24401-1 BACKGROUND DOCUMENT
RESOURCE CONSERVATION AND RECOVERY ACT
SUBTITLE C - HAZARDOUS WASTE MANAGEMENT
SECTION 3001 -(IDENTIFICATION AND LISTING OF
HAZARDOUS WASTED,
5261.10 -^Criteria for Identifying Characteristics
of Hazardous Waste ' j
J J
§261.11 -/Criteria for Listing Hazardous Waste J
§260.22 -(petitions to Amend Part 261 to Exclude a
Waste Produced at a Particular Facilitv f
U.S. ENVIRONMENTAL PROTECTION AGENCY
OFFICE OF SOLID WASTE
April 30, 1980
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Table of Contents
Page
Introduction 1
Synopsis of Proposed Rules 2
Rationale for Proposed Rules 5
Summary and Consideration of Comments and Reconsideration 10
of the Proposed Rules
Regulatory Strategy 10
Criteria for Identifying Characteristics 22
Comments on Criteria for Listing 27
Reconsideration of Criteria for Listing 35
Delisting Procedures 61
Final Rules 63
Section 261.10 63
Section 261.11 64
Section 260.22 67
Appendix I 72
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INTRODUCTION
The purpose of this document is to describe the basis and purpose
that the Agency used in establishing final (1) criteria for identifying
characteristics of hazardous waste, (2) criteria for listing hazardous
waste and (3) procedures for delisting hazardous wastes. This document
refers to §§250.12 and 250.15 of the Proposed Rules published on
December 18, 1978, and to S5261.10, 261.11, and 260.22 of the Final
Rules. The document also relates to Sections 3001(a) and 1004(5) of the
Resource Conservation and Recovery Act, as amended, (RCRA).
Section 3001(a) of RCRA requires the Administrator to "develop and
promulgate criteria for identifying the characteristics of hazardous waste,
and for listing hazardous waste, which should be subiect to the provisions
of this subtitle (Subtitle C - Hazardous Waste Management), taking into
account toxicity, persistence, degradability in nature, potential for
accumulation in tissue, and other related factors such as flammability,
corrosiveness and other hazardous characteristics." This statutory require-
ment to establish criteria for characteristics of hazardous waste and for
listing hazardous waste is non-discretionary. Provision for delisting
hazardous wastes is not explicitly mentioned in the statute. The discretionary
authority for establishing procedures for delisting is based on Section
2002(a)(l) of RCRA which authorizes the Administrator "to prescribe ....
such regulations as are necessary to carry out his functions under this
Act."
Section 1004(5) of RCRA defines "hazardous waste" to mean "a solid
waste, or combination of solid wastes, which because of its quantity,
concentration, or physical, chemical, or infectious characteristics may:
(1) cause, or significantly contribute to an increase in mortality
or an increase in serious irreversible, or incapacitating
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reversible, illness; or
(2) pose a substantial present or potential hazard to human health
or the environment, when improperly treated, stored, transported,
or disposed of, or otherwise managed."
This definition, together with the factors delineated in Section 3001(a),
provides the statutory test that is to be used by the Agency in developing
criteria for characteristics and listing of hazardous waste under Section
3001(a) of RCRA.
SYNPOSIS OF PROPOSED RULES
The Proposed Rules established separate criteria for identifying charac-
teristics of hazardous waste and listing of hazardous waste (see §§250.12 (a)
and (b), respectively, of the Proposed Rules). The criteria for identifying
characteristics required (1) that the characteristic be defined in terms
of specific physical, chemical, toxic, infectious or other hazardous properties
of a solid waste and (2) that such properties be measurable by available,
standardized testing protocols. These criteria explicitly required that a
characteristic be quantitative and specific and that it be determinative
through standardized, readily available testing methods. Section 250.10(d)(l)
of the Proposed Rules made it clear that generators of solid wastes were
required to use characteristics to determine whether their solid wastes were
hazardous wastes. Section 250.14 of the Proposed Rules stated that the
Agency also would use characteristics to list hazardous wastes.
As indicated above, the term "characteristic(s) of hazardous waste(s)"
takes on a very special meaning in the Proposed Rules (and in the Final Rules).
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It denotes a hazardous property or set of properties that are highly quantifiable
and readily measurable or otherwise determinable so that they can be readily
and confidently used by generators of solid wastes to determine whether
their solid wastes are hazardous wastes. This meaning is much more specific
and narrowly drawn than the traditional meaning of the term, or even the
meaning that the term takes in a few parts of the legislative history
where "characteristic" appears to be a synonym for "properties") and does
not carry the connotation of quantitativeness, specificity, measurability
or generator usability that has been attached to this term in the regulations.
In short, as used in these regulations, a characteristic is a hazardous
property or a set of hazardous properties that can be used by generators
in evaluating his wastes. Hazardous properties which cannot be used in
this way, or which the Agency believes should not be used in this way, are
called "factors" in this document and in the Final Rules.
The criteria for listing a hazardous waste required either (1) that
the waste possess one or more of the established characteristics or (2) that
the waste meet the definition of hazardous waste given by Sections 1004(5) of
RCRA. The Agency elected to establish a rebuttable presumption for listing
wastes which met these criteria. Types or classes of waste were listed, rather
than individual wastes from individual sources, and a presumption was created
that all individual wastes within the type or class listed were hazardous
wastes. The delisting mechanism (discussed later) enabled an individual
waste of a listed type or class of waste to be delisted thus rebutting the
presumption with respect to the individual waste.
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Under the criteria for listing, listed hazardous wastes would be
regulated unless! or until dellsted (individual waste only). Wastes
that were not listed would be hazardous waste if found (primarily by
generators) to possess one or more of the characteristics. Implicit in
this approach is the certainty that attaches to the listing of hazardous
wastes. The regulated community, as well as the regulating agencies (EPA
and the States), would face no doubts about the status of a waste if it is
listed as a hazardous waste. No testing or other complex determinations of
hazardousness would be required relative to listed hazardous wastes. The
hazardous status of unlisted wastes would be uncertain until tested or
assessed against the established characteristics.
The requirements for delisting (see §250.15(a) of the Proposed Rules)
were essentially the inverse of the basis for listing. Where a waste was
listed because it possessed a characteristic, the requirement for delisting
was demonstration that the waste did not possess the characteristic.
Where a waste was listed for reasons other than a characteristic (i.e.,
the waste met the definition of the Act), the requirement of delisting
was demonstration that the waste did not possess the properties (e.g.,
chronic toxicity) that caused it to be listed by EPA. In addition, the
requirements for delisting prescribed (1) the information to be submitted
as part of a demonstration, (2) the procedures the Agency would use in
approving or disapproving a demonstration and in allowing a demonstration
to become effective, and (3) certain due process procedures.
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RATIONALE FOR THE PROPOSED RULES
The proposed criteria for characteristics and listing and the require-
ments for delisting were based on a regulatory strategy that assumed that
(1) characteristics defining all of the intrinsic hazardous properties of
solid waste (e.g., ignitability, corrosivitv, reactivity, toxicitv, genetic
activity, bioaccumulation potential and radioactivity) could eventually be
established and would be used by generators to self—determine whether
their solid wastes are hazardous wastes and (2) EPA would list classes or
types of hazardous wastes where it had good reason to believe that all or
most individual wastes in the listed class possess one or more of the
established characteristics. Under this approach, characteristics would
capture all solid wastes, even those not listed as hazardous wastes,
deemed to be hazardous under the statute. Accordingly, even those solid
wastes for which the Agency had insufficient data or knowledge to support
a listing would be brought into the hazardous waste management system through
self-determinations by generators of solid wastes. The obiective of this
strategy was to establish a system that assured broad coverage of hazardous
wastes in the absence of the Agency's listing of hazardous wastes.
The listing of hazardous wastes, under this regulatory strategy, was
intended to provide a high degree of certainty for the generators of solid wastes,
the public and the regulating agencies about which solid wastes were hazardous.
Listing, therefore, had the purpose of reducing or eliminating the burden
on generators and the regulating agencies of having to test or otherwise
determine whether certain solid wastes were hazardous wastes. As such,
listing was a refinement of, not a substitute for, the basic element of
the regulatory strategy—case-by-case application of characteristics by
generators.
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Under this approach, the burden of determining which solid wastes
were hazardous would initially fall largely on generators through application
of the characteristics because EPA would initially only be able to list a
limited number of wastes. Over time, this burden would be reduced by the
Agency's listing of more and more wastes. The principal burden on EPA
would be to define, establish and revise characteristics (as appropriate).
A secondary burden on the Agency would he to initially list and, over
time, extend the listing of hazardous wastes.
The strategy recognized that the listing of wastes would not be perfect.
For administrative efficiency, classes or types of wastes, rather than the
wastes from individual sources, would be listed for the most part (although
listing of individual waste streams would be permissible ). The Agency
recognized that some individual wastes within a listed class or type of
waste, might not be hazardous wastes", because of different raw materials
or manufacturing processes used or because of other atypical factors.
Consequently, provision for delisting of fundamentally different
individual wastes within classes or types of listed hazardous wastes was
embodied in the Proposed Rules.
In developing the Proposed Rules, the Agency was unable to fully effect
the above described regulatory strategy. Characteristics could onlv be
developed and proposed for some of the hazardous properties of wastes.
These were characteristics for ignitability, corrosivity, reactivity and
toxicity (limited to toxicity caused by contaminants governed by Interim
Primary Drinking Water Standards). With respect to these characteristics,
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the above described regulatory strategy was incorporated in the Proposed
&
Rules. With respect to other hazardous properties (chronic organic toxicity
to humans, aquatic toxicity, phytotoxicity, genetic activity, I/ bioaccumulation
potential, radioactivity, and infectiousness), EPA was unable to propose
characteristics because it lacked sufficient information and data to support
such characteristics and their associated test protocols. The Agency believed,
however, that such characteristics eventually could be developed and established
and, toward that end, the Agency published an Advance Notice of Proposed
Rulemaking on December 18, 1978, to initiate their development. Because
of this belief, the Agency elected to follow the above-described regulatory
strategy, but with an important, temporary deviation: the listing of wastes for
which characteristics had not yet been established.
Although characteristics were not established for wastes listed for
radioactivity, genetic activity, organic toxicity, bioaccumulative potential
and infectiousness, the Agency, in fact, did follow a set of characteristic-like
I/ Where used in this document, "genetic activity" refers to carcinogenicity,
mutagenicity and teratogenicity.
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criteria, together with the consideration of other factors, to list such wastes.
Although these criteria were not delineated in the criterion for listing hazardous
wastes under §250.12(b)(2), they were implicitly reflected in the delisting require-
ments of §250.15(a)(5) and (6). These criteria were:
1. For wastes listed because of radioactivity, the criterion was
that the waste contained less than 5 picocuries per gram of
radium-226, if a solid-state waste, or contained less than 50 picocuries
per liter of radium-226 and radium-228 combined, if a liquid-state
waste.
2. For wastes listed because of genetic activity, the criterion was that
the extract of the waste (as derived by the proposed Extraction
Procedure) contained less than one milligram per liter of any
compound on the Controlled Substance List in Appendix IX of the
Proposed Rules or gave a positive response in any one of a series
of tests specified in §250.15(a)(6)(i) of the Proposed Rules.
3. For wastes listed because of bioaccumulative potential, the criterion
was that the extract of the waste (as derived by the proposed Extrac-
tion Procedure) gave a positive response in the Bioaccumulation
Potential Test prescribed in Appendix XI of the Proposed Rules.
4. For wastes listed because of organic toxicity, the criterion was
that the extract of the waste (as derived by the proposed Extraction
Procedure) contained an organic substance having a calculated human
LD50 of less than 800 milligrams per kilogram at a concentration in
milligrams per liter greater than or equal to 0.35 times its LD50
expressed in units of milligrams per kilogram.
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In addition, for delisting infectious wastes, the waste would have to be shown
not to contain microorganisms or helminths of CDC (Center for Disease Control)
Classes 2 through 5 of Etiologic Agents (see §250.14(b) of the Proposed Rules).
The important feature of this interim approach was that it clearly
placed the burden on EPA to bring a large number of the most hazardous wastes
into the hazardous waste management system through listing, as opposed to
placing this burden on generators through application of characteristics.
The principal advantages and disadvantages of this approach were well
recognized by the Agency. Clearly, for many wastes, principally toxic
organic wastes, generators would be relieved of the burden of waste testing
which they would find expensive, difficult and objectionable. EPA, however,
would be saddled with the burden of testing and evaluating the broad array
•of industrial solid wastes tcT determine which should be listed as hazardous
waste. This would require considerable resources and, to the extent that
resources likely would be limited, listing of all or most hazardous wastes
would require several years. Until such listing was completed, desired
regulatory coverage of hazardous wastes would be incomplete. This would
constitute initial and temporary under-regulation.
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SUMMARY AND CONSIDERATION OF COMMENTS AND RECONSIDERATION OF THE PROPOSED RULES
Regulatory Strategy. A number of commenters expressed differing points
of view on the regulatory strategy authorized by the Act for identifying
hazardous wastes. Some felt that wastes could only be listed as hazardous
wastes against established characteristics. These commenters seemed to
argue for a three level system: criteria for characteristics, characteristics,
and listing against characteristics, similar to the system proposed for
ignitable, corrosive, reactive and certain toxic wastes. These commenters
made little or no distinction between characteristics and criteria for
listing hazardous waste, apparently believing them to be one and the same.
In fact, they referred to the legislative history (H.R. Report 94-1491) which
spoke about the "bifurcation of developing the criteria.... separate from the
identification and listing of hazardous wastes." Most of these commenters
also argued that listing was-the only statutorilv authorized approach for
identifying hazardous wastes, thereby agreeing with the comments summarized next.
A number of commenters felt that the characteristics should be used only by
EPA for listing hazardous wastes and should not be imposed on the regulated
community to determine the hazardous status of unlisted wastes. These
commenters were concerned about the burden placed on generators to employ
costly, sophisticated and perhaps imprecise tests to evaluate unlisted
solid wastes. Some of the commenters felt that the tests were costly,
that the burden of testing properly rested on the regulating agencies
(EPA or the States). Others felt that many generators, particularly small
generators, would avoid testing because of the high costs and complexity
of the tests or because of their incapacity to perform the tests. Con-
sequently, these commenters felt that small generators would designate
marginally hazardous or non-hazardous wastes as hazardous wastes in order
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to "be safe" and avoid possible civil or criminal penalties that could
attend errors in testing. These commenters felt that this would lead to
over-regulation, would be costly to industry and would aggravate the disposal
capacity problem.
At the other end of the spectrum, several commenters contended that
characteristics should be used for both listing of hazardous wastes by
EPA and case-by-case designation of unlisted wastes as hazardous wastes by
generators. These commenters felt that this would assure the broadest
possible regulatory coverage of hazardous wastes (until it was possible
for EPA to list all hazardous wastes) and that such broad coverage was
environmentally essential.
In summary, there was wide disagreement as to what Congress intended in
Section 3001(a) of the Act. Importantly, virtually all of these comments were
directed at the proposed regulatory strategy covering the listing of hazardous
wastes for which characteristics were not proposed (primarily those listed
for organic toxicity, genetic activity, bioaccumulation potential, radioactivity
and infectiousness).
The Agency disagrees with those commenters who argued that characteristics
should be used only for listing wastes and should not be imposed on generators
to self-determine if their unlisted wastes are hazardous wastes. It further
disagrees with commenters who contended that the statute does not authorize
these two approaches for designating hazardous waste. The Agency believes
that the statutory language plainly contemplates two distinct mechanisms
for bringing a waste into the hazardous waste system. Section 3010 provides
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that "Not later than ninety days after promulgation or revision of regulations
under Section 3001 identifying by its characteristics or listing any substance
as a hazardous waste subject to this subtitle " (emphasis added), any
generator or transporter of hazardous waste or operator of a hazardous
o
waste facility shall file notice with the Administrator providing information
about the "identified or listed hazardous waste..." This language explicitly
envisions either of two methods for determining whether a given waste is
hazardous: (1) identification in accordance with the characteristics or
(2) listing. Similarly, Section 3001(c) provides that " — the Governor of
any State may petition the Administrator to identify or list a material as
a hazardous waste." (emphasis added). Additionally, Sections 3002, 3003,
3004 and 3005 refer to generators, transporters and treatment facility
operators of "hazardous waste identified or listed under this subtitle..."
(emphasis added). Thus, Con-gress indicated clearly that there are two
distinct mechanisms for bringing waste into the hazardous waste system.
Given that the statute authorizes (and, presumably, expects) the
use of two mechanisms, it is left to the discretion of the Agency
to fashion the nature and content of each mechanism. Even here, however,
that statute provides implicit guidance on the intended nature for these
two mechanisms. The intended nature of the listing mechanisms seems
to be clear and obvious. Under this mechanism, the Agency is to list
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particular hazardous wastes^-' or classes or types of hazardous waste based on
data and information it has collected about the wastes and based on its determi-
nation that these particular wastes are hazardous in accordance with the statutory
definition of hazardous waste. Once listed, the generator's responsibility is
simple and straight-foreward: to designate, as a hazardous waste, any and
all wastes that meet the descriptions of the wastes listed.
The nature of the identification mechanism also appears reasonably apparent
in the statute. Under this mechanism, the Agency is to establish characteristics
V
of hazardous wastes and hazardous wastes are to be identified by these
characteristics.^' Admittedly, the statute does not explicitly indicate
who is to identify individual wastes by their characteristics. If Congress
had. intended EPA to determine whether wastes met the characteristics,
however, then there would have been no point in making a distinction between
the two mechanisms. Furthermore, if the Agency (and authorized States)
were obligated to perform identification against established characteristics,
that would entail an extensive, resource intensive monitoring and testing
program, literally involving the sampling and testing of each and every
solid waste not listed as a hazardous waste. This could encompass individual
sampling and testing of hundreds of thousands of solid wastes and, in many
cases, repeated sampling and testing of these wastes because of their
variability over time.
If See Section 3001 (b) of RCRA.
2/ See Section 3010 of RCRA.
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The Agency does not believe that the Congress contemplated such an
absurd result. Rather, the Agency believes that the Congress contemplated
just the opposite: the sampling and testing of solid wastes by generators
•
(and by owners or operators of hazardous waste treatment, storage and
disposal facilities). Section 3002 (1) of RCRA explicitly prescribes that
requirements be placed on generators to perform "recordkeeping practices
that accurately identify the quantity of such hazardous wastes generated,
the constituents thereof which are significant in quantity..." Such record-
keeping cannot be accomplished without first sampling and testing of the
wastes. Section 3002(4) requires generators to "furnis(h)...information
on the general chemical composition of such hazardous waste to persons
transporting, treating, storing, or disposing of such wastes." Finally,
Section 3005 (1) requires applicants for hazardous waste management permits
*
to supply "estimates with respect to the composition, quantities, and
concentrations of any hazardous waste..." Taken together, these requirements
clearly indicate that the statute contemplates (and, in fact, directs)
that the regulated community carry a responsibility to sample and test or
otherwise determine the quantity and composition of the hazardous wastes that
they generate and manage. It is thus wholly reasonable to conclude that
the Congress contemplated that these same responsibilities were to be assumed
by the regulated community in the identification of hazardous wastes for which
characteristics have been established.
Such a reading of the statute not only places responsibility for identifying
unlisted hazardous wastes or those parties who generate them—a fundamental
purpose of the statute in the Agency's view-but also capitalizes on the
advantage of the "division of labor" in identifying such wastes. Whereas the
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the Agency and the authorized States will not have the resources to sample and
test all unlisted wastes, the Agency believes that the large number of generators
do have this capacity (within limits as discussed below) and can and should be
expected to assume this responsibility. In simple terms, assigning responsibility
for identifying unlisted hazardous wastes to generators spreads this responsibility
to an estimated 67,000 generators^/ rather than 51 entities, the Agency and the
authorized States .£/ Clearly, this approach has considerable merit from
the standpoint of administrative efficiency. Moreover, generators of
hazardous wastes are "continually on the scene," so to speak and therefore,
are capable of intimately knowing their various solid wastes, knowing and
predicting the variability of these wastes and readily and efficiently
sampling these wastes. To expect the Agency and the authorized States to
have such "on the scene" capacity in order to efficiently and effectively
identify unlisting wastes is clearly unrealistic. In summary, the Agency
concludes that practicality and a reasoned reading of the statute argue
for the implementation of the identification mechanism by generators.
Based on the foregoing, EPA has retained, in the Final Rules, the same two
mechanisms-for designating wastes that were reflected in the Proposed Rules.
Where appropriate, certain characteristics are established and are required to
be used by generators to identify hazardous wastes (they may be and, in fact,
are used also by EPA to list wastes"known to possess one or more of these
I/ Accounting for the exemptions for small quantity generators in §261.5 of
~ the Final Rules, the Agency estimates that 67,000 generators will be covered
by the Subtitle C regulation.
2/ The number of 51 entities will inevitably be smaller (probably 35 to 45) because
~ only a portion of the 50 States will be authorized to assume responsibility for
the program.
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characteristics). Hazardous wastes are also listed, using the criteria
for listing established in the Final Rules.
The Agency clearly recognizes that the identification mechanism has its
limitations and must be used with considerable care. First and foremost,
this mechanism must only employ characteristics which, in and of themselves,
sufficiently define the properties of a waste that cause the waste to meet the
definition of hazardous waste prescribed in Section 1004(5) of RCRA. In other
words,"a solid waste that possesses the property or properties described in
an established characteristic must meet the statutory definition of hazardous
wastes without consideration of any other properties of or factors about the
waste or its constituents. Where properties or factors outside of those defined
in the characteristic must be considered to reach a determination that a waste
meets the statutory definition of hazardous waste, a. characteristic is not
sufficient for the purpose of designating a hazardous waste. In those cases
«
where multiple factors are required to determine the hazardous status of a
waste, the Agency has employed the listing mechanism to designate the waste.
This represents a change in regulatory strategy from that advanced in the
Proposed Rules; a change which is in response to comments. Basically, the
Agency has concluded that the intended characteristic for organic toxicity,
genetic activity, bioaccumulation potential, radioactivity, and infectiousness,
that were discussed in the Proposed Rules (and were preliminarily proposed in
the Advance Notice of Proposed Rulemaking) are not, in and of themselves,
capable of identifying wastes as hazardous without consideration of additional
properties and factors outside of those defined in those characteristics.^/
.'/ Further discussion of this conclusion is presented later in this document.
"* Suffice it to say at this point however, that the subject characteristics as
proposed in the ANPR did not take into consideration all relevant factors necessary
to substantiate the hazardousness of wastes.
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Consequently, the Agency has deferred establishment of these characteristics
and has decided, at this time, to use the listing mechanism to designate
hazardous wastes that possess properties of toxicity not covered in the EP
toxicity characteristic, namely genetic activity, bioaccumulation potential,
radioactivity, or infectiousness.
At the same time, the Agency has concluded that the characteristics of
ignitability, corrosivity and reactivity are sufficient to use in the identifi-
cation i.e., self-testing mechanism because they define a degree and nature
of hazardousness that meets the statutory test of hazardous wastes, without
considering outside factors (substantiation of this conclusion is presented
in separate background documents covering these characteristics). With
respect to the proposed toxicity characteristic, the Agency has concluded
that a modified version of this characteristic^-/ can be used in the
identification mechanism because it., too, defines a degree and nature of
* •
hazardousness that meets the statutory definition (substantiation of this
conclusion is presented in a separate Background Document covering this
characteristic which has been re-named "Characteristic of EP Toxicity" in
the Final Rules). In summary, the Final Rules establish four characteristics
(for ignitability, corrosivity, reactivity and EP toxicity) that are required to
be used by generators of solid wastes to self-determine if their unlisted
wastes are hazardous.
A second factor that the Agency considered in the use of the identification
mechanism was that of the implementability of characteristics that would have
to be used by generators. The Agency concluded that characteristics should be
definitive and determinative if they were to be properly and successfully used
I/ The concentration limits of contaminants that define this characteristic
~ have been increased ten-fold in the Final Rules.
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by the diverse group of generators that would have to use them. Also, character-
istics should be reasonably simple and straightforward and should not require
complex determinations. Finally, the test protocols included in characteristics
should be standardized and readily available to generators (or the private-sector
laboratories that might serve them) and should be within the performance capability
of generators (or private-sector laboratories). Although EPA intends to use the
listing mechanism to eventually list most, if not all, hazardous waste, the
identification mechanism initially and, to some extent, always will play a very
important role in bringing into the hazardous waste management system waste for
which EPA does not have sufficient information to list. It is therefore in the
Agency's interest, and in the interest of generators and the public at large, that
the characteristics used in the identification mechanism be highly definitive,
determinative, and usable by generators so that they avoid both overregulation and
underregulation.
The factor of implementability was carefully considered by the Agency, both
in response to the many comments on this matter and as a result of Agency initiative.
In part, these factors also helped EPA reach the decision to defer characteristics
for organic toxicity, genetic activity, bioaccummulation potential, radioactivity,
and infectiousness. Aside from the insufficiency of these characteristics in
incorporating all relevant properties and factors necessary to the determination of
hazardousness (discussed above), these characteristics, as preliminarily proposed
in the ANPR, were, for the most part complex and required the use of test methods
that are not yet fully standardized or widely available. On the other hand, the
Agency concluded that these factors of implementability did not impair the
characteristics for ignitability, corrosivity, reactivity and EP toxicity
established in the Final Rules. The Agency believes that these characteristics
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are definitive, determinative, and reasonably simple and that their test protocols
are standardized, available and within the performance capacity of generators or
private-sector laboratories (substantiation of these contentions are presented
in the separate Background Documents covering these characteristics).
With respect to comments on the burden of characteristics on small generators
of hazardous wastes, §261.5 of the, Final Rules, with a few exceptions, excludes
from the regulation the hazardous wastes generated by persons who generate
or accumulate less than 1,000 kilograms of hazardous waste in any calendar month ._l/_2_/
An estimated 693,000 generators are excluded from regulation under this
provision. A detailed description and discussion of this exclusions are
presented in a separate Background Document. The Agency believes that this
I/ However, this exclusion level will eventually be reduced to 100 kilograms
~ in any calendar month.
2/ Pesticide containers and residues employed and generated by farmers are not
~ subject to regulation if they are disposed of in specified ways. As
provided in §262.51, farmers who triple-rinse pesticide containers and
dispose of pesticide residues in accordance with the pesticide label
instructions are not subject to Subtitle C regulations with respect to
these wastes. Other hazardous wastes generated by farmers are not excluded
unless they are generated or disposed of in quantities less than 1,000
kilograms in any 30-day period.
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exclusion addresses many of the concerns of commenters on this matter.
Admittedly, there are some small and many medium-size generators who
will not be affected by this exclusion. However, with respect to these
generators, the Agency believes that the four characteristics established
in the Final Rules are not unreasonably costly,£/ difficult to employ,
imprecise or beyond the performance capacity of these generators or the
private-sector laboratories that are available to serve them. It is probably
inevitable, as suggested by some commenters, that some of these generators
will avoid self-determination of unlisted wastes by merely declaring
their solid wastes to be hazardous wastes, in order to "be safe" and avoid
any possibility of criminal or civil penalties. This is permissible under
the requirements of §262.11 which requires generators to determine whether
their unlisted solid wastes are hazardous but does not require them to
test their wastes to make this determination. The Agency believes that
these instances will be reasonably few because considerations of the
regulatory obligations attaching to hazardous wastes management will
discourage overinclusive hazardous wastes destinations. In any case, the
Agency does not believe it would be justified in eliminating the character-
istics merely to avoid the excessive designation of hazardous
I/ The cost of testing for all four characteristics is estimated to be less
~~ than $1,000 (based on cost estimates by commercial laboratories) and,
in many instances, the cost will be less because the generator can
safely assume that his wastes do not possess some of the characteristics;
e.g., the ignitability and reactivity characteristics. Sampling expenses
will vary, but also deemed to be reasonable since generators ordinarily
will use their own personnel to gather samples.
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wastes by some small and medium generators. The quantities of the wastes that
might be "ovefdesignated" as hazardous wastes will be small because of the small
size of these generators. As a result, the additional costs and the impact on
available disposal capacity will be modest, but the human health and environ-
mental impacts could be significant.
The Agency disagrees with commenters who contended that hazardous waste
should only be listed against established characteristics.J/ It agrees that
hazardous waste must be listed against criteria for listing (established in
§261.11) and may be listed against characteristics (in which case the
criteria for listing will provide for listing against characteristics).
Section 3001(b) of the statute is auite explicit on the point that listing
must be based on the criteria for listing required to be established under
Section 3001(a>.
The Agency is not unsympathetic to the concerns that probably lie
behind the comments urging the listing of hazardous wastes only against
characteristics; that concern being that the proposed criterion for listing
(see §250.12(b)(2) of the Proposed Rules) was not very specific. In the absence
of -specific listing criteria in the Proposed Rules, the commenters quite
naturally saw the need for characteristics which essentially would provide
the missing criteria. The Agency has addressed this concern by substantially -
expanding the final criteria for listing (see §261.11 of the Final Rules).
This expansion is discussed subsequently in this document.
I/ Where "characteristics" have the very specific and narrowly drawn meaning
~~ described on pp. 2 and 3.
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Finally, the Agency recognizes that the regulatory strategy, in limiting
the utilization of the identification mechanisms to the four characteristics
established in the Final Rules and relying on the listing mechanism to
bring all other wastes into the system, is in partial disagreement with
. those commenters who urged, for environmental reasons, broad use of the
identification mechanism to cover hazardous waste for which the Agency now
or in the future may not have sufficient information to list. This is the
result of the balancing of two contradictory objectives: achieving broad
coverage and keeping the burden of the identification mechanism on generators
within attainable bounds. This has been a difficult balance for the Agency
to make, but it believes it has achieved a reasonable result. Even so, the
Agency is cognizant that the coverage of hazardous waste by the initial
listing contained in the Final Rules is incomplete. To rectify this
situation, the Agency intends to pursue a dedicated effort over the ensuing
years to more completely characterize the solid wastes generated by industry
and, through this, list additional hazardous wastes in future revisions of
the Final Rules. With the initiation of this effort in FY 1980 and its
planned funding for FY 1981 and FY 1982, the Agency will make a maior
effort to correct the short-comings in the initial listing.
Criteria for Identifying Characteristics. Only a few comments were
received on the criteria for identifying characteristics (§250.12(a) of the
Proposed Rules). One comment urged that site-specific or management-
specific considerations be incorporated in the criteria as well as the
characteristics in order to implement the "when improperly....managed"
clause of the statutory definition of hazardous waste. The Agency agrees
that possible and plausible scenarios of improper management should be
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considered both in establishing characteristics and in listing hazardous
wastes. To assure such consideration, it has explicitly added the statutory
language, including the phrase "when...improperly managed", in the criteria
for establishing characteristics (see S26l.lO(a)(l)(ii) of the Final
Rules). However, EPA strongly believes that the initial determination of
whether a waste is hazardous is not made on a site-specific basis (indeed,
the statutory definition of hazardous waste seem conclusive on this point),
so that site-specific and management-specific factors are not included in
either the criteria or the characteristic. Furthermore, it is obviously
impossible to incorporate actual site-specific or management-specific
considerations in the characteristics or listed wastes without developing
separate, individual characteristics or listing criteria for each of the
many thousands of wastes. Such considerations are properly left to the
issuance of permits for individual treatment, storage and disposal facilities
and this, in fact, is provided for in Parts 264, 265 and 122 of the regulations.
Another comment contended that the criteria and characteristics should
account for persistence and degrada'bility in nature.
The Agency agrees that the properties of persistence and degradation^'
should be considered, where appropriate,.in identifying characteristics of
hazardous waste. The Agency, in fact, did consider the properties of persistence
and degradation in establishing the four characteristics of ignitability,
corrosivity, reactivity and E? toxicity. However, it turns out that these
I/ Persistence and non-degradation are synonymous but are used together to
~ reflect the wording of the Act.
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properties do not play a raaior role in these characteristics. The first three
of these characteristics principally address properties of waste that may
cause hazards in the initial management of a waste; therefore, persistence and
degradation are not believed to be significant factors. In addition, the
properties (e.g., flash point, oxidizing potential and pH) of these characteristics
do not depend on degradable constituents and therefore their persistence does not
change. In the EP toxicity characteristic, the hazardous constituents are
either highly persistent, non-readily degradable pesticides or non-degradable
persistent heavy metals.
Several commenters urged that the criteria allow for two classifications
of hazardous wastes: very hazardous and less hazardous wastes. One such
commenter suggested that this distinction be based on the distinction
between paragraphs (A) and (B) of the statutory definition of hazardous
waste. The Final 'Rules (5261.11) provide criteria for listing which distinguish
between extremely hazardous waste and less (but still substantially) hazardous
waste. Section 261.11(a)(2) provides the listing criterion for the former, while
§261.11(a)(3) provides for the latter. The Final Rules do not, however,
make such a distinction in the criteria for characteristics or in the
characteristics themselves, because the Agency has not determined how this
can be accomplished and, as discussed in another background document,
the Agency does not feel that such a distinction adds much to the regulatory
scheme created by the regulations. In a sense, the characteristic for
reactivity defines extremely hazardous properties that comport with paragraph
(A) of the statutory definition of hazardous waste and, in some regards,
the characteristic of ignitability defines very hazardous properties.
Consequently, some distinction between extreme and lesser hazardness is
implicitly incorporated in the final characteristics.
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A few cotnmenters objected to the use of poorly documented and
unrepresentative damage cases in EPA's files as the basis for the criteria
and characteristics. Another commenter obiected to the reliance on regulations
of other agencies as the basis for criteria and characteristics because
such regulations are not necessarily designed for environmental protection
and therefore are not necessarily transferable. These comments on the use
of damage cases and reliance on regulations of other agencies were in
reference to a statement made in the preamble of the Proposed Rules (43 Fed.
Reg. 243 at 58950) to the effect that these factors were used in developing
a candidate set of characteristics.
The Agencv believes that the cotnmenters misunderstood the Agency's use
of information from damage cases and its use of regulations of other agencies
in establishing both criteria for characteristics and the characteristics. The
Agency used these factors as "points of departure" in initially identifying
candidate criteria and characteristics. Ultimately, however, the Agency
based.its development of criteria and characteristics primarily on relevant
scientific and technical information and principles. However, data from
damage cases have been used as secondary and supporting information where
they are relevant. Regulations of other agencies also have been similarly
used.
One commenter felt that test procedures should be validated for precision
and accuracy before being used for regulatory purposes. This is also the policy
of the Agency, as discussed earlier in this document, and as discussed in more
detail in the Background Documents supporting the individual characteristics.
All tests employed in the characteristics of hazardous waste have been standardized
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or validated either by the Agency or other regulatory or standard-setting
organization (e.g., the ASTM in the case of flash point). Standardization
and validation of the Extraction Procedure has been completed since its
proposal. This is more fully described in the Background Document for the
EP toxicity characteristic and has, in part, been discussed in several
studies which were made available, for public comment, since proposed
rulemaking.
Finally, one coramenter suggested that the criterion of "available" -test
protocols be expanded to reflect currently commercially available analytical •
methodology approved and disseminated by EPA. The Agency agrees that the
criteria for characteristics should specify that test protocols be commercially
available. It believes that point had been clearly expressed in the proposed
rules. In order to further clarify this point, however, the final criteria
for characteristics have bee-n--modified to specify that test protocols must be
"reasonably within the performance capability and capacity of generators...
or private-sector laboratories that are available to serve generators..."
(see §261.10(a) (2)(i) of the Final Rules). With respect to the comment
that test methods should be approved and disseminated by EPA, the Agency
believes that prescription of a test protocol in the Final Rules constitutes
EPA approval and that descriptions of the test protocol in the Final
Rules, where they are not widely available in published literature, constitutes
adequate dissemination.
Other than the changes mentioned above in response to comments, the
final criteria for identifying characteristics have not been substantially
changed from those proposed. It has been edited, however, to provide clearer
exposition.
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Comments on Criteria for Listing. A large number of commenters found
o
the proposed criteria for listing hazardous wastes for which characteristics
had not been established (§250.12(b)(2)) to be insufficient. Their arguments
were many and varied. Many felt that the mere articulation of the statutory
definition did not constitute establishment of the criteria required by
Section 3001(a) of the Act. They contended that this approach was circular
(a waste is a hazardous waste if it meets the definition of a hazardous
waste) and was vague and non-specific. They felt that it constituted an
abrogation of a.non-discretionary duty under Section 3001(a) of the Act
to establish criteria that do not expand on and further quantify the
definition of hazardous wastes given in the Act. They argued that the real
criteria appeared tc be those characteristics presented in the Advance
Notice of Proposed Rulemaking (ANPR—concurrently published with the proposed
rules on December 18, 1978). As such, they contended that'EPA was proposing
to list hazardous wastes against criteria that had not been proposed and
criteria that, in fact, were quite tentative by virtue of their publication
in pre-proposal form in an ANPR. They found the criteria, when combined
with the characteristic-like delisting rules (5250.15(a)), to be a capricious
double standard, allowing EPA to'assume a vague, ill-defined and perceivably
light burden in listing wastes (apparently not using the delisting test
protocols to support the listing of wastes) while requiring the regulated
community to undertake a greater and inflexible burden of specific and
sophisticated testing to delist such wastes. One commenter equated this
approach to being declared guilty until proven innocent. These commenters
felt that EPA should be held to the same rules for listing as required for
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delisting. In summary, these commenters felt that EPA should not and
legally could not list hazardous wastes against the proposed §250.12(b)(2)
criteria unless or until these criteria were expanded and converted into
highly specific characteristic-like criteria.
The Agency agrees that the proposed criterion for listing wastes for
which no characteristics had been established was not explicit and it agrees
that Section 3001(a) of RCRA clearly requires the Agency to establish specific
criteria for listing hazardous wastes. Accordingly, the Agency has established
a more specific and expanded set of listing criteria in $261.11 and these
are discussed below. Because these criteria have been extensively expanded
over the proposed listing criteria, they are being promulgated as Interim
Final Rules and public comments are being invited on them. It is the
Agency's intent to review and_,consider any public comments received and to
promulgate §261-11 as a Final Rule, with any appropriate changes justified by
public comments, by or before the effective date of Part 261.
The Agency admits that the implied criteria for listing wastes because of
organic toxicity, genetic activity, bioaccumulation potential and radioactivity
were largely the characteristics presented in the ANPR (however, other factors
outside of these characteristics were also considered in the listing of these
wastes). After consideration of the comments received on the ANPR and the
Proposed Rules, and after considerable reassessment of the whole matter of
listing criteria, the Agency has concluded that the characteristics presented
in the ANPR are not sufficient either as characteristics or as criteria for
listing. First, as currently constructed and presented in the ANPR, they fail
to incorporate all of the multiple factors necessary to characterize the
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hazardousness of wastes for the purpose of regulation under Subtitle C.
This failing is seen in the subsequent discussion on the interim final
listing criteria where multiple factors are incorporated therein. Secondly,
with respect to their use as characteristics, most of the ANPR characteristics
depended on testing methods that are not yet fully standardized and validated
for wide use by a diverse regulated community or are not all widely used
by or available to the regulatory community. Although the Agency intends
to further develop and perfect the ANPR characteristics, it has concluded
that they are not now sufficiently complete and sufficient for broad use
as characteristics or as unaugmented criteria for listing.
A large number of commenters were more specific in pointing out the short-
comings of the proposed §250.12(b)(2) criteria or, alternatively, pointing
to the specific provisions that should be incorporated in that criteria.
Several found that the criteria gave no consideration to quantity and/or
concentration. Others found it deficient in the consideration of synergistic
effects, degradation potentials and degree of toxicity combined with potential
exposure. Some believed that the criteria should account for typical or
probable management practices and, in this same vein, one commenter thought
that the criteria should consider the management aspects of commingling of
incompatible wastes.
The Agency concurs with the comments that urged that the criteria for
listing hazardous waste where an explicit characteristic has not been •
established, must consider multiple factors including quantity, concentration,
degree and nature of toxicity, persistence, degradation, and possible and
plausible improper management practices. The Agency recognizes that the
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proposed criteria for listing hazardous waste did not specifically provide for
consideration of multiple factors; however, it did not preclude their considera-
tion.
The Agency does not agree that the criteria for listing can or should
explicitly consider synergistic effects or the commingling of incompatible
wastes. These factors are very site specific and the Agency has concluded that
they are best considered in the management standards under Parts 264 and 265
and in the issuing of hazardous waste management facility permits under
Part 122.
A few commenters believed that the criteria should be structured so as to
avoid listing wastes that would be adequately managed in facilities meeting the
guidelines promulgated under Subtitle D of the Act. The Agency does not agree
with this comment and the reasons are discussed in the following section in
relation to the statutory mandate to employ a criterion of "improper management"
in listing wastes.
A few believed that the criteria should account for small quantities; some
of these contending that the criteria should provide coverage of all small
quantities of very hazardous wastes and others contending that it should serve
to exclude small quantities. One commenter was concerned about the inclusion of
small quantities of municipal wastes. The Agency has given considerable attention
to the regulation of small quantities and these are discussed in a separate
background document covering the applicability of the Final Rules to small quantity
generators (also see §261.5 of the Final Rules). Coverage of municipal wastes
(household wastes) is discussed in the preamble to Part 261-
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The Agency agrees with most of these comments, and these comments,
have resulted in a re-development of the criteria for delisting. These
substantive delisting criteria are found in §§260.22(c)(d) and (e) and are
being promulgated as Interim Final Rules because their counterpart criteria
for listing hazardous wastes are being promulgated as Interim Final Rules.
The substantive delisting criteria are, very simply, the inverse of the
listing criteria of §261.11. For those wastes listed because they exhibit any
of the characteristics of hazardous waste, the criterion for delisting is to
demonstrate that the waste from an individual facility does not exhibit the '
characteristic which caused the Agency to list the waste (see §260.22(c)
of the Interim Final Rule). For those wastes listed because they meet the
listing criterion of §261.11(a)(2)—Acutely Hazardous Wastes'having the
Hazard Code "H"—the delisting criterion (see §260.22(e» is to show that the
waste does not meet the listing criterion of §261.11(a)(2)—that is, that it
is not acutely toxic—and that it does not meet the criterion of §261.11(a)(3)
when considering the factors listed therein. The latter showing is necessary
because, even though a waste may be found not to be acutely hazardous in
accordance with §261.11(a)(2), it may still be less acutely toxic or chronically
toxic in accordance with §261.11(a)(3). When the Agency lists a waste
under §261.11(a)(2), it presumes that the waste also meets §261-ll(a)(3).
Finally, for wastes listed because they meet the listing criterion of
§261.ll(a)(3)—Toxic Wastes having the Hazard Code "T"—the delisting criterion
(see §260.22(d)) is to show that the waste either does not have the hazardous
constituent(s) that caused the Agency to list the waste or that consideration
of the factors listed in §261.11(a)(3) argue against listing the waste as a
hazardous waste.
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The basic rationale for these delisting criteria is the same as that of
the Proposed Rule in the sense that delisting is a means of showing that an
individual generator's waste is fundamentally different from the class or
type of hazardous waste listed and therefore should not be listed. In fact,
the delisting procedure is actually put in the form of a rulemaking procedure.
Thus, delisting petitions will be treated as rulemaking and a successful petition
will result in an actual modification of the listing description; e.g., Subpart D
would be modified to show that the listing is no longer "waste A from process B"
but instead "waste A from process B except those wastes generated by the XYZ
plant."
The rationale for the substantive, criteria, however, has changed significantly
from that employed in the Proposed Rule. The interim final criteria are no
longer based on specified testing^' but, as stated above, are based instead on
a showing against the same considerations that went into the listing of a
waste. This change has been necessitated by the changes made in the criteria
for listing. The Agency reasoned that persons who petition for delisting
a waste, should be held to the same showing that the Agency made in listing
the waste and should not be held to a specific testing regime that may or
may not have been used in listing the waste. Accordingly, delisting petitions
should show why and how the factors considered by EPA in listing a waste do
not apply to the individual waste for which delisting is requested. For each
I/ Except in the case of delisting wastes that are listed because of characteristics.
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waste, the showing for delisting will vary because the factors considered in
listing each waste varies.
The Agency believes that the delisting criteria are fully consistent
with the listing criteria and are appropriate arid equitable in the sense
of requiring consideration of the same factors that went into the initial
listing determination. The Agency believes that these features meet the
concerns of most of the commenters.
Many comments were received on the procedural aspects of delisting. These
have been carefully considered and are discussed in Section VII C of the preamble
to Part 261. Consideration of these comments and the Agency's own reconsideration
of the Proposed Rule have led to restructuring and modifications which are
reflected in §§260.20 and 260.22, and are also discussed in the preamble
to Part 261.
A fair number of commenters were concerned about the inadequacy or pot-
ential inadequacy of disposal capacity and argued that the criteria should
operate to list only the most hazardous wastes and avoid listing the less
hazardous and certainly the non-rhazardous wastes to avoid exceeding a
limited disposal capacity throughout many parts of the country. In a
variant on this theme, one commenter thought that the identification and
listing of wastes under Section 3001 of the Act (and even the generator
requirements under Section 3002) should be deferred until after the management
requirements of Section 3004 are promulgated and well in place. These
issues are discussed in the preamble to Part 261. In brief, the Agency
does not have the statutory authority to avoid listing wastes because of
potential disposal incapacity. It can, however, and does intend to consider
capacity problems in its implementation of the regulations and in the
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scheduling and issuing of permits.
Several commenters expressed concern about the stigma that would
attach to hazardous wastes and believed that the criteria should take this
factor into account, particularly with respect to wastes that have re-use
or recycling potential. These commenters contended that the stigma of the
hazardous waste label would serve to dissuade the beneficial re-use or
recycling of many marginally hazardous wastes which were listed. The
B
issue of regulating hazardous wastes that are re-used or recycled, including
the subsidiary stigma issue, is fully discussed in the preamble to Part 261.
Several commenters were concerned that the listing of classes or types
of waste could encompass non-hazardous members of the class (wastes that are
fundamentally different than other members of the listed class of wastes).
These commenters believed that the criteria should consider this aspect of
listing. This is discussed in the following section.
Finally, one commenter pointed out that the statutory definition of
hazardous was based on terms of "substantial....hazard" not "may cause
harm" as -stated in the preamble of the proposed rules. The Agency concurs
and has been careful to base the interim final criteria for listing on the
"substantial hazard" test of the statute (see discussion in next section).
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Reconsideration of the Criteria for Listing In consideration
of the public comments, the Agency has provided a much more expanded
set of criteria for listing hazardous waste than proposed and has
B
devoted a complete section of the Final Rules (§261.11) to these
criteria. In overview, §261.11 provides the following:
- §261.11(a)(l) provides the criterion for listing hazardous
wastes because they exhibit a-ny of the characteristics
identified in Subpart C
- §261.11(a)(2) provides the criterion for listing hazardous
wastes because they are acutely toxic or acutely hazardous
wastes and may be fatal to humans in low doses
- §261.11(a)(3) provides the criterion for listing hazardous
wastes because they contain one or more of the hazardous
•
constituents listed in Appendix VIII and may pose substantial
present or potential hazard to human health or the environ-
ment when improperly managed
- §261.11(b) provides for listing types or classes of hazard-
ous wastes as opposed to individual hazardous wastes
- §261.11(c) provides for the establishment of exclusion
limits for hazardous wastes listed i-n Subpart D, where
such exclusion limits are applicable to the special require-
ments for small quantity generators under §261.5(c)
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In addition, Appendix VIII of the Final Rules provides a list
of toxic and genetically active constituents which are employed
in the criterion for listing Toxic Wastes under $261.11(a)(3).
The three criterion of §261.11(a) all draw heavily on
the statutory definition of hazardous waste found in Section
1004(5) of RCRA. The criterion in §261.11(a)(2) is based on
part (A) of the statutory definition, and the §261.11(a)(3)
criterion is based on part (B) thereof, read in conjunction
with Section 3001. The following discussion describes the
Agency's thinking in establishing these three criteria.
1- Criteria for Listing Wastes Possessing a Characteristic
EPA's first criteria for listing is if a waste
exhibits the characteristic of ignitability, corrosivity,
reactivity, or EP Toxicity. The listing determination is
o
quite straight forward, showing whether or not the waste in
fact possesses the appropriate characteristic.
2. Criteria for Listing Wastes Which are Acutely Hazardous
This criteria implements part (A) of the statutory
definition of hazardous waste which provides that wastes are
hazardous if they "may cause, or significantly ontribute to
an increase in serious irreversible, or incapacitating
illness." The Agency believes that this language is intended
to provide the basis for wastes that are acutely toxic or
otherwise acutely hazardous and may pose a direct hazard to
human health.
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The Agency believes that part (A) of the statutory
definition was intended to cover wastes that are acutely
hazardous to human health (whereas §261.11(a)(3) addresses
wastes which may pose chronic as well as acute effects, and
may pose a substantial adverse hazard to humans and environmental
receptors other than humans). Use of terms such as "increase
in mortality", "increase in serious irreversible.. *illness"
and "increase in serious...incapacitating reversible illness"
seem to connote that the focus of this provision was on
human health. The Agency interprets these terms to apply to
acute effects as opposed to chronic effects, because long-
term chronic effects generally necessitate some consideration
of environmental fate and waste management, which are not
mentioned in the 'definition (see discussion below). Furthermore,
consideration of chronic effects are covered by part B of the
hazardous waste definition, and the Agency believes Congress
0>
intended part A of the definition to have some independent
force (see H.R. Rep. No. 94-1491, 94th Cong., 2d Sess. 25).
The Agency also believes that for this class of wastes,
environmental fate and waste management techniques are not
considerations in determining hazard. The Agency believes
that the environmental fate factors of persistence, degradation
potential and bioaccumulation potential in Section 3001(a)
have little or no importance because the language of 1004(5)(A)
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describes a type of hazard which is acute and therefore may
be operative before these factors can manifest their effects.
Moreover, the Agency believes that the factor of improper
management is not important under this element because the
language connotes a type of hazard that is capable of operating
under a wide range of management conditions from improper
conditions up to conditions that would constitute proper
management for other wastes. In fact, whereas the phrase
"improperly.. .managed" is an integral element of part (B) of
the statutory definition of hazardous wastes, the absence of
this phrase in part (A) of the definition signifies that
improper management is not an important factor.
Accordingly, the §261.ll(a)(2) criterion provides for
listing wastes that are "found to be fatal to humans in low
doses." Recognizing however, that acute effects data on
humans is limited to scattered epidemiological observation and
do not begin to cover the-chemicals and wastes that very
clearly are acutely hazardous to human, the §261.11(a)(2)
criterion provides for use of surrogate acute effects
-------
values used -- respectively, less than 50 milligrams for
kilogram, less than 2 milligrams per liter and less than 200
milligrams per kilogram — are levels that will produce
definite acute effects — increased mortality and increased
serious illness — in humans even though the data derive
from animal studies. These values are selected with reference
to values used by groups such as the Department of Transportion,
Consumer Product Safety Commission, and National Academy of
Sciences use in determining if substances are poisonous or
acutely toxic.
These surrogates serve to enable the use of the
§261-ll(a)(2) criterion to list acutely toxic wastes. The
Agency believes it is also essential to list wastes that are
acutely hazardous to humans for reasons other than acute
toxicity; e.g., wastes that are highly reactive and produce
acute hazards by virtue of their explosivity or generation of
0>
acutely hazardous vapors, or wastes containing substantial
concentrations of potent carcinogens. To reach these wastes,
the §261.11(a)(2) criterion incorporates the verbatim language
of part (A) of the statuory definition of hazardous wastes.
In the interim final listing of wastes in Subpart D, the
§261.11(a)(2) criterion has been used exclusively to list
commercial products that appear in §261.33(e). The use of
this criterion for this listing is discussed in the background
document covering §261.33. This limited use of this criterion
is not intended, however, to denote that the criterion cannot
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be used to list wastes In $$261.31 or 261.32. It merely
denotes that the Agency does not now have data that supports
the listing of generic or process wastes because of acute
hazardousness.
The effect of the §261-ll(a)(2) criterion is to create a
class of listed wastes that are clearly more immediately
hazardous than the other wastes listed. The higher class of
hazardous wastes created by the §261.11(a)(2) criterion is
reflected in two other provisions of Part 261. Under §261.5(c),
much lower exclusion limits than 1000 kilograms per month
are created for small quantity generators that produce or
accumulate wastes listed under this criterion and, under
§261.33(c), containers that have held wastes listed under
this criterion are, as a class, listed as hazardous wastes.
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3- Criteria for Listing Toxic Wastes
a. Overall Methodology In Applying the Criteria
§261.11(a)(3) of the Interim Final Rule provides the
criterion for listing Toxic Wastes, i.e., wastes that are
hazardous wastes because they contain toxic or genetically
active constituents and are not appropriately listed under
the criteria of §§261.11(a)(l) or 261.11(a)(2)._J/ This
criterion is used to list most of the hazardous wastes listed
in §§261.31 and 261.32 of Subpart D and, as such, is probably
the most important of the listing criteria. This criterion
provides that a solid waste is a hazardous waste if it contains
any of the hazardous constituents listed in Appendix VIII
unless the Agency, after considering one or more of the
factors delineated in the criterion, determines that the
waste does not meet part (B) of the statutory definition of
hazardous waste. The factors that the Agency may consider
include:
- the nature of the toxicity of the hazardous constituent
listed in Appendix VIII
_!/ Section 261.11(a)(2) provides the criterion for listing
acutely toxic and otherwise acutely hazardous wastes.
Acutely toxic wastes, therefore, are not appropriately
listed under §261.11(a)(3). Section 261.11(a)(l) provides
the criterion for listing wastes that possesses any of
the characteristics identified in Subpart C including the
characteristic of EP toxicity. A waste that possesses EP
toxicity could be listed under either §261-ll(a)(l) or §261.11(a)(3)
and, where this is the case, the Agency will use §261.11(a)(l).
However,, a waste that does not possess the characteristic of EP
toxicity and cannot be listed under §261.11(a)(l) may still be
hazardous because, as discussed in the EP Toxicity background
document and the preamble, the EP toxicity characteristic
does not necessarily encompass all those wastes which
possess hazardous concentrations of the constituents delineated
in the EP toxicity characteristic. In addition, factors other
than those taken into account by the characteristic may
justify such listing.
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- its concentration in the waste
- its potential to migrate or otherwise escape from the waste
- its persistence and potential for Segradation in the waste
- its bioaccumulation potential
- the plausible and possible types of improper management
to which the waste may be subjected
- other appropriate factors
These factors, their importance, and their application, are
discussed in more detail below.
The first consideration is whether the waste contains a
constituent listed in Appendix VIII. Appendix VIII lists 387
toxic and constituents that have been shown to have toxic,
carcinogenic, mutagenic, or teratogenic effects on humans or
other life forms and clearly "may pose substantial present or
potential hazard to human health or the environment", or
"cause or significantly contribute to an increase in mortality
or...serious...illness." Appendix VIII includes most of the
toxic constituents listed under Section 307(a) of the Clean
Water Act and many of the constituents listed under Section
311 of that Act. It also includes those constituents regulated
under section 112 of the Clean Air Act and, in addition,
covers the constituents regulated under the Primary Drinking
Water Standards of the Safe Drinking Water Act, Finally, it
includes genetically active constituents which the Agency's
Cancer Assessment Group has evaluated and determined to
present sufficient threat to human health to warrant appropriate
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regulation under the several regulatory programs managed by
the Agency and it includes the most acutely toxic substances
listed in the NIOSH^Registry or regulated by the Department
of Transportation as a transportation hazard. In short,
Appendix VIII tracks the several lists of hazardous constituents
being used by the Agency. For each constituent listed in
Appendix VIII, the Agency also has prepared a Health and
Environmental Effects Background Document-jV Each document
describes and evalutes the adverse effects of the constituent
to humans and other life forms and substantiates that the
constituent poses a substantial hazard to human health or the
21
environment.
If the waste contains one or more of the hazardous
constituents listed in Appendix VIII, the waste is presumed
to be hazardous, unless after considering other factors, EPA
concludes that the waste is not capable of posing a substantial
present or potential hazard to health or the environment
I/ These Background Documents will be made available for public
~~ comment when the Part 261 rules are promulgated. This will be
in conjunction with the invitation for public comments on the
criteria for listing (§261-11), Appendix VIII and the listing
of hazardous wastes (Subpart D) which are being promulgated
as Interim Final Rules. The Agency intends to consider any
comments received on these Interim Final Rules and the Background
Documents and to make appropriate changes in the rules, including
Appendix VIII, prior to promulgation of Final Rules for these
segments.
II The Agency recognizes that Appendix VIII is far from a
~ complete list of all hazardous constituents. It includes
only those constituents for which the Agency has sufficient
data or has been able to review the available data in order
to make listing determinations. It will be the Agency's
intent to amend Appendix VIII as it has information and ca-
pacity to do so.
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when improperly managed. Very simply, the first determination,
if affirmative, creates a presumption that the waste is a
c
hazardous waste. The second determination serves to confirm
or reject this this presumption. If the presumption is
confirmed, the Agency will list the waste as a hazardous
waste. If rejected, the Agency will not list the waste as a
hazardous waste.
The Agency believes this approach to be fully in accord
with the statutory scheme. Under section 1004(5)(B), a waste
is hazardous if it "may pose a substantial present or potential
hazard to human health or the environment when improperly
managed." (Emphasis added.) This is obviously a broad
standard which affords the Agency considerably discretion.
Thus, use of the conditional "may", reinforced by the reference
to "potential" hazard, indicates that the administrative
focus is to be on those wastes capable of causing substantial
harm. Further, wastes are hazardous if they could cause
substantial harm if managed improperly, whether or not they
are in fact handled in such a way as to minimize or obviate
the risk of danger. In the toxicity listing criteria, the
Agency therefore has focused on waste's potential capacity
for harm by identifying particular constituents which clearly
pose substantial hazard to human health or the environment.
It is reasonable to suspect or presume that any waste that
contain any of these substances may pose substantial hazard.
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There is ample evidence that the hazardous constituents
contained in wastes often can migrate or otherwise escape
from the waste and enter into the environment where they can
pose a substantial hazard. Further, there is ample evidence
that wastes often are improperly managed and, when so managed,
the migration or escape of hazardous constituents into the
I/
environment is highly probable.
As noted, once it is determined that a waste contains
one or more of the Appendix VIII constituents, it will be
presumed to be hazardous unless, often considering certain
designated factors listed in 261.11(a)(3)(i) - (xi), EPA
determines that it does not meet the definitions of hazardous
waste in Section 1004(5)(B). The specific factors (discussed
in detail below) are drawn from Sections 1004(4) and 3001 of
the Act, or are otherwise deemed probative to the issue of
hazardousness. Congress in fact directed the Agency to
consider multiple factors when listing as hazardous any waste
not found to be "hazardous per se" (in the Agency's
interpretation, not meeting the criteria of §261.11(a)(2)):
The listing of any substance not found to be hazardous
per se should be accompanied by an explanation as to when
such wastes are considered hazardous. Such explanation should
relate to the quantity, concentration,...toxicity, persistence
and degradability in nature, potential for accumulation in
human tissue and other factors..." (H.R. Rep. 94-1491 at 25).
I/A further advantage to the Agency's approach is that it
effectively alerts the interested public to the wastes the
Agency is considering listing, and thus provides an opportunity
to the public to make appropriate plans.
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It should also be mentioned that the companion Senate
bill to RCRA contained a scheme very close to the present
§261.11(a)(3). It provided that at a minimum the Administrator
should designate as hazardous each mixture of solid waste
which contained a toxic or hazardous substance listed in
section 112 of the Clean Water Act or sections 307(a) and
section 311(b) of the Clean Water Act unless consideration of
listing criteria indicated the waste was not hazardous.
S.Rep. No. 94-988, 94th Cong., 2d sess. 14. The Senate bill
thus envisioned a presumption for listing based on the presence
of a toxic constituent, which presumption may be rebutted by
consideration of further factors. Although this bill was not
ultimately adopted, the concept was never rejected, and
again suggests that the Ageny's overall listing methodology
reflects congressional intent.
b. Discussion of Factors to be Considered in Determining
the Validity of the Presumption of Hazardousness Based
on Presence of an Appendix VIII Constituent.
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§261.11(a)(3) requires consideration of the following
factors before a final listing determination is made:
— The nature of the toxicity presented by the
constituent.
— The concentration of the constituent in the waste;
— The potential of the constituent or any toxic
degradation product of the constituent to migrate from the
waste into the environment under the types of improper
management considered.
— The persistence of the constituent or any toxic
degradation product of the constituent;
— The potential for the constituent or any toxic
degradation product of the constituent to degrade into non-
harmful constituents and the rate of degradation;
—• The degree to which the constituent or any degradation
product of the constituent bioaccumulates in ecosystems;
— The plausible types of improper management to which
the waste could be subjected;
— The quantities of the waste generated at individual
generation sites or on a regional or national basis;
— The nature and severity of the human health and
environmental damage that has occurred as a result of the
improper management of wastes containing the constituent;
— Actions taken by other governmental agencies or
regulatory programs based on the health or environmental
hazard posed by the waste or waste constituent.
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— Such.other factors as may be appropriate.
These factors generally involve the waste's inherent
potential for causing harm (the nature of the toxicity
presented by the constituent(s) of concern, and whether the
constituent(s) is present in significant concentrations, and
whether the waste is generated in large quantities and the
environmental fate and transport mechanisms to which waste
constituents are subject (whether waste constituents may
migrate from the waste if improper management occurs, persist
in the environment, and reach environmental receptors so as
to pose a potential substantial hazard). In certain cases,
actual damage incidents involving the waste or waste constituents
demonstrate empirically that waste constituents may migrate,
persist, and cause substantial harm if mismanaged.
As explained more fully in the preamble to the Section
3001 regulations, in weighing these various factors, the
Agency's principal focus is on the identity of and nature of
toxicity of the waste's constituents, and whether the
constituents are present in significant concentrations; in
other words, on the waste's potential capacity to cause harm.
This approach, as already noted, is justified by the conditional
wording of the hazardous waste definition, which commands
implicitly that the listing mechanism be aggressive enough to
bring into the hazardous waste management system any waste
that might pose a substantial potential hazard if mismanaged.
Environmental fate and transport issues are certainly relevant
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in determining whether substantial hazard could result
from waste mismanagement. The Agency does not, however, seek
to demonstrate that waste constituents will migrate and
persist in sufficient concentrations to cause substantial
hazard. Instead, fate and transport information is considered
to determine if the potential for harm inherent in the waste
by virtue of its composition will not eventuate. There thus
must be fairly strong assurance that mismanaged waste
constituents will not migrate and persist to cause substantial
hazard before the Agency will choose not to list a waste on
this basis. The degree of assurance required also increases
as the relative toxicity of waste constituents increases, or
as waste constituents comprise a higher percentage of the
I/
total waste.
The following discussion explains in more detail the
relevance of the particular factors used in determining
whether the listing presumption (based on the presence of
Appendix VIII constituents) is valid. The nature of the
toxicity of the waste constituent(s) is clearly important*
The more dangerous the waste constituent, the likelier the
Agency is to list the waste. Carcinogens are of special
concern, since one single exposure may result in substantial
hazard. (See EPA Water Quality Criteria, 44 FR 15926, 15930
(March 15, 1979)).
_l/Needless to say, the relative balancing of these factors
~ varies with each waste, as explained in the background
documents covering each individual listing determination.
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The concentration of the hazardous constituent in the waste
is an important factor. Obviously, higher concentrations enhance
the possibility that the constituent will pose substantial hazard.
The potential for the hazardous constituent to migrate or
otherwise escape from the waste and enter into the environment
is an important factor. By and large, hazardous constituents
that do not migrate from the waste do not cause hazardous
effects because direct exposure of humans and other life
forms to wastes is limited.2/ For example, humans rarely do
directly ingest, inhale or otherwise come into intimate
contact with the waste to suffer the consequences of the
toxic effects of its constituents. For the most part, the
concern about the waste is the migration of the hazardous
constituents into groundwaters, surface waters or air where
human or other life-form exposure can take place. Accordingly,
the migratory potential of waste constituents via each
realistically - occurring exposure pathway must be considered.
Migration and transport mechanisms include solubilization
of the hazardous constituents in aqueous solutions and the
2/ This Is not always the case. Occasionally, humans and other
~ life forms are directly exposed to wastes containing hazardous
constituents and the toxic effects of the constituents are
direct. Some real examples are where the waste is inadvertently
mixed with human or animal foods, where hazardous waste containers
are re-used for a variety of purposes and where children, workmen
and animals come into direct contact with the wastes, usually
unknowingly (children and animals at Love Canal) or accidently
(personnel handling the waste).
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attendant leaching of these constituents into groundwaters or
draining into surface waters; the volatilization or sublimation
of these constituents and the attendant migration into the
atmosphere; the incomplete thermal destruction of the hazardous
constituents when the waste is burned and the attendant escape
of these constituents into the atmosphere. In addition, migratory
potential of the toxic degradation products of waste constituents
(if formed) also must be considered, since the migration or
escape of these by-products into the environment can be as
important as the migration or escape of the parent hazardous
constituent.
The persistence, or alternatively, the degradation potential
of the hazardous const'ituent(s) also is important. Obviously,
the hazardousness of a hazardous constituent is of much less
concern if it rapidly degrades in the waste or in the environment,
since the likelihood of exposure is reduced. There are some
organic constituents which degrade rapidly in water, (in
hours, days or weeks), while at the other end of the spectrum,
there are constituents that degrade very slowly or do not
degrade at all (e.g., toxic heavy metals) and therefore are
highly persistent. Clearly, the hazardousness of a persistent
hazardous constituent is enhanced because there exists a
longer opportunity to migrate to a receptor (a human or
animal). Again, as above, the persistence or degradation
potential of not only the hazardous constituent itself but also
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the degradation by-products thereof can be of concern. For example,
the parent hazardous constituent can be thermally destroyed at
a given set of burning conditions (temperature, dwell time, etc.)
but create highly toxic daughter products that escape into the
atmosphere and pose substantial hazard to human health or the
environment.
The potential for bioaccumulation can be an important factor.
Frequently, the toxic effect of a hazardous constituent is signifi-
cantly magnified (as much as several thousand-fold) through accumu-
lation through the food chain so that the ultimate receptor
(usually humans or food fish or animals) are subjected to very
high constituent concentrations. The effects of PCB's, for
example, are manifested largely because of bioaccumulation.
Similarly, the hazardous constituent might bioaccumulate in
the final receptor from low level exposure over a period of
time. For example, cadmium can be accumulated in humans
over a life-time of exposure to ultimately cause an injurious
effect.
The various combinations of these factors also are important.
A high concentration of a moderately toxic constituent may cause
a waste to pose a substantial hazard. On the other hand, a low
concentration of a highly toxic constituent may cause the waste
to have such an effect. Other combinations may cause the Agency
to reach a conclusion that confirms the presumption of hazardousness.
These include but are not limited to: moderate to weak toxicity
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and low concentrations but high persistency or high potential to
bioaccumulate or both; moderate to weak toxicity but high concentra-
tion, high migration potential or high persistency; and low concen-
trations, but strong toxicity, high migration potential, high
persistency or high bioaccumulation potential. In short, there
are many combinations of the above discussed factors that influence
the hazardous potential of a waste that contains any of the hazardous
constituents listed in Appendix VIII.
In addition to the foregoing, the factors of quantity of waste
and plausible and possible types of improper management to which
the waste may be subjected are important. Obviously, higher
quantities of wastes have the potential of releasing greater
amounts of hazardous constituents (assuming that the constituents
are capable of migrating from the waste), and thereby
contaminating larger expanses of groundwater, increasing
exposure and risk. Concern, however, is not confined to the
quantities of wastes generated at individual facilities.' In
some' cases, the aggregate quantities of wastes generated
•nationwide or in individual areas of the country may be
important. Also, the aggregate quantities of different wastes
containing the same hazardous constituents may be of concern.
For example, the individual small quantities of degreasing
solvents may not, as individual quantities, pose a substantial
hazard, but the large aggregate national quantity and the
large quantities generated in metropolitan areas present a
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significant insult to air quality and contribute to substantial
human health hazard.
Similarly, individual quantities of wastes may not pose a
o
substantial hazard when disposed of separately, but do pose a
substantial hazard when aggregated at a particular disposal
site.
The improper management to which a waste may be subjected
is often a very influential factor in defining the hazardousness
of the waste. The statute of course mandates that improper
management is a factor in listing (and identifying characteristics
of) hazardous waste (except for very hazardous wastes listed
under part (A) of the statutory definition of hazardous
waste). The Agency also recognizes that it must be reasonable
in selecting the standard; the statue requires that the
potential hazard posed by the waste be substantial before a
waste is hazardous. Hazardous arising from wholly unrealistic
or improbable waste management, in the Agency's view, are not
substantial.
In exercising its discretion, therefore, the Agency
concludes that considerations of improper management should
be limited to plausibly or possible - occurring mismanagement.
Furthermore, there is no single standard of improper management;
rather a scenario of improper management has to be developed
for each waste, based upon the types of management the waste
could normally undergo. Thus, for a waste which is typically
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land disposed, a scenario of improper land disposal should be
used; that is, a scenario that assumes little protection of
groundwater or surface water contamination from the leaching
or drainage o£ hazardous constituents from the waste. For a
waste which is capable of being disposed by burning, a scenario
of improper burning should be employed, a scenario that is
based on comparatively low burning temperatures, dwell times
and other conditions and is based on little or no 'air emission
control. For a waste that might manifest its hazardous
properties in transportation or storage, a scenario of improper
packaging or containerizing and inadequate labeling should be
assumed. In all cases, the scenario should be one that is
reasonably possible and plausible, not one that very rarely
would occur or is otherwisftunrealistic.
It must be emphasized that the fact that a waste is
properly managed by particular generators or particular
classes of generators does not make the waste non-hazardous,
as the statute requires the determination of hazardousness to
consider potential dangers when improper management occurs.
The Agency is quite aware of the fact that whether or not a
waste may pose a substantial hazard depends heavily on how it
is handled or managed. Undoubtedly, many of the wastes listed
in Subpart D under the criteria for listing are sometimes
managed in a manner that alleviates or even eliminates their
hazardous risk. However, there is no guarantee that this
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always is or will be the case and, in fact, there is ample
evidence in recorded damage cases that it frequently is not
the case. Consequently, the Agency believes that the statute
mandates the listing of wastes against management scenarios
that would result in the greatest hazardous risk, provided,
of course, that such scenarios are not artificial or unrealistic
and are reasonably plausible and possible for the given type
of waste.
Additional Considerations
The Agency recognizes that there will be those who
might wish to have the Agency use the criterion in a very broad
or very narrow way, as will fit their particular interests. At
one end of the spectrum, there will be those who will expect the
Agency to exhaustively consider all possible factors to test the
presumption of hazardousness and further, to reject the presumption
on the slightest negative finding from any of the factors. At the
other end of the spectrum, there will be those who will expect or
will petition the Agency to Initiate listing of a waste that
has the slightest potential of containing any of the hazardous
constituents listed in Appendix VIII and, further, to maintain
the presumption and list the waste in the absence of data necessary
to reasonably consider the potentially relevant factors. The Agency
believes that both expectations would overreach the wise and reason-
able use of the criterion. It believes, on one hand, that an
exhautive consideration of all possible factors will rarely
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be necessary. Instead, consideration of only those factors that
reasonably can be expected to support or challenge the presumption
is sufficient. It believes, on the other hand, that the public
interest will not be well served by the listing of wastes on
presumptions only, with little or no consideration of other
factors. Many wastes contain one or more of the hazardous
constituents listed in Appendix VIII but do not pose substantial
hazard because of the low concentration or the low quantity
of the waste or because of other factors or combinations
thereof. Consequently, the Agency intends to use the §261.11(a)(3)
criterion with considerable discretion to avoid abusive use.
Finally, the §261.11 (a)(3) criterion may be used to list
wastes that contain any of the toxic metals or pesticides listed in
Table 1 of the EP toxicity characteristic (§261.24) but which do
not fail that' characteristic and so cannot be listed under
§261.11(a)(l). The EP toxicity characteristic is based on
the concentration of any of these constituents in the extract
of the waste exceeding 100 times the maximum concentration
limits in the Primary Drinking Water Standards (PDWS). As
such, this characteristic identifies wastes that have the
capacity to release high concentrations of persistent hazardous
constituents I/ into the groundwater under a plausible scenario
If The toxic metals do not degrade and therefore are persistent,
~ The toxic pesticides degrade very slowly and therefore
are highly persistent.
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of improper land disposal. The EP toxicity characteristic
serves to identify only the most hazardous of those wastes
that are hazardous because of their content of PDWS contami-
nants, since the characteristic is binding (i.e., a generator
either passes or fails the test), so that there is some risk
of over inclusiton if the test is too rigorous. The listing
criterion of §261.11(a)(3) therefore is used to identify the
remaining subset of those wastes, i.e., wastes, which after
individualized consideration are shown to pose a substantial
potential hazard if improperly managed, even though the EP
extract of the waste contains less than 100 times the PDWS
contaminants. When listing one of these wastes, the Agency
usually identifies factors not measured by the EP Toxicity
Characteristic which justify the listing, Including the
concentration of PDWS contaminants in the waste (as opposed
to the waste extract), quantity of waste generated, damage
incidents involving the waste, or indicia of actual waste
mismanagement. Other factors are attenuative exposure pathways
for the waste, such as exposure via surface water or air,
scenarios of improper management, such as improper land
treatment or land disposal where food crops are or may be
grown, or improper burning. In the case of the first of
these examples, lesser concentrations of the toxic constituents
than defined by the EP toxicity characteristic may be
sufficient to contaminate soils and permit food crop uptake
of significant amounts of some of the toxic metals, such as
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cadmium or lead, and thus pose a substantial hazard to human health
through consumption of the contaminated food crop. In the case
of burning, lesser concentrations than defined by the EP toxicity
characteristic may result in significant atmosphere emission of
the toxic metals that may pose substantial hazard to human health
through inhalation where wastes may be plausibly mismanaged.
4. Listing of Classes or Types of Wastes
§261.11(b) of the Final Rules provides for listing of classes
or types of waste, so-called generic listings, which encompass
wastes generated in the production of a variety of products.
It is the intent of the Agency to use this criterion primarily
to list classes or types of wastes where the Agency determines
that there is a high likelihood that most members of the
class or type of waste are hazardous pursuant to the criteria.
The legal justification for this approach is set out in the
preamble to the Section 3001 rules. As with listings of
wastes generated during production of particular products,
the delisting mechanisms allows individual generators to show
that their wastes are not hazardous.
It should also be noted that even where waste listings
encompass only wastes from the production of a single product,
the Agency typically will list a class or type of waste
based on information from representative individual facilities
within the class or type, and obiously not on information
from all facilities generating the waste. Thus, even these
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non-generic listings in a sense involve listing of classes or
types of wastes. Again, the delisting mechanism is available to
individual generators if their waste differs fundamentally from
that described in the listing document.
5. Criteria for Listing and Small Generator Exclusion Limits
§261.11(c) provides for use of the listing requirements to
establish, in §261.5(c), exclusion limits for specific hazardous
wastes listed in Subpart D. The exclusion limits set forth in
§261-5(c) apply to small quantity generators. Where the Agency
believes that the general exclusion limits of 1000 kilograms per
month is insufficient to protect human health or the environment
with respect to certain wastes, it will set lower exclusion limits
for such wastes. The considerations that go into the establishment
of such exclusion limits are the same as those which go into a
determination to list a hazardous waste. Consequently, the Agency
reasoned that the same criteria could and should be used for both
purposes. In effect, §261-11(c) only applies to the use of the
criteria of §§261.11(a)(2) and 261-ll(a)(3).
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Delisting Procedures. Many ccmmenters found the delisting requirements
of §250.15(a) deficient. Many of these ccntuents were similar to, linked
to or flowed out of the Garments summarized above under Comments on Criteria
for Listing. Many contended that these requirements were vague, unworkable
and infeasible, but specific reasons for or examples of these remarks were
not given. Many found the requirements, particularly the test protocols,
to be too burdensome on generators and beyond the performance capacity of
many of them, particularly small generators. Sane of these carmenters
called for elimination of these requirements. EPA presumes that these
connenters would find the same problems, if not more problems, with the
imposition of characteristics to cover unlisted wastes, given that such
characteristics would impose involuntary testing requirements on the regulated
coTEiunity. Other carmenters contended that the delisting requirements
were too inflexible because delisting demonstrations could only use the
limited number and types of tests specified by the requirements. These
cctTtnenters argued for allowing other tests or submission of other (equivalent)
information to support delisting. Some of these conmenters pointed out
that multiple factors and considerations, including consideration on how
the waste is actually managed, govern the hazardousness of wastes and
therefore should be considered in delisting. They contended that the
proposed delisting requirements did not allow for consideration of multiple
factors. These Garments augmented those summarized above which pointed to
deficiency in the listing criteria relative to nultiple factors. Many
comienters found the delisting requirements and particularly the test
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protocols to be preliminary, evaluated and inappropriate because (1) EPA
did not have sufficient confidence in them to propose them as listing
criteria or characteristics, (2) EPA declared them (the* test protocols, at
least) to be unreliable in the preamble of the Proposed Rules and (3) EPA
was concurrently initiating pre-rulemaking on these requirements and protocols
through the concurrent publication of an Advance Notice of Proposed Rule-
making. These comments were clearly directed at the delisting requirements
for organic toxicity, genetic activity, bioaccumulation potential and
radioactivity. In most cases, they were linked to the comments summarized
above that contended that delisting requirements, without companion listing
criteria, constituted a capricious double standard. Some commenters believed
the opposite, that the delisting requirements and test protocols, (that
is, broadly applicable characteristic-like rules) were, in fact, not prelimi-
nary and unevaluated. They believed that those proposed delisting tests and
others could be justifiably used in both listing and delisting to assure
broad and essential protection of the environment. Finally, a few commenters
suggested that the regulation should allow extending the delisting of an
individual waste to other similar wastes or to classes or types of waste
within the class of waste listed.
In summary, the comments on the technical aspects of the delisting
requirements were very similar to those submitted on the listing criteria
and the regulatory strategy for identifying wastes. As already indicated,
virtually all of these comments seemed to have been directed at the requirements
for delisting toxic organic, genetically active, bioaccumulative and radioactive
wastes. None seemed to be directed at the delisting requirements for wastes
listed because they exhibited the characteristics of ignitability, corrosivity,
reactivity and EP toxicity.
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FINAL RULES
§261.10 Criteria for identifying the characteristics of hazardous
waste
(a) The Administrator shall identify and define a
characteristic of hazardous waste in Subpart C only upon
determining that:
(1) A solid'waste that exhibits the characteristic
may:
(i) cause, or significantly contribute to,
an increase in mortality or an increase in serious irreversible,
or incapacitating reversible, illness; or
(ii) pose a substantial present or poten-
tial hazard to human health or the environment when it is
improperly treated, stored, transported, disposed of or other-
wise managed; and
(2) The characteristic can be:
(i) measured by an available standardized
test method which is reasonably within the capability of genera-
tors of solid waste or private sector laboratories that are
available to serve generators of solid waste; or
(ii) reasonably detected by generators of
solid waste through their knowledge of their waste.
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§261.11 Criteria for listing hazardous waste
(a) The Administrator shall list a solid waste as a
hazardous waste only upon determining that the solid waste meets
one of the following criteria:
(1) It exhibits any of the characteristics of
hazardous waste identified in Subpart C.
(2) It has been found to be fatal to humans in low
doses or, in the absence of data on human toxicity, it has been
shown in studies to have an oral LD50 toxicity (rat) of less than
50 milligrams per kilogram, an inhalation LC 50 toxicity (rat) of
less than 2 milligrams per liter, or a dermal LD50 toxicity (rabbit)
of less than 200 milligrams, per kilogram or is otherwise capable
of causing or significantly contributing to an increase in
serious irreversible, or incapacitating reversible, illness.
(Waste listed in accordance with these criteria.will be designated
Acute Hazardous Waste.)
(3) It contains any of the toxic constituents
listed in Appendix VIII unless, after considering any of the
following factors, the Administrator concludes that the waste
is not capable of posing a substantial present or potential
hazard to human health or the environment when improperly treated,
stored, transported or disposed of, or otherwise managed:
(i) The nature of the toxicity presented by
the constituent.
(ii) The concentration of the constituent
in the waste.
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(iii) The potential of the constituent or any
toxic degradation product of the constituent to migrate from
the waste into the environment under the types of improper
management considered in (vii) below.
(iv) The persistence of the constituent or
any toxic degradation product of the constituent
(v) The potential for the constituent or
any toxic degradation product of the constituent to degrade into
non-harmful constituents and the rate of degradation.
(vi) The degree to which the constituent or
any degradation product of the constituent bioaccumulates
in ecosystems. -*---
(vii) The plausible types of improper manage-
ment to which the waste could be subjected.
(viii) The quantities of the waste generated
at individual generation sites or on a regional or
national basis .
(ix) The nature and severity of the human
health and environmental damage that has occurred as a result of
the improper management of wastes containing the constituent.
(x) Actions taken by other governmental
agencies or regulatory programs based on the health or
environmental hazard posed by the waste or waste constituent.
(xi) Such other factors as may be appropriate.
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Substances will be listed on Appendix VIII only if they have
i
been shown irf scientific studies to have toxic, carcinogenic,
mutagenic or teratogenic effects on humans or other life
forms.
(Wastes listed in accordance with these criteria will be designated
Toxic wastes .)
(b) The Administrator may list classes or types of solid
waste as hazardous waste if he has reason to believe that individual
wastes, within the class or type of waste, typically or•frequently
are hazardous under the definition of hazardous waste found in
Section 1004(5) of the Act.
(c) The Administrator will use the criteria for listing
specified in this Section_to establish the exclusion limits
referred to in §261.5(c).
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§260-22 Petitions to amend Part 261 to exclude a waste produced
at a particular facility
(a) Any person seeking to exclude a waste at a particular
generating facility from the lists in Subpart D of Part 261 may
petition for a regulatory amendment under this section and
§260.20. To be successful, the petitioner must demonstrate to
the satisfaction of the Administrator that the waste produced
by a particular generating facility does not meet any of the
criteria under which the waste was listed as a hazardous waste
and, in the case of an acutely hazardous waste listed under
§261.11(a)(2) , that it also does not meet the criterion of
§261.11(a)(3) . A waste which is so excluded may still, however,
be a hazardous waste by operation of Subpart C of Part 261-
(b) The procedures in this section and §260.20 may
also be used to peti tio..ru..the Administrator for a regulatory
amendment to exclude from §261.3(a)(2)(ii) or (c), a waste
which is described in those . sections and is either a waste
listed in Subpart D, contains a waste listed in Subpart D, or
is derived from a waste listed in Subpart D. This exclusion
may only be issued for a particular generating, storage,
treatment, or disposal facility. The petitioner must make
the same demonstration as required by paragraph (a), except
that where the waste is a mixture of solid waste and one or
more listed hazardous wastes or is derived from one or more
hazardous wastes, his demonstration may be made with respect
to each constituent listed waste or the waste mixture as
a whole. A waste which is so excluded may still be
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a hazardous waste by operation of Subpart C of Part 261.
(c) If the waste is listed with codes "I", "C", "R",
or "EM in Subpart D, the petitioner must show that demon-
0
stration samples of the waste do not exhibit the relevant
characteristic defined in §§261.21, 261.22, 261.23 or
261.24 using any applicable test methods prescribed therein.
(d) If the waste is listed with code "T" in Subpart D,
the petitioner must demonstrate that:
(1) Demonstration samples of the waste do not con-
tain the constituent (as definetl in Appendix
VI-I) that caused the Administrator to list the
waste, using the appropriate test methods pre-
scribed in Appendix III; or
(2) The waste does not meet the criterion of
§261«11(a)(3) when considering the factors in
§261.11(a)(3)(i) through (xi).
(e) If the waste is listed with the code "H" in Subpart D,
the petitioner must demonstrate that the waste does not meet
both of the following criteria:
(1) The criterion of §261.11(a)(2).
(2) The criterion of §261.11(a)(3) when considering
the factors listed in §261.11(a)(3)(i) through
(xi).
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(f) [Reserved for listed radioactive wastes.]
(g) [Reserved for listed infectious wastes.]
(h) Demonstration samples must consist of enough repre-
sentative samples, but in no case less than four samples, taken
over a period of time sufficient to represent the variability
or the uniformity of the waste.
(i) Each petition must include, in addition to the infor-
mation required by §260.20(b):
(1) The name and address of the laboratory facility
performing the sampling or tests of the waste;
(2) The names and qualifications of the persons
sampling and testing the waste;
(3) The dates of sampling and testing;
(4) The location of the generating facility;
(5) A descrip-tion of the manufacturing processes or
other operations and feed materials producing
the waste and an assessment of whether such
processes, operations or feed materials can or
might produce a waste that is not covere'd by
the demonstration;
(6) A description of the waste and an estimate of
the average and maximum monthly and annual
quantities of waste covered by the demonstration;
(7) Pertinent data on and discussion of the factors
delineated in the respective criterion for
listing a hazardous waste, where the demonstra-
tion is based, on the factors in §261.11(a)(3);
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(8) A description of the methodologies and equipment
used to obtain the representative samples;
(9) A description of the sample handling and prep-
aration techniques, including techniques used
for extraction, containerization and preservation
of the samples;
(10) A description of the tests performed (including
results);
(11) The names and model numbers of the instruments
used in performing the tests; and
(12) The following statement signed by the generator
of the waste or his authorized representative:
I certify under penalty of law that I have
personally examined and am familiar with the
information submitted in this demonstration
and all attached documents, and that, based on
my inquiry of those individuals immediately
responsible for obtaining the information, I
believe that the submitted information is true,
accurate, and complete. I am aware that there
are significant penalties for submitting false
information, including the possibility of fine
and imprisonment.
(j) After receiving a petition for an exclusion, the
Administrator may request any additional information which he
may reasonably require to evaluate the petition.
(k) An exclusion will only apply to the waste generated
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-at the individual facility covered by the demonstration and
will not apply to waste from any other facility.
(1) The Administrator may exclude only part of the waste
for which the demonstration is submitted where he has reason to
believe that variability of the waste justifies a partial
exclusion .
(m) The Administrator may (but shall not be required to)
grant a temporary exclusion before making a final decision
under §260.20(d) whenever he finds that there is a substantial
likelihood that an exclusion will be finally granted. The
Administrator will publish notice of any such temporary exclu-
sion in the Federal Regis ter.
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APPENDIX I
REASON FOR INCLUSION OF HAZARDOUS CONSTITUENTS IN APPENDIX VIII
(1) Health and Environmental Effects Document
(2) NIPDWS Substance
(3) CAG Carcinogens
(4) Acute toxicity as listed in NIOSH Registry,
Sax,or DOT regulations
(5) RPAR Substance
Reason(s) Substance
(1) Acetaldehyde
(4) (Acetato)phenylmercury
(!)• Acetonitrile (I)
(4) 3-(alpha-Acetonylbenzyl)-4-
hydroxycoumarin and salts
(3) 2—Acetylaminofluorene
(1) Acetyl chloride (C)
(4) 1-Acetyl-2-thiourea
(4) Acrolein
(1) Acrylamide
(1),(3) Acrylonitrile
(3) Aflatoxins
(3),(4) Aldrin
(4) Allyl alcohol
(4) Aluminum phosphide (R)
(3) 4-Aminobiphenyl
(3) 6-Amino-l,la,2,8,8a,8b-hexahydro-
8-(hydroxymethyl)-8a-methoxy-5-
methylcarbamate azirino(2 f,3':3,4)
pyrrolo(l,2-a)indole-4, 7-dione (ester)
(Mitomycin C)
* The abbrevation N.O.S signifies those members of the general
class "not otherwise specified" by name in this listing.
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Reason( s)^ Substance
(4) 5-Aminomethyl-3-isoxyzole
(4) 4-Aminopyridine
(3) Amitrole
(1) Antimony and compounds, N.O.S.*
(3) Aramite
(2),(3) Arsenic and compounds, N.Q.S.
(3),(4) Arsenic acid
(3),(4) Arsenic pentoxide (R)
(3),(4) Arsenic trioxide
(3) Auramine
(3) Azaserine
(1),(2) Barium and compounds, N.O.S.
(4) Barium cyanide
(3) Benz[c]acridine
(1),(3) Benz[a]anthracene
(3) Benzene
(2) Benzenearsonic acid
(4) Benzenethiol
(3) Benzidine
(3) Benzo[b]fluoranthene
(3\ Benzo[j]fluoranthene
(3) Benzo [ a] pyr ene
(1) Benzotrichloride (C,R)
(1),(4) Benzyl chloride
j_ sis(2-chloroethoxy)methane
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Reason(s) Substance
(U>(3) Bis(2-chloroethyl) ether
(3) N»N-Bis(2-chloroethyl)-2-naphthylamine
C1) Bis(2-chloroisopropyl) ether
(1),(3),(4) Bis(chloromethyl) ether
d) Bis(2-ethylhexyl) phthalate
(4) Bromoacetone
(1) Bromomethane
(1) 4-Bromophenyl phenyl ether
(4) Brucine
(4) 2-Butanone peroxide
(1) Butyl benzyl phthalate
(4) 2-sec-Butyl-4,6-dinitrophenol (DNBP)
(2), (3) Cadmi'um and compounds, N.O.S.
(3) Calcium chromate
(4) Calcium cyanide (R)
(4) Carbon disulfide (I)
(3) Chlorambucil•
(3),(5) Chlordane (alpha and gamma isomers)
(1) Chlorinated benzenes, N.O.S.
(3) Chlorinated ethane(s), N.O.S.
(1) Chlorinated naphthalene(s), N.O.S.
(1) Chlorinated phenol(s), N.O.S.
(4) Chloroacetaldehyde
(3) Chloroalkyl ethers
(4) p-Chloroaniline
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Reason( s) Substance
(1) Chlorobenzene
(3), (5) Chlorobenzilate
l-( p-Chlorobenzoyl)-5-methoxy-
2-methylindole-3-acetic acid
o
(1) p-Chloro-m-cresol
(1) l-Chloro-2 , 3-epoxybutane
(1) 2-Chloroethyl vinyl ether
(1),(3) Chloroform (I)
(1) Chloromethane (I)
(3) Chloromethyl methyl ether
(1) 2-Chloronaphthalene
(1) 2-Chlorophenol
(4) l-( o-Chlorophenyl) thiourea
(4) 3-Chloropr opionitr ile
(4) alpha-Chloro toluene
(4) Chloro toluene( s) , N.O.S.
(2) (3) Chromium and compounds, N.O.S.
(1),(3) Chrysene
/3) Citrus red No. 2
/4\ Copper cyanide
(1),(3) Creosote . -
/•i \ Cro tonaldehyde
/•AN Cyanides
v ' (soluble salts and complexes), N.O.S. (R)
(4)
Cyanogen
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Substance
(4) Cyanogen bromide
(*) Cyanogen chloride
(3) Cycasin
(!) 2-Cyclohexyl-4 , 6-dinitro phenol
(3) Cyclophosphamide
(3) Daunomycin
(1) DDD
(1) DDE
d),(3) DDT
(3), (5) Diallate
(3) Dibenz[a,h]acridine
(3) Dibenzf.a, j] acridine
(3) --Bibenz [ a , h] anthracene
(Dibenzo [a,h]anthracene)
(3) 7H-Dibenzo[c ,g] carbazole
(3) Dibenzo [ a , e] pyr ene
(3) . Dibenzo[ a ,h]pyrene
(3) Dibenzo [a, i] pyrene
(3) 1 , 2-Dibromo-3-chloropropane
(3) 1 , 2-Dibromoethane
(1) Dibr omomethane
M ) Di-n-butyl phthalate
H) Dichlorobenzene( s) , N.O.S.
(1) (3) 3 , 3 '-Dichlorobenzidine
]_) 1 , L-Dichloroethane
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Substance
(O>(3) 1,2-Dichloroethane
(1) trans-1 ,2-Dichloroethene
(!) Dichloroethylene(s) , N.O.S.
(1) 1 ,1-Dichloroethylene
(1) Dichloromethane
(1) 2,4-Dichlorophenol
(1) 2,6-Dichlorophenol
v
(2), (4) 2,4-Dichlorophenoxyacetic acid (2,4-D)
(1) Dichloropropane( s)
(4) Di chlorophenylar sine
(1) 1, 2-Dichloropropane
(1) Dichl oropr opanol( s) , N.O.S.
(1) -Dachloro propene( s) , N.O.S.
(1) 1,3-Dichloropropene -
(3), (4) Dieldrin
(3) Diepoxybutane (I)
(4) Diethylarsine
(4) 0,0-Diethyl-S-(2-ethylthio)ethyl ester of
phos porothioic acid
(3) 1,2-Diethylhydrazine
/3\ 0,0-Diethyl-S-methylester phosphorodithioic acid
(4) 0,0-Diethylphosphoric acid, 0-p-ni trophenyl ester
(!) Diethyl phthalate
o,0-Diethyl-0-(2-pyrazinyl>phosphorothioate
Diethylstilbestrol
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Reason(s) Substance
(3) Dihydrosafrole
(4) 3,4-Dihydroxy-alpha-(methylamino)-
methyl benzyl alcohol
(4) Di-isopropylfluorophosphate (DFP)
(4),(5) Dimethoate
(3) 3,3 '-Dimethoxybenzidine
(3) p-Dimethylaminoazobenzene
(3) 7,12-Dimethylbenz[a]anthracene
(3) • 3,3'-Dimethylbenzidine
(3) Dimethylcarbamoyl chloride
(3) 1,L-Diraethylhydrazine
(3) 1,2-Dimethylhydrazine
(4) 3,3-Diraethyl-l-(raethylthio)-2-butanone-
0-((methylamino) carbonyl)oxime
(1) * Dimethylnitrosamine
(4) alpha,alpha-Dimethylphenethylamine
(1) 2,4-Dimethylphenol
(1) Dimethyl phthalate
(3) Dimethyl sulfate
(1) Dinitrobenzene(s), N.O.S.
(4) 4,6-Dinitro-o-cresol and salts
(1),(4) 2,4-Dinitrophenol
(1) (3) 2,4-Dinitrotoluene
(1) 2,6-Dinitrotoluene
^j_) Di-n-octyl phthalate
(3) 1,4- Dioxane
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Reas_°JiLLl Substance
(3) 1,2-Diphenylhydrazine
(3) Di-n-propylnitrosamine
(4) Disulfoton
(4) 2,4-Dithiobiuret
(4) Endosulfan
(2),(4) Endrin and metabolites
(1),(3) Epichlorohydrin
(4) Ethyl cyanide
(4) Ethylene diamine
(3) Ethylene bis dithiocarbamate (EBDC)
(3) Ethyleneimine
(3) Ethylene oxide (I)
(3) Ethylenethiourea
(3) ' Ethyl methanesulfonate
(1) Fluoranthene
(4) Fluorine
(4),(5) • 2-Fluoroacetamide
(4),(5) Fluoroacetic acid, sodium salt
(1),(3) Formaldehyde
(3) Glycidyl aldehyde
(1) Halomethane(s), N.O.S.
(3),(5) Heptachlor
Q\ Heptachlor epoxide (alpha, beta,
and gamma isomers)
(1),(3) Hexachlorobenzene
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Substance
(1)>(3) Hexachlorobutadiene
(1)»(2),(3) Hexachlorocyclohexane (all isomers)
(1) Hexachlorocyclopentadiene
(3) Hexachloroethane
(4) 1, 2, 3, 4,10, 10-Hexachlor o-l,4, 4a, 5,8,8 a-hexahydr o-
l,4:5,8-endo,endo-dimethanonaphthalene
(1) Hexachlorophene
(4) Hexachloropropene
(4) • Hexaethyl tetraphosphate
(3) Hydrazine (R )
(4) Hydrocyanic acid
(1) Hydrogen sulfide
(3) Indeno(l, 2 , 3-cd) p yr ene
(3) lodomethane
(4) Isocyanic acid, methyl ester
(3) Isosafrole
(3) ° Kepone
(3) Lasiocarpine
(1\ (2) Lead and compounds, N.O.S.
(1),(2),(5) Lead acetate
(1),(2) Lead phosphate
(1\ /2) Lead subacetate
n) Maleic anhydride
Q\ Malononitrile
/\ Melphalan
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Substanc
^jCZ) Mercury and compounds, N.O.S.
(3) Methapyrilene
(4) Methomyl
(4) 2-Methylazlridine
(3) 3-Methylcholanthrene
(3 ) 4,4 ' -Me thyl en e-bis- (2-chloro aniline')
(1) Methyl ethyl ketone (MEK) (I)
(4) Methyl hydrazine
(4) 2-Methyllactonitrile
(1) Methyl methacryla te (R)
(3) Methyl inethanesulf onate
(4) 2-Methyl-2-(methylthio)propionaldehyde-
o-(methylcarbonyl) oxime
(3 ) N-Methyl-N'-nitro-N-nitrosoguanidine
o
(4) Methyl parathion
(3) Methylthiouracil
(3) Mustard gas
(1 ) ' Naphthalene
(1) 1 , 4-Naphthoquinone
(3) l-Naphthylamine
(3) 2-Naphthylamine
(4) l-Naphthyl-2-thiourea
/3) Nickel and compounds, N.O.S.
)s(4) Nickel carbonyl
Nickel cyanide
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Reason(s) S_ub_s ranee
(4) Nicotine and salts
(4) Nitric oxide
(4) p-Nitroaniline
(1) Nitrobenzene (I)
(4) Nitrogen dioxide
(3) Nitrogen mustard and hydrochloride salt
(3) Nitrogen mustard N-oxide and
hydrochloride salt
(4) Nitrogen peroxide
(4) Nitrogen tetroxide
(4) Nitroglycerine (R)
(1) 4-Nitrophenol
(3) 4-Nitroquinoline-1-oxide
(3) Nitrosamine(s)
(3) N-Nitrosodi-n-butylamine
(3) N-Nitrosodiethanolamine
(1),(3) N-Nitrosodiethylamine
(1)}(3) N-Nitrosodimethylamine
(4) N-Nitrosodiphenylamine
(1 ) , (3 ) N-Nitrosodi-n-propylamine
(3) N-Nitroso-N-ethylurea
(3) N-Nitrosomethylethylamine
(3) N-Nitroso-N-methylurea
^3^ N-Nitroso-N-inethylurethane
(3)^(4) N-Nitrosomethylvinylamine
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Reason(s) Substance
(3) N-Nitrosomorpholine
(3) N-Nitrosonornicotine
(3) N-Nitrosopiperidine
(3) N-Nitrosopyrrolidine
(3) N-Nitrsosarcosine
(3) 5-Nitro-o-toluidine
(4) Octamethylpyrophosphoramide
(4) Oleyl alcohol condensed
with 2 moles ethylene oxide
(4) Osmium tetroxide
(4) 7-Oxabicyclo[2.2.1]heptane-2,3-dicarboxylic acid
(4) Parathion
(1) Pentachlorobenzene
(1) Pentachloroethane
(1),(3),(5) Pentachloronitrobenzene (PCNB)
(4) Pentachlorophenol
(3) Phenacetin
(1) Phenol
(4) Phenyl dichloroarsine
(4) Phenylmercury acetate
(4) N-Phenylthiourea
(4) Phosgene
(4) phosphine
Phosphorothioic acid, 0,0-dimethyl
ester, 0-ester with N,N-dimethyl
benzene sulfonamide
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Substance
(!) Phthalic acid esters, N.O.S.
(!) Phthalic anhydride
(3) Polychlorinated biphenyl(s), N.O.S.
(4) Potassium cyanide
(4) Potassium silver cyanide (R)
(3 ) Pr onamide
(4) 1 ,2-Propanediol
(3) 1,3-Propane sultone
(4) Propionitrile
(3) Propylthiouracil
(4) 2-Propyn-l-ol
(1) Pyridine
(3 ) Reserpine
(3) - Saccharin
(1),(3) Safrole
(2) Selenious acid
(1) (2) • Selenium and compounds, N.O.S.
(1),(2),(3) Selenium sulfide (R )
(4) Selenourea
M ) (2) Silver and compounds, N.O.S.
(4) Silver cyanide
(4) Sodium cyanide
Streptozotocin
Strontium sulfide
Strychnine and salts
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Reas o n ( s ) - .
- — Substance
2»4,5-Tetrachlorobenzene
>
^ ' 2»3,7, 8-Tetrachlorodibenzo-p-dioxin
^^ Tetrachloroethane(s) , N.O.S.
(1) ,(3) ,(4) l,lf 1, 2-Tetrachlo roe thane
t1) »<4> 1,1,2,2-Tetrachloroethane
(^)>(3) Tetrachloroethene (Tetrachloroethylene)
C^-' Te trachlor otaethane
(!) 2,3,4,6-Tetrachlorophenol
(4) Tetraethyldithiopyrophosphate
(4) Tetraethyl lead
(4) Tetraethylpyrophosphate
(1) Thallium and compounds, N.O.S.
(4) Thallic oxide
(1) Thallium (I) acetate
(1) Thallium (I) carbonate
(1) Thallium (I) chloride
(1) • Thallium (I) nitrate
(4) Thallium selenite
(4) " Thallium (I) sulfate
(3) Thioacetamide
(4) Thios emicarbazide
(3 ) Thiour ea
(4) Thiuram
(1 ) Toluene
n N Toluenedi aiuine
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Substance
o-Toluidine hydrochloride
Tolylene diisocyanate
!>•<*>. <3> Toxaphene
' ' Tribromomethane
'*' 1» 2,4-Trichlorobenzene
(1),(2) 1 ,1,1-Trichloroethane
t1) 1,1,2-Trichloroethane
(3) Tr ichloroethene (Tr ichloroethylene)
(*) Trichloromethanethiol
(1) 2 , 4 , 5-Tr ichlorophenol
(1)»(3) 2,4,6-Trichlorophenol
(5) 2 ,4 , 5-Trichlorophenoxyacetic s.cid (2,4,5-T)
(2) 2,4,5-Trichlorophenoxypropionic
acid (2,4,5-TP) (Silvex)
(1) Tr ichloropropane( s )
(1) 1 , 2 , 3-Tr ichloropropane
(1) 0 , 0 ,0-Triethyl phosphorothioate
(1) Tr initrobenzene
(3) - Tris( l-azridinyl)phosphine sulfide
(3) Tris(2, 3-dibromopr opyl) phosphate
(3) Trypan blue
(3) Uracil mustard
(3) Urethane
(4) Vanadic acid, ammonium salt
4 Vanadium pentoxide (dust)
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Reason(s) ,. t_
- ~ • - Substance
Vinyl chloride
Vinylidene chloride
Zinc cyanide
Zinc phosphide (R )
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