Nonnuclear Industrial Hazardous Waste:

Classifying for Hazard Management

November 1981

NTIS order #PB82-134305
Library of Congress Catalog Card Number 81-600170

For sale by the Superintendent of Documents,

U.S. Government Printing Office, Washington, D.C. 20402
Preface

The Office of Technology Assessment is currently conducting an assessment on

nonnuclear industrial hazardous waste at the request of the House Committee on Energy and Commerce. Its Chairman, Rep. John D. Dingell, asked OTA for a preliminary

report on hazard classification because this critical issue, one of several being studied in

the OTA project, will likely be addressed this fall.

This technical memorandum addresses the following topics:

● basic issues surrounding a degree-of-hazard classification approach;

 the potential for incorporating a degree-of-hazard concept through classification in current regulations of the Resource Conservation and Recovery Act

(RCRA);

● various ‘methods for applying a degree-of-hazard classification system; and

 some questions to be addressed in making the decision whether or not to select

and incorporate a degree-of-hazard classification system at the Federal and

State level.

OTA’s analysis to date finds that a well-designed degree-of-hazard classification

system might provide a strategy for cost-effective management of nonnuclear industrial

hazardous waste, However, it would be important to choose several degrees of hazardousness and not to exclude types of waste, such as those generated in relatively small

quantities and some chemicals with known chronic (long-term) toxicity, without making assessments of the levels of hazard they pose to the public.

While a regulatory system based on degree-of-hazard classification may appear

reasonable and cost effective, it should not be regarded as a panacea for the critical national problem posed by industrial waste. Moreover, it is not necessarily a radical

departure from existing regulations. No change in RCRA would be needed, and a

quantitative hazard classification scheme could be incorporated incrementally into

various segments of the current program. Hazard classification, based on scientific data

for waste, management technologies and sites, should be viewed as an evolutionary

rather than revolutionary development for industrial waste management and regulation.
Nonnuclear Industrial Hazardous Waste Advisory Panel

Myron Tribus, Chairman’

Massachusetts Institute of Technology

David Anderson

Bethlehem Steel Corp.

Frank Collins

Oil, Chemical and Atomic Workers

International Union

Jeffrey Diver

Waste Management, Inc.

Phillippa Foot

University of California, Los Angeles

Thomas H. Goodgame

Whirlpool Corp.

Diane Graves

Sierra Club

Sam Gusman

Conservation Foundation

Rolf Hartung

University of Michigan

Robert L. Judd

State of California

Kenneth S. Kamlet

National Wildlife Federation

Terry Lash

Keystone Center

“Resigned as of Aug. 21, 1981.

● *Resigned as of Sept. 24, 1981

David Lenett

Environmental Defense Fund

Joe J. Mayhew

Chemical Manufacturers Association

John M. Mulvey

Princeton University

Steven J. Picco

State of New Jersey

Delbert Rector

State of Michigan

Gerard A. Rohlich

University of Texas, Austin

Kenneth J. Rothman**

Harvard School of Public Health

Reva Rubenstein

National Solid Waste Management

Association

W. Earl Tatum

E.I. du Pent de Nemours & Co.

George M. Woodwell

Marine Biological Laboratory, Woods Hole

NOTE: The advisory panel provided advice and critique, but does not necessarily approve, disapprove, or endorse this technical memorandum for which OTA assumes full responsibility.

iv
Nonnuclear Industrial Hazardous Waste Project Staff

Lionel S. Johns, Assistant Director, OTA

Energy, Materials, and International Security Division

Audrey Buyrn, Materials Program Manager

Joel S. Hirschhorn, Project Director

Suellen Pirages, Senior Analyst

Iris Goodman, Research Assistant

Michael Gough, Consultant (OTA Health Program)

Administrative Staff

Carol A. Drohan Patricia A. Canavan

Contractor

Sterling Hobe Corp.

OTA Publishing Staff

John C. Holmes, Publishing Officer

John Bergling Kathie S. Boss Debra M. Datcher Joe Henson
Acknowledgments

The following also provided considerable assistance in the review of various drafts of this

memorandum:

S. Daniels, Dow Chemical Co. G. Hurlbert, State of Michigan

H. Yakowitz, National Bureau of Standards H. A. Caves, State of Oklahoma

B. Simonsen, IT Corp. E. Falk, Union Carbide Corp.

E. Tower, State of Washington J. Carmichael, State of Texas

S. Barkin, National Materials Advisory Board H. A. Wray Associates

C. Perket, Environmental Engineer and W. H. Prior, Kaiser Aluminum, Inc.

Management Ltd.
Contents

Page

Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Concept of Degree of Hazard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Technical Basis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Degree of Hazard Concept v. Hazard Classification. . . . . . . . . . . . . . . . . 10

Objective and Purpose of a Classification System. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Economic Effectiveness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Uncertainties in Implementation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Degree of Hazard in the Current Regulatory Approach . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Methods for Classifying Waste and Facilities by Degree of Hazard. . . . . . . . . . . . . . . . . . . . . . . . . 17

Classification Using Technical Criteria. . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Rank-Order Classifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Multiple Discriminators. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Classification by Environmental Containment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Unresolved Questions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Appendix: Dangerous Waste Criteria for the State of Washington . . . . . . . . . . . . . . . . . . . . . 33

References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

List of Tables

Table No. Page

1.

2.

3.

4.

5.

6.

7.

8.

9.

10.

11.

A-1.

List

Toxic Doses for Selected Hazardous Waste Constituents . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Selected Examples of a Degree-of-Hazard Interpretation in Current RCRA Regulations. . . 15

Toxicity Criteria in the California System of Degree-of-Hazard Classification. . . . . . . 18

Criteria for the Texas System of Degree-of-Hazard Classification. . . . . . . . . . . . . . . . . . . . . . . 19

Criteria for the Washington System of Degree-of-Hazard Classification. . . . . . . . . . . . . . . . . . 20

Proposed Technical Criteria for Classifying Nonnuclear Industrial Hazardous Waste. . . . . 21

Comparison of Proposed Degree-of-Hazard Classification Systems. . . . . . . . . . . . . . . . . . . . . 21

Michigan’s System for Rank-Order Assessment of Critical Materials. . . . . . . . . . . . . . . . . . . . 23

Suggested Effect and Exposure Factors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Suggested Environmental Parameters for Classifying Facility Sites. . . . . . . . 25

Potential Classification Scheme Based on Containment and Destruction. . . . . . . . . 26

Toxic Category . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

of Figures

1.

—

2.

3.

4.

A-I

Information and Decision Flow for Current and Alternative Waste Management . . . . . . . . 7

Factors of Importance to Degree-of-Hazard Assessments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Decision Analysis Illustrating the Impact of Degree of Hazard on the Choice of

Management Practice. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Research, Development, and Analysis Requirements and Possible Benefits of

Implementation of a Hazard Classification System. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Toxic Dangerous Waste Mixtures. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Summary

The management, or in some cases mismanagement, of industrial waste present various

levels of hazard to the public. Nonnuclear industrial waste range from being relatively harmless

to being so extremely hazardous that the waste

must be totally isolated from humans and the

environment, destroyed or permanently detoxified. In developing regulations to implement the

Resource Conservation and Recovery Act of

1976 (RCRA), the Environmental protection

Agency (EPA) chose not to classify waste

beyond a designation of hazardous or nonhazardous. Moreover, EPA has excluded types of

waste, such as those generated in relatively small

quantities and some chemicals with known

chronic (long-term) toxicity, without making assessments of the levels of hazard they present to

the public. The Office of Technology Assessment finds that a well-designed degree-of-hazard

classification system might provide a strategy

for cost-effective management of nonnuclear industrial waste. A quantitative classification system incorporating the degree-of-hazard concept

is possible because the following two conditions

are met:

● particular waste, management programs,

and sites have important shared characteristics; and

 scientific criteria and data that describe hazards are either available or can be, in principle, obtained.

Alternatively, a qualitative degree-of-hazard approach without specific categories requires less

effort to develop criteria and data, and its apparent simplicity may be attractive from a programmatic perspective. In the long term, such an

approach could prove to be inefficient, since

scientific information appropriate for classification may be needed in the future. In addition,

much of the information obtained in a qualitative approach on a case-by-case basis often is

not fully used, may be unnecessary, and often is

not appropriate for classification.

The present state of knowledge, however,

does not lead to an easy endorsement or condemnation of the use of a hazard classification

system for implementing the mandates of

RCRA. While a system based on degree of hazard may appear reasonable and cost effective,

degree-of-hazard classification should not be

regarded as a panacea for the national problem

posed by disposal of nonnuclear industrial hazardous waste. Moreover, it is not necessarily a

radical departure from existing regulations.

Classification by hazard could be incorporated

incrementally into various segments of the current program. Hazard classification should be

viewed as an evolutionary rather than revolutionary development for industrial waste management.

The objectives of a classification system are

twofold:

 to identify with greater certainty industrial

waste that pose the most severe threats to

human health and environment; and

● to allow development of management strategies that reflect the differences in potential

hazards of industrial waste.

Waste classification methods include technical

criteria based on waste characteristics, rankordering based on results of specified tests,

grouping by particularly important characteristics (multiple discriminatory factors), and ordering the potential of facilities to contain or destroy the waste. Because of incomplete information and data about industrial waste streams,

none of these methods can be implemented without first developing scientifically based criteria

that reflect both real world exposures and intrinsic properties of waste. Although much of the

preliminary investigative effort required to develop a degree-of-hazard classification system

has been initiated in compliance with other environmental regulations, further evaluation of all

schemes is needed.

The benefits of using degree-of-hazard classification in regulating industrial waste include concentration of regulatory action on waste that

pose the greatest hazards; a more effective

allocation of the resources of generators, disposers, and government; a means to establish

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priorities for reduction of the waste stream by

changing manufacturing processes, end product

substitution or recycling of waste; a means to increase the public’s knowledge about the variation in hazard posed by industrial waste; and

finally a means to assure that the intent of

RCRA is achieved.

A number of questions, however, require examination. There is concern about the costs to

EPA for developing a classification system, and

also the cost to society for time that might be

lost during a transitional period in implementation of RCRA. Uncertainties surround availability of appropriate data, the ability to establish

scientifically based criteria, and increased complexity of regulations. Finally, the costs that

result both from developing a degree-of-hazard

system and from not designing a classification

approach need to be determined.
Background

The concept of degree of hazard is receiving

increased attention as discussion of the current

system for regulating nonnuclear industrial hazardous waste (NIHW) continues. For example, it

has been reported that the Executive Office of

Management and Budget has requested the Environmental Protection Agency (EPA) to conduct

a review of the Resource Conservation and Recovery Act (RCRA) regulations; this review may

include a study of the potential for incorporating

references to the degree of hazard of various

waste. (1) Moreover, the House Committee on

Science and Technology has identified classification of hazardous waste as a major issue.(2)

There appears to be no question among those

who deal with the issue that there are differing

degrees of hazard and that different means of

handling treatment disposal are warranted.

The problem is in applying degrees of hazard to

specific wastes. Both economically and from an

environmental and health standpoint, the issue

is legitimate,

Because of the complexity of industrial waste, it

does not seem appropriate, however, to reference or consider degree of hazard without understanding the meaning of the concept, the

necessity of establishing technical criteria for

classifying waste, and the problems surrounding

implementation of a classification system in Federal and subsequent State hazardous waste regulations. A discussion of each area is presented in

this document.

As part of a comprehensive, ongoing assessment of nonnuclear industrial waste, OTA is

studying the potential application of a degree-ofhazard concept to regulatory policies. For the

purposes of this report, degree of hazard reflects

the relative level of particular characteristics

selected by EPA for defining a hazardous waste

(i.e., toxicity, ignitability, corrosivity, and reactivity). Risk assessment, in contrast, estimates

the probability of adverse impacts resulting

from a hazard during particular exposure conditions. Risk analysis estimates the social and economic costs that would result from a particular

level of risk. This document is limited to a discussion of a degree-of-hazard system as a means

to reduce risks posed by management of NIHW.

The first phase of the OTA study is a review

of the methodology that might be adapted for

use in classifying and managing industrial waste.

Subsequent phases will explore unresolved questions that have been raised at this stage of the assessment and will analyze further the feasibility

of implementing a degree-of-hazard concept

within the current regulatory structure. As a

means of providing a basis for understanding the

concept and potential benefits as well as anticipated problems, this paper discusses the

following:

basic issues surrounding a degree-of-hazard

classification approach;

the potential for incorporating a degree-ofhazard concept through classification in

current regulations;

various methods for applying a degree-ofhazard classification system; and

some questions to be addressed before the

decision whether or not to select and incorporate a degree-of-hazard classification system at the Federal and State level can be

made.

RCRA was enacted, in part, to regulate the

management of hazardous waste.(3) Regulation

of NIHW, however, is a complex problem. The

types of waste that must be regulated consist of

discarded byproducts from industrial production processes and residues created by commercial use of industrial compounds. These include,

for example, wastewater sludges from a variety

of processes, organic chemical residues, spentplating bath solutions from electroplating processes, and emission-control dust/sludges from

secondary lead smelting, The chemical, physical, and toxicological properties of these NIHW

are quite diverse and produce effects on human

health and the environment that vary in character and severity. Because industrial waste generally comprise mixtures of compounds, often

there is uncertainty surrounding the specificity

of cause and effect relationships between the

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presence of a hazardous waste and a perceived

adverse impact. This diversity (in types of

waste, their properties and effects) and lack of

certainty present a challenge for designers and

enforcers of Federal environmental policies to

find a regulatory structure that is cost effective,

capable of being implemented on a national

level, and compatible with the variety of NIHW

being generated as well as the diversity of environmental conditions.

The legislative history of RCRA suggests that

Congress was aware of the complex nature of

NIHW and was concerned with appropriate

ways to identify waste that present the most hazard to human health and the environment. Preliminary discussions centered on such issues as

volumes of the waste being considered and the

certainty, or lack thereof, of identifying adverse

effects. For example, the following observation

was made in a congressional committee

report .(4)

The Committee anticipates the identification

of two basic types of substances: those which

are hazardous in their elemental and most common form, regardless of concentration, and

those which when present in sufficient concentration or when mixed with other substances

constitute hazardous waste. The criteria for

identification of these substances should make

such a distinction based on the danger to human

health and the environment. The listing of any

substances not found to be hazardous per se

should be accompanied by an explanation as to

when such waste are considered hazardous.

Some members of Congress suggested that the

act should make reference to regulating NIHW

according to the extent to which waste pose a

health or environmental threat. In subsequent

discussions on amendments to the act however,

Sen. Jennings Randolph, one of the key sponsors

of RCRA, maintained:

. . . that flexibility can be accomplished within

the current agency consideration of the proposed regulations and the comments received in

a manner consistent with the statute.(5)

The final act neither requires nor precludes the

development of a regulatory system based on

classifying NIHW by the potential to cause harm

if managed improperly.(6)

In developing regulations to implement the

RCRA mandate, EPA chose not to classify waste

beyond a designation of hazardous or nonhazardous. The Agency’s position was taken for

two reasons.(6)

The Agency does not believe that any of the

degree-of-hazard systems suggested by commentors (or any the Agency could itself conceive) are capable of actually distinquishing

different degrees of hazard among the myriad

hazardous wastes and also reasonably relating

management standards to these degrees in a

technically and legally defensible way. . . (and)

believes that the final regulations already

achieve the objectives of a degree-of-hazard

system; thus such a potentially complex and

challengeable system is unnecessary.

Comments received by EPA on the December

1978 publication of the first set of proposed regulations, however, suggest that regulating

NIHW according to degrees of hazard could be a

cost-effective strategy.(7) Several arguments for

this type of system have been presented.(8) First,

the use of a degree-of-hazard approach concentrates regulatory action on waste that exhibit a

high level of hazard and have the greatest probability for exposure to humans and other organisms. A degree-of-hazard system could prevent

excessive regulation of waste shown to present

either a low hazard potential or a low probability of exposure. Moreover, although there is

general recognition of the need to reduce waste

generation at the source, through such measures

as process or end-product change, without some

classification of waste it is difficult to establish

appropriate priorities and goals for waste

reduction.

Second, the volume of waste to be handled by

procedures outlined in the regulations is anticipated to be quite large; EPA estimated that

NIHW generated in 1980 could range from 28

million to 56 million metric tons with annual increases of 3.5 percent expected .(9,10) A system

of classifying waste by degree of hazard could

facilitate effective management programs by

concentrating limited resources of generators,

disposers, and government on those materials of

greatest concern. For example, there are a limited number of appropriate sites where waste
5

can be disposed safely in land (i. e., with minimal

contamination of surface or ground water).

Given this limited availability, it is suggested

that a management policy should be developed

whereby the most hazardous waste are destroyed, detoxified, or as a last option sent to the

most secure land disposal sites, and the less hazardous materials are assigned to sites requiring

fewer controls and lower management costs.

Analyses and forecasts of landfill capacities on a

National, State, or regional basis are likely to be

made more accurate and useful if hazard classification becomes used.

Finally, a degree-of-hazard approach to waste

management could be used to direct educational

efforts toward increasing the public’s understanding of those properties of waste and environmental conditions that contribute to contamination problems. While the public has

become increasingly aware of dangers associated

with disposal of NIHW, this awareness has been

accompanied by misunderstandings about the

diversity of hazards posed by different types of

materials. This lack of understanding is due in

part to limited access by the public to the available information about the expected threats to

health or the environment. As the public becomes more knowledgeable about differences in

hazard posed by the variety of NIHW, greater

acceptance of waste treatment or disposal sites

might result for low-hazard waste sites and for

high-hazard waste sites that reflect the most appropriate and safe management. It can be argued, however, that as the public learns more

about specific waste and dangers they pose, developing a necessary consensus on siting could

be delayed.

More recently, some concern has been expressed that the current regulations of EPA

could eventually undermine the intent of RCRA

by allowing some potentially hazardous waste

to escape regulation.(n) For example, it has

been suggested that the listing mechanism for

identifying hazardous waste reduces the efficacy

of the act. The current EPA list is considered by

some to be deficient with initial exclusions of

many hazardous materials and the potential to

remove identified hazardous waste from the list.

Because of a failure to establish clear criteria,

certain types of exclusions in current regulations

could reduce the effectiveness of RCRA, particularly in the long term. These exclusions include

small generator exemptions, materials covered

under other environmental regulations (e. g.,

Clean Water Act), specific exemptions of materials through the delisting-petition process, and

the potential to designate a hazardous materiaI

for recycling purposes and therefore removing it

from regulatory control.

Arguments can be made that it would be more

prudent to provide an all-inclusive regulatory

policy with established criteria rather than one

which allows a variety of exclusions. For example, the policy might be to classify all industrial

waste and not to exclude any from some level of

regulation (i. e., using permit by rule for less or

nonhazardous waste). An aura of uncertainty is

created when the potential exists at some future

time to relist waste currently exempted and delist waste currently included. A degree-of-hazard approach based on classifying and regulating

all industrial waste could facilitate private sector

investment decisions for waste management facilities by providing a more certain regulatory

environment and could shift the current regulatory emphasis from the legal to more technological arenas.

The format for applying a degree-of-hazard

classification system, however, would have to

be designed carefully. A very complex system

might be unworkable and unmanageable. A system using three to four broad classes of hazard

(e.g. high, medium, low, and nonhazardous)

with specific criteria for each could provide a

reasonable regulatory framework. Such a system could include the disposition of all industrial

waste including small quantities, specific lesshazardous waste with their related liability

needs, material covered under other regulations,

and waste designated for recycle or reuse.

Included in the comments on the 1978 proposed regulations were several proposals for

classifying both waste and management facilities

by the degree of hazard posed to human health

or the environment. After review of these

systems, EPA determined that a satisfactory

classification scheme could not be readily developed nor implemented within the time period
6

mandated by Congress. EPA was under a courtordered schedule to develop Federal regulations.

EPA was already late in meeting the schedule

and pressed to develop a program quickly. EPA

felt that the objectives of a classification system

could be met just as efficiently through a phased

approach in promulgating regulations. For example, the initial list of NIHW included those

which EPA considered to pose the highest risk

and for which the most information on health

and environmental impacts was available. EPA

intended to add other waste to the list over time.

In addition, the first set of proposed regulations

included exclusion levels for small quantities of

waste, a variance procedure allowing disposers

to demonstrate that the level of required insurance was not consistent with the degree of

risks associated with their facility, and pe

ing procedures for requesting lower levels

surance. Also, in this first phase of regu

development, EPA stated the intent to

itionof ina tory

tailor

management requirements reflecting differences

in potential hazards of NIHW as well as differences in environmental conditions surrounding the facility site.

A comparison of the current regulatory system with a proposed degree-of-hazard alternative approach is illustrated in figure 1. The

current system could lead to a situation of some

over-regulation of low-hazard waste and some

under-regulation of highly hazardous waste,

i.e., if the final management standards do not reflect stringent controls. This could result in an

imbalance in the ratio of management costs and

the level of risk that results from the management choice. Instead of optimal management

costs and potentially low levels of resulting risk,

the consequences are uncertain (dotted lines)

and could be either high management cost for

low-risk waste or low management costs with

potentially high levels of risk resulting from the

management choice. Assuming that classification criteria can be developed that will correctly

distinguish degrees of hazard (such an assumption cannot yet be made with certainty), the

alternative approach has the potential for reducing uncertainty and providing a more appropriate balance between management costs and

the expected level of risk resulting from the management choice.
1 I I * I t III
Concept of Degree of Hazard

As part of the decision process of whether to incorporate a degree-ofhazard concept into Federal regulations, it is appropriate to examine the

technical basis of the concept, its application in a classification system, objectives and purpose, economic effectiveness, and uncertainties that surround implementing the concept for management purposes.

TECHNICAL BASIS

The degree to which accumulation and dispersion of nonnuclear industrial hazardous

waste (NIHW) could pose a hazard to human

health and the environment depends on many

factors as illustrated in figure 2: characteristics

of the waste contributing to its toxicity and the

need for safe handling (e. g., ignitability, corrosivity, and reactivity); concentration and

duration of the exposure; properties that determine its movement in the surrounding environment, the potential for degradation and accumulation in living organisms; the sensitivity of

exposed organisms to the waste; and site-specific

environmental and management conditions that

enhance or inhibit movement of the waste to a

point for potential exposure. Because of the

potential for both acute and chronic toxicity,

this factor has received the most attention when

developing degree-of-hazard criteria for classification systems.

The toxicity of NIHW is a function of the inherent capacity of waste constituents to produce

adverse effects. The major determinants of the

magnitude of these effects are the characteristics

of waste (e. g., chemical, physical, and toxicological properties), the quantity of the waste

constituent to which humans and other organisms are exposed for a specific period (e. g., the

dose, which equals the concentration available

for some hours, months, or years), and the sensitivity of organisms being exposed (e. g., oxygen

is highly toxic to anerobic bacteria but not to

humans, and herbicides directly kill plants but

not animals). Of these factors, toxicity and dose

are of prime importance when assessing the

potential hazard of NIHW.

For any chemical there is a dose level that will

produce adverse effects in any organism; likewise there is a concentration sufficiently low

that no adverse effect can be observed (i. e., the

response observed in the test population cannot

be distinguished from normal background incidences). Chemical and physical properties of the

particular chemical and the sensitivity of an affected organism are factors that influence

amounts required to cause harm. Thus, the dose

SOURCE: Office of Technology Assessment.

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9

of one chemical required to produce death in one

species (e. g., rat) will be different from the lethal

dose of another chemical for that same species;

the lethal dose for one chemical also will vary

among species (e. g., monkey, dog, and human).

In addition, not all animals or humans respond

to the same concentration or exposure route in a

similar fashion. For example, nitrates in water

can be ingested by an adult human with no adverse effect, but these nitrates at certain concentrations are toxic to infants. Finally, some compounds are toxic if inhaled, but do not present a

risk if ingested or if applied to the skin (e.g. silica

sand).

Differences in concentrations that can lead to

a hazardous effect are particularly significant

when considering constituents of NIHW. Examples of these differences for acute toxicity are

presented in table 1. All of the compounds presented in this table have been designated as hazardous constituents by EPA based on results

from scientific studies of toxicity, carcinogenicity, mutagenicity, or teratogenicity. (13) The

amount of each substance listed in the table that

is required to produce the same result (i. e., death

in 50 percent of the test population) varies greatly and ranges from 3 mg/kg for cyanide to 5,000

mg/kg for toluene. (14) (It is interesting to note

that the lethal dose for a commonly used product—table salt—is equal to 3,000 mg/kg, an

amount less than that for toluene. Because of the

lack of evidence that salt is carcinogenic,

mutagenic, or teratogenic, it has not been designated a hazardous constituent for waste. As

table 1 suggests, not all constituents of NIHW

are equally toxic; the level of toxicity depends

Table 1 .—Toxic Doses for Selected Hazardous

Waste Constituents

Compound LD50a

Cyanide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Phenylmercuric acetate . . . . . . . . . . . . . . . . . . . . . . . 30

Dieldrin. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

Pentachlorophenol . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

DDT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113

Naphthalene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1,780

Toluene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5,000

aAmount (mg/kg body weight) that IS lethal for 50 percent of the test Population, in these examples followlng oral administration to rats.

SOURCE: Examples of compounds are taken from EPA regulations, sec. 261.33

and app. Vlll (13). LDM concentrations are taken from I?eg/stry o/

TOXIC Effects of Ctrernmal Substances, 1980 edlfforr (14).

on properties of the waste constituents, amounts

(dose) available for uptake by plants and animals, and concentrations accumulating in surface and ground water.

The quality of an adverse effect (i.e., immediate death, reversible or irreversible illness)

is also influenced by the exposure period. A

large quantity of any compound given in a single

dose can produce death in organisms (humans

included). For some types of substances deleterious consequences may not be observed or

may be much less serious when the same dose is

encountered over a long time period. For example, although table salt can produce severe effects at extremely high doses, small amounts ingested during prolonged use do not often present

health problems, except for particularly sensitive individuals. The importance of concentration and exposure period in determining potential risk is the basis for setting standards that

describe permissible levels of some compounds

present in our food, water, and air.

Chemical and physical properties of NIHW

and interactions among constituents determine

the potential for degradation and accumulation

in organisms, as well as their movement in the

environment. Some classes of compounds can be

degraded easily by micro-organisms or through

physical processes such as photolysis and

hydrolysis. Other compounds are extremely

stable and can accumulate to dangerously high

levels in the environment or organisms. Concentrations and interactions of waste constituents

also influence rates of degradation and accumulation. Likewise, interactions among waste

constituents can result in products with

solubilities different from the original compounds, thus affecting their movement among

environmental media.

The actual exposure of humans and other

biota to waste constituents depends not only on

chemical and physical properties of the waste

but also on characteristics of the storage, treatment, or disposal system. Rates of movement of

NIHW in the environment to points of potential

exposure are influenced by such factors as type

of soil, climatic conditions at the site, hydrogeological factors (e. g., the presence of underlying bedrock or aquifers), and “steady-state”
10

conditions can be disrupted by natural disasters, ●

such as floods or earthquakes. Some chemicals

may migrate rapidly through the environment

that surrounds the management site and may accumulate in surface or ground water; others may

bind with soil particles and remain isolated from ●

vegetation or water. Thus an analysis of the

potential risk that NIHW will pose to human ●

health or the environment must include a consideration of not only the hazard potential of ●

constituents but also the fate of constituents or

their degradation products should they move ●

from the disposal storage, or treatment site.

The degree to which the presence of a specific

waste produces a hazard requires assessment of

certain critical information:

toxicological data including limits of confidence (hazards associated with exposures of

specific organisms to specific chemicals at

specific concentrations for specific durations);

safety evaluations (hazards associated with

ignitability, corrosivity, and reactivity);

waste loads (chemicals and quantities to be

stored, treated, or disposed at a site);

environmental fate (factors influencing the

movement of waste at a site); and

exposure (estimates of the chemical concentration and residence time at the point of exposure by organisms, e.g., in ground

water).

DEGREE= OF= HAZARD CONCEPT V. HAZARD CLASSIFICATION

Degree of hazard is a concept which

acknowledges that various waste managed or

mismanaged in various ways at different sites

pose different degrees of hazard to the public.

The practical application of this concept, however, requires some means of using data and information to carry out a specific task, such as

permitting a facility for waste management. In

other words, there must be some measure of different degrees of hazard if the concept is to be

applied.

A formal classification system of some type

could be used to apply the degree-of-hazard concept because the following two conditions are

satisfied:

particular waste, management strategies,

and sites have important shared characteristics; and

scientific criteria and data that describe hazards are either available or can be, in principle, obtained to make classification an objective and quantitative system.

An alternative is to apply the degree-of-hazard concept in a qualitative manner, i.e., some

type of “go/no-go” system in which waste, or

combinations of waste and management systems, are labeled as hazardous or not hazardous,

or perhaps as low or high priority. Such qualitative approaches, however, usually use a minimal amount of technical data and scientific information. There is little effort to apply established criteria either on a case-by-case basis or to

broader applications. Moreover, such qualitative approaches make it extremely difficult to

analyze resulting decisions.

The primary advantage of a classification approach based on a degree-of-hazard concept is

that a systematic, technical framework for dealing with complex cases is provided. This approach can be both reactive and anticipatory.

Because a qualitative approach requires less effort to develop criteria and data, its apparent

simplicity may be attractive from a programmatic perspective. However, it has little value

for long-term organization of information and

understanding of unifying principles. Moreover,

information obtained in a qualitative approach,

usually on a case-by-case basis,

ate for quantitative analysis.

Objective and Purpose

Classification System

The objective of classify

of hazard is twofold:

is not appropriof a

ng NIHW by degree
11

to identify waste that pose the most severe

threats to human health and environmental

deterioration, and

to allow development of cost-effective management strategies for each level of hazard

within the classification scheme. (Although

transportation is an important aspect of a

management strategy, the OTA assessment

of NIHW does not include transportation of

materials from generator to disposer. )

The basic premise of any system for categorizing

NIHW, however, is that the waste and/or constituents of the waste stream can be grouped according to those properties that define quantifiable effects and determine exposure under specific conditions. Because waste streams often can

contain more than one hazardous constituent, it

is unlikely whether enough information on these

types of properties is currently available for actual waste streams. Information on individual

constituents (once identified within the waste

stream) is relevant, and would permit a possible

minimal estimate of degree of hazard by compiling the combined results, ignoring synergistic

and antagonistic interactions among constituents. As pointed out in a report by the Surgeon General, the necessary information, however, is not yet available for many of the waste

constituents .

A review . . . suggests that toxicologic information is deficient or missing. . . Many of the

chemicals are not commercial products but are

their precursors or process intermediates. A major toxicologic problem is that humans are likely

to be exposed to a combination of mixtures of

chemicals. There are virtually no data on or experience in testing mixtures of chemicals for potential health effects.

Drawing upon specific technical information,

a classification system could rank waste and

waste streams by degree of hazard. Different

categories could be established according to

specified ranges of the probability of injury to

human health or the environment that might

result if the waste or waste constituents were to

escape from the management site. In addition,

management options could be matched to each

class of waste to assure that NIHW are handled

in the most cost-effective manner possible. This

match may not always be easy to accomplish.

Conceivably some waste could be difficult to

manage effectively, regardless of the identified

level of hazard, An example is the PCB-contaminated sediment proposed for dredging from

the Hudson River, Because of the relative concentrations of PCBs within the volume of sediment removed, incineration is impractical and

landfilling is considered by many to be undesirable.

The development of a classification system,

however, has four requirements:

1.

2.

3.

4.

establishment of standard criteria and

methods, which are widely available and

generally accepted by the scientific community;

identification of widely accepted indicators

of the relationships of real-world exposure

to potential toxicity;

definition of acceptable levels of hazard for

each category in the classification system;

and

an equitable and inexpensive mechanism to

administer the program.

Fulfillment of these requirements will not be simple, as there currently is debate about the best

testing scheme (#I); and choice of indicator species (#2); particularly when evaluating chemical

effects on the environment. (16,17)

Classification of waste by degree of hazard

could serve several purposes:

●

●

●

●

●

it could facilitate establishing priorities of

NIHW for inclusion in Federal or State regulations;

it could indicate the level of emergency

measures required in the event of an accidental or deliberate spill;

it could set priorities in use of scarce highsecurity landfill facilities or more costly

technologies for treatment or disposal;

it could influence general management policies that determine the stringency of regulation, liability coverage, or the required

level of monitoring; and

it could provide a scale by which cost factors are included in determining the choice

of management procedures.
12

Economic Effectiveness

Compared to present Resource Conservation

and Recovery Act (RCRA) regulations, the use

of a hazard classification system could change

dramatically the way in which many hazardous

waste are disposed. Many facilities treat all

waste similarly and costs to users are generally

high; with a hazard classification system it may

be possible to reduce costs for the disposal of

some less hazardous waste. Because of the high

hazard posed by some waste now being handled

in a least costly (but legal) manner, the disposal

method may have to be changed to a more expensive practice. The basis for requiring such a

change in disposal practices is that the more

costly management alternative would be more

effective in detoxifying or destroying waste classified as extremely hazardous.

In order to illustrate the potential economic

effectiveness and logic of applying a degree-ofhazard classification system, decision analysis

can be made by using proxy disposal alternatives, as illustrated in figure 3. This comparison

assumes that landfill disposal corresponds to current RCRA regulations without use of a degreeof-hazard classification. Using this type of classification, extremely hazardous waste would be

incinerated in this example to assure their complete destruction. Although landfills have a

Figure 3.— Decision Analysis Illustrating the Impact

of Degree of Hazard on the Choice of Management

Practice

lower cost per ton of waste, there is some probability of failure. Failure is defined as the creation of a hazard for people or the environment at

some future time, even using currently accepted

best available technology and engineering judgment. The costs used in this figure are based on

present technology and practices; the cost of

cleanup represents an average number based on

documented remedial activities. These figures,

however, should not be considered precise, and

are used only for illustration.

The purpose of using a decision analysis is to

illustrate that although incineration may appear,

in the short term, to be substantially more expensive than landfills, when the probability of

future damage (the critical probability in this example is 15 percent) and cleanup costs ($2,000/

ton) are relatively high, the decision to choose

incineration is logical and economical. For this

illustration, it is assumed that cleanup costs are

borne (directly or indirectly, such as through

insurance costs) by the decisionmaker, who is

considering alternatives. In other words, when a

waste is considered to present a high enough

hazard and major risks are taken into account

(internalized into the economic decisionmaking), using a management strategy with higher

initial costs than other alternatives can be appropriate. If the perceived or estimated probability

of landfill failure is 20 percent (as in example B in

fig. 2), then incineration costs are $100 less per

ton than landfill costs. When the probability is

reduced to 10 percent (e. g., a value associated

with a lower degree of hazard for a different

waste or a different site), however, landfill

becomes the most cost-effective alternative,

assuming that monitoring is 100-percent effective and cleanup takes place before damage occurs to human health or the environment.

SOURCE Off Ice of Technology Assessment
13

UNCERTAINTIES IN IMPLEMENTATION

No matter which degree-of-hazard classification system is considered for use with NIHW

management, uncertainties regarding potential

hazards will always exist due to limited data on

waste, health and environmental effects, and

sites. If the uncertainties are identified and

acknowledged, a workable system might still be

developed. The major requirement in formulating a classification system is the assurance

that both objectives of a degree-of-hazard approach are met, It is not sufficient to only identify those NIHW of priority concern; if a degreeof-hazard system is to be effective, management

strategies that reflect differences among categories of hazard also are needed. Design of treatment and disposal facilities needs to focus on the

capability to minimize off site migration of waste

constituents; while this focus is necessary, it

could make permitting a more difficult task as

prediction of offsite migration is often difficult.

The impact of this type of system on large and

small industries is also unknown.

Implementing the mandate of RCRA through

a regulatory approach based on degree of hazard

requires development of a realistic, yet uncomplicated, system. This point was emphasized in a

recent report by the Conservation Foundation

on developing a classification system for management of low-level radioactive waste.

A workable and enforceable system must be

devised that takes account of limited financial,

institutional, and physical resources. When illconceived rules exist, the public and participants

in the waste management system will disobey

not only the senseless rules but also the significant, well-drafted ones. Compliance is especially important with rules directed towards defining and classifying wastes, since ignoring safeguards at this initial step will hinder the effectiveness of subsequent stages of waste disposal.(18)
Degree of Hazard in the Current

Regulatory Approach

Those regulations aimed at defining which

waste are hazardous are not currently based on a

strictly interpreted degree-of-hazard concept:

the established criteria identify waste only as

hazardous or nonhazardous. If a waste stream is

to be considered hazardous and therefore within

the jurisdiction of the Resource Conservation

and Recovery Act (RCRA) regulations, it must

first meet one of three criteria, and then it is

evaluated by the Environmental Protection

Agency (EPA) to determine whether listing is required. EPA has chosen in some instances to

use considerable discretion in applying the second and third criteria when designating a waste

stream as hazardous, and in others to apply appendix VIII of EPA’s regulation in an indiscriminate manner. The three criteria are:

● The waste exhibits any of the characteristics

(i.e., toxic, ignitable, corrosive, or reactive)

identified in subpart C, Characteristics of

Hazardous Waste, of the regulations. (It is

the responsibility of industry to determine if

a waste meets this criterion. )

● The waste is fatal to humans in low doses;

or studies indicate the following acute toxicit y levels: oral LD50 in rats—less than 5 0

mg/kg, inhalation LC50 in rodents—less

than 2 mg/l, dermal LD50 in rabbits—less

than 200 mg/kg; or “. . . is otherwise capable of causing or significantly contributing

to an increase in serious irreversible, or incapacitating reversible, illnesses.’’

 The waste contains any constituents listed

in appendix VIII, Hazardous Constituents,

of the regulations, unless after evaluating

several 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, disposed of, or otherwise managed. . .“ (13)

Based on these criteria, EPA has prepared lists

of designated hazardous waste from nonspecific

14

sources, specific sources, and discarded products

listed as acute hazard or toxic waste. EPA can,

and probably will, make additions to these four

lists as well as to appendix VIII and could develop other lists of waste classes that it considers

to be hazardous and therefore subject to regulation.

Development of a regulatory framework for

managing NIHW has just begun; thus an evaluation of the effectiveness of current regulatory approach is premature. Although a degree-of-hazard scheme based on specific criteria has not

been explicitly applied by EPA, incorporation of

the concept that different hazards exist is implied

or used in some sections of EPA proposed regulations, With reference to the degree-of-hazard

concept, and the use of phrases such as “substantial threat, ” “hazard posed, ” and “extent

necessary to protect human health and environmerit, ” an opportunity is provided for judgments to be made, probably in the courts, without technical basis. To date, no scientifically

based criteria have been established by EPA that

can be used to make decisions about threats or

hazards posed or the extent to which humans

and the environment are protected. Put another

way, many generators and disposers of waste as

well as third parties such as insurance companies

face an “unbounded” situation (e.g, in setting

liability limits), with no programs being developed for adding substantive meaning to the

qualitative language frequently used in proposed

regulations.

Table 2 illustrates selected sections of the proposed regulations where degree of hazard may

be considered by the permitting authority, either

in identifying NIHW or in the management of

NIHW storage, treatment, or disposal. For example, EPA has excluded from federally permitted disposal sites those waste in amounts

that are less than 1,000 kg/month (for administrative convenience) and is considering a

further change to reflect tighter restrictions (less

than 100 kg/month) suggesting that these are
15

Table 2.—Selected Examples of a Degree-of-Hazard Interpretation in Current RCRA Regulations

Identification of NIHW

Small quantity generators.—Waste from a small quantity generator are not subject to regulation under parts

262-267 and 122-124 and are not subject to the notification requirements of 3010 of RCRA. A small quantity

generator is one who generates less than 1,000 kg of

waste per month, or less than 1 kg of acutely hazardous waste.

Criteria for listing hazardous waste.—One condition for

listing a solid waste as a hazardous waste is if the

waste contain any of the constituents listed in app. VIll

unless after considering any of the factors listed (e.g.,

nature of toxicity, persistence, bioaccumulation potential and migration potential of the constituents, and

quantities of waste generated) the Administrator concludes that the waste is not capable of posing a

substantial threat to human health or the environment.

Transportation

Pretransport requirements. -Packaging required in

accordance with DOT regulations, which are based on

hazard classes.

Labeling required in accordance with DOT regulations,

which are based on hazard class.

Marking required in accordance with DOT regulations,

which are based on hazard class.

Placarding required in accordance with DOT regulations, which are based on hazard class.

Spills. —Use DOT spill-reporting system, which is based

on severity of spill.

Emergency

Preparedness and prevention.—

●

●

●

Facility design and operation.—Design, construct,

maintain, and operate facility to minimize fire, explosion, or release of hazardous waste, which would

threaten human health and the environment; includes

use of performance standards.

Emergency equipment.— Emergency equipment required only if the waste handled pose a hazard, which

requires specific kinds of equipment.

Arrangements with authorities.—Arrangements required as appropriate for the type of waste handled

and the potential need for such services.

Contingency plan and emergency procedures.—Plan

must be designed to minimize hazards to human health

and the environment from fires, explosions, or release

of waste.

Facilities

Security.— Prevent unknowing entry and minimize possibility of unauthorized entry, unless contact with the

waste will not injure unauthorized persons or livestock

and if unauthorized entry will not result in inability to

comply with standards.

Environmental performance standard for new land

disposal facilities.—Prevent ion of adverse affects to

ground water, surface water, air quality, and subsurface environment through consideration of parameters

including the volume, physical and chemical characteristics of the waste in the facility, the potential for

human health risks caused by exposure to waste constituents, the potential damage to wildlife, crops

vegetation, and physical structures caused by exposure

to waste constituents, and the persistence and permanence of the potential adverse effects.

Regional Administrator may waive any of the design,

operation, closure and postclosure requirements to

achieve treatment of a waste provided the environmental performance standard is met.

Regional Administrator may specify additional requirements where necessary to comply with the environmental performance standard.

Closure: plan and fund.—Closure must result in control,

minimization, or elimination of postclosure releases to

the extent necessary to protect human health and the

environment. Fund required to meet cost of closure.

Insurance: sudden and nonsudden.—Minimum liability

amounts specified may be increased or decreased

depending on hazards posed. Premiums charged reflect

degree and duration of risk.

Technology

Underground injection.—An injection well must be designed to assure compliance with the environmental

performance standard.

An injection well must be operated in a manner that

will comply with the environmental performance standard.

Methods for operating an injection well must reflect a

consideration of the volume and physical and chemical

characteristics of the waste injected in the well.

Incineration.—Regional Administrator selects principle

organic hydrocarbons (POHCs) based on hazard posed

considering incinerability, concentration and quantity.

Performance standard requiring 99.99 percent destruction of selected POHCs.

Range of acceptable operating limits determined for

each waste feed.

SOURCE Consideration of Hazard In the Regulations unpublished document from Environmental Protection Agency, Off Ice of Solid Waste

not sufficient quantities to pose a threat to humans or other organisms. ) The pretransport

health or the environment. (These exclusion requirements are based on regulations of the Deamounts do not consider the potential toxicity of partment of Transportation that, in turn, are

these waste, however; a very toxic waste pro- based on classes of hazard. The regulations govduced in small quantities could be hazardous to erning spills are based on the ‘severity’ of the
16

spill. (No definition of severity is provided and

the March 1981 craft of the National Contingency Plan defines quality of a spill according to

the size of the discharge.) The proposed facility

standards are based on performance rather than

specific design, but do not provide criteria for

assessing performance; if the type of waste or

the environmental conditions surrounding the

site are such that little or no migration of constituents were possible from the site to potential

sources for exposure of humans or other living

organisms, application of performance standards could permit less stringent control measures

to be used. (20)

As the regulations are currently designed the

stringency of control for any facility whether

onsite or off site is apparently determined by the

permitting authority within each State or region.

While this may provide the opportunity to regulate NIHW disposal by degree of hazard, uniform application of this type of approach is not

assured, particularly in the absence of specified

criteria for evaluating predicted performance of

facilities. EPA’s approach does permit site- and

waste-specific flexibility in permitting facilities.

Left to the interpretation of individual permitting authorities, confusion and unequal enforcement could result. Some of the confusion and inconsistency might be avoided through public

participation (i. e., through concern about siting

new facilities) in the permitting process and

through the use of litigation to prevent authorization of those facilities that are perceived as

not being safe. It is uncertain, however, if these

are the most appropriate ways to achieve effective management and enforcement of EPA

regulations.

Because RCRA regulations are in the interim

final stage, it is possible to apply the concept of

degree of hazard within the current structure.

For example, specific criteria based on degree of

hazard for the waste to be handled could be developed for assessing the performance of storage, treatment, or disposal facilities. In addition,

a degree-of-hazard classification and management system could be incorporated into the regulations incrementally, thus reducing transitional uncertainties that would arise if the entire

program were changed radically and suddenly

from its present design. As table 2 suggests, EPA

is moving toward application of a degree-of-hazard concept in a qualitative manner. The major

uncertainty is whether a rigorous classification

scheme with scientific criteria can be and should

be implemented fully within the regulations.
Methods for Classifying Waste and

Facilities by Degree of Hazard

There are several ways to develop a system of

classifying both NIHW and management facilities by degree of hazard: grouping by technical

criteria, rank order by test results for specific

characteristics, the use of multiple discriminatory factors for categorization that concentrates on important exposure and effects

data, or classifying by environmental containment, Of these various methods, only the first

has received much attention. The other schemes

have been applied in narrowly focused tasks and

are very speculative options for adaption in

management of nonnuclear industrial hazardous

waste (NIHW). The systems presented in the following discussion serve only as examples of

these various types of classification methodology. The omission of any specific design does

not reflect a judgment as to the appropriateness

of the omitted example. Because of the variety of

potential designs, the intent is to indicate the

diversity of methods, rather than to discuss all

potential approaches.

CLASSIFICATION USING TECHNICAL CRITERIA

As States begin formulating their own regulations for management of NIHW, the majority

are using a scheme based on technical criteria to

identify waste as hazardous. At present, however, definitions of the term hazardous vary

widely among the States. For example, a recent

survey indicated that 45 States use general or

qualitative definitions of hazardous, but the

term is not uniformly applied in all State

laws. (21) Among these 45, 34 States include

characteristics such as flammability, corrosiveness, and toxicity to narrow their definition of hazardous waste, but only eight of these

States specify test protocols and acceptable

ranges for test results. Thirteen States followed

the lead of the Environmental Protection Agency (EPA) and developed lists of NIHW. Of the

total 45 States in this survey, only five considered measures of volume or specific chemical,

physical, and toxicological characteristics to

distinguish between more than one class of

NIHW; these include California, Illinois,

Maryland, Pennsylvania, and Washington. Four

States—California, Rhode Island, Texas, and

Washington—proposed detailed programs using

different technical criteria of toxicity to classify

NIHW in response to the 1978 proposed regulations. Recently other States, including Kentucky, Ohio, and Michigan, have developed

some form of a degree-of-hazard program for

managing NIHW. The programs discussed below are presented only as illustrations of this

type of classification methodology.

California.—California has a two-tier system

for classifying hazardous waste, hazardous and

extremely hazardous. Criteria based on toxicity,

flammability, pressure-generating reactivity,

corrosivity, irritancy, and sensitizing properties

are used to describe each category, The major

determining factor that distinguishes between

the two groups seems to be the level of toxicity.

To designate a waste as hazardous, certain toxicity measurements are required: acute toxicity

(i.e., short-term response), carcinogenicity,

chronic toxicity, and estimates of degradability

and bioaccumulation (see table 3). The category

designated as hazardous has acute toxicity test

results in a range of 51 to 2,000 mg/kg, contains

substances that are known or suspected to be

carcinogens, are considered nondegradable, accumulate in tissue, and can contribute to chronic

health problems. The extremely hazardous category includes those materials that are shown to

have high levels of acute toxicity (equal to or less

than sO mg/kg), that are defined by California

law as carcinogens, or that have been tested in

the laboratory and results indicate that they are

17
18

‘Table 3.—Toxicity Criteria in the California System of Degree-of-Hazard

Classification

Limits a

Extremely hazardous Hazardous

%tg of material/kg body weight of Organism

SOURCE. Sterllng Hobe Corp. (12).

potential carcinogens, cause chronic toxicity,

are nondegradable, and accumulate in tissue.

Except for differences between the moderate and

high levels of acute toxicity and the State definition of some carcinogens, no quantifiable measures have been provided to distinguish the other

toxicity criteria between categories, except for

threshold limits of certain compounds that have

been specified in the California legislation. Limited technical justifications for minimal differences between criteria for classifying waste as

hazardous or extremely hazardous have been

provided,

Although the California proposal places

NIHW in different classifications, management

practices do not vary between the two categories. The waste ( i.e., hazardous or extremely

hazardous) are sent to the same type of facility

and treated in a similar manner. Transportation

and admninistrative procedures for handling

NIHW (e.g., recordkeeping) are maintained separately for each category. The utility of the proposed classification without differences in management practices is dubious.

A further classification system exists in this

State under the authority of the Water Quality

Control Board and is independent of the above

system. Waste are put into one of three groups

based on the probability of ground water contamination. These waste are directed to match

facility sites that have specific geological structural standards related to each group of waste.

Rhode Island. —The State of Rhode Island has

developed and implemented a system that attempts to rank the materials using several characteristics of hazard, e.g., levels of toxicity, reactivity, flammability, and irritancy. Distinctions such as high, moderate, and slight are designated for each characteristic. Qualitative and

quantitative definitions of each level (e.g., moderate flammability) are provided. Responsibility

for determining correct classifications of the

waste lies with the generator. The transport

manifest includes a description of waste constituents and the designated classification. State

officials use this information to verify that an

appropriate classification has been made. If a

disagreement about the assigned class results

between generator and State officials, conflicts

are resolved through further testing.

Industry representatives have worked closely

with State officials in formulating criteria for

each degree-of-hazard category. Although

this scheme is comprehensive and detailed, it is

currently being used only in recordkeeping and

for limiting routes of transportation. The State

has developed criteria for land disposal; however, all waste are currently sent to out-of-State

disposal facilities.
Texas.–Prior to development of the EPA

proposed regulations, the Texas Department of

Water Resources proposed using a classification

system based on differences in the potential for

adverse effects on human health or the environment.(23) The definitions and specific measurements were derived to identify potential impacts

resulting only through land disposal of industrial

solid waste. The system included both a list of

hazardous substances and criteria for designating new waste as hazardous. Table 4 illustrates the type of measures proposed for classifying materials. The basic difference between

Class II and Class III in this scheme was that the

latter represents inert materials, e.g., essentially

insoluble and not readily decomposable materials including rock, brick, glass, dirt, certain

plastics, and rubber. Placement of a NIHW

within a particular class was to be based on analysis performed by the appropriate State agency.

Some important characteristics of potentially

hazardous waste (e.g., chronic toxicity, genetic

impairment, and persistence) were not included

in the Texas system. Also, criteria were designed

solely for use in land disposal and little indication of the applicability of the scheme for other

management practices was provided. The Texas

definition of Class I materials corresponded to

EPA’s current definition of hazardous waste, as

both of the other classes identify relatively nonhazardous materials. If the plan were to be implemented under EPA regulations, State officials

would manage waste from Classes II and III on a

Table 4.—Criteria for the Texas System of

Degree-of-Hazard Classification

Class I Class II Class Illa

Hazard indexb . . . . >50 >50

LD50 measures c . . .

p H

d 

. . . . . . ... , . . . <2.5, > 12 2.5 –12 2.5 – 12

Corrosion ratee . . . <0.25 in/yr >0.25 in/yr >0.25 in/yr

Flash pointf 

. . . . . . >140° F >140° F

asee text for Composltlonal differences between Class II and class Ill

bf+epreserlts the potential hazard to the environment If lmPrOPf3rlY disposed

based on measures of toxlclty and solubillty of the substance.

cMedlan lethal dose; dose required to kill ~ percent Of a POPU(atlOfl exposed fo

the chem!cal of concern.

dMeasure of actdlty or alkallnlty; pH 7 indicates neutral solution; <PH 7 In.

dlcates acidic Solut!on, >pH 7 Indicates alkaline or basic solutlon.

ecorroslon rate on steel (SAE IOZO) at a test temperature of 130“F as detefmlned by NACE.

f Determined by a Pensky+fartens Closed Cup Tester using ASTM Std. D.93-73.

SOURCE Sterllng Hobe Corp. (12)

waste- and site-specific basis. Management practices for waste classed as hazardous (Class I)

would closely follow the regulations by

EPA. (23) Therefore, as presently designed this

proposed system does not really provide a

degree-of-hazard approach.

One major drawback to these three systems

(i.e., California, Rhode Island, and Texas) is

that there is no consideration of actual or potential concentrations at the source of exposure. As

discussed previously, it is the concentration at

the time of exposure that has the greatest influence on the severity of any adverse effect.

Any system that does not consider dose level

cannot be consistently effective in providing relevant protection either for human health or for

maintaining a clean environment. Another important problem with these systems is that criteria for listing new waste as hazardous are not

comprehensive enough to adequately “catch” all

potential NIHW. Primary measures of toxicity,

either in the hazard index or LD50 criterion, depend only on acute toxicity. No consideration is

given to waste that may result in chronic health

problems or long-term, low-level deterioration

of the environment. Thus a number of chronically hazardous waste could pass the tests provided in these systems, but could still pose hazards to humans and other organisms.

Washington.—The Department of Ecology

for the State of Washington has developed a

classification system that includes some consideration of concentration and potential exposure, This system has two classes designated

as extremely hazardous and dangerous. The distinguishing criteria among the two classes include characteristics of persistence, concentrations in the waste stream, potential to cause genetic effects, level of toxicity, and concentrations of specific classes of known toxic chemicals

(e.g., polycyclic aromatics). Table 5 illustrates

these distinctions. Extremely hazardous waste

are further ranked into two categories: 1) hazard

resulting from toxic effects on humans and wildlife; 2) hazard attributed to the persistence of the

material. Specific criteria for extremely hazardous waste include complex combinations of different measures of acute toxicity and percent

volume of specific waste constituents. An important aspect of this system is that the method-
20

Table 5.—Criteria for the Washington System of Degree-of-Hazard Classification

Extremely hazardous Dangerous

Oral, rat, LD50

a

. . . . . . . . . . . . . . . . . . . . . . <500 mg/kg <5,000 mg/kg

Aquatic fish, LC50 . . . . . . . . . . . . . . . . . . . <100 mg/l <1,000 mg/l

Halogenated hydrocarbons . . . . . . . . . . >1% >0.01%

Polycyclic aromatics . . . . . . . . . . . . . . . . >1% None

Concentration of heavy metals in EPA

leach test. . . . . . . . . . . . . . . . . . . . . . . . 10,000 x DWSb

100 x DWS

Nonbioaccumulative carcinogens . . . . . — IARCC human or animal:

positive or suspected

Corrosivity, reactivity, ignitability . . . . . — EPA definition

aFor Purg compounds or Slrnple rni xtures book designation using the NIOSH Register and the designation diagram are POSSL

ble, set! appendix.

bDWS = drinking water standard.

CIARC =, International Agency for Cancer Research. This group weighs published studies on suspected cancer causing

agents and issues findings.

SOURCE: Provided by E. W. Tower, Solid Waste Management Division, Off Ice of Land Programs, Department of Ecology,

State of Washington, Olympia, Wash.

ology has been developed for classifying waste

mixtures and permits an evaluation of potential

hazard at the point of exposure. (24) (see also appendix.) Any nontoxic waste in amounts exceeding 100 lb/week that is considered corrosive, explosive, or flammable is classified as dangerous

waste. Disposal of this class of materials is regulated less stringently than extremely hazardous,

In this system, the generator is responsible for

determining the correct classification of a waste.

If toxic constituents are known, classification

can be made without testing; if waste components are not known with any degree of certainty, either qualitatively or quantitatively,

analytical tests must be conducted to identify

constituents and determine their degree of hazard. The State has developed standardized rat

and fish bioassays to be used as biological indicators of toxicity in the degree-of-hazard assessments. Tests must be performed to ascertain

flammability and corrosivity of dangerous

waste. A prose test (narrative description) is applied to determine explosive potential.

The degree-of-hazard approach has also been

applied to facility standards. Washington State

law requires that extremely hazardous waste

must be disposed at the Hanford site where the

climate and topography of the eastern section of

the State is best suited to contain these more hazardous wastes. Dangerous waste can be disposed

of at any other permitted site, which follows the

criteria established by EPA. State officials consider that these restrictions address the exposure

potential of NIHW to humans or other biota.

The Washington State system has been in

operation since 1978 and as yet no major problems have emerged. This approach for classifying and managing NIHW appears more stringent than the EPA regulations. Therefore, problems could develop for interstate transportation

and the acceptance of out-of-State waste by

Washington State disposers.

Other Schemes.—In reponse to the December

1978 publication of regulations proposed for implementing RCRA, 12 classification schemes

using a degree-of-hazard approach were proposed to EPA in addition to the State

systems. Most of the 12 schemes formulated

technical criteria using qualitative or quantitative measures of toxicity, safety hazards, environmental fate, and management practices.

Many of the proposals lacked detail on technical

criteria and served only to suggest how a classification system might be developed. Three of

these proposals did provide some detail about

the type of criteria to be applied in each category. Table 6 illustrates these characteristics.

All of the proposed schemes, including those

of the four States, have major disadvantages.

Table 7 provides a comparison with respect to

the type of technical criteria required. Those

characteristics that may be considered to be of

prime importance for identifying NIHW include

estimates of potential genetic impairments (e. g.,

carcinogenicity, mutagenicity, teratogenicity),

measures of acute and chronic toxicity, degree of

persistence and bioaccumulation, estimates of

potential concentrations in waste, indications of
21

Table 6.—Proposed Technical Criteria for Classifying Nonnuclear Industrial Hazardous Wastes

System 1 System 2 System 3

Class I Genetic impairment and persistence;

or high-level acute toxicity; or

moderate acute toxicity and persistent; exceeds 1,000 X drinking water

standards.

Class II Genetic impairment and not persistent; or moderate acute toxicity and

bioaccumulates or persistent; or 300

to 1,000 X drinking water standards.

Class Ill Low acute toxicity and bioaccumulates or persistent; or 100 to

300 X drinking water standards.

High acute toxicity and concentration exceeding 100-mg/kg

waste; or reaction at normal

temperature and pressure; or

or forbidden explosive (by law).

Flash point <1000

F, considered

hazard during management; or

flammable compressed gas; or

pH <2 or >13; or corrodes steel;

or highly reactive; or exceeds

100 X drinking water standards.

Flash point 100° - 200° F; or

hazard during burning; pH 3-12;

or less than 100 X drinking

water standards.

Moderate to high acute toxicity; or

genetic impairment, persistent or

bioaccumulates; or reactive or

infectious.

Low acute toxicity; or ignitable,

corrosive or reactive; or low in feetibility.

SOURCE Sterllng Hobe Corp (12)
22

the potential for exposure to sensitive biota or to

humans, and measures of ignitability, corrosivity, and reactivity. Except for the Washington

State system, concentrations of the waste-stream

constituents have not been considered. In most

of these systems, chronic toxicity is not a criterion, nor is there any assessment of the potential for movement from the waste site. Some of

the proposed systems rely on previously set

standards, when such standards (e. g., water

quality criteria standards) exist for only a few

compounds. This approach could permit some

extremely hazardous waste constituents to remain unregulated. Finally, none of the systems

to date has management strategies or facility criteria that relate to the different identification

categories in a relevant way.

RAN K= ORDER CLASSIFICATIONS

With passage of the Toxic Substances Control

Act (TSCA) the need for mechanisms by which

chemicals could be given priority for further toxicity testing received much attention. Several models have been developed that combine

test scores for a variety of toxicity tests: LD50 or

L C50 ranges, carcinogenicity potency, chronic

health effects, teratogenicity potential, etc. In

rank-order schemes the compound of concern

receives a “score” that is based on a particular

combination of results from several types of

tests. Those results or tests considered to be

most important for the assessment (i. e., carcinogenicity) can be weighted to reflect this relative

importance. Once the composite score is calculated, chemicals can be ranked by their scores

and priorities established for further action.

Although the rank-order type of approach has

not been applied directly to industrial waste,

there is some potential for its usefulness in

NIHW management. For example, table 8 illustrates a rank-ordered system developed by the

State of Michigan. The State uses thi s

method to identify compounds for its Critical

Materials Register. A system such as that illustrated in table 8 could be adapted and used as a

means to classify waste or waste constituents according to degree of hazard. Particular test

results could have a greater influence on a hazard designation and thus receive more weight in

a classification scheme. For example, scores for

properties such as persistence or bioaccumulation could be multiplied by a factor of two, giving these characteristics greater weight in the

ranking. Hazard categories then could be designated by the total expected scores, for

example:

Combined score

Extremely hazardou s 46

Moderately hazardous. ., 25-45

Slightly hazardous , 24

This range of categories is given only as an

example of how the system might operate.

Before limits for each group could be defined

and justified, careful consideration of all criteria

is needed. Development of such criteria would

require extensive research efforts.

Several schemes similar to rank-order assessments have been proposed as methodology for

performing hazard assessment, (28,29) Table 9 illustrates the types of factors included in assessments of potential biological impact and dispersion of NIHW. Recently, ranked classifications

based on the statistical technique of discriminant

analysis were proposed. This type of analysis was used to classify waste streams from

selected smelting and refining industries. This

particular approach was suggested as being appropriate for rank-order classification of management practices or facility sites.

Recently this type of classification has received some criticism. (31) These criticisms focus

on the following points:

 combining scores of different effects into

one index for ranking purposes entails making a value judgment; and

● there is no logical basis for assigning

weights to specific factors due to the diver-
23

Table 8.— Michigan’s System for Rank-Order Assessment of Critical Materials

1. Acute toxicity

Score Category

Oral L D50 Dermal LD50 Aquatic 96 hour LC5 0

mg/kg mg/kg mg/l

7 <5 <5 <1

3 5-50 5-200 1-10

2 >50-500 >200-500 >10-100

1 >500-5000 >500-5000 >100-1000

0 >5000 >5000 >1000

●

Insufficient information

Il. Carcinogenicity

Scor e Category

7 Human positive; human suspect;

animal positive

3 Animal suspect

2 Carcinogenic by a route other than oral or dermal;

strong potential carcinogen by accepted

mutagenicity screening tests or accepted cell

transformation studies

1 Potential carcinogen by accepted mutagenicity

screening tests or accepted cell transformation

studies

o Not carcinogenic

●

Insufficient information

Ill, Hereditary mutagenicity

Score Category

7 Confirmed

4 Suspect - multicellular organisms

2 Suspect - micro-organisms

o Not a hereditary mutagen

●

Insufficient Information

IV. Teratogenicity

Score Category

7 Confirmed

3 Suspect

o Not teratogenic

.

Insufficient information

— ——. .

SOURCE Michigan Department of Natural Resources (27)

Table 9.—Suggested Effect and Exposure Factors

Exposure Effects

Bioaccumulation Genetic impairment

Persistence Reproductive changes

Mobility Acute toxicity

Environmental concentrations Chronic toxicity

Geographic dispersion Ecosystem changes

Population factors Dose factors

SOURCE Modified from TSCA-interagency Testing Committee, subgroup S

(31)

v. Persistence

Score Category

4 Very persistent

3 Persistent

2 Slowly degradable

1 Moderately degradable

o Readily degradable

.

Insufficient Information

VI. Bioaccumulation

Score Bioaccumulation Log P

7 >4000 >6.00

3 1000-3999 5.00-5.99

2 700-999 4.50-4.99

1 300-699 4.00-4.49

9 <300 <4.00

●

Insufficient information

VII, Esthetics

Score Category

Fish tainting/taste and

odor (threshold level

in water - mg/l)

3 0.0001-0.001

2 >0.001-0.01

1 >O.O1 -0.1

0 >0.1

VIII. Chronic adverse effects

Score Categor y

4 Irreversible effects

2 Reversible effects

Foaming, floating

film, and/or major

color change

Yes

No

1 Adverse effects by route other than oral, dermal or

aquatic

o No detectable adverse effects

●

Insufficient information

sity and composition of the various test

parameters.

It has been argued that this method of setting

priorities eliminates the necessary indications of

the relative importance of any individual factor.

For example, the fact that a chemical may be

persistent and produce chronic effects could be

very important, but might be overshadowed if
24

no other adverse effects were measured. Much the wide range of waste-management problems

developmental work will be required before that currently exist.

such rank-order approaches can be applied to

MULTIPLE DISCRIMINATORS

A new concept based on multiple discriminatory factors, commonly termed red-flag, is

being considered as an appropriate way to rank

chemicals under TSCA jurisdiction. In this

approach a chemical receives scores based on

specific test results, similar to those presented in

table 8. Within each test category, however, a

minimum score termed a discriminatory factor

(e.g., a score greater than 2 for persistence or

greater than 3 for bioaccumulation) is identified

that serves to “flag” the chemical for further

attention.

A classification system for NIHW could be

developed using the red-flag approach and combining exposure and effect factors (see table 9).

The discriminatory factors could be combined in

a logical manner within each class. For example,

a chemical might be classed as extremely hazardous if it received high scores

flags) in areas of carcinogenic

(and therefore red

effects, chronic effects, bioaccumulation, persistence, and mobility. Another example includes classifications

based on a hazard index that is developed by

combining certain discriminatory factors; for example, by combining quantity discharge, bioaccumulation, and persistence into one index value

or by using a combination of environmental

concentration, bioaccumulation, and persistence. This type of analysis represents a new approach in identifying priority compounds and

can be considered only as a speculative option

for use in classifying NIHW. Before acceptance

or rejection of the concept, however, careful

study is needed to determine if this approach is

appropriate for identifying as well as managing

the treatment and disposal of NIHW.

CLASSIFICATION BY ENVIRONMENTAL CONTAINMENT

Another speculative type of classification

system categorizes facilities by the ability to

minimize escape of potentially harmful substances. Here the emphasis is on management

rather than identification. Classification schemes

for sites are available, but these have focused

primarily on identifying the hazard potential of

abandoned dumps .(33,34) With some modification these schemes could be applied to landfill,

incineration, or treatment facilities as well.

Although there are serious technical concerns

over the rating levels presented in table 10, this

system illustrates the types of variables that appear to be appropriate. These include the distance to nearest population and drinking wells,

critical environments, distance to nearest surface

water, depth from facility to ground water,

amount of precipitation, soil permeability,

bedrock permeability, and depth to bedrock.

Once facilities are classified, the waste streams

could be grouped according to those chemical

and physical properties that are major factors

contributing to the potential movement of

NIHW constituents from the facility to the surrounding environment. Appropriate classes of

waste could be matched to management at the

appropriate site. Such a classification has been

suggested previously .(35) For example, NIHW

with a high potential to escape from the facility

(i.e., readily soluble in water) and not easily environmentally degraded might be put into those

sites that could minimize exposure to humans

and other biota. A system very similar to this

concept has been considered for defining and

classifying low-level radioactive waste. (18) It

has been suggested that management facilities

for low-level waste could be designed and

classed according to a specific containment time;
25

Table IO.—Suggested Environmental Parameters for Classifying Facility Sites

Rating factors

Population within 1,000 ft

Distance to nearest

drinking-water well

Distance to nearest

off site building

Land use/zoning

Critical environments

Distance to nearest

surface water

Depth to ground water

Net precipitation

Soil permeability

Bedrock permeability

Depth to bedrock

Rating scale levels

o

0

Greater than

3 miles

Greater than

2 miles

Completely remote

(zoning not

applicable)

Not a critical

environment

Greater than

5 miles

Greater than 100 ft

Less than 10 inches

Greater than 50

percent clay

Impermeable

Greater than 60 feet

1 2 3

1 to 25

1 to 3 miles

1 to 2 miles

Agricultural

Pristine natural

areas

1 to 5 miles

51 to 100 ft

– 10 to + 5 inches

30 to 50 percent clay

Relatively impermeable

31 to 60 ft

26 to 100

3,001 ft to

1 mile

1,001 ft to

1 mile

Commercial or

industrial

Wetlands, floodplains, and preserved

areas

1,001 ft to

1 mile

21 to 50 ft

+ 5 to + 20 inches

15 to 30 percent clay

Relatively permeable

11 to 30 ft

Greater than 100

0 to 3,000 ft

o to 1,000 ft

Residential

Major habitat of

endangered or

threatened species

0 to 1,000 ft

o to 20 ft

Greater than +20

inches

O to 15 percent clay

Very permeable

o to 10 ft

SOURCE: Modified from JRB Associates (33)

this containment potential is related to the halflife of radioactive waste. The report stresses,

however, that “no one factor would control the

assessment of risks, and . . . other screens must

be considered. Screens for classifying waste

. . . should include: toxicity, concentration,

chemical and physical form, compounds that

waste may decay to or become during storage,

volume, and possibility of release and mobility. ”

The report continues . . , “Since all waste do not

require the same degree of containment or care,

various types of disposal techniques should be

used; this would more efficiently allocate limited

resources. It should be possible to save space

and money while preserving or enhancing administrative simplicity. ” Although these statements were made for management of radioactive

waste, they are applicable to management of industrial hazardous waste as well.

Table 11 illustrates a potential scheme for

classifying facilities based on the need to minimize escape of hazardous components. Materials could be classed according to the environmental mobility and degradable characteristics

and assigned for treatment or disposal in the appropriate facility class. In such a system a facility would not be limited to handling waste

within its permit class but could receive waste

within lower classifications (e. g., a Class A

facility could receive all classes of waste; Class B

facility could receive Class B, C, and D waste

but not Class A). Although the prohibition of

landfills in the Class A designation may appear

to be a radical action, restricted use of landfills

for certain high-priority hazardous waste had

been considered by the New York State legislature. (36)

The California Office of Appropriate Technology (OAT) has completed a comprehensive study of hazardous waste disposal in

California. (37) Using currently available data,

OAT identified six classes of high priority waste

and concluded that these waste were unsuited

for land disposal. The study reviewed alternative management options for these classes of

waste and made the following recommendation

for use of the most secure landfills (Class I):

The State should abandon the concept of

Class I landfills as repositories for almost all

types of hazardous waste by restricting land dis-
26

Table 11 .—Potential Classification Scheme Based on Containment and Destruction

Landfills Incineration or treatment facilities

Class A

— Permitting requires specific operational criteria, detailed environmental

evaluation, and stringent monitoring;

facility used for waste requiring

special handling.

Class B

— Permit corresponds to currently

proposed facility standards.

Class C

— Permit by rule for recycling or routine

treatment or detoxification process.

Class D

— Permitted to dispose of nonhazardous

waste.

Restricted unless special

authorization provided by

EPA.

Permitted, if in compliance

with technical standards

based on ability to contain

NIHW.

Permitted for large volume

specialty waste (e.g., utility

waste, oil-drilling waste).

Sanitary landfills.

Designed to destroy (incinerate or biodegrade)

or detoxify (biologically or chemically)

NIHW that pose extreme hazard to human

health or the environment; some potential

for generating toxic residues.

Designed to detoxify (naturally or induced)

NIHW within finite containment period and

in compliance with technical standards.

Designed to handle readily degradable, or

totally recycled NIHW, or waste that

are incinerated without producing toxic

byproducts.

Municipal waste treatment and disposal.

SOURCE: Based on material provided by B. L, Simonsen, IT Corp., Wilmington, Calif.

posal to those waste which have been specifically identified as safe for this method of

disposal.

It appears likely that this recommendation will

be accepted by the State legislature.

The basis for this is type of scheme is the ability

of a facility to properly contain the NIHW for a

specified time period and to match this time

period with the duration for degradation or

mobility potential of the waste. Thus, those

facilities that are shown to be able to contain the

waste for a specified time or are capable of completely destroying the waste (e.g., incineration)

could be used to handle NIHW that are shown

to be highly persistent and nondegradable. If it is

known that controlled release is likely or that

there is potential for surface or ground water

contamination at some time in the future then

these sites could be used to handle waste with

degradation potentials that match the expected

time of escape from the facility. As mentioned

above, this is a highly speculative approach.

Before implementation at any level of operation

(i.e., National or State) is possible, full investigation is needed to determine the proper

facility-environment parameters, including facilities other than landfills, and to decide whether

suitable parameters can be measured for NIHW.

A thorough review of the application of this

scheme to disposal of radioactive wastes could

provide some insight into which factors are most

important.
Unresolved Questions

Because of the current lack of information and

data, none of the schemes discussed in the previous section could be immediately implemented

in a regulatory policy. Each approach has advantages and disadvantages that require substantial further evaluation. The systems that

propose to classify on the basis of specific technical criteria do not consider all of the characteristics that are important for hazard assessments.

The more complete systems, California, Washington, and System #1 (see table 7) do include

the majority of hazard characteristics: potential

to cause genetic impairment, acute toxicity,

chronic toxicity, persistence, concentration (to a

limited degree), bioaccumulation, and characteristics of safety evaluation. These approaches,

however, do not consider directly such factors

as dose, exposure potential, environmental

mobility, and sensitive environments or populations. (The Washington system addresses these

points indirectly. ) Approaches using rank order

or multiple discriminators (e. g., the Michigan

system illustrated in table 8) generally rely

primarily on effects data without much attention

being given as yet to exposure data. The multiple discriminator system, proposed for setting

priority chemicals under the Toxic Substances

Control Act (TSCA), does include some environmental or exposure parameters and thus

could have greater promise for application in

managing nonnuclear industrial hazardous

waste (NIHW). The advantage of classifying

facility and waste according to containment or

destruction ability is apparent, but there is

uncertainty with this approach also. Verification

is needed to assure that waste can be characterized in a way that reliably quantifies the potential for degradation and environmental mobility. If it could be assumed that those persistent

and relatively immobile chemicals are also those

with the highest level of hazard, then the lack of

toxicity criteria in the last approach would not

be disadvantageous; however, conclusive evidence that supports this assumption is not yet

available.

Although no perfect system exists at the present time, further consideration of the appropriate use of a degree-of-hazard concept in regulating NIHW is warranted, given the increased

attention this concept has received domestically

and internationally. A recent report of the North

Atlantic Treaty Organization (NATO) indicates

that definition and classification of hazardous

waste is a task that requires attention by member countries. The NATO countries have

followed three approaches:

●

●

●

The

describing hazardous waste in qualitative

terms,

defining hazardous waste using criteria

based on standard testing procedures, and

defining hazardous waste by the quantity of

harmful constituents.

end-result for each country has been an industrial waste list that varies in detail and in the

number of hazardous categories.

Before applying a full-scale effort toward

designing an appropriate classification system,

important questions require resolution:

● Is there is a need to change or modify the

current regulatory approach?

 Can appropriate criteria for a degree-ofhazard classification be established?

. Can the analytical burden imposed on industry be efficiently reduced by a degree-ofhazard classification system?

1. Is there a need to change the current Federal

approach?

Now that the Environmental Protection

Agency (EPA) has begun formulating the

regulatory structure for managing NIHW, an

evaluation of the advantages and disadvantages

of a degree-of-hazard concept is appropriate

before decisions can be made to implement this

type of approach. Consideration of what can be

gained by changing or modifying the current

structure is needed. Serious questions concerning the degree-of-hazard approach include:

● What are the costs required of EPA for

additional research and development efforts

aimed toward the design of an appropriate

scheme? What are the costs in time lost for

27
28

●

●

●

●

regulating and enforcing proper management of NIHW while a scheme is being developed? Any benefits derived from using a

classifying system based on degree of hazard must be greater or at least equal to these

development and opportunity costs.

What evidence exists to support the contention that use of a degree-of-hazard concept

in managing NIHW would be more cost effective than the current program? To date

quantitative evidence does not exist. An indepth analysis of this point is needed before

encouragement or condemnation of the

concept can be made.

Is it necessary to change the current regulatory structure in a drastic way? It may

not be necessary to apply a degree-of-hazard system as a replacement for the current

regulatory approach. The EPA program is

relatively new and opportunities exist

whereby this type of system can be integrated in an evolutionary manner in the

current program. Incorporating a degreeof-hazard scheme as a component of the

current program would reduce transitional

uncertainties that are sure to arise if the

entire regulatory system were to be changed

abruptly.

Are there sufficient data currently available

to apply an appropriate degree-of-hazard

classification system? In which areas will it

be necessary to do basic or targeted research before such a system can be developed? Are there substantial problems related to testing techniques, available standards for measurements, and variability of

data? These questions are now being examined by OTA.

What is the most appropriate group for expeditiously designing this type of management system: EPA, private or Government

research groups (e. g., National Bureau of

Standards), or organizations that represent

several interested parties (e. g., consumers,

producers, regulators)?

While advocates of a degree-of-hazard

classification and management system agree that

these questions are important, they argue that

the current program is inadequate, and suggest

that a degree-of-hazard scheme could be developed and effectively implemented. The California Office of Appropriate Technology (OAT)

study indicates that categorization of industrial

waste is possible and recommends that Department of Health Services should develop a “categorization scheme for hazardous waste as a

means of linking waste with preferred methods

of treatment and disposal . . .“(37) A recent

cost-benefit analysis finds:(39)

. . . that more stringent (and therefore more

costly standards) should be set on the more hazardous waste and less stringent standards for

those waste that pose smaller health risks. If one

set of standards is imposed on all types of health

risks, a serious misallocation of resources will

result with some risks being overregulated, in

the sense that dollars spent elsewhere would

provide greater reduction in health risks and

perhaps, some hazardous waste risks not being

regulated strictly enough.

Thus the current EPA attitude, supporters suggest, should be to encourage rather than discourage investigation of the concept.

Critics of EPA’s regulations have made the

following statements:

●

●

●

●

●

The waste are not categorized by intrinsic

properties that could lead to a hazardous

situation.

The criteria for listing waste rely primarily

on measures of genetic impairment and

acute toxicity; measures related to mobility,

degradability, and long-term exposure are

needed also.

Performance standards, as currently proposed, do not provide adequate guidelines

for the uniform application of the permitting process.

The current approach leads to extensive

regulation of high-volume, low-hazard

waste and inadequate regulation for very

low-volume, but extremely high-hazard

waste.

The current regulations do not encourage a

cost-effective means to control NIHW nor

to recover components from it, and because

of its exclusive rather than inclusive orientation may actually encourage increased activity to remove large quantities of hazardous waste from regulatory control.
29

2. Can appropriate criteria for hazard classes

be established?

Although specific criteria are proposed for all

the classification methods, the justification for

selected criteria has not been provided or

thoroughly investigated. Given the paucity of

information about the cause-effect relationship

between some compounds and environmental or

health hazard plus the uncertainties surrounding

the extrapolation of data from one species to estimates of risk for another, skeptics have suggested that scientific justifications cannot be

developed for a standardized classification system. The specificity of hazardous conditions and

the extreme diversity of NIHW prevents the development of realistic guidelines or standards

related to a degree-of-hazard approach. In the

current climate of decreasing resources, development of a degree-of-hazard system may produce

an unwarranted burden for data-collection. The

current program is not yet complete and there is

little justification at this date to discount the

effectiveness of EPA’s approach.

With increasing emphasis on cost-benefit

analyses by EPA and the current administration,

supporters of a degree-of-hazard concept maintain that technical justifications and scientifically

based criteria can and must be developed if the

current program is to operate effectively. Moreover, establishing boundaries for a classification

system would be no different from setting standards (e. g., EPA standards established for permissible levels of regulated substances). The task is

not easy, however; it could take several years to

develop a workable system, one that improves

existing systems. (The current regulatory program also will take time before it is fully

implemented, e.g., EPA has suggested it could

be up to 6 years before facilities receive permits. )

The variety of preparatory efforts that are necessary include a review of those data currently

available (e. g., chemical, physical, and toxicological) and those data needed to establish the

system; evaluations of interrelatedness of data

for classes of compounds; directed research to

justify certain boundaries or criteria for classes

of compounds; and development of models of

environmental fate and projected health impacts

to suit degree-of-hazard evaluations.

The concept of degree of hazard is not new.

Assessments of the potential hazard to human

health and the environment created by many

types of materials are required in other environmental regulations (e. g., Clean Air Act;

Clean Water Act; Federal Insecticide, Fungicide,

and Rodenticide Act; TSCA; and Superfund)

and much of the preparatory work discussed

above has been initiated already. In fact, EPA

has explored the possibility of developing a

screening mechanism for compliance with TSCA

that groups new chemical notifications by categories of high, medium, and low risk. (40)

Drawing upon the information and data required by these other regulations, the increased

understanding of the principles for human and

ecosystem toxicology, and elements of currently

proposed classification systems, supporters suggest that scientifically justified criteria could be

established for a degree-of-hazard classification

scheme. These criteria could include the level of

toxicity, safety characteristics, environmental

fate, potential for movement once released to

the environment, and concentrations released

from the disposal facility; the establishment of

these criteria at the national level would reduce

much of the current uncertainties within the

EPA program and could provide continuity

among the State programs.

3. Can the analytical burden inherent i n

NIHW management be reduced by a degree-ofhazard approach?

Once any regulatory system is fully implemented, generators and disposers will be required to conduct some analytical tests on waste

streams for use in leachate-monitoring activities.

These tests include screening tests for chemical

and toxicological properties for a wide range of

compounds. Skeptics of a degree-of-hazard system contend that it is unclear whether the analytical and financial capability currently exists to

accomplish the large-scale testing effort that a

classification system could demand, particularly

for small companies. While it is true that extensive testing could be required initially to facilitate classifying particular waste material, supporters of the concept argue that subsequent

analysis required of industry is routine and

minor by comparison. Extensive retesting is nec-
30

essary only if and when the industrial process

generating the waste has been changed or in

those industries using batch processes. Also the

development of adequate analytical capabilities

is necessary even under the current regulatory

system; the analytical burden imposed on industry for delisting a material now judged hazardous by EPA is currently substantial (even though

EPA may not have provided a comparable analytical justification for listing the waste); thus

supporters maintain that a degree-of-hazard

concept would net add substantially to the analytical burden. This position, however, is controversial.

If a degree-of-hazard system is developed, it

will be necessary to establish analytical criteria

(chemical and toxicological) with some care. It is

conceivable that the cost of meeting these criteria could be greater than actual disposal costs

for small volume or one-time waste generators

(i. e., waste generated through cleanup of a process unit or through accidental upset in the system; waste resulting from batch rather than continuous processes where the waste composition

varies from job to job). Care will be needed to

develop analytical criteria and methodologies

which are economically and technically applicable to these situations as well as to large-scale

waste generation.

Federal and industry efforts to validate datagathering activities for multiple evaluation of

similar waste and similar facilities could reduce

some of the costs and eliminate duplication of effort. Considerable effort will be needed to establish accredited laboratories where required tests

can be performed. Establishing a network of

laboratories could reduce the economic burden

for small and large industries alike. Some effort

in developing test methodology will be needed.

Although test protocols may already be available for analysis in one medium (e. g., water)

they generally are not easily transferable to

other media (e. g., air or soil).
In its ongoing assessment of nonnuclear industrial waste disposal, OTA will continue its

investigation of the advantages and disadvantages of degree-of-hazard classification and the

potential for incorporating it into a regulatory

policy framework. Further evaluation is needed

to answer the questions raised here and to identify, if not resolve, the uncertainties that can

emerge when developing a classification and

management system based on degree-of-hazard,

rather than some qualitative use of the concept

only. Of particular importance is an assessment

of how to implement such a scheme — no t necessarily as a replacement, but as a growing component of the current program. For example, it

may be appropriate to maintain the national

framework as it currently exists and to incorporate degree-of-hazard classification in areas

dealing with permitting or liability requirements. Another alternative is to allow the

States, as ultimate managers of the nonnuclear

industrial hazardous waste (NIHW) problem, to

develop degree-of-hazard classification and

management systems within their programs. If

this were a practical outcome of an implementation analysis, then efforts to develop uniform

criteria within the Environmental Protection

Agency (EPA) regulations would be desirable.

Full implementation of such a system requires

developing a set of technological criteria and

treatment/disposal alternatives for managing

the various classes of waste. The availability of

these alternatives is another area of some uncertainty that requires further investigation.

Figure 4 summarizes those areas that require

further research, development, and analysis,

and the possible benefits of implementing a Federal hazard classification system for management of industrial waste. Before a Federal system can be designed and implemented it will be

necessary to develop information about waste

generation, management needs and options,

classification criteria, and policy opportunities,

and the costs of obtaining these, Without addressing these information needs and the uncertainties surrounding them, the optimistic results

indicated in figure 4 may not occur or classification could have negative impacts on a national

waste management effort. If properly developed, however, a hazard classification system

might provide a cost-effective means of handling

the hazards posed by management of industrial

waste. However, an analysis of the current approach and a degree-of-hazard approach is

needed.

The problems and uncertainties of developing

and applying a degree-of-hazard classification

and management system to NIHW might be resolved by combining the interests of the public

for health protection, the needs of industry, the

initiative of State programs, and the efforts of

the scientific community, The anticipation of a

greater potential for protecting human health

and the environment and long-term economic

benefits provides an important incentive for reconsidering this concept as a potentially cost-effective way to manage NIHW.

Development of an efficient management

system, whether it follows a classification approach or not, requires that certain factors be

taken into account. The system must be designed to maximize compliance and must be enforceable; therefore, it is necessary to consider

ultimate ease of administration and capability

for institutional compliance. If the system undergoes frequent and unrealistic changes, tremendous problems can result, as was emphasized by the Conservation Foundation’s report

on low-level radioactive waste disposal. (18)

The proper role of the scientist in defining

and classifying . . . waste, now often unclear,

frustrating and constantly changing, is also a

key element in establishing an administratively

workable system. Scientists initially develop the

information used in promulgating standards

and then are required to comply with and implement classification systems that have

emerged from the political process. However,

the rules that emerge from the standards-setting

process may not reflect the actual capability or

practice of those who must comply with them.

31
32

Figure 4.—Research, Development, and Analysis Requirements and Possible Benefits of Implementation of a

Hazard Classification System

What must be done

1

What might result

SOURCE: Off Ice of Technology Assessment.

Finally, resource constraints must be assessed power—are directed toward waste that pose the

realistically. A well-designed, cost-effective greatest risks for both the short and long terms

management system will make certain that the for human health or the environment.

limited resources–whether economic or man-
Appendix: Dangerous Waste Criteria for

the State of Washington

The following description illustrates the categorization of one class of waste and suggests methods

for applying the scheme to waste mixtures. This information was provided by the Department of Ecology, State of Washington.

WAC 173=303=100 Dangerous

Waste Criteria

(I) The Dangerous Waste Criteria consist

(a)

(b)

(c)

(d)

The “Dangerous Waste Charac

WAC 173-303-090;

of:

eristics,

Toxic Dangerous Waste, WAC 173-303-101

Persistent Dangerous Waste, WAC

173-303-102; and

Carcinogenic Dangerous Waste, WAC

173-303-103.

(2) Applicability. Any person who has established

that his waste meets any of the Dangerous Waste Criteria is a dangerous waste generator, and shall comply with the requirements set forth in this chapter for

generators.

(3) Relation to Lists. The Dangerous Waste Criteria shall be the primary means used by the department to modify the Dangerous Waste Lists set forth

under WAC 173-303-080.

WAC 173=303=101 Toxic

Dangerous Waste

(1) Purpose. This section describes methods for

determining the toxicity of a waste and the criteria by

which a toxic waste shall be designated as a dangerous or extremely hazardous waste.

(2) Categorization. Table A-1 establishes categories (X, A, B, C, or D) for particular toxicity levels.

The X category is the most toxic, and the D category

is least toxic. Substances which have toxicity levels

Table A-1 .—Toxic Category

Aquatic (fish) ‘Oral (rat) Inhalation (rat) Dermal (rabbit)

Category L D50 - (ppm) L D50 (mg/kg) L C50 (mg/L ) L D50 (mg/kg)

x - < 0 1 <05 -

- <002 -<-2

A 01- 1 0 5 5 002-0 2 2-20

B 1 10 5-5 0 02- 2 20-20 0

c 10- 100 50-50 0 2.2 0 200-200 0

D 100- 1 000 500-500 0 20-20 0 200-20,000

— . —

below the D category are generally considered to be

nontoxic.

(3) Establishing Waste Toxicity. A person shall

establish the toxicity of his waste or waste constituents by applying his knowledge about his waste,

and/or by using the following information sources

and testing methods:

(a) The National Institute for Occupational

Safety and Health (NIOSH) document “Registry of Toxic Effects of Chemical Substances” (Registry);

(b) The U.S. EPA’s regulation 40 CFR table

117.3 (Spill Table); and

(c) The bioassay testing methods adopted under

WAC 173-303-110 (3).

(4) Book Designation Procedure.

(a)

(b)

A person may use the Book Designation

Procedure described in this paragraph only

if:

(i)

(ii)

(iii)

He knows the toxicity categories (as set

forth in paragraph (2), above) for the

significant toxic constituents in his

waste;

He knows the concentrations of the

significant toxic constituents in his

waste; and

He can demonstrate to the department

beyond a reasonable doubt that any

waste constituents about which he has

limited or no knowledge do not significantly affect the toxicity of his waste.

Equivalent Concentration (E. C.). A person

who is book designating his waste shall

determine the equivalent concentration (in

percent) of the toxic constituents in his waste

by using the following formula:

E.C. (%) = X% + A% + B% + C% + D%

10 100 1,000 10,000

where (X, A, B, C, or D) 70 is the sum of all

the concentration percentages for a particular toxic category.

Example 1. A person’s waste contains: Aldrin (X category)-O.Ol%; Diuron (B category)-l%; Benzene (C category )-4%;

Phenol (C category )-2 %; Cyclohexane (C

category )-5 70; Water (nontoxic)— 87%.

His equivalent concentration (E. C.) would

be:

33
34

E.C. (‘o) = 0.01% + 0% + 1 % + (4% + 2% + 5%) + 0%

10 100 1,000 10,000

= 0.01% + 0% + 0.0170 + 0.01170 + 0% = 0.03170

So his equivalent concentration equals

0.031%.

(c) Toxic Dangerous Waste Graph. To book

designate his waste, a person-shall use the

Toxic Dangerous Waste Mixtures Graph

below (fig. A-1) by finding the equivalent

Figure A-1 .—Toxic Dangerous Waste Mixtures

100,000

10,000

1,000

100

10

1

0.1

DW

EHW

0.001 001 0.1 1.0 10 100

Equivalent concentration (percent)

concentration percentage for his waste

along the absicissa, finding his total waste

quantity along the ordinate, and plotting

the point on the graph where the horizontal

line drawn from his total waste quantity intersects the vertical line drawn from his

waste mixture’s equivalent concentration. If

the plotted point is in the area marked

dangerous waste (DW), he shall designate

his waste as a dangerous waste; if the

plotted point is in the area marked extremely hazardous waste (EHW), he shall designate his waste as an extremely hazardous

waste.

DW = dangerous waste

EHW = extremely hazardous waste

SOURCE: E. W. Tower, Solid Waste Management Division, Off Ice of Land Programs, Department of Ecology, State of Washington, Olympia,

Wash
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. .‘ S . GOVERNMENT ‘R INTI?JC OFFICE : 1981 0 - 84-65 3