounds 

### - examples,- argon, nitrogen - were given a score of zero en this factor despite not having peen tested. o Adequately tested in animals with negative results in each of two.species b. .Letter. Scores Assigned*: xxx Needs testing, strongly suspect (close structural ,relationship. to known carcinogen,-positive result in validated in vitro test, inconclusive but suspicious .positive animal tes_t, etc.) xx Needs testing, suspect, (structural resemblance to known carcinogen, etc.) x. Needs testing, some reason for suspicion (potentorgan-specific toxin, enzyme inducer, suspect cocarcinogen, etc.) *Ch~rals presently undergoing testing for carcinogenicity in

the framework of th~ NCI bioassay program were'-scored as suspect carcinogens. Their special status was documented for the:~bers of the Committe~. c., Criteria for Accepting.Positive Test Results (scores 2 or 3) Validated. positive findings in animal studies consisted of ".any test.results which clearly indicated treatment-related.

carcinogenicity or tumorigenic effects. This was based on the criteria set. out in.the report of the National Cancer Advisory Board. Subcommittee' on Environmental Carcinogenicity, "General Criteria. for Assessing the Ev~dence for Carcinogenicity of Chemical Substances (1976)".

./ FEDERALREGISTER,VOL. 42, NO. 197-WEDNESDAY, OCTOBER 12, 197755072 

# I NOTICES d. Criteria for Accepting Negative Test. Results (including zero scores) In general. the protocol of the'test ~onformed to. or was' 'reasonably consistent with the currentNCI Guidelines (J.M.Sontag'et al...Guidelin~sfor Carcinogen Bioassay in Small Rodents, DREW 76-801).. It was recognized that many older tests do not conform to these guidelines. Therefore,. good scientific judgment was applied to the evaluation of these tests in order to determine whether differences 'in protocols significantly weakened confidence in the reported negative results. Inassigning a zerQ score, the'guiding principle was the judgment that further testing was unnecessary. Factor 2; Mutagenicity

'. a.. Numerical Scores Assigned: 2 Mutagen in two or more test syst7ms* 1

. Mutagen in one test system o Tested in more than one system with negative resultsand no reason for suspicion (similar to inactive compounds. etc.) *These and o~her scores were normalized to the 0-3 scale.or

x-xxx scale respectively for all factors involved. b. Letter Scores Assigned:xxx Needs testing. strong reason for suspicion (structural similarity to known mutagen, reported carcinogenicity. teratogenicity, or other. cellular toxicity) xx Needs testing. some reason for suspicion (structural similarity to known.~utagensand/or carcinogens)

. x. Needs testing. no. reason to assign high priority
c. Examples of Short-Term Test Systems Considered for Scoring Were: The Salmonella/mic=osometest. (Ames).E. coli WP2 uvr

. A. etc. test (Bridges. Witkin). B. subtilis M45 Rec-. etc. test (Kada),.E. coli pol A+/pol A1- test (Rosenkranz). Yeast test (Zimmerman). Neu~ospora test (de Serres) and'Drosophilatest (Vogel).. Mammalian cells in culture and in vitro transformations were also considered.

. 

### 40

FEDERAL REGISTER, VOL. 42, NO. 197-WEDNESDAY, OCTOBER 12, 1977

--NOTICES Factor 3: Teratogenicity

a. Numerical ScoresAssigned: 3 Confirmed teratogen inhumans or in twoappropriate animal ppecies 2 Confirmed teratogen in 1 animal species 1 Insufficient or inadequate experimentaldata for definite conclusions, but either (a)no experimental or structural reason for suspicion, or (b)lowbiological activity 0 Adequately tested n two suitable animal species with negative findings for teratogenic activity b. Letter ScoresAssigned:
XXX Needs testing, strongly suspect (closestructural relationship to known teratogen, inconclusivebut suspicious positive animal tests, etc.)

zx Needs testing, suspect (equivocalresult in anima test, etc.)

x Needp testing, some reason for suspicion -

c. Criteria forAcceptance of Teratogenicity Tests Accepted teratogenicity tests conformed reasonably to the recommendations and principles outlined in'"Principles for Evaluating Chemicals in theEnvironment," NationalAcademy of Sciences, pp. 173-182, 1975; and "The Testing of Chemicals for Carcinogenicity,Mutagenicity,Teratogenicity," Department of Health and Welfare,Canada, pp. 137-176, March 1973. Factor 4: AcuteToxicity

a. n-mnaerical ScoresAssigned: 3 extremely toxic: < 50mg/kg 2 very toxic: 50-500mg/kg 1 moderatelytoxic: 0.5-5 g/kg 0 very slightly toxic: > 5g/kg

41

FEDERAL REGISTER, VOL 42, NO. 197-WEDNESDAY, OCTOBER 12, 1977 5507355074

FEDERAL REGISTER, VOL 42, NO. 197-WEDNESDAY, OCTOBER 12 NOTICES b. Letter Scores Assigned:*
xx not tested, but suspected to be in range 2-3

X not tested,but suspected to be in range 0-1 *See factor 2fornormalized scored.

c. Criteria for Quantitation ofAcute Toxicity Standard systems oftoxicity rating based on probably lethal dose in humans were used when available . Lowest lethal doses and LD50 values in various animal systems were also widelyused.
Factor 5: Other Toxic Ef!ects

a. Numerical ScoresAssigned: 3 Effects at low doses (Guidelines: < 1mg/kg/day) 2 Effects atmoderate doses (Guidelines: 1-10 mg/kg/day) 1 Effects at high doses (Guidelines: >10 mg/kg/day)
O Very low or negligible biological activity (e.g., nitrogen, argon, etc.) 0 b. Letter Scores Assigned:
XXX Needs testing (structural similarity to another chemical-which rates 2 or 3., questionable reports of effects which need confirmation, etc.)

xx Needs testing, some reasons for suspicion

x Needs testing, inadequate information available to give high pirority

c. Criteria for Scoring This factor includes both reversible and irreversible effects, delayed-orcumulative toxicity, organ-specific effects, effects on reproduction, behavior, etc. The score entered reflects the toxic effects-noted in animals (or in humans if data were available) at the lowest dose-range. If the chemical was reported or suspected to havemore than one toxic effect, xxx orxx for one type of toxic effect superseded any numerical score for another. Also,x for one type of toxic effect superseded 2or 1 for another. In many cases, reports of one type of effect at low doses engendered suspicion of the likelihood of others; in such cases the chemicalwas scored with the appropriate number of x's, unless thoroughly tested. 42Factor 6: Bioaccumulation
a. Numerical Scores Assigned: 3 High Q104)* 2 Appreciable (102-104) I Low (4102) 0 Experimental evidence for non-accumulation (<); water soluble compounds *The degree of bioaccumulation (more precisely, the tissuespecific.storage factor) is defined as the concentration of the chemical in the tissues (at "steady state" or after prolonged exposure) divided bythe concentration ofthe chemical in the ambient medium. b. Letter Scores Assigned., XXX Testing important, judged likely tobe high

xx Testing.important, judged not likely to behigh, but likely to be appreciable

x Needs testing, little or no experimental data

c. Criteria for Scoring Bioaccumulation is used here in its broad sense of the accumulation of a chemical in one ormore tissues ofan animal (or plant) to levels higher than those in the ambient medium. Forpurposes of screening chemicals, it was considered significant primarily in cases in which the accumulation in tissues represented an enhanced probability of effects, either on the organ in which the cheilcal was concentrated, or on animals which feed on the organism which accumulated the chemical. High degrees ofbioaccumulation are usually found only in aquatic organisms. For these organisms, bioaccumulation is known to be dependent primarily onwater solubility and-it is empirically predicted by the octanol/water partition coefficient. Zero scores were assigned to completely water soluble organic chemicals. Substances which are easily metabolized will notbe bioaccumulated even if they have a high partition coefficient (example, chloroform). Thus ease of metabolismwas a factor considered in evaluating the potential for bioaccumulation.

43 4.

FEDERAL REGISTER, VOL 42, NO. 197-WDNESDAY, OCTOBER 12, 1977 NOTICES 55075NOTICES Factor 7: Ecological Effects
a. Numerical Scores Assigned: 3 Effects at low concentrations (10-9 or less in air or water)* 2 Effects atmoderate concentrations (10-7- 10-9 in air orwater) 1 Effects athigh concentrations (10-6orgreater in air orwater) 0 No reported effects that couldjustify priority for testing *In airfor gases orvapors: I part ofchemical per billion parts

airby volume (ppb). Inwater for liquids and solids: 10-9 gram per cubicmeter (ng/m3) b. Letter Scores Assigned:*

xx Testing needed, possibility ofmajor orwidespread effects

x Testing needed, possibility ofminor or local effects *See factor 2for normalized scores.
c. Criteria for Scoring: Ecological effects considered includedbeside tonic effects onnon-human animals and plants, ecosystem effects, effects on atmosphere and climate, ozone depletion, etc. Generally, numerical scores (establishedhazard),wereassigned only to alimite number of.thoroughly tested chemicals (e.g., pesticides, some-metal containing compounds, or some specific chemicals).. In other cases, thepotential for ecological effectswas judged according to availability of data on toxicity inparticular, published information on specific tests, structural similaritT to-compounds ofbetter known eco-toxicity,:publisheddata on depletion potential for stratospheric; ozone. Zero scores were assigned only to compounds with low biological activity (LD5O> 1 g/kg orAQTR > 100 ppm). B. An extra,factorwas scored if thepresence of acontaminant in a commercialproduct was the-majorreason for concern, or if a trace- degradation productwas themajor reason for concern (examples: dioxin, methyl mercury)....

44

FEDERAL REGISTER, VOL 42, NO. 19Z-WEDNESDAY, OCTOBER- 12i T977' 55Q76NOTICES Factor 8: Contaminants and Environmental Degradation or Conversion Products
a.. Numerical orLetter Scores Assigned: 1 C6ntaminants, etc., known to be important 0 Contaminants, etc., not suspected, orknown to be of no importance.
X Contaminants, etc., suspect,needs testing b. Criteria for Scoring: The scores for this factor were not averaged. A letter score tookpriority over anumerical score at anytime; if no letter score was assigned to a chemical, the numerical score 1 was overriding. A zero scorewas assignedonly if it was scored unanimously by all scorers. The score for this factorwas not added: (1)if the principalbreakdownproduct was themajor problem and it was thebasis for scores on other criteria suchas persistence and toxicity (examples: DDE, PAN); (2) for in vivo metabolism of carcinogens to active forms (e.g., arene oxides, activated nitrosamines, etc. etc.). C. It is ofrelevance for the scoring method to addthat in order to facilitate the inclusion of a zero score in aletter score average, the zero score was changed into 0.1X. Also, in some instances fractional numerical or letter scores were assigned by scorers. D. Thefollowing literature sources were extensively used by the scorers: References of general interest 1. NIOSHRegistry of Toxic Effects of Chemical Substances (1976) 2. Zirk-Othmer Encyclopedia of Chemical Technology. Edited by A. Standen, Interscience Publishers, New York (1963, 1972). 3. The Condensed Chemical Dictionary, 9th ed. Van Ilostrand Reinhold Co., NewYork (1977). 4. TheMerck Index, 9th ed. Merck & Co., Inc., Rahway,N.J. (1976). 5. Chemical Consumer Hazard Information System. Consumer Product Safety Commission, Washington, D.C. (1977). 6. A Study of Industrial Data onCandidate Chemicals for Testing. Stanford Research Institute, Palo Alto, California, (1976).
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FEDERAL REGISTER, VOL-42, NO. 19T-WEDNESDAY, OCTOBER 12, 1977 NOTICES 7. TheEncyclopedia of Chemistry. Hanpel &Hawley, 3rd ed. Van Nostrand Reinhold Co., NewYork (1973). 8. Brown, S.L., et al. Research Program on Hazard Priority Ranking ofManufactured Chemicals, Phase II- Final Report toNational Science Foundation. StanfordResearch Institute Menlo Park, California (1975). 9. Dorigan, J., et al. Scoring of OrganicAir Pollutants, Chemistry, Production and Toxicity of Selected Synthetic Organic Chemicals, MITRE, I4R-6248 (1976). 1. References on Carcinogenicity Cl. Survey of Compounds Which Have BeenTested for Carcinogenic ActivityThrough 1972-1973 DHEW PublicationNo. NIH 73-453, NationalCancer Institute, Bethesda, Maryland
C2K Suspected Carcinogens - A subfile of the NIOSHToxic SubstancesList. C3. IARC Monographs on the Evaluation of Carcinogenic Risk of Chemicals to Man. Lyon, France. WHO, Internationdl Agency for Research on Cancer. C4. Chemicals Being Tested for Carcinogenicityby the Bioassay Program, DCCP. National Cancer Institute (1977). C5. Informa=ton-Bulletin on.the Survey of Chemicals BeingTested for Carcinogenicity, No. 6. WHO, Lyon, France (1976). 2,3. References onMutagenicity and Teratogenicity I MNi. Shepard, T.H. Catalog of Teratogenic Agents. Johns Hopkins University Press, Baltimore (1973).
MTZ EMIC/Environmental utagenicity Information Center File, National Laboratories, Oak Ridge,Tennessee. 4,5. References onAcute ToxicityandOtherToxic Effects AOl Thienes, C.L. &Haley, T.J. ClinicalToxicology.Lea &Febiger, Philadelphia (1972). AOZ..Gosselin, Hodge, Smith &Gleason. Clinical Toxicology of CommercialProducts, 4th ed. The Williams and WUiins Company, Baltimore (1976). A03. Casarett, L.J. &Doull, J.Toxicology, theBasic Science of Poisons. McM:illanPublishing Co., Inc., NewYork. A04. Debruin, A. Biochemical. Toxicology of Environmental Agents. Elsevier/North Holland, Inc., NewYork (1976). 46NOTICES A05. Threshold Limit Values for Chemical Substances and Physical Agents in theWorkroom Environment with Intended Changes for 1976. American Conference ofGovernment Industrial Hygienists. A06. Criteria for aRecommended Standard - Occupational Eposure to
.... , prepared by NIOSH.. A07. Browning, E.Toxicity andMetabolism of Industrial Solvents. Elsevier, Amsterdam (1969). A08. Browning,E. Toxicity of IndustrialMetals, 2nd ed. Appleto=-Century-Crofts, NewYork (1969). A09. Fairhall, L.T. Industrial Toxicology, 2nd. ed. Williams &Wilkins Co., Baltimore, Maryland (1969).
AOIO. Sax, N.I. DangerousProperties of Industrial Materials, 3rd ed. Reinhold Publishing Corp., NewYork (1975). A011. Chemical-Safety Data Sheets. Manufacturing Chemists Association, Washington, D.C. A012. Industrial SafetyData Sheets. National Safety Council, Chicago, Illinois. 6,7. References pn Bioaccumulation and Ecological Effects BE1. Applegate,V.C., J.H. Howell, A.E. Hall, Jr. &N.A. Smith, 1957 Toxicity of4.346 Chemicals to Larval Lampreys and Fishes.U.S. Dept. Interior, Fish &Wildlife Se_-rice. Special Scientific Report-Fisheries No. 207. Wash., D.C. BE2. Battelle Columbus Laboratories 1971, Effects of Chemicals onAquaticLife: Selected Data from theLiterature through 1968. Vol. 3 ofWater Quality Criteria DataBook. U.S. Environmental Protection Agency, Washington, D.C. BE3_Hahn,W., and P. Jensen, Water Quality Characteristics of Hazardous Materials; Teatas A &1.University, (1974) (Taken ftom theNIOSHRegistry of Toxic Effects of Chemical Substances (1976).
BZ&. Kemp, H.T., R.L.Little,V.L. Holoman, and R.L. Darby. !973, Effects of Chemicals on Aquatic Life (Compilation Dated 1968-1972). Water Quality DataBook - Vol. 5U.S. Environmental Protection Agency, Duluth, Linn. BE5_ Leo, A., C. Hansch, & 1). Elkins, Partition Coefficients andTheir Uses. Chem.Rev. 71:525-616 (1971). BE6. Lincer, J.L., UE.Haynes, and IUI.L. Elein, 1976. The Ecological Impact of Synthetic Organic Compds. on Estuarine Ecosystems. U.S.Environmental-ProtectionAgency, GulfBreeze, Florida,EPA-600/3-76-075. 

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FEDERAL REGISTER, VO.. 42, NO. 197-EDNESDAY, OCTOBER 12, 1977 5560NOTICES BE7. Metcalf,R.L., P.Y. Lu, and I.2. Kapoor, 1973. Environmental Distribution and Metabolic Fate ofKey Industrial Pollutants and Pesticides in aModel Ecosystem. Illinois University, Water Resources Center,ResearchReport 69 ,Urbana, Illinois. BE8. Pimentel,D. 1971. Ecological Effects of Pesticides on Non-target Species. Executive Office ofthe President, Office of Science and Technology, Washington, D.C. BE9. Sauter, S., K.S. Buxton, K.J. Malek, and S.R. Petrocelli, 1976. Effects of Exposure to HeaveMetals on Selected Freshwater Fish. Toxicity of Copper, Cadmium, Chromium, and Lead to Eggs of SevenFish Species. Environmental Protection Agency, Duluth, Minnesota. EPA-600/3-76-105. BElO. National Academy of Sciences. 1973. Water Quality Criteria, 1972. U.S. EnvironmentalProtection Agency,Ecological Resaerch Series No. EPA-R3-73-033. BEll. McKee, J.E., and HLW. Wolf (eds.) 1963. Water Quality Criteria, 2nd Edition. StateWater QualityControl Board, Sacramento, California. BE12. U.S. Environmental ProtectionAgency. 1976. CriteriaDocument PCBs. Washington, D.C. BE13 National Institute of EnvironmentalHealth Sciences, 1973. Symposium onPhthalate Ester Plasticizers. Environmental Health Perspectives, Experimental Line 3. BE14 National Academy of Sciences 1975a. Principles for Evaluating Chemicals in the Environment. Washington D.C. BE15' NationalAcademy of Sciences 1975b. Assessing Potential OceanPollutants. WashingtonD.C. BEI& U.S. Environmental ProtectionAgency 1975. Quality Criteria forWater (prelminarydraft). WashingtonD.C. BE17 National Academyof Sciences 1976. Halocarbons: Effects on Stratospheric Ozone,Washington D.C.

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