### 33418 Federal Register / Vol. 54, No. 155 / Monday, August 14, 1989 / Rules and Regulations

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 302
[SW H-FRL 3281-8

Reportable Quantity Adjustments

AGENCY: U.S. Environmental Protection Agency (EPA). ACTION: Final rule.

SUMMARY: Sections 103(a) and (b) of the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA), as amended, require that persons in charge ofvessels

or facilities from which hazardous substances have been released in quantities that are equal to or greater than their reportable quantities (RQs) immediately notify the National Response Center ofthe release. Section 102(b) sets an RQ ofone pound for hazardous substances, except those substances forwhich different RQs have been established pursuant to section 311(b)(4) ofthe Clean Water Act (CWA). In addition to these reporting requirements section 304 of the Superfund Amendments and Reauthorization Act of 1986 (SARA) Title IIIrequires that releases of hazardous substances in quantities equal to or greater than their RQs (or

one pound ifa reporting trigger is not established by regulation) be reported to State and local authorities.

Section 102(a) ofCERCLA authorizes the U.S. Environmental Protection Agency (EPA or "the Agency") to adjust RQs for hazardous substances andto designate as hazardous substances those substances that, when released into the environment, may present substantial danger to the public health

or welfare or the environment. Currently there are 725 CERCLA hazardous substances.' In this rulemaking, EPAis

IEPAproposed RQ adjustments for the hazardous substances whose RQs are promulgated Inthis finalrule on March 16, 1987.As ofthat date, therewere 717 CERCLA hazardous substances. Changes to the list ofCERCLA hazardous substances since March 16, 1987are described below.Four hazardous waste streams (K123, K124, K125,and K126) were added in a finalrule (51 FR 37725) that became effective onApril 24, 1987, bringing the total numberofCERCLA hazardous substances to 721. EPA removed iron dextran and strontium sulfidefrom the listIntwofinal rules (53 FR43878 and 53FR 43881) effective October 31, 1988,thus reducing thenumberofCERCLA hazardous substances to 719. Six hazardous substances (waste streams K004, K085, K066,K088, K090, andK091) were added to theCERCLA listina finalrule (53 FR35412) thatbecame effective on March13,1989, increasing the numberof CERCLA 

### promulgating theRQ adjustments forsix ofthe 273 hazardous substances whose RQs were proposed to be adjusted in a March 16, 1987Notice ofProposed Rulemaking (NPRM). These six substances are: 1,4-dioxane, 2- ethoxyethanol, ethylene oxide, 2- nitropropane, perchloroethylene, and saccharin. By making the adjustments contained in this rulemaking, the Agency will be able to focus its

resources on those releases which are most likely to pose potential threats to public health or welfare or the environment. In addition, by making these adjustments, EPAwill relieve the regulated community ofthe burden of reporting releases which are unlikely to pose such threats. EFFECTIVE DATE: August 14, 1989. ADDRESSES: The toll-free telephone number ofthe National Response Center is 1-800/424-8802; in the Washington, DC metropolitan area the number is 1- 202/267-2675.

Docket:Copies ofmaterials relevant
to this rulemaking are contained in Room M2427 at the U.S. Environmental Protection Agency, 401 M Street, SW, Washington, DC 20460 (Docket Number 102 RQ-273C). The docket is available for inspection between thehours of9:00

a.m. and 4:00 p.m. Monday through Friday, excluding Federal holidays. To review docket materials, you may make

an appointment by calling 1-202/382- 3046.The public may copy a maximum of50 pages from any regulatory docket
at no cost. Additional copies cost $.20
perpage. FOR FURTHER INFORMATION CONTACT. Ivette 

### 0. Vega, Response Standards and Criteria Branch, Emergency Response Division, U.S. Environmental Protection Agency (OS-210), 401 M Street, SW, Washington, DC 20460, or the RCRA/ Superfund Hotline at 1-800/424-9346; in the Washington, DC metropolitan area at 1-202/382-3000.
SUPPLEMENTARY INFORMATION: 

### The
contents oftoday's preamble are listed in the following outline: I.Introduction

A. Statutory Authority B. Background ofthis Rulemaking II. Reportable Quantity Adjustments

A. Introduction

hazardous substances to 725, whichIs the current total.Lastly, based ona final rule published elsewhere in today's Federal Register. ammonium thiosulfate willbe removed from the CERCLA list60 daysfrom today's date, thus reducing the number of CERCLA hazardous substances to 724. B.Reportable Quantity Adjustment Methodology

- 1.Summary of the Methodology 2.Responses to Comments Received on

the Methodology

a.Carcinogen Hazard Ranking Methodology and the 100-Pound Maximum RQ

b. Use of NTP and IARC Determinations

c. Application of EPA's Carcinogen Assessment Guidelines C.Substances for Which RQs Are

Adjusted 1. Summary 2.

Response to Comments III. Summary of Supporting Analyses A. Executive Order No. 12291 B.Regulatory Flexibility Act C.Paperwork Reduction Act List ofSubjects

I. Introduction

A. Statutory Authority

Section 102(b) ofthe Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA) (Pub.L. 96-510), 42 U.S.C. 9601 etseq., as amended by the Superfund Amendments and Reauthorization Act of 1986 (SARA) (Pub. L. 99-499), establishes reportable quantities (RQs) ofone pound for releases of hazardous substances, except for hazardous substances whose RQs were established at a different level pursuant to section 311 ofthe CWA. Section 102(a) ofCERCLA authorizes EPA to adjust all ofthese RQs by regulation. Sections 103(a) and (b) of CERCLA require that the person in charge of a vessel or facility notify the National Response Center immediately when there is a release ofa hazardous substance in an amount equal to or greater than the RQ for that substance. This notification requirement serves as

a trigger for informing the government of

a release so that Federal personnel can evaluate the need for a Federal removal

or remedial action and undertake any necessary action in a timely fashion. Under section 104 ofCERCLA, the Federal government may respond whenever there is a release or substantial threat ofa release ofa hazardous substance into the environment. Responses are to be taken,
to the extent practicable, in accordance with the National Oil and Hazardous Substances Pollution Contingency Plan (40 CFR Part 300),.which was originally developed under the CWA and which has been revised to reflect the responsibilities and authority created by
CERCLA.

### Federal Register / Vol. 54, No. 155 / Monday, August 14, 1989 / Rules and Regulations

Ifa release meets certain statutory criteria set out inCERCLA section 103(f)(2), the release may be subject to

more limited reporting requirements. Specifically, a release is subject to these limited requirements ifthe release: (1) Is continuous and stable in quantity and rate, and is from a facility for which notification has been given under CERCLA section 103(c), or (2) is a release for which notification has been given under CERCLA sections 103(a) and (b) for a period sufficient to establish continuity, quantity, and regularity of the release. Notification must still be givent annually and when there is a statistically significant increase in the release. In addition, CERCLA section 103 provides a reporting exemption forfederally permitted releases. The definition of federally permitted release in CERCLA section 101(10) specifically identifies releases permitted under certain other Federal or Stateprograms. Several commenters claimed that their particular releases are subject tocontinuous and/

or federally permitted release treatment. EPApublished proposed regulations to clarify the reduced reporting requirement forcontinuous releases on April 19, 1988 (53 FR 12868). EPA also clarified the reporting exemption for federally permitted releases in proposed regulations published on July 19, 1988 (53 FR 27268). Comments on continuous and federally permitted release Issues submitted in response to the March 16, 1987 NPRMwill be addressed in the upcoming final rules for continuous and federally permitted releases.

In addition to thereporting requirements established by CERCLA, section 304 ofSARA Title III requires the owners and operators ofcertain facilities to report releases ofCERCLA hazardous substances to State and local authorities. SARA Title IIIsection 304 notification must begiven immediately after the release ofan RQ or more (one pound or more ifa reporting triggeris not established by regulation) to the community emergency coordinator for each local emergency planning committee for any area likely to be affected by the release, and to the State emergency response commission ofany State likely tobe affected by therelease. These notification requirements apply only toreleases that have potential for off-site exposure and that are from facilities at which a "hazardous chemical" (defined by regulations under the Occupational Safety and Health Act of1970 (29 CFR 1910.1200(c)) and section 311 of SARA Title I1)is produced, used,

or stored. Section 109 ofCERCLA and section 325 ofSARA Title III authorize EPA to

assess civil penalties for failure toreport releases of hazardous substances that equal or exceed their RQs. Section 103 ofCERCLA, as amended, authorizes EPA to seek criminal penalties for submitting false ormisleading information in a notification made pursuant to CERCLA section 103, and increases the maximum penalties and years ofimprisonment for violation of the CERCLA section 103 reporting requirement.

B. BackgroundofThisRulemaking

On May 25, 1983, EPAproposed arule (48FR 23552) to clarify procedures for reporting releases ofCERCIA hazardous substances and to adjust RQs for387 ofthe then 696 hazardous substances. 2 In the May 25, 1983 Notice ofProposed Rulemaking (NPRM) EPA also compiled forthe first time the list of "hazardous substances" defined under section 101(14) ofCERCLA. In the preamble to that NPRM, EPA discussed in detail the CERCLA notification provisions, the methodology and criteria used to adjust the RQ levels, and the RQ adjustments proposed under section 102 ofCERCL4. and under section 311 of the CWA. EPApromulgated final RQ adjustments for 340hazardous substances in an April 4, 1985 final rule (50 FR 13456) and for an additional 102 substances in a September 29, 1986 final rule (51 FR 34534). In an NPRM published on March 16, 1987 (52 FR 8140), EPAproposed RQ adjustments for 273 hazardous substances. The March 16, 1987 Federal Register also contained

an NPRM in which EPA proposed RQ adjustments forradionuclides.3 In addition, in an NPRM published on March 2, 1988 (53 FR 6762), EPA reproposed RQ adjfistments for lead metal and four lead compounds, and proposed to delist ammonium thiosulfate as a CERCLA hazardous substance.

2 Since the May 25. 1983 NPRM, 31 substances have been added and two substances havebeen deleted from the CERCLA list, bringing the total number ofCERCLA hazardous substances to725. The 31 substances added to the list are: waste stream F024 (49 FR 5308; coke ovenemissions (49 FR 36560)-waste streams F020, F021,F022. F023, F020, F027,and "023(50 FP 1978): waste streams Kl11.K112. K113.K114, K115, andK16. o-toluidine andp-toluidine (50 FR 42936); waste streams (117, Kila,and K136 (51 FR5327); 2-ethoxyethanol (51 FR 6537; waste streams K123, 1(124, K125, and K126 (51 FR 37725); and waste streams K064, K065, K066, (0188, K090, and K091 (53 FR 35412). The two substances deleted from the list are: iron dextran (53FR 43878) and strontium sulfide (53 FR 43881).

8RQ adjustments forradionuclides were promulgated in a final rule published on May 24, 1989 (54 FR22524). 

### This rulemaking finalizes the RQ adjustments forsix ofthe 273 hazardous substances whose RQs were proposed for adjustment in the March 16,1987 NPRM. This rule contains EPA's responses to all issues raised bythe commenters relating tothe RQ adjustment methodology for potential carcinogenicity, except those methodology issues not relevant to the six RQ adjustments promulgated in this final rule (forfurther discussion, see Section II.B.2 ofthispreamble). This rule also contains responses to public comments received on the specific RQ adjustments for thehazardous substances in thisrulemaking. Comments were received on the proposed RQ adjustments foronly three hazardous substances (1,4-dioxane, perchloroethylene, and saccharin) ofthe sixhazardous substances for which RQ adjustments are promulgated in this rule.

RQ adjustments for 258 hazardous substances, including 254 ofthe 273 hazardous substances whose RQs were proposed for adjustment in the March 16, 1987 NPRM, are contained in a final 

### rulepublished elsewhere in today's Federal Register. As explained in SectionI1.C.2.i ofthepreamble to the other final RQ adjustment rulepublished in today's Federal Register,EPA will address the RQs for the remaining 13 substances ofthe 273 substances that

were the subject of the March 16,1987 NPRM in a future action.

Section 306(a) ofCERCLA, as amended by SARA section 202, requires the U.S. Department ofTransportation (DOT) tolist and regulate CERCLA hazardous substances as hazardous materials under the Hazardous Materials Transportation Act. Pursuant to thisrequirement, DOT promulgated

on November 21, 1986, a final rule (51 FR 

### 42174) providing that, when a hazardous substance is shipped in a quantity equal to orgreater than its RQ, itmust be identified as such in shipping papers and by package markings. This rule became effective on July 1, 1987 (51 FR 46672). The rule requires shippers of 

### hazardous substances in quantities at or above theirRQs to place the notation "RQ" and the name ofthe substance on shipping papers and package markings.

RQs for many ofthe hazardous substances proposed for adjustment in the March 16, 1987 NPRM (including the 

### six substances whose adjusted RQs are being promulgated today) were proposed to be adjusted upward from their statutory RQs. The estimated production volume forthe six hazardous substances whose adjusted RQs are being promulgated today is4.6 billion 33419

### 33420 Federal Register / Vol. 54, No. 155 1 Monday, August 14, 1989 / Rules and Regulations

pounds annually. Because this amount represents a relatively large proportion ofthe total production volume ofall 273 hazardous substances proposed forRQ adjustment in the March 16, 1987NPRM, many shippers would be subject to a regulatory burden that is notjustified by the hazards that these substances pose to human health and the environment. Once final RQ adjustments are promulgated for these six hazardous substances, shippers ofless than the adjusted RQ of a substance will not be subject to DOT regulations relating to shippingpapers and package markings. Accordingly, EPA is expediting the promulgation ofa final rule adjusting RQs for these substances by making this rule effective immediately upon promulgation. Because thisrule "grants

orrecognizes an exemption orrelieves a restriction" under section 553(d)(1) of the Administrative Procedure Act (APA), the APA requirement that final rules become effective no less than 30 days after publication does not apply.

In finalizing these RQ adjustments, this rule amends Table 302.4 of40 CFR Part 302. Section II ofthis preamble discusses the RQ adjustments promulgated in this rulemaking and the methodology used in making these adjustments. Section IIalso includes EPA's responses to public comments on the March 16, 1987 NPRM that are relevant to the six RQ adjustments made in this rule and to the RQ adjustment methodology on which these six adjustments are based. Section III provides a summary ofthe analyses supporting thisrulemaking.

II. Reportable QuantityAdjustments
A. Introduction

In thisrulemaking, the Agency adjusts RQs based upon specific scientific and technical criteria that relate to the possibility ofharm from the release ofa hazardous substance at certain levels. The quantity released is but one factor considered by the government when assessing the need to respond to such a release. Other factors, assessed on a case-by-case basis, includd but are not limited to: (1)The location of the release; (2) its proximity to drinking water supplies or othervaluable
resources; and (3)the likelihood of exposure or injury to nearby populations. The RQ adjustments made today will enable the Agency to focus its

resources on those releases that are most likely to pose potential threats to public health or welfare or the environment. These adjustments will also relieve the regulated community

-and emergency response personnel from the burden ofmaking and responding to 

### reports ofreleases that are unlikely to pose such threats.

Inthis final rule, theAgency is adjusting RQs for 1,4-dioxane, 2- ethoxyethanol, ethylene oxide, 2- nitropropane, perchloroethylene, and saccharin.With the exception of2- ethoxyethanol (which was notidentified

as a potential carcinogen uhder the identification methodology discussed in SectionII.B. below), all ofthese hazardous substances have been evaluated forpotential carcinogenicity

as well as otherprimary criteria. The final RQ adjustments promulgated today

are based on the results ofthis evaluation. In the case of2- ethoxyethanol, its final RQ adjustment is based on the primary criterion of chronic toxicity (see the discussion below).
B.ReportableQuantity Adjustment Methodology
1. Summary ofthe Methodology

The Agency has wide discretion in adjusting the statutory RQs for hazardous substances under CERCLA. Administrative feasibility and practicality are important considerations. TheAgency's methodology for adjusting RQs begins with an evaluation ofthe intrinsic physical, chemical, and toxicological properties ofeach hazardous substance. Theintrinsic properties examinedcalled "primary criteria"-are aquatic toxicity,mammalian toxicity (oral, dermal, and inhalation), ignitability, reactivity, chronic toxicity,4 and 

### potential carcinogenicity.

TheAgency rankshazardous substances for each infrinsic property (except potential carcinogenicity) on a five-tier scale, associating a specific range ofvalues on each scale with a particular RQ value.5

### This five-tier scale

uses the five RQ levels ofone, 10, 100, 1000, and 5000pounds, originally established pursuant to CWA section 311 (see 40 CFR 117 and 44 FR 50776). For hazardous substances evaluated for potential carcinogenicity, each substance is assigned a hazard ranking of"high," "medium," or "low." These hazardrankings correspond to RQ levels

4EPA is aware that some chronic effects result from acute (short-term) exposures and considers such data inthe chronic toxicityevaluations.The Agency Isfurther evaluating data onchronic effects resultingfrom acuteexposures to ensure that such data receive adequate consideration in the RQ adjustment process.

5All ofthe RQs promulgated In this rulemaking
are subject to theAgency's review ofthe most recent systemic (i.e,. relatingto aparticularorgan system) toxicitydata.These RQswillbe revised, if necessary,in afuture rulemaking based on the results ofthis review. ofone, 10, and 100 pounds, respectively (see below). Each hazardous substance evaluated under the various primary criteria is assigned several tentative RQ values based on its particular properties

as data allow. The lowest of the tentative RQs becomes the "primary criteria RQ" forthat substance.After the primary criteria RQs are assigned, substances are further evaluated for their susceptibility to certain degradative processes, which are used

as secondary adjustment criteria. These natural degradative processes are biodegradation, hydrolysis, and photolysis (BHP). For further discussion ofBHP, see Section II.B.2.a ofthe preamble to the final rule in which EPA promulgates RQ adjustments for 258 hazardous substances, published elsewhere in today's Federal Register.

Ifa hazardous substance,.when released into the environment, degrades relatively rapidly to a lesshazardous form by one or more of the BHP processes,6 its RQ (as determined by the primary RQ adjustment criteria) is raised one level. This adjustment is made because the relative potential for harm to public health orwelfare orthe environment posed by the release of such a substance is reduced by these degradative processes. Conversely, ifa hazardous substance -degrades to a more hazardous product after its release, the original substance is assigned an RQ equal to the RQ for the more hazardous substance, which may be one ormore levels lower thanthe RQ forthe original substance. The downward adjustment is appropriate because the hazard posed by the release ofthe original substance is increased as a result ofBHP.

To identify those CERCLA hazardous substances that may be potential carcinogens, EPAreviewed four sources ofhuman epidemiologic and/or animal bioassay data on hazardous substances that suggest possible carcinogenic effect. These sources are: (1)The Annual Reports on Carcinogens ofthe National Toxicology Program (NTP), U.S. Department ofHealth and Human Services; (2) the Monographs ofthe International Agency for Research on Cancer (IARC); (3) final Agency determinations published in the Federal Register identifying substances as potential carcinogens; and (4) ongoing determinations by the Agency's Office ofHealth and Environmental

6The specificthresholds for theapplication of BlHP tohazardous substances arediscussed in the TechnicalBackground Document to Support Rulemaking Pursuant to CERCLA Section 102, Volume 1.March 1985, availablefor inspection at Room M2427, U.S. EPA, 401 M Street, Sw., Washington. DC 20460.

### Federal Register / Vol. 54, No. 155 / Monday, August 14, 1989 / Rules and Regulations

Assessment that substances may be potential carcinogens, based on either published orunpublished data.7 

### The Agency compared the list ofsubstances derived from these four sources with the listofthe CERCLA hazardous substances to determine which hazardous substances should be evaluated for potential carcinogenicity.

Not all ofthe substances so identified

are subsequently ranked for potential carcinogenicity. Only those substances that fall within theAgency's weight-ofevidence Groups A, B,or Cdiscussed below (i.e., known, probable, orpossible human carcinogens) areranked and assigned tentative RQs based on potential carcinogenicity.

Theevaluation ofhazardous substances forpotential carcinogenicity initially involves a qualitative assessment ofthe available scientific literature on the substance. The data are reviewed to determine the degree of certainty orweight of evidence that a particular hazardous substance is a human carcinogen. The substance is then classified in an overall weight-ofevidence category (A, B,C,D,or E).

Ahazardous substance is placed in Group A (knownhuman carcinogen) only if "sufficient" evidence fromhuman epidemiologic studies supports a causal connection between exposure to the hazardous substance and cancer. Group B (probable human carcinogen) is divided into two subgroups, B1 and B2. Group B1 includes hazardous substances for which the weight of evidence ofhuman carcinogenicity based on epidemiologic studies is "limited." Group B2 includes hazardous substances for which there is "no data," "inadequate evidence," or "no evidence" ofhuman carcinogenicity from epidemiologic studies,but for

- 

### which the weight of evidence of

carcinogenicity based on animal studies is "sufficient." Group C (possiblehuman carcinogen) includes hazardous substances with "limited" evidence of carcinogenicity in animals and "inadequate evidence," "no data," or "no evidence" from human epidemiologic studies. As mentioned in the March 16, 1987NPRM (52 FR 8144), 

### Group Dsubstances (not classifiable for human carcinogenicity) and Group E substances (evidence of noncarcinogenicity for humans) are not

IIn addition to this application ofunpublished
data to identify potential carcinogens, EPA intends
to use such data for the purpose ofranking potential carcinogens under the CERCLA RQ methodology. Currently, the Agency is evaluating unpublished data received on the weight ofevidence and potency ofcertain potential carcinogens and will present the results ofthis evaluation, alongwith any RQ adjustments, in a future rulemnking. 

### , considered potential carcinogens for purposes ofthis rulemaking.

-

The evaluation ofhazardous substances forpotential carcinogenicity also involves a quantitative assessment ofthe available data to calculate the relative strength ofa hazardous substance to elicit a carcinogenic response (i.e., the "potency factor"). 8 

### This quantitative assessment allows the Agency to rankpotential carcinogens on
a numerical scale by identifying the mostpotent substances as the most hazardous. Group I 

### includes those hazardous substances with the highest potencies. Other potential carcinogens with medium and low potencies are placed in Groups 2and 3,respectively.

The final step in the hazard ranking procedure is to combine the qualitative weight-of-evidence groups and the quantitative potency factor groups using

a matrix to yield a relative hazard ranking for each substance. Thus, hazard rankings are based on two factors-weight ofevidence and potency-that theAgency believes are important indescribing carcinogenic hazards. The following is thematrix used to assign hazard rankings to potential carcinogens in today's two final rules:

HAZARD RANKING

Weight-of- Potency group evidence

group 1 (highest) 2 3 (lowest)

A

....................... High

.............. High

.......... Medium. B

....................... High

.............. Medium

.... Low. C

....................... Medium

........ Low

........... Low. D

....................... No hazard ranking Is made. The other primary criteria are used to assign the RQ.

E

....................... No hazard ranking Is made. The other primary criteria are used
to assign the RO.



### The matrix is used to group thepotential carcinogens into "high," "medium," and "low" hazard categories, and is arranged so that as the weight of evidence and the potency decrease, the hazard ranking also decreases. RQ levels are then assigned to the hazard rankings as follows: high-one-pound RQ; medium-10-pound RQ; and low100-pound RQ.

For a more detailed discussion ofthe RQ adjustment methodology based on the primary criterion ofpotential , carcinogenicity, see the preamble to the

8For an explanation ofhow potency factors are calculated, see the Technical Background Document
to Support Rulemaking Pursuant to CERCLA Section 102, Volume 3, available for inspection atRoom M2427, U.S. EPA, 401 M Street, SW., Washington, DC 20460. March 16, 1987NPRM (52 FR 8140) and the Technical Background Document to Support Rulemaking Pursuant to CERCLA Section 102, Volume 3, available forinspection at Room M2427, U.S. EPA, 401 M Street, SW., Washington, DC 20460.

EPA stated in the March 16, 1987 NPRM (see 52 FR 8146) that it was reviewing itsposition on consideration ofbenign tumors and pooling oftumor sites and types, as set forth in the Agency's Guidelines for Carcinogen Risk Assessment. 9 The effect ofthis review on RQs forpotential carcinogens is discussed in the preamble to the final rule published elsewhere in today's Federal Register in which EPA promulgates RQ adjustments for 258 hazardous substances.
2. Responses to Comments Received on the Methodology

The Agency received 35 comment letters on the March 16, 1987NPRM (52 FR 8140). Ten of these letters contain
comments that address the RQ adjustment methodology proposed in that NPRM forevaluating CERCLA hazardous substances for potential carcinogenicity. The comments on the RQ adjustment methodology are grouped into five categories: (1) Carcinogen hazard ranking methodology and the 100-pound maximum RQ; (2) the

use ofNTP and IARC publications in the Agency's identification methodology; (3) the Agency's use ofits Guidelines for Carcinogen RiskAssessment to derive RQs; (4) the application ofthe secondary RQ adjustment criteria ofBHP to potential carcinogens; and [5) the application ofthe CWA mixture rule to hazardous waste streams. Because none ofthe six hazardous substances that are the subject ofthis final rule meets the criteria for applying BHP and none are hazardous waste streams, the following discussion focuses on the first three
comment categories. Comments that fall within the last two categories are addressed in a final rule published elsewhere in today's Federal Register that promulgates RQ adjustments for 254 of the 273 hazardous substances proposed for adjustment in the March 16, 1987NPRM.

0As discussed inSection II.B.2.c below,the Guidelines provide that benign tumors should be considered along with malignanttumors unless thereis evidence that the benign tumors do not have thepotential to progress tc malignancies ofthe

same histogenic origin. The Agency pools tumor sites andtypes when each site ortype, viewed. separately, shows atumor incidence that is elevated significantly above the incidence incontrol animals (51 FR33992, September 24, 1986). 

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### 33422 Federal Register / Vol. 54, No. 155 / Monday, August 14, 1989 

## I Rules and Regulations

a. CarcinogenHazard Ranking Methodologyandthe 100-Pound Maximum RQ.Inthe March 10, 1987 NPRM (52FR 8140), EPA proposed RQ adjustments forpotential carcinogens of
one, 10, and 100 pounds. Several commenters objected to the proposed 100-pound maximum RQ for-potential carcinogens. The commenters 'recommended thathazardous substances with no greater than "inadequate" evidence ofcancer in humans and "limited" evidence of

cancer in animals receive 1000- or5000- pound RQs.

EPA disagrees with the commenters forthe reasons discussed below. First,

as stated in theMarch 16, 1987 NPRM, although cancer is a uniquehealth effect with its own special properties, it is also

a type ofchronic effect.EPA, therefore, has determined that reference to the Agency's chronic toxicity methodology is appropriate in assigning RQs to potential carcinogens. Under the chronic toxicity methodology, each substance is assigned two rating values, one based

on the dose that causes a particular effect, and one based on the severity of' the effect. Thedose ratings range from

one to 10, with 10 representing the most toxic substances. The effect ratings also range from one to 10,with 10 representing the most severe effect. The product ofthe dose and effect ratings for each substance yields a composite ranking score between one and 100. Because cancer is a life-threatening effect, the effect rating for cancer would be 10 ifcancer were ranked on the chronic toxicity scale. Therefore, the composite score for anypotential carcinogen would be at least 10. A composite score of 10 corresponds to an RQ of 1000 pounds. Thus, a 5000-pound 

### RQ for a potential carcinogen would be inappropriate based on theAgency's chronic toxicity scale (see 52FR 8145).

Two commenters statedthat this analogy between chronic toxicity and potential carcinogenicity is notvalid because chronic toxicants haveknown human health effects, whereas the human health effects ofpotential carcinogens are often determined by speculation based on animal data.EPA believes that these commenters have exaggerated the distinction between the. data for chronic toxicity and the data for potential carcinogenicity. The human health effects ofboth chronic toxicants and potential carcinogens arebased to a large degree on observation ofhealth effects in experimental animals. Therefore, the Agency believes that reference to its chronic toxicity methodology indetermining the RQ levels forpotential carcinogens is appropriate.

Second, EPAbelieves that the special properties ofpotential carcinogens are important in assigning RQ levels to these substances. These special properties are: (1) Thelack ofa demonstrated threshold level below which a potential carcinogen presents

no risk ofcancer, (2) the cumulative
nature ofcancer risks; and (3)the fact that cancer has a latent period that does
not allow direct observation of carcinogenic risks from substances newly released into the environment (52 FR 8145, March 16, 1987).

These three special properties of potential carcinogens suggest a conservative approach by the Agency in assigning RQ levels to these substances. Where a potential carcinogen does not have a threshold level ofexposure below which it presents no risk of
cancer, each individual exposure, regardless of amount, may cause irreversible health effects. The lack of demonstrated threshold levels for potential carcinogens also means that

an individual may develop cancer (an irreversible health effect) at doses that

cause no other physical effects. The cumulative nature of cancer risks means that each additional exposure, at any dose, further increases the likelihood of

a carcinogenic response. Additionally, for substances that have a latent period that does not allow direct observation of carcinogenic risks, the Agency has greater reason to be conservative in assessing the health risks accompanying exposure at any dose. Inparticular, the latent period ofcancer, when taken together with the fact that cancer may develop from doses too small to cause other physical effects, means that individuals may not be aware that they need to leave release sites at which they may be exposed to dangerous levels of potential carcinogens. The Agency, therefore, has determined that the special properties ofpotential carcinogens justify assigning lower RQs (i.e.,one, 10, and 100pounds) to potential carcinogens than the RQs that

are assigned to other hazardous substances (i.e., one, 10, 100, 1000, and 5000pounds).

In summary, a 100-pound maximum RQ for potential carcinogens is retained because (1) reference to theAgency's chronic toxicity scale shows that a 5000- pound RQ would be inappropriate for any potential carcinogen; and (2) the Agency believes that the special properties ofpotential carcinogens justify a more conservative approach in setting RQ levels forthese substances than for other hazardous substances. 

### Several commenters objected to the fact thatthe Agency assigns the same "low" hazard ranking (and resultant 100- pound RQ) to weight-of-evidence Group C,potency Group 3potential carcinogens that it assigns to weight-ofevidence Group B2, potency Group 3 potential carcinogens. Thus,the commenters disagreed with the proposed 100-pound maximum RQ for potential carcinogens. Thecommenters recommended that hazardous

. substances with no greater than "inadequate" evidence ofcancer in humans and "limited" evidence of

cancer in animals (i.e., weight-ofevidence Group C)receive 1000- or5000- pound RQs.

At thistime. EPA has decided to retain the 100-pound maximumRQ for potential carcinogens. However, EPA plans to evaluate the RQ adjustment methodology for potential carcinogens, particularly the weight-of-evidence Group C,potency Group 3substances. 0 

### The results ofthis evaluation will be addressed in a future Agency action. Note thatthis continuing investigation does not alter today's determination that these substances be assigned RQs ofno
more than 100 pounds.

b. Useof NTPandJARC Determinations. Several commenters suggested that theAgency notrely on NTP and IARC determinations as a basis for RQ rulemakings and recommended that EPAindependently evaluate the qualitative evidence of carcinogenicity for each hazardous substance.In the March 16, 1987 NPRM (52

### FR 8143), theAgency proposed a procedure forscreening thelist of CERCLA hazardous substances to identifyhazardous substances that might require assessment for potential carcinogenicity. TheNTP annual reports and IARC monographs are used only as
an initial screen forsubstances to be evaluated for potential carcinogenicity by the Agency.The conclusions reached byIARC or NTP on specific chemicals do not determine directly whether a hazardous substance is considered a potential carcinogen for purposes of establishing RQs. Rather,EPA follows

10Five individual hazardous substances are in this category: 5-nitro-o-toluidine saccharin; ptoluidine; 1,1,,2-tetrachloroethane; and 1,1.2- trichloroethane. EPAis promulgating anRQ adjustment of100 pounds forsaccharin in this final rule. RQ adjustments of100pounds for the other four weight-of-evidence Group C.potency Group 3 substances are promulgated ina final rule published elsewhere intoday'sFederal Register.Inthat same. final rule, EPA also promulgates RQ adjustments for
seven waste streams (F0S2, K073, K095,K0M8. K112. K13,andK114) thatcontain one ormoreof thefive weight-of-evidence GroupC,potency Groupa substances.

### o. Federal Register / Vol. 54, No. 155 /Monday, Augusl 14, 1989 / Ruiles and Regulations

theprocedures set out in its Guidelines for Carcinogen RiskAssessment to make this determination.

c.Applicationof EPA's Carcinogen Assessment Guidelines. EPA's methodology foradjusting RQs for potential carcinogens is derived from the Agency's Guidelines on Carcinogen Risk Assessment. Thecomments addressed in this section are directed toward the Guidelines' classification of potential carcinogens. Although the discussion ofthese issues below is not
an independent defense of the Guidelines, the Agency's responses to public comments in this rulemaking are fully consistent with EPA's response to comments received during preparation of the final Guidelines.

Two commenters objected to the Agency's lack ofdistinction between the B1and B2 weight-of-evidence Groups for hazardranking purposes. These commenters suggested that weight-ofevidence Groups B1 and B2be distinguished by assigning B2potential carcinogens hazard rankings one level higher than the hazard rankings for B1 potential carcinogens.

As discussedin Section II.B.1 above, theAgency has divided weight-ofevidence Group Binto two subgroups, BI and B2.Where there is limited evidence ofcarcinogenicity from epidemiologic studies, a hazardous substance usually isplaced in Group B1. Hazardous substances forwhich there is "sufficient" evidence from animal studies and "inadequate" evidence or "no data" fromhuman epidemiologic studies are usually placed in Group B2. Thedecision to divide Group Binto two subgroups reflects only the type of evidence of carcinogenicity, not a judgment that B2 substances are of lesserconcern than B1 substances. Furthermore, because it is reasonable to treat hazardous substances forwhich there is sufficient evidence of carcinogenicity in animals (GroupB2) as ifthey present a carcinogenic riskto humans, such substances, alongwith other substances for which there is limited evidence from human epidemiologic studies (Group 131), are classified as probable human carcin gens (Group B). Thus, the Agency believ s that,for RQ adjustment purpodes, no distinction in levels of*

concern is warranted between Group Bi and Group 132 substances.

Two commenters suggested that the Agency not count benign tumors equally with malignant tumors when there is no evidence that the benign tumors are precursors ofmalignant tumors orare life threatening. EPA agrees with the commenters that benign tumors should not be treated equally with malignant tumors ifthere is no evidence that the benign tumors will progress to malignancies ofthe same histogenic origin. It is recognized, however, that benign tumors frequently induce malignant tumors and that benign tumors often progress to malignant tumors (see 51 FR 33992, 33994, citing Interdisciplinary Panel on Carcinogenicity, 1984, Science 225:686, note 4). In such cases, theAgency's consideration ofbenign tumordata in assessing potential carcinogenicity is appropriate.

Several commenters disagreed with the Agency's useof body surface area ratios for deriving human potency values from animal potency calculations and recommended the useof bodyweight ratios instead. The commenters argued that the useofbody surface area
as an interspecies scaling factor is based on data relating to the noncarcinogenic effects ofdrugs. The Agency's use ofbody surface area to extrapolate from animals to humans

was discussed in the response to comments on theProposed Guidelines for Carcinogen Risk Assessment. In that response, theAgency concluded that the choice of thebody surface area scaling factor couldbejustified by the data on effects ofdrugs in various species, and thatEPA would continue to use this scaling factorunless data on aspecific agent suggests that a different scaling factor isjustified. Furthermore, because RQs are based on a relative ranking of substances, the consistent application of scaling factors to all substances should nothave a material effect on therelative rankings.

Two commenters objected to the Agency's policy ofpooling tumors at different sites. TheAgency pools tumor sites,however, onlywhen each site, viewed separately, shows a significant elevated tumorincidence. EPA believes that pooling oftumor sites isjustified in these limited circumstances because an agent that induces cancer in two locations is ofgreater concern than an agent that induces cancer in only one location.

The same two commenters objected to the Agency's useof effective dose (which takes into account absorption, distribution, metabolism, and excretion ofpotential carcinogens) to calculate potency. The commenters argued that administered dose (the actual experimental dose) should be used to estimate relative carcinogenic potency forpurposes ofassigning RQs. The commenters acknowledged that effective dose is appropriate for estimating absolute measures ofrisk. Thecommenters failed to demonstrate, however, that-effective dose is inappropriate formeasuring relative risk. As a practical matter, formost hazardous substances (approximately 90 percent), EPA uses administered dose because the Agency lacks information necessary to distinguish between administered dose and effective dose. Nevertheless, where such information is available, the Agency prefers to use effective dose rather than administered dose, because the former is more appropriate for measuring relative levels ofrisk (e.g., RQ levels). Effective dose is used to determine carcinogenic potency only when a substance has undergone extensive studies that have been subject
to peer review.

One commenter stated that the Agency proposed to regulate animal carcinogens in the same manner as known human carcinogens and that regulation should focus on exposures to substances with known human health effects. This commenter is mistaken in believing that the RQ adjustment methodology treats animal and human carcinogens equally. The hazard ranking methodology used to establish RQs for potential carcinogens assigns lower RQs to known human carcinogens of the

same potency as known animal carcinogens for which the human evidence is limited orinadequate. Moreover,EPA does not believe that its regulation ofpotential carcinogens should be limited to those which have known human health effects, because the Agency strongly believes that animal data are relevant to predict the potential for a carcinogenic response at

some dose in humans.

One commenter argued that extrapolation from continuous low-dose exposure studies to effects ofone-time releases cannot be made. The Agency acknowledges that estimating the absolute effect ofone-time releases from experimental data is difficult. However, the establishment ofRQs is not based

on an assessment of absolute effects, and the Agency believes that the Guidelines for Carcinogen Risk Assessment (which were followed in this rulemaking) provide a reasonable basis for determining arelative ranking ofpotential carcinogens. These guidelines have been peer reviewed and revised based on public comments and therefore provide a reasonable basis for carcinogenic assessment. Furthermore, the commenter failed to note certain implications of the relationship between one-time releases and one-time exposures. One-time releases can contaminate water or soil, resulting in continuous low-dose exposures over a period ofyears. Thus, the Agency's extrapolation from continuous low-dose 

### 33423

### 33424 Federal Register / Vol. 54, No. 155 / Monday, August 14, 1989 / Rules and Regulations

exposure studies to effects ofone-time releases is reasonable.

This commenter also noted that there

are significant uncertainties involved in low-dose extrapolation. EPA agrees and, therefore, has developed an RQ methodology that does not uselow-dose extrapolation, Themethodology relies instead on theED1O, thatis, the dose that causes an increased cancer incidence of 10percent. Use oftheED10 is advantageous because it eliminates the issue of low-dose extrapolation for RQ adjustment purposes.

The same commenter argued thatlow doses of certain heavy metals are essential to human health, and that low exposures to suspected carcinogens may not pose significant incremental risks. Thus, according to the commenter, extrapolation over a wide range of doses may not be appropriate.

EPAagrees with the commenter that certain substances canhave both beneficial effects at low doses and toxic effects at high doses. In addition, low doses canhave bothbeneficial and toxic effects simultaneously. The question ofwhether a particular release will cause exposed individuals to experience toxic effects, however,is a question of risk assessment tobe made by the Federal On-Scene Coordinator (OSC) based on all available information pertinent to the particular release. As statedearlier, the establishment and adjustment ofRQs is intended to be a reporting trigger rather than a risk assessment.

For the reasons discussed above, EPA has decided atthis time that no changes to theAgency's Guidelines for Carcinogen Risk Assessment are necessary. Nevertheless, theAgency continually reviews the Guidelines; if

new information orprocedures become available, the Agency will consider whether revisions are warranted.
C.Substances forWhichRQsAre Adjusted
1.Summary

Today's final rule adjusts theRQs for six ofthe273 hazardous substances whose RQs were proposed to be adjusted in theMarch 16, 1987NPRM. These sixRQ adjustments are shown in the following table:

H 

# IProposed and Hazardous Statutory final RQ substance I

_ _ adjustment

100 1000

10 10 100 Hazadous Stattory Proposed and Hazadous Stattory final RQ substance RQ adjustment

Saccharin and salts... 1 100

EPA has promulgated the proposed RQ adjustments without change for each of these six substances. For the reasons discussed in Section I.B. of this preamble, the Agency has decided to expedite the promulgation ofRQ adjustments for these six substances.

2. Response to Comments

Public comments on the March 16, 1987 NPRM addressed proposed RQ adjustments for three ofthe six hazardous substances In this rulemaking: 1,4-dioxane, saccharin, and perchloroethylene. No comments were received on the proposed RQ adjustments for 2-ethoxyethanol, ethylene oxide, and 2-nitropropane.

Two commenters supported adjusting the RQ for 1,4-dioxane from the onepound statutory level to 100 pounds. One commenter supported theproposed RQ adjustment of100pounds for saccharin because, the commenter suggested, the new reporting level would be consistent with public health

concerns in general, and with.the lack of hazard posed by a potential release of between one and 100 pounds of saccharin during transportation. The Agency agrees that the one-pound statutory RQ for saccharin does not appropriately reflect its carcinogenic potential. Saccharin is a weight-ofevidence Group C, potency Group 3 substance which therefore receives a low hazard ranking and a 100-pound 

### RQ.

Three commenters recommended that perchloroethylene should be classified

as a weight-of-evidence Group C substance, rather than as a GroupB2 substance as proposed in the March 16, 1987 NPRM. The available rattumor data and mouse tumor data, when considered together, support the Agency's current position that perchloroethylene should fall into the B2 category based on sufficient animal evidence ofcarcinogenicity (see Addendum to Health Assessment Document forTetrachloroethylene (Perchloroethylene), External Review Draft, April 2, 1986; NTIS #PB86- 174489). EPA's position on this issue is consistent with the IARC classification ofperchloroethylene. However, it Is important to note that EPA's B2 classification forperchloroethylene is based on a draft carcinogenicity assessment that has not yet been finalized. If this classification changes based on the final assessment, and.the 

### change warrants'an adjustment ofthe RQ forperchloroethylene, theRQ will be adjusted in a future rulemaking. Pending the results ofthe Agency's final carcinogenicity assessment, theB2 classification and 100-pound RQ adjustment for perchloroethylene will be maintained in this final rule.

In a finalrule published elsewhere in today's Federal Register, the Agency responds to public comments on 254 of the273 RQ adjustments proposed in the March 16, 1987NPRM. As explained in Section ILC.2.i ofthe preamble to that finalrule, EPA will address the RQs for theremaining 13 substances thatwere the subject oftheMarch 16,1987 NPRM in a future action. IILSUMMARY OF SUPPORTING ANALYSES
A. ExecutiveOrder No.12291
Executive Order 

### (E.O.) 12291 requires thatregulations be classified as major or nonmajor forpurposes ofreview bythe Office ofManagement and Budget (OMB). According to E.O. 12291, major rules areregulations that are likely to result in:

(1)An annual effect on the economy of$100 million ormore; or

(2) A major increase in costs orprices forconsumers, individuaL industries, Federal, State, or localgovernment agencies, orgeographic regions; or

(3)Significant adverse effects on competition, employment, investment, productivity, innovation, or on the ability ofUnited States-based enterprises to compete with foreignbased enterprises in domestic or export markets.

An economic analysis performed by the Agency, available forinspection at Room M2427, U.S. EPA, 401M Street, SW., Washington, DC 20460, shows that today's finalrule is nonmajor,because the rule willresult in estimated net cost savings of$1.5 million annually. The annual net cost savings ofallRQ adjustments promulgated or proposed to date (includingthose contained in this final rule) is estimated to be $34.7 million. It should be noted that these net cost savings reflect only those effects of theRQ adjustments that are: (1) Readily quantifiable in dollars; and (2) associated with thenotification requirements under CERCLA section 103 and SARA section 304 (including the associated activities of recordkeeping, notification processing, monitoring, and response).

This final rule has been submitted to OMB for review, as required by E.O. No. 12291. 1,4-Dioxane

................ 2-Ethoxyethanol........ Ethylene oxide

........... 2-Nitropropane

............ Perchloroethylene._...

### Federal Register / Vol. 54, No. 155 / Monday, August 14, 1989 / Rules and Regulations

B.RegulatoryFlexibility Act

The Regulatory Flexibility Act of 1980 requires that a Regulatory Flexibility Analysis beperformed for all rules that

are likely to have a "significant impact

on a substantial number ofsmall entities." To determine whether a Regulatory Flexibility Analysis was necessary for today's final rule, a preliminary analysis was conducted using a computer model that simulated the typical operation ofa small U.S. chemical company.

The results ofthe simulation indicate that the upper-bound total cost of compliance-to small firms is negligible. See the Regulatory Impact Analysis of Reportable Quantity Adjustments Under Sections 102 and 103 ofthe Comprehensive Environmental Response, Compensation, and Liability Act. Volume I,March 1985, available for inspection at Room M2427, U.S. EPA, 401 M Street, SW., Washington,,DC 20460. Therefore, because today's final rule is not expected tohave a significant impact on small entities, EPA certifies that no Regulatory Flexibility Analysis is necessary.
C.Paperwork ReductionAct

EPArequires an Information Impact Analysis for all rules that impose a paperwork burden on the public. This analysis estimates the burden imposed

on parties outside EPA for activities such as notification or recordkeeping. Today's final rule will provide a decrease in the paperwork burden imposed on the regulated community for information collection associated with fewer releases being reportable. Because the effect ofthis final rule on the paperwork burden is a reduction. EPA has determined that no further Information Impact Analysis need be performed. 

### The information collection requirements contained in this rule have been approved by the OMB under the provisions of the Paperwork Reduction Act,44 U.S.C. Section 3501 etseq., and have been assigned OMB control number 2050-0046.

The public reporting burden for this collection ofinformation is estimated to vary from 8 to 11 hours per response. including time for reviewing instructions, searching existing data
sources, gathering and maintaining the data needed, and completing and reviewing the collection ofinformation.

Send comments regarding the burden estimate or any other aspect of this collection ofinformation, including suggestions forreducing this burden, to Chief.Information Policy Branch, PM223, U.S. Environmental Protection Agency, 401 M Street. SW., Washington. DC 20460; and to the Office of Information and Regulatory Affairs, Office ofManagement and Budget, Washington, DC 20503, marked "Attention: Desk Officer forEPA."

Listof Subjects in 40 CFR Part 302

Airpollution control, Chemicals, Hazardous materials, Hazardous materials transportation, Hazardous substances. Hazardous wastes, Intergovernmental relations, Natural
resources, Oil pollution, Pesticides and pests, Reporting and recordkeeping requirements: Superfund, Waste
treatment and disposal. Water pollution control,Water supply.

Dated: June 26.1989. William K.Reilly. Administrator.

For the reasons set forth in the preamble, 40 CFR Part302 is amended

as follows: PART 302-DESIGNATION, REPORTABLE QUANTITIES, AND NOTIFICATION

1.The authority citation forPart 302 is revised to read as follows:

Authority: 42 U.S.C. 9602;33 U.S.C. 1321 and 1361.
§302.4 [Amended]

2. Section 302.4 is amended by revising the following entries in Table 302.4 and Appendix A to read as set forth below.The note preceding Table 302.4 is republished without change.

Note: The numbers under the column headed "CASRN" are the Chemical Abstracts Service Registry Numbers for each hazardous substance. Other names by which each hazardous substance is identified in other statutes and their implementing regulations

are provided in the "Regulatory Synonyms" column. The "Statutory RQ" column lists the RQs for hazardous substances established by section 102 ofCERCLA. The "Statutory Code' column indicates the statutory source for designating each substance.asa CERCLA hazardous substance: "1" indicates that the statutory source is section 311(b)(4) ofthe Clean Water Act, "2"indicates that the

source is section 307(a) ofthe Clean Water Act. "3" indicates that the source is section 112 ofthe Clean AirAct, and "4"indicates that thesource isRCRA section 3001. The "RCRA WasteNumber". column provides the
waste identification numbers assigned to various substances byRCRA regulations.The column headed "Category" liststhe code letters "X," "A," "B," "C," and "D," which are associated with reportable quantities of1,10. 100, 1000, and 5000 pounds, respectively. The "Pounds (kg" column provides the reportable quantity adjustment for each hazardous substance in pounds and kilograms.

TABLE 302.4-LiST OF HAZARDOUS SUBSTANCES AND REPORTABLE QUANTITIES

CAS Statutory Final RO
Hazardous substance CSNRegulatory synonyms I CRA Cate

- RO Codet waste aor Pounds (Kg)

r so. gory o

t.2.Benzisothiazolin-3-one, l.1-dioxide, and salts

.....

1 .4-Diethylene dioxide

............ ... .......

1.4-Dioxane

........... ...... ...................................
Ethene, 1.1,2,2-tetrachloro-

........................................

2.Ethoxyethanol

.................................................. Ethylene glycol monoethyl ether

............................. 81072 Saccharin and salts

.................................................

123911

123911

127184 1,4-Doxane

..................................................................

1.4-Diethylene dioxide

............... . ..........

Perchloroethylene

........................................................ Tetrachloroethene

......................................................... Tetrachoroethylene

............... .............

110805 Ethylene glycol monoethyl ether

. ... ............

110605 2-Ethoxyetlanol

............................................................. U108

U108

U210

U359

U359 100 (45.4)

100 (45.4)

100 (45.4)

100 (45.4)

1000 (454)

1000 (454) 

### 33425

### 33426 Federal Rigigtdr 

### /' Vol. 54, No.'155J 

### Monday, August 14, i989 / Rules auid Regulations

TABLE 302.4-LIST OF HAZARDOUS SUBSTANCES AND REPORTABLE QUANTITIES-Continued

Statutory Final RO
Hazardous substance CASRN Regulatory synonyms RCRA CateRO Codet waste Pounds (Kg) No. gory

Ethylene oxide

.............. ................ 75218 Oxirane

............................................................................ 1. 4 U115 A 10(4.54)
2-Nitropropane

.............................................................. 79469 Propane, 2-nitro-

.............. ................... .. 4 U171 A 10 (4.54)

Oxirane

............................................................................ 75218 Ethylene oxide

.......................................................... I

. 4 Ul15 A 10 (4.54)
Perchloroethylene

......................................................... 127184 Ethene, 1,1,2,2-tetrachloro-

.......................................... 1" 2,4 U210 B 100 (45.4) Tetrachloroethene

.......................................................... Tetrachloroethylene

...................................................... Propane, 2-nitro-.

................................................. 79469 2-Nitropropane

.......................... 1. 4 U171 A 10 (4.54)

Saccharin and salts

........................ 81072 1,2-Benzisothiazolin-3-one,l,l-dioxide,and salts 1* 4 U202 B 100 (45.4)
Tetrachloroethene

.......................................................... 127184 Ethene, 1,1,2,2-tetrachloro-.

......................................... 1 2,4 U210 B 100 (45.4) Perchloroethylene

.......................................................... Tetrachloroethylene

....................................................... Tetrachloroethylene

.......................................... 127184 Ethene, 1,1,2,2-tetrachloro

.......................................... 1* 2,4 U210 B 100 (45.4) Perchloroethylene

.......................................................... Tetrachloroethene

................. . ............

t-indicates thestatutory sourceas defined by 1,2, 3,or 4 below: 1--indicates that the statutory sourcefor designation of this hazardous substance under CERCLA Is CWA Section311 (b)(4) 2-indicatesthat the statutory sourcefor designation of this hazardous substance underCERCLA is CWA Section307(a) 3-Indicates that the statutory sourcefor designation of this hazardous substance under CERCLA is CAA Section 112 4-indicates that the statutory source for designation of this hazardous substance under CERCLA is RCRA Section 3001 1*-indicates thatthe 1-pound RQ is a CERCLA statutory RO

Appendix A

SEQUENTIAL 

### CAS REGISTRY NUMBER LIST

OF CERCLA HAZARDOUS SUBSTANCES

CASRN Hazardous substance

75218

. Ethylene oxide Oxirane

79469

. Propane, 2-nitro2-Nitropropane

81072

....... 1,2-Benzisothiazolin-3-one,l,l-dioxide, and salts Saccharin and salts

110805

. Ethylene glycol monoethy ether 2-Ethoxyethanol

123911 1,4-Diethylenedioxide 1,4-Dioxane

127184

. Ethene, 1,1,2,2-tetrachloroPerchloroethylene Tetrachloroethene Tetrachloroethylene

[FR Doc. 89-15745 Filed 

### 8-11-89; 8:45am] BILLING CODE S660-50-M ENVIRONMENTAL PROTECTION
AGENCY

40 CFR Parts 116,117,and 302
[SW H-FRL 3372-81
Reportable Quantity Adjustments; Delisting of Ammonium Thiosulfate

AGENCY: U.S. Environmental Protection Agency (EPA). ACTION: Final rule.

SUMMARY: Sections 103(a) and (b) ofthe Comprehensive Environmental Response, Compensation, and Liability Act of1980 (CERCLA), as amended, require that persons in charge Ofvessels

or facilities from which hazardous substances have been released in quantities that are equal to or greater than their reportable quantities (RQs) immediately notify the National Response Center ofthe release. Section 102(b) sets an RQ ofone pound for hazardous substances, except those substances forwhich different RQs have been established pursuant to section 311(b)(4) ofthe Clean Water Act (CWA). In addition to these reporting requirements, section 304 ofthe Superfund Amendments and Reauthorization Act of1986 (SARA) Title III requires that releases of hazardous substances inquantities equal to or greater than their RQs (or

one pound ifa reporting trigger is not 

### established by regulation) be reported to State and local authorities.

Section 102(a) ofCERCLA authoizes the U.S. Environmental Protection 

### Agency (EPA or "the Agency") to adjust RQs forhazardous substances and to designate as hazardous substances those substances that, when released intothe environment, may present substantial danger to thepublic health

orwelfare orthe environment. Currently, there are 725 CERCLA hazardous substances. 1 In this rulemaking, EPA is promulgating final RQ adjustments for258 hazardous substances. Of these 258 hazardous substances, 254 had RQs proposed for adjustment by EPA in a Notice of Proposed Rulemaking (NPRM) published

on March 16, 1987 (52 FR 8140). 2 RQs for four additional hazardous substances that were not proposed for adjustment in the March 16, 1987 NPRM are also included in this final rule. These four hazardous substances are waste streams that were listed as hazardous under section 3001 ofthe Resource Conservation and Recovery Act (RCRA)

'See Note I at the end of the textof this preamble.

2See Note 2 at the end ofthe textofthis preamble.