EPA749/R-96-
OOla
c/EPA
United States
Environmental Protection'
Agency
Pollution Prevention
and Toxics
(7407)
Winter 1995/1996
EPA749-R-96-001a
Chemicals in the Environment
Public Access Information
The Three Rt& of Risk
Risk Assessment in the
Office of Pollution
Prevention and Toxics
Hazard Identification and
Dose-Response
Assessment
Ranking and Screening
Risks in the Existing
Chemicals Program
OPPT Structure Activity
Team
Cancer Expert System
Use Cluster Scaring
System
Integrated Risk
Information System
Exposure Assessment
Estimating Exposure: The
Graphical Exposure
Modeling System
(GEMS)
TRf Environmental
Indicators
Using Generic Scenarios
to Estimate Exposure
Risk Characterization
Risk Management:
Keeping Risks Within
Reason
The Existing Chemical
Program's Risk
Management
Procedures
The Design for the
Environment Program's
Cleaner Technology
Substitutes Assessment
Communicating
Environmental Risk
Ci
v-
?
CD
b>
Exposure
n
The Three R's of Risk
Odelia Funke, Chief, Information Access Branch
This issue of Chemicals in the
Environment focuses on topics
and information relating to
risk. Dealing with various aspects of
risk is central to EPA's and OPPT's
mission. But the term "risk" is
ambiguous and controversial. It has
also become a significant issue for
political and policy debates regarding
national environmental programs and
regulations.
What is risk and how is it used in
environmental decision-making? How
does EPA communicate these issues to
the public in order to solicit public
input for policy, explain policy
decisions or influence behavior?
These questions delineate three
important aspects of risk that EPA
considers in its programs: risk
assessment, risk management, and risk
communication.
EPA makes a distinction between risk
assessment activities, which it defines
as a scientific inquiry of the problem,
and risk management activities, which it
defines as the analysis and process to
determine what should be done about
any particular problem.
Risk assessment should be conducted
based on scientific evidence. Risk
management includes consideration of
political, economic, social and moral
choices. Each of these aspects of risk
has elements of uncertainty (which vary
from case to case) and each requires
assumptions and judgments.
Risk assessment is currently a topic of
considerable debate. Part of the
controversy involves the kinds of
definitions and assumptions scientists
use, and part involves disagreements
about how reliable risk calculations are.
For example, how much risk (or harm)
is "too much," something that should
be controlled or prevented? What
should assessors do to compensate for
missing data? At what point is an effect
"adverse" for humans or ecosystems?
(continued on page 2)
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Chemicals in the Environment
Winter 1995/1996
In explaining how OPPT addresses risk, the articles
describe some of the issues we face and key concepts
underlying our approach to risk assessment, management
and communication. Other articles explain some of the
tools we use in dealing with matters of risk.
Risk Assessment
Identifying risk and assessing its severity is the first stage.
Risk is based not only on the properties or components
of a material or pollutant, but also on who or what is
exposed to it, and how they are exposed. Risk assessors
therefore consider how toxic the material is, who or what
may come into contact with it, and whether that contact
could be harmful. This is primarily a scientific
investigation, which involves collecting and analyzing
data from many scientific disciplines. It requires complex
analysis, and investigators never have complete
information, so they must make assumptions and
Chemicals in the Environment: Public Access Information
is published fay EPA's Office of Pollution Prevention and
Toxics (OPPT) to increase public access to and awareness
of information on toxic chemicals and pollution
prevention available through OPPT.
This resource is also accessible through the EPA Gopher
(gopher.epa.gov} and Web server (http://www.epa.gOY),
It is located under EPA Offices and Regions / Office of
Prevention, Pesticides and Toxics { Toxic Substances /
Chemicals in the Environment: Public Access Bulletin.
Project Manager: Georgianne McDonald
Editor: RandaU Brionfchuis
Internet: bnnkhuis.randail@epamail.epa.gov
Publisher: Chuck Freeman
Internet: freeman.charfes@eparaail.epa.gov
Assistant Editor/Publisher: Gwen Shepard
Advisory Board
OPPT Divisional Representatives;
David Di Fiore, CCZ>
Dan Fort, EETD
Oddia Funke, IMD
Ruth Heikkinen, EAT> (jbrPPD)
Ted Jones, CSRAD
Mike McDonefl, EAD
Joe Merenda, HERD
TimTorma,CMD
Mailing Address: ;
Chemicals in the Environment; Public Access Information
U.S. EPA
Office of Pollution Prevention and Toxics <74Q7)
40lMSt.,SW :
Washington, DC ^20460
judgments for example, they study effects on animals
and use the results to judge effects on humans.
Risk Management
Risk management activities answer the question of what
to do about risk. (Can a particular problem be
prevented? How might it be controlled? How much
control; who controls, and at what cost? Should
protective measures be required or voluntary?) In the
risk management stage, OPPT considers various policy
options, decides what to do, and implements those policy
choices. Opportunities for disagreement are even greater
than in the assessment stage. OPPT must analyze what
actions might effectively address a risk, how much each
different approach would cost society, and what is the
most feasible approach given statutory, economic and
political constraints. Decisions determine not only how
much protection is enough, but who pays. Risk
management decisions are an attempt, based on the
scientific findings, to balance a variety of requirements,
needs and possibilities.
Risk Communication
Risk communication is an ongoing and intricate process.
OPPT transmits information, proposed policies, and the
rationale for decisions to the public, and solicits
information about needs and expectations as well as
responses to specific policy proposals from the public. It
is a mutual process of education about risks and
appropriate responses. Communication occurs through a
wide variety of mechanisms and processes, both formal
and informal. In the past several years, OPPT has
increased its efforts to make information available to the
public and has been working to identify groups who
might be interested in this information. The Office has
created new channels for dialogue with and comment
from the public to improve communication, but this is an
ongoing challenge.
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Issue No. 2
Public Access Information
Risk Assessment in the Office of Pollution Prevention and Toxics
Joseph A. Cotruvo, Director, Chemical Screening and Risk Assessment Division
While all substances are hazardous or
potentially harmful under some
circumstances, most can be used safely. The
fundamental question is what is the likelihood that harm
will occur under any condition of production, use, misuse
or release, and who is being subjected to that risk.
Ultimately, that risk information is usually combined
with benefit, cost, and other impact information in
addition to legal and policy elements to arrive at a risk
management decision.
Risk assessment is one of the many tools and often is the
underpinning to important and costly regulatory and
policy decisions aimed at reducing potential adverse
effects. There has been a lot of controversy
recently on the subject of risk assessment as
though it were an arcane activity, which if
only done "properly" would solve most of
the controversy raised about the
appropriateness of contested regulatory
decisions. However, things are neither that
simple nor that sinister.
Chemical risk assessment is, in fact, a rather
straightforward, but not simple or uncontroversial,
concept. It is an attempt to objectively analyze
information on the 1) hazard, 2) exposure, and 3) dose-
response of a substance to arrive at a prediction of the
probability that adverse effects could occur to humans or
the environment. The great difficulty is the necessity of
making those predictions in the absence of complete and
definitive data in each of those three areas. We must
often use animal data to project the human health
hazard, given limited data on actual human exposure,
dosimetry (measurement of the amount of exposure),
mechanism (how a chemical affects the human body),
population distribution, and higher risk groups. Even
human epidemiology studies often raise more questions
than they answer.
Because of this lack of solid information, there is usually
considerable uncertainty associated with any quantitative
conclusion that results. Further, this lack of data means
scientists must rely on assumptions, extrapolations, and
judgments, and as a result, conclusions are often value-
laden. However, risk assessment does not have a corner
on the uncertainty market; other impact assessments
(such as cost/benefit) often have just as much
uncertainty, because many underlying factors cannot be
accurately measured or predicted.
EPA and OPPT are strongly committed to improving risk
assessments and improving the understanding of their
content by emphasizing peer review and risk
characterization as key elements in the process.
Given the uncertainties and complexities and lack of
"definitive" information, peer review is an essential
element of a credible assessment. It is important to seek
critical reviews of an assessment from knowledgeable
scientists who were not parties to its preparation. These
independent reviewers help us determine whether there
are deficiencies and whether the assessment is objective,
credible and consistent with mainstream scientific
thinking. Peer reviewers should represent the full
spectrum of credible perspectives, regardless of
affiliation. In 1995, as part of an EPA-wide
effort, OPPT formalized its policy to set
standards for peer review of important
risk assessments.
Finally, the way we communicate the
results of an assessment is critical to our
credibility and the users' understanding. It is
essential that the assessment be characterized
(described) in such a way that it is understandable to
a range of readers (including the decision makers) and
that the thought process for developing the conclusion is
transparent. This means we should clearly differentiate
between facts, default assumptions, and judgments. We
should point out uncertainties and describe possible
alternative interpretations.
OPPT conducts a wide variety of risk assessments to
support a number of different programs and decisions.
These differ in structure and intensity depending on their
intended use. In general, all of these assessments are a
team effort. Human and ecological hazard information
is reviewed by the Health and Environmental Review
Division; exposure information is provided by the
Economics, Exposure and Technology Division. These
two reviews are converted into a risk assessment by staff
of the Chemical Screening and Risk Assessment Division.
For example, in the New Chemicals Program, several
thousand submissions of new chemicals are received each
year, and often little or no toxicity or exposure data are
provided by the submitting companies. The New
Chemicals Team has, over the years, developed
streamlined evaluation processes using: historical
information, expert judgment based on information on other
(continued on page 5)
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Chemicals in the Environment
Winter 1995/1996
Hazard Identification and Dose-Response Assessment
Joe Merenda, Director, Health and Environmental Review Division
In the context of risk assessment, hazard identification
focuses on the qualitative question "What are the
potential dangers?" while dose-response assessment
deals with the quantitative question "How much danger
is there?" Hazard identification and dose-response
assessment must be teamed with exposure
assessment (in a qualitative or quantitative
form) to yield practical answers to these
questions.
Hazard Identification
Chemicals can present a wide variety
of hazards to humans, other living
organisms, and non-living components
of our environment. Biological
effects often considered in hazard
identification include: lethality to
exposed organisms; temporary or
permanent impairment of normal biological functions;
heritable genetic change; increases or decreases in the
population size and range of one or more species; and the
overall health and productivity of ecosystems. Potential
non-biological effects include: reduced visibility from
airborne particulates; damage to historic structures by air
pollutants; and climate change from global warming.
Biological and non-biological effects can interact, further
complicating things. For example, the primary reason for
concern about depletion of stratospheric ozone (a non-
biological effect) is its secondary biological effects,
including increased skin cancer risk to humans and
potential effects on aquatic populations.
There are two key elements of hazard identification: (1)
identifying potential hazards and (2) weighing the
evidence of whether or not a particular hazard is likely to
be of practical significance. Both elements require a
combination of knowledge and judgment. Hazard
identification depends on knowledge or inference of the
properties and effects of the specific chemical being
addressed, along with broad knowledge and
understanding of relevant scientific areas such as
chemistry, biochemistry, biology, toxicology, and ecology.
Well-designed and executed studies of a chemical's
ability to cause a particular effect are the preferred basis
to conclude whether or not that chemical can cause nerve
damage in humans, reduced growth and survival in
aquatic invertebrates, or any of a myriad of other
potential hazards. Often, though, no studies are
available of a specific chemical's ability to cause a
particular type of adverse health or environmental effect.
This is especially true for newly-developed chemicals that
must be reviewed by OPPT scientists before companies
can manufacture or import them.
Structure-activity relationships provide an essential tool
for hazard identification in such cases. In brief,
structure-activity approaches attempt to predict
the hazards of a chemical from qualitative or
quantitative analysis of hazard data for other
chemicals having structures or properties
similar to the chemical in question. [See page 7
for more information on OPPT's Structure Activity
Team.]
Uncertainty is a major element in most hazard
identification efforts. Key factors that often
contribute to uncertainty include:
lack of sufficient test data for the chemical of interest
or for suitable analogs. (Structure-activity can go only so
far in substituting for actual test data.)
testing in surrogate species. (How well do data from
laboratory strains predict potential effects in humans or
other species?)
conflicting evidence. (Genetic tests in microbes may
suggest that a chemical could cause cancer in humans, but
if a limited study of the chemical in mice shows no evidence
of cancer, which evidence should be given more weight?)
unanticipated effects. (Until relatively recently, no one
knew to look for a chemical's potential to destroy
stratospheric ozone.)
Dose-Response Assessment
The goal of dose-response assessment is to provide a
numerical basis for translating exposure information into
an evaluation of risk. Although hazard identification may
have documented a chemical's ability to cause a
particular health or environmental effect, whether that
hazard is of great or little practical concern depends on
how anticipated exposure levels compare to exposure
levels at which the adverse effect is expected. Dose-
response assessment typically uses one of two basic
approaches: reference levels or unit risk.
The "reference level" approach generally is used when a
chemical's effects are presumed to be significant only if
some threshold amount of exposure is exceeded. The
lowest exposure level at which the effect of concern has
(continued on page 5)
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Issue No. 2
Public Access Information
Risk Assessment in OPPT (continued from page 3)
similar chemicals, and modeled exposure potential, based
upon their knowledge of physical/chemical properties,
manufacturing processes and uses. Thus, our scientists
can conduct rapid and specific assessments suited to the
legally required decision to accept, disallow, or
conditionally allow production of the new chemical
within 90 days.
OPPT also uses risk assessments to evaluate chemicals
already in production. The Toxics Release Inventory
(TRI) contains data on hundreds of chemicals released by
manufacturing. A limited assessment (dependent upon
numerous factors) contributes to TRI listing and delisting
decisions. OPPT also provides Chemical Fact Sheets for
outside users. These provide basic information on the
toxicity of various chemicals with conclusions as to the
significance for humans and ecological health, without
quantifying exposures or evaluating estimated risks.
The Existing Chemicals Risk Assessment process
produces screening level assessments in the first stage of
the Risk Management (RM1) process. These assessments
inform the initial judgment as to whether there is
sufficient concern about a chemical in production to
warrant a more detailed assessment later in the RM
process. Here, data should be available, often from
OPPT data sets, for a preliminary assessment although
seldom is it alone sufficient if a more comprehensive
follow-up analysis is needed. More detailed information
might be needed for a major impact decision, and the
Chemical Testing Program could be a vehicle for
generating more data.
There have also been extensive assessments conducted in
the course of TSCA implementation for substances like
asbestos and formaldehyde. These can be extremely
detailed and lengthy and require significant resources.
A risk assessment is only one component of the risk
management decision. It is a living analysis that should
reflect the best information and thinking on that subject
as important new information is developed in this rapidly
changing field. We should expect to be challenged and
always be open to newer, better ideas. In this way, the
uncertainties in this analytic construct will be reduced
and it will come closer and closer to describing reality.
This does not mean that a risk management decision to
act or not to act must always await the next pending
piece of data. A risk assessment is a snapshot in time
and risk management judgments must be made on the
merits of available information and in a timely manner.
Hazard Identification and Dose-Response Assessment (continued from page 4)
reliably been demonstrated (or the highest exposure at
which that effect has been absent in an appropriate
study) provides the starting point to define a reference
level. This level is adjusted to account for any known
differences between the test species and the target species
and, more significantly, for key elements of uncertainty
anticipated in applying the study results to the
population to be protected.
Such uncertainty factors often include: the possibility
that the target species will be more sensitive to the
chemical's effects than the test species; use of limited
duration testing to predict effects of long-term exposure;
and variation in susceptibility to the effect among
individuals in the exposed population. Risk is judged by
comparing anticipated exposure with the relevant
reference level. An exposure far below the reference level
implies low risk of that hazard, while an exposure
considerably above the reference level suggests a cause for
concern.
The "unit risk" approach attempts to describe
mathematically how the likelihood of a particular effect
depends on exposure. This is the approach generally is
used for cancer-causing chemicals, for which any
exposure is presumed to present some risk, with the risk
increasing as the exposure increases. Laboratory test data
showing the percentage increase of animals developing
tumors at different exposure levels are used to estimate
a chemical's cancer unit risk. The latter can then be
used, along with anticipated exposures to the chemical,
to estimate (very roughly) how many cancer cases might
occur in a particular population size.
A variety of factors contribute to uncertainty in the unit
risk and risk estimates based on it. These often include:
qualitative or quantitative differences in how humans
and the test species absorb and metabolize the chemical
or respond biologically to the chemical and its
metabolites; and uncertainty in the reliability of risk
estimates for large populations exposed to low levels of a
chemical that are based on exposing relatively small
numbers of laboratory animals to high levels.
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Chemicals in the Environment
Winter 1995/1996
Ranking and Screening Risks in the OPPT Existing Chemicals Program
Jim Darr, Health and Environmental Review Division
Background and Purpose
The primary objective of the Office of Pollution
Prevention and Toxics (OPPT) Existing Chemicals
Screening Program is to identify health and
environmental risks and to promote risk reduction and
pollution prevention. A complementary objective is the
identification of testing needs.
The basic criteria employed in screening are:
Toxics Substance Control Act (TSCA) Jurisdiction
Toxicity Factors
Exposure Factors
Assessment/Regulatory Status
Testing Needs
Opportunities for Risk Reduction and Pollution
Prevention
Screening decisions are based on limited information and
professional judgment. For example, toxicity evaluations
typically are based on readily available data
supplemented by Structure-Activity predictions.
Potential exposure may be estimated from an analysis of
production and use patterns.
The "universe" of chemicals of
primary interest to the TSCA
program consists of the approximately
14,000 non-polymeric chemicals or L
chemicals that are submitted by ' '
companies that are intended for
manufacture and are produced in
annual quantities greater than
10,000 Ibs. Most screening efforts
focus on a subset of high production
volume chemicals, that is, those
chemicals produced in annual
quantities greater than one million
pounds. OPPT, the Chemical Manufacturers
Association, and the Synthetic Organic Chemical
Manufacturers Association have developed a mechanism
for manufacturers to voluntarily provide key use and
exposure data that assist OPPT's screening of high
production volume chemicals.
OPPT has developed a variety of techniques to cope with
the wide variety of problems and uncertainties
encountered in reviewing this large and diverse set of
chemicals. The various approaches and techniques
employed in the screening program fall into two basic
categories: reactive and proactive.
Reactive Screening - Single Chemical Reviews
TSCA Section 8(e) "substantial risk" notices submitted
by industry are the major input to reactive screening. The
data most commonly submitted to OPPT are from
toxicologic studies but some exposure studies such as
environmental monitoring or product contamination
analyses are also submitted. OPPT performs an initial
sorting of Section 8(e) studies by means of a "triage" or
priority setting review that assigns a high, medium, or
low level of concern to each study. Studies flagged as
high concern undergo further screening according to the
criteria listed above.
Studies submitted under TSCA Section 4 and
assessments conducted under the Organization for
Economic Cooperation and Development's Screening
Information Data Sets (SIDS) program are also major
inputs to OPPT's screening program. Additional
initiatives for screening high production volume
chemicals are also being studied.
Proactive Screening - Cluster Reviews
OPPT believes that it must take the initiative to
identify health and environmental risks beyond
those brought to our attention by external data
submissions. These proactive efforts involve the
systematic analysis of defined lists of chemicals or
sets of data that indicate potential concerns. A
key proactive effort is the review of "clusters" of
chemicals. A duster is simply a group of chemicals
related by defined characteristics. These
characteristics may indude chemical structure,
physical/chemical properties, use/exposure patterns, or
who might be exposed to it. Two major efforts to rank
dusters of chemicals are:
1) The Use Cluster Scoring System (UCSS), which
ranks industrial and commercial uses of chemicals
by a wide variety of hazard and exposure factors.
The UCSS considers both health and ecological
hazards and ranks exposures to workers,
consumers, the general population, and ecological
receptors.
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Issue No. 2
Public Access Information
2) The Source Ranking Database (SRD), which ranks
consumer and commercial products with respect to
the risks they present through indoor air
exposures. The SRD considers both acute and
chronic health hazards and ranks exposures by
using data on products, settings (e.g. home, school,
or office), and populations. (Note: The SRD is not
currently available to the public.)
Information Products
The creation of user-friendly information products is an
important output from the screening program.
Oftentimes, the most efficient and effective way to
achieve risk reduction is to make relevant hazard and
risk information readily available to the people who make
the day-to-day decisions regarding the manufacture,
processing and use of chemicals. Screening information
products include the 8(e) Triage database, SIDS
assessment documents, and exposure profiles on high
volume chemicals. The development of products derived
from the Use Cluster Scoring System and the Source
Ranking Database is also being studied.
For more information about ranking and screening risks, contact
Jim Dan at (202) 260-3441. For more information about the
Source Ranking Database, contact Christina Cinalli, (202)
260-3913.
OPPT Structure Activity Team
Pauline Wagner, Health and Environmental Review Division
The OPPT Structure Activity Team (SAT) is an
interdisciplinary team of chemists, biologists,
lexicologists, and technical information specialists
who evaluate the potential environmental fate, health
effects, and environmental hazards of new and existing
chemicals. For over fifteen years the SAT has been a
leader in developing and applying the principles of
chemical structure-biological activity to the hazard
assessment of chemicals for which data are either sparse
or non-existent.
Historically, the mission of the SAT has been focused on
the New Chemicals Program, Section 5 of the Toxic
Substances Control Act (TSCA), where a determination
of "unreasonable risk to human health and/or the
environment" must be made within a 90-day time period
on each of approximately 2,000 chemicals submitted
every year. In order to accomplish this task, the SAT has
not only expanded upon traditional structure-activity
relationships (SARs), but has developed new methods of
assessing the hazards presented by various classes of
chemicals, particularly in the area of toxicity to aquatic
organisms. A recent comparative study with the
European Union (EU) conducted jointly with EU
scientists has demonstrated conclusively that the
methods developed by the SAT are appropriate and
valid.
In recent years, the SAT has increasingly been called
upon to screen existing chemicals for potential hazard to
human health and/or the environment. Using the SAR
principles developed for new chemicals and creating
innovative search strategies to identify both published
and unpublished data, the SAT has been able to
effectively screen over 3,500 existing chemicals, not only
for OPPT, but also for a variety of other EPA Offices and
other government agencies. These efforts aid in
furthering the Agency goal of protecting human health
and the environment.
The SAT is recognized internationally as a unique
scientific endeavor for its success in predicting potential
hazards for chemicals with inadequate or absent hazard
data. Subsequently to the successful joint EU/EPA
comparative study, the methods employed by the SAT
have been studied by the Canadian, Japanese, and
Australian governments in order to more effectively
screen chemicals that are of concern in their respective
countries. Domestically, the SAT has interacted with the
U.S. chemical industry to share the SAR principles
routinely used in evaluating new chemicals. This type of
cooperation will result in the strengthening of
environmental protection through the use of less toxic
chemicals.
For more information, call Pauline Wagner, (202) 260-3981.
More information about the Structure Activity Team and its
work is available in "The New Chemicals Process at the
Environmental Protection Agency (EPA): Structure-Activity
Relationships for Hazard Identification and Risk Assessment,"
Toxicology Letters 79(1995):67-73.
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Chemicals in the Environment
Winter 1995/1996
The OPPT Cancer Expert System
Ernest V. Falke, Ph.D., Senior Scientist, Health and Environmental Review Division
The Office of Pollution Prevention and Toxics
(OPPT) has been developing a Cancer Expert
System (OncoLogic). This system is a user-
friendly computer-based system which will be used to
predict whether a chemical is likely to cause cancer. The
basis for the system is a network of Structure Activity
Relationship (SAR) "knowledge rules," which are based
on the relationship between a chemical's structure and its
biological and chemical activities, developed by OPPT
experts in cancer hazard assessment. The finished
product contains more than 30,000 rules.
The data and information for the knowledge rules have
been acquired from research conducted by OPPT's
experts and other researchers, much of which has been
summarized in Chemical Induction of Cancer (seven
volumes of which have been published over the past two
decades); the assessment of thousands of new chemicals
in the Toxic Substances Control Act (TSCA)
Premanufacturing Notification (PMN) Program under
which manufacturers are required to submit health and
safety studies to EPA for review; and the ongoing review
of relevant National Cancer Institute/National
Toxicology Program animal studies; and EPA toxic
substances and pesticides databases.
The system consists of four subsystems for fibers,
polymers (large molecules built up by linking repeated
subunits of simple reactive chemicals known as
monomers), metals/metalloids, and organic chemicals.
Using the system, one can evaluate virtually any type of
chemical class.
To date, the first three subsystems are essentially
complete and are operational. The core structure (for
example, chemical structure input and reasoning /
justification software) of the Organic Chemicals
Subsystem has been completed. Additionally,
approximately 60% of the chemical classes to be
evaluated in the Organic Chemicals Subsystem have been
incorporated into the Cancer Expert System. The system
will automatically generate a cancer hazard concern level
(six levels ranging from low to high) together with text
presenting the scientific rationale used to establish the
concern level.
The functional arm of trie system can modify the cancer
concern level for a chemical based upon additional
biological testing data that correlate with carcinogenicity
independent of the chemical's structure (for example, the
ability of a chemical to affect the internal operations of
a cell or its DNA).
The Cancer Expert System is expected to be complete in July
1996. Please contact Ernest V. Falh (202) 260-3433
(Internet: Falh.Ernest@epamail.epa.gov) for more information.
The Use Cluster Scoring System: A Use-Based Approach to Setting
Priorities
Daniel Fort, Economics, Exposure, and Technology Division
E
PA's Office of Pollution
Prevention and Toxics
(OPPT) is developing a
system for use in screening
and prioritizing chemicals.
This system is known as the
Use Cluster Scoring System
(UCSS). The UCSS was
designed around the idea of identifying and analyzing
clusters of chemicals that can be used to do a particular
task. For example, instead of considering a single
chemical used as a paint stripper, a set of chemicals that
act as paint strippers is considered. By screening and
scoring these "use clusters," resources may be more
directly focused upon effective risk reduction through
work with manufacturers or users.
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Issue No. 2
Public Access Information
EPA's Science Advisory Board (SAB) reviewed the system
in 1995 and found that "clustering chemicals by intended
functions could provide efficient risk screening, as well as
improved pollution prevention opportunity
identification." The UCSS may also help other public
and private sector organizations in identifying dusters of
potential concern and providing an initial indication of
potentially safer substitutes for classes of chemicals.
The UCSS currently consists of over 380 "use clusters"
comprising over 3,500 chemicals. The system contains
hazard and exposure information aggregated from many
databases that are currently used across EPA as well as
other government agencies. Also, the system uses
predictive methodologies to determine hazard and
exposure for chemicals lacking specific data. Beyond
cluster and chemical scores, the UCSS retains and
displays all underlying data for chemicals and dusters for
further consideration by users.
In response to the SAB's recommendations, modification
of the system will be implemented. It is anticipated that
the UCSS will be made available through the Internet in
early 1996.
For more information, contact Daniel Fort at (202) 260-1694,
FAX. (202) 260-0981 (Internet: fort.daniel@epamail.epa.gov)
or Jay Jon at (202) 260-7971, FAX (202) 260-0981
(Internet: jon.jay@epamail.epa.gov).
Integrated Risk Information System
Vanessa Vu, Deputy Director, Health and Environmental Review Division
The Integrated Risk Information System (IRIS)
database, produced by the U.S. Environmental
Protection Agency (EPA) since 1986, is a
database containing EPA's consensus scientific positions
on potential human health effects that may result from
long-term exposure to environmental pollutants.
Currently, IRIS contains summary information on the
hazard identification and dose-response assessment of the
potential carcinogenic and non-carcinogenic effects for
both inhalation and oral exposure of over 500 substances.
IRIS contains full bibliographic citations for each
substance file, directing the user to the primary cited
studies and pertinent scientific information. In addition,
IRIS substance files may contain one or more of three
supplementary information sections: a summary of EPA's
Office of Water's Health Advisories,
a summary of EPA regulatory
actions, and a summary of physical
and chemical properties.
EPA's goal is to develop high
quality human health information
based on credible sdence. Since
October 1994, new or revised,
scientific information put on IRIS has
undergone external review, in addition to Agency's
final review by EPA scientists across programs and
regions. IRIS users are cautioned that IRIS does not
contain human exposure information.
The data in IRIS, combined with specific exposure
information, can be used to help characterize the public
health risks of a given situation. This risk
characterization can then serve as input for a risk
management dedsion designed to protect public health.
There are currently two means of public access to the
IRIS data base. The primary method of access for the
public is TOXNET, the TOXicology Data NETwork,
which is maintained on-line by the National Library of
Medicine (NLM), National Institutes of Health. IRIS on
TOXNET is updated monthly to reflect new or revised
assessments. IRIS users can gain access to TOXNET by
direct call or through several widely used
telecommunications networks. IRIS is also available
through NLM's International MEDLARS Centers. The
second means of public access to IRIS is to purchase
high-density diskettes from the National Technical
Information Service (NTIS). IRIS diskettes are
updated quarterly rather than monthly.
For more information on IRIS and how to access it,
contact the IRIS Information Hotline, National
Center for Environmental Assessment Cincinnati
Office, Office of Research and Development, U.S.
EPA, 26 West Martin Luther King Drive,
Cincinnati, Ohio 45268, Telephone: (513) 569-
7254, Fax: (513) 569-7159.
For further information on gaining access to IRIS via
TOXNET, contact the IRIS Representative, Specialized
Information Services Division, National Library of Medicine,
8600 Rockville Pike, MD 20894, Telephone: (301) 496-
6531. For information on ordering IRIS diskettes, contact the
National Technical Information Service, 5285 Port Royal
Road, Springfield, VA 22161, Telephone: (703) 487-4650.
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Chemicals in the Environment
Winter 1995/1996
Exposure Assessment
Thomas Murray, Chief, Exposure Assessment Branch, Economics, Exposure, and Technology Division
Exposure assessment attempts to answer the
questions, "How much of a pollutant is out there?"
and "To what amounts are we exposed?"
Exposure occurs through contact with a pollutant; such
contact can occur by inhaling air, drinking water, eating
food, or touching a variety of products that contain the
pollutant.
The concentration of the pollutant in these media and
the length of contact are important components of
exposure assessment. The results of an exposure
assessment are considered along with the hazard
assessment, which attempts to answer the general
question, "How hazardous is the pollutant?" Together,
the answers to these two questions are used to determine
whether there is a risk posed by the pollutant i that
requires Agency attention.
Exposure assessments in OPPT typically
include occupational exposures in the work
place, exposures to the general population
from pollutants in the air and drinking
water, consumer exposure through the use , \
of household products, and
environmental exposure to aquatic life.
In general, exposure assessment involves
three steps, which can be performed
at
a simple, screening level or as an
extensive, in-depth look at a
pollutant's life-cycle.
Chemical Properties and Fate
The first step in assessing exposure is predicting the
behavior of a pollutant in the environment. We review
available data sources for information on water solubility
and vapor pressure, which is used in estimating
occupational and consumer exposures. We also use
information on decay rates in the atmosphere, surface
water, soil, and ground water to estimate exposures to the
general population and the environment.
In addition, based on the way the pollutant is expected
to be discharged, we look at other ways that the
pollutant's behavior may affect its concentration and
ultimate fate in the environment. For example,
pollutants discharged to surface water are likely to
undergo wastewater treatment, so we predict a probable
rate of pollutant removal during treatment.
Concentrations
Once we have an idea of the pollutant's behavior in the
environment, we look at how much and where it is
released. These release estimates are generated using
industrial engineering expertise and typical production
volumes. Manufacturing and processing operations are
reviewed to determine potential releases in the work
place, such as fugitive vapors from open vats, that could
reach workers as well as those that leave the facility and
enter the environment.
We have a number of tools which allow us to gather
information about the environment into which the
pollutant is being discharged, and to estimate the
resulting concentrations there. These tools range from
mathematical equations for simple dilution in a work
room, to complex computer models which can trace a
pollutant's path through the environment over
time. These computer models are capable of
accounting for the pollutant's decay as it
travels through the environment, as well as
estimating overlapping concentrations
resulting from many nearby sources.
Exposures
The last step in an exposure assessment is
the estimate of the populations working or
living near a pollutant discharge, and the
potential doses to which they may be exposed. To
estimate potential dose, we evaluate the level of contact
an individual is likely to have with the pollutant by each
possible route. To do this, we consider those human
activities such as inhaling air or drinking water
contaminated with the pollutant that would affect the
amount of contact with the pollutant.
Often we calculate potential doses using established
assumptions like a typical breathing rate of twenty cubic
meters per day, and a typical drinking water consumption
of two liters per day. Finally, we estimate the number of
people potentially exposed to these doses using either
general estimates of the number of employees involved in
an industrial process or the number of nearby people
using a population database like the Census data.
For more information, contact: Tom Murray, (202) 260-1876
Internet: murray.thomas@epamail.epa.gov
JO
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Issue No. 2
Public Access Information
Estimating Exposure: The
Graphical Exposure Modeling
System (GEMS)
Thomas Murray, Chief, Exposure Assessment Branch,
Economics, Exposure, and Technology Division
The Graphical Exposure Modeling System (GEMS)
supports exposure and risk assessments by
providing easy access to a number of tools
routinely used to estimate pollutant exposures. These
exposure estimates include estimated concentrations in
the environment and the populations potentially exposed
to these concentrations. There is also a stand-alone
version of GEMS for the PC called PCGEMS; it contains
many, but not all, of the features of GEMS.
GEMS contains a number of computer models which use
mathematical algorithms to calculate an estimate of
pollutant concentration based on a number of
environmental factors. These models include media-
specific capabilities for modeling pollutant releases to the
atmosphere, surface water, soil, and ground water. There
are also several screening-level models to predict chemical
partitioning, the separation of components of a chemical
mixture, among the environmental media.
To support the models, GEMS contains several databases
of information needed to perform an exposure
assessment. There are data available on sources of
pollutant release to the environment, including a link
with the Toxics Release Inventory System (TRIS) to
retrieve environmental release estimates submitted to
EPA under the Emergency Planning and Community-
Right-to-Know Act of 1986 (EPCRA). There are
nationwide environmental data, including weather data
and stream characteristics, that are used to more
realistically model the way the pollutant will spread
through the environment.
Finally, in order to determine the number and location of
people potentially exposed to a pollutant, GEMS has
access to the 1990 Census population data, as well as
information on drinking water facilities and the size of
the population they serve.
Public Hotlines and
Clearinghouses referred to
in this issue
EPA Programs
Emergency Planning and Community
Right-to-Know Act Hotline, (BOO) 535-
0202; in the Washington, B.C.,
metropolitan area, (703) 920-9877
Integrated Risk information System (IRIS)
Information Hotline, (513)569-7254
National Center for Environmental
Publications and Information (NCEPI),
FAX (513) 489-8695
Pollution Prevention Information
Clearinghouse (PPIC), (202) 260-1023
Toxic Substances Control Act Assistance
Information Service (TSCA Hotline),
(202) 554-1404
TRt User Support (202) 260-1531
Other numbers
National Library of Medicine,
IRIS Representative, (301) 496-6531
National Technical Information Service
(NTtS), (703) 487-4650
For an overview of the GEMS program or to request a copy of
the GEMS User's Guide, contact Cathy Turner at (202) 260-
3929. For further information, contact Lynn Delpire, (202)
260-3928, or Patricia Harrigan, (202) 260-8479.
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Chemicals in the Environment
Winter 1995/1996
TRI Environmental Indicators
Nicolaas W. Bouwes, Economics, Exposure, and Technology Division
The Office of Pollution Prevention and Toxics
(OPPT) has developed a new way to track the
potential impacts of Toxics Release Inventory
(TRI) chemical emissions over time. OPPT is planning
to develop four indicators of potential acute and chronic
health and ecological impacts.
The model, a Microsoft Windows-based computer
application, uses chemical data submitted by
manufacturers to EPA's TRI. The model combines these
data with weighting factors representing toxicity,
exposure characteristics, and potentially affected
populations or receptor populations to generate relative
ranking numbers. Numeric values or "indicator
elements" are calculated for each combination of facility,
chemical, and environmental medium (for example, air,
water, land). The total of these indicator elements forms
a TRI Environmental Indicator.
Each year's indicator will provide one perspective on how
the potential impact of TRI emissions is changing. An
indicator can also provide information broken down by
medium, chemical, region, state, type of industry or
Standard Industrial Classification (SIC) Code, or a
combination of these. The model produces four
alternative outputs: pounds of release, pounds weighted
by toxicity, pounds weighted by toxicity and population
size, and the full model which includes pounds, toxicity,
surrogate exposure and receptor population size.
Comparing these allows analysts to identify patterns of
relative contribution to the full indicator.
Potential uses include examining trends and ranking of
chemicals for other possible projects. Since the model
results are exportable in a dBase format, they can be used
for further analysis in other software applications.
The Indicators have been under development since 1991,
with the planned methodology widely distributed for
comment in 1992 at a public meeting. The "chronic
health indicators" model is now being tested, with plans
for sensitivity and uncertainty analyses in FY96. The
indicators' input data, relative toxicity scores, and
updated methodology are scheduled to be circulated for
EPA review in early fiscal year (FY96). We hope to have
100
the first version of the computer model available for
distribution within EPA by the end of FY96. The
revised/updated version of the methodology should be
available in about three months.
For more information contact Nicolaas Bouwes at: (202)260-
1622; bouwes.nick@epamail.epa.gov
Emergency Planning and Community Right to Know Act (EPCRA): Release
Information Required by Section 313
Under Section 313 of EPCRA, certain manufacturing facilities are required to submit a "Form R," in which
they report releases of over 300 different toxic chemicals into the environment and other information about
the companies to EPA. This information collected by EPA makes up what is called the Toxics Release
Inventory {TRI). To find out how to access TRI data submitted by industries, call TRI User Support at
(202) 260-1531, To obtain information on EPCRA Section 313 reporting requirements, call the
EPCRA/Superfund Hotline at (800) 535-0202, or (703) 920-9877 in the Washmgtorj, D.C., metropolitan
area.
12'
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Issue No. 2
Public Access Information
Using "Generic Scenarios" to Estimate Exposure
Nhan Nguyen, Economics, Exposure, and Technology Division
Ideally, occupational and environmental release
assessments should be based on monitoring data.
However, for many chemicals being assessed in the
Office of Pollution Prevention and Toxics risk screening
programs, monitoring data are very limited or are not
available. New chemicals do not usually have exposure
and release information during processing and use. The
chemical engineers in the OPPT Chemical Engineering
Branch (CEB), in the absence of such data, use various
data sources and modeling techniques to estimate
exposures and releases.
One of the data sources that CEB engineers use to
estimate exposures and releases of chemicals are "generic
scenarios." These scenarios are based on information
from past chemical cases, technical references, industry
contacts and other EPA reports.
Each generic scenario provides information on a specific
process or commercial use. It contains generic
information and assumptions on how chemicals are
handled or used in a process, the unit operations
involved, chemical usage rates, number of workers and
their activities, formulation composition or method of
arrangement, potential points of release, cleanup and
disposal practices, and sometimes exposure and release
monitoring data. For example, a generic scenario on
textile dyeing is often used to estimate the population of
workers potentially exposed, the exposure dose rates,
duration of exposure, and releases for a new chemical
that will be used as a reactive dye in fabric.
The estimates of the population potentially exposed, the
exposure dose rates and releases are based on
assumptions such as percent exhaustion or percent
deletion rates for acid dyes, quantity of fabric used per
batch, number of batches handled per day, and
concentration of dyes in the dye bath. The assumptions
for this scenario were developed based on information
from a comprehensive joint EPA/industry study on textile
dyes.
Development of generic scenarios is an ongoing effort in
CEB. There are now over 50 generic scenarios.
Additional generic scenarios will be developed during
1996 to help OPPT in estimating exposure and releases
to chemicals in a variety of industries. The generic
scenarios have been developed for internal use; they have
not been peer-reviewed and are considered to be in draft
form.
For additional information about the generic scenarios, contact
Nhan Nguyen at (202) 260-3741, FAX (202) 260-0981
(Internet: nguyen. nhan @epamail. epa.gov).
13'.
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Chemicals in the Environment
Winter 1995/1996
Risk Characterization
Lois Dicker, Chemical Screening and Risk Assessment Division (Chair, OPPT Risk Assessment Work Group)
O!
IPPT has been an
active participant in
the Agency's new
program for improving risk
characterization since March
1995 when Carol Browner
issued new risk
characterization policy and
guidance. She has called on each Program Office to
develop specific policies and procedures for risk
characterization suited to their own risk assessment/risk
management needs. The emphasis is on being "CLEAR,
CONSISTENT, TRANSPARENT, and REASONABLE."
Within OPPT we have taken the activity of risk
assessment and risk characterization seriously. Beginning
in 1993 we formed a Quality Action Team to examine
problems in our risk assessment process. As an outcome
of the QAT we have a standing interdivisional work
group (the Risk Assessment Work Group) which explores
risk assessment issues and problems. We have compiled
a large collection of "Information Tools" (procedures,
guidance, and supplemental documents) for risk
assessment/risk characterization.
The work group is currently completing a draft, "OPPT
Risk Characterization Statement," which will act as the
Office specific operating plan for how we perform risk
characterizations. In addition, the group will be
preparing an "Appendix" to the Statement giving more in
depth information on preparing hazard, exposure, dose-
response and risk assessments, and risk characterizations.
These two documents will serve as updates to OPPT's
current compilation of Information Tools for Risk
Assessment/Risk Characterization.
Within OPPT there are three major types of risk
assessments performed based on level of effort
screening level assessments (for example, as in the New
Chemicals Program), intermediate level assessments
(such as the RM1 and RM2 assessments in the Existing
Chemicals Program), and comprehensive assessments
(special, more in-depth assessments for existing
chemicals). OPPT requires each risk assessment to
contain a risk characterization at the level of detail
appropriate for the type of assessment.
A characterization for a new chemical may be a single
paragraph, while one for an in-depth assessment could be
many pages. Every risk characterization should cover the
following points:
(1) The scope of the assessment,
(2) A statement of the bottom line of the risk
conclusions,
(3) A summary of the key issues,
(4) Methods used in the assessment,
(5) Summary of overall strengths and uncertainties
of the assessment,
(6) Putting the risk assessment into context with
other similar risks, and
(7) Highlighting other important information
bearing on the assessment.
It is felt that to "characterize" risk is not just to restate
what has been said in the hazard, exposure, and
dose/response assessments; but to truly integrate the
information to give the risk manager a dear picture of
risk conclusions and the train of thought which supports
those conclusions. The Agency has recognized that this
is not an easy task, and has scheduled a series of
colloquia and round tables to grapple with how to write
a good risk characterization.
Currently, OPPT uses a variety of resources to assure
adequate risk characterization. It relies on use of its
collection of Risk Information Tools, adherence to the
Agency's 1995 risk characterization policy and guidance,
and also its own internal review procedures which include
review by management, technical work groups, technical
staff peer review, and regularly scheduled decision
meetings. For comprehensive risk assessments additional
review such as outside peer review, consultation with
other EPA experts, or Science Advisory Board review are
utilized.
OPPT will be among the featured Offices at the next EPA
Risk Characterization Colloquium. The focus will be on
the "Risk Characterization Statement" and whether it is
helping risk assessors develop good risk characterizations.
We are looking forward to discussions with other parts of
the Agency, and to further improving how we do risk
characterizations within OPPT.
For more information on risk characterization, call Lois Dicker,
(202) 260-3387.
ia
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Issue No. 2
Public Access Information
Risk Management: Keeping Risks Within Reason
David Di Fiore, Chemical Control Division
To understand "risk management," one must first
understand the concept of risk as used in the
field of human health and environmental
protection. Risk is a function of the inherent
harmfulness of a compound, or its "hazard," and the
extent to which individuals or the environment are
exposed to that compound.
When analysis indicates that a potential
serious risk exists to people, wildlife or
the environment the Agency looks
for ways to control or limit the
risk; this process is called "risk
management." Deciding what
risks need to be managed and
what is the most effective and
efficient way to accomplish risk
reduction is a complicated
endeavor, with a great many
variables and uncertainties.
Under its Toxic Substances Control Act authority, the
Agency seeks to control those risks where the potential
for harm are significant and where good reason would
indicate that the risk ought to be controlled. To make
this determination, the Agency relies on the best
available information concerning risk and related matters,
and on the knowledge and experience of its scientific,
technical and regulatory staff.
The Agency has a wide array of tools at its disposal to
accomplish risk managementfor example, rule making,
voluntary agreements, and programs that inform
individuals about risks and how to protect themselves
and the environment EPA tries to use the appropriate
tool for a given risk situation. For example, if in the
process of manufacturing a new chemical, a company
intends to release its waste water to a stream and as a
result fish and other aquatic organisms might be
killed or seriously harmed, the Agency
must make a risk management
decision.
In this situation, the Agency might
ask the company to restrict releases
by adopting a manufacturing
process that avoids water release or
through the use of recycling,
treatment technology or
alternative disposal methods.
Any one of these steps could
eliminate the risk or reduce it to
an acceptable level. Typically,
the Agency would ensure that
this risk reduction takes place by
entering into an agreement in
which the manufacturer promises not to release the new
chemical to water or to release only up to certain
amounts. This agreement, a common approach to risk
management in the New Chemicals Program, is called a
"consent order" and is legally binding and enforceable.
The Agency employs many voluntary approaches to risk
management as well, as discussed elsewhere in this
publication. Additionally, EPA employs voluntary
approaches to risk management prior to making its final
risk management decisions.
For more information contact David Di Fiore at (202) 260-
3374.
13'.
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Chemicals in the Environment
Winter 1995/1996
The Existing Chemicals Program's Risk Management Procedures
Deborah Williams, Chemical Control Division
HOW DOES THE EXISTING CHEMICAL PROGRAM
PROTECT HEALTH AND THE ENVIRONMENT?
Risk Management Initiatives
The Existing Chemicals Program develops and evaluates
strategies for preventing pollution and reducing the risks
associated with chemicals currently in production or use.
Risk Management 1 (RM1) is the first step in the
process leading to the development of options to reduce
or eliminate risk and is about six months in length. This
step is designed to initially screen and select, from among
the subset of approximately 15,000 commercial
chemicals, those chemicals that appear to be of greatest
concern to human health and the environment.
Risk Management 2 (RM2) is the next step in the
process and is approximately 12 to 24 months in length.
In RM2, RM1 chemicals that appear to pose a problem
are further investigated and analyzed, and options are
developed for addressing any concerns
identified. Not all RM1 cases reach
RM2.
In Post Risk Management 2 v\ ^ * (CH )
(Post-RM2), the Program *** 3 2
implements one or more of the
options recommended in RM2 to reduce or eliminate the
risks (negotiation of voluntary agreements, rules
development, etc.). Post-RM2 can range between three
months and two years. Some RM2 cases do not need a
formal Post-RM2 phase.
WHEN IS TESTING REQUIRED?
When specific chemical concerns are found in RM
activities, but important data needs remain in order to
adequately assess potential risk, the chemical is referred
for development of appropriate testing action and placed
on the "Master Testing List" (MTL). This consolidated
listing of the testing priorities under the Toxic
Substances Control Act (TSCA) establishes an agenda for
development of testing actions which are implemented by
formal TSCA Section 4 Test Rules, TSCA Section 4
Enforceable Consent Agreements (EGAs), or Voluntary
Testing Agreements. In addition, the MTL contains the
priority industrial chemical testing needs of other parts
of EPA as well as other Federal agencies. In some cases,
voluntary exposure/risk reduction actions can be
combined with testing actions and result in Product
Stewardship agreements.
HOW DOES THE PROGRAM USE THE TESTING DATA?
All new data submitted as a result of Existing Chemicals
Program testing actions are promptly evaluated. The new
data is then reviewed together with other available
information on the chemical in the RM1 component of
the Program or the RM2/post-RM2 component from
which the testing need originated. In cases where
another "client," such as the Consumer Product Safety
Commission, originated the testing need/action, copies of
the new data are provided for their use promptly upon
EPA's receipt.
WHAT KINDS OF CASES ARE PART OF THE RISK
MANAGEMENTAGENDA?
The program uses three case types chemical, use, and
facility. Chemical specific cases examine the life cycle of
one chemical to see what risks it might present, and what
risk management, if any, is necessary. Use cluster cases
examine one use of chemicals (such as aerosol spray
paints) and examines all the chemicals that might be
used for that purpose. The
CHO CRT f (flHr 1> primary goal is to find safer
3^2 chemical substitutes for
that use. Facility specific
cases look at individual chemical or manufacturing
facilities in the United States to see if some may present
health or environmental concerns for nearby
communities, based on one or more chemicals produced
or used on site.
WHAT TOOLS ARE USED BY THE PROGRAM
MANAGE CHEMICAL RISK?
TO
Embracing creative and flexible approaches to managing
cases in the Existing Chemicals Program has produced a
number of successes that have made, and are making a
difference in protecting health and the environment.
These approaches have put the Program on the cutting
edge of how EPA conducts its work in the 1990's.
For more information about the program, please contact the
TSCA Hotline at (202) 554-1404.
16
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Issue No. 2
Public Access Information
The Design for the Environment Program's Cleaner Technologies
Substitutes Assessment
Jed Meline, Economics, Exposure, and Technology Division
The Design for The Environment (DfE) Program in
the Office of Pollution Prevention and Toxics
creates voluntary partnerships with specific
industry sectors to evaluate the trade-offs among
substitute products, processes or technologies. The
assessment of trade-offs is only part of a DfE project.
The project partners, which may include trade
associations, universities, public interest groups, suppliers
and individual businesses, work together to create
outreach products and tools to convey the infor
mation necessary to help
businesses incorporate
environmental considerations
into their decision-making
process. Outreach products
developed by the DfE
Program have included case
studies, brochures, videos,
computer software,
technology demonstrations,
and training workshops.
The methodology created
by the DfE Program to
complete this evaluation is
called a Cleaner Technology
Substitutes Assessment or CTSA. Building upon the risk
management process used by EPA's Existing Chemicals
Program, the risk characterization involved in the CTSA
utilizes the level of rigor necessary only to capture the
differences between the substitutes.
In addition to the environmental and human health risk
information, the CTSA also includes many other
components necessary to inform business decision-
making and promote behavior change toward cleaner
alternatives. These components include field
demonstrations of the substitutes to assess performance
and cost, energy and natural resource considerations,
pollution prevention opportunities, process safety
concerns, Federal regulatory status, international trade
issues, recycle and control opportunities and social
benefits and costs.
The DfE Program is working with a number of industries
including printing (lithography, flexography, and screen
printing), dry cleaning, and electronics/printed wiring
board. The first draft CTSA was the Screen Printing-Screen
Reclamation CTSA released in October 1994. Many of
the related outreach products conveying the human
health and environmental risk trade-offs, pollution
prevention opportunities and technology alternatives are
available. Several more CTSAs are scheduled for release
in 1996.
The DfE Program is also developing a CTSA Methodology
and Resource Guide to explain the methodology and many
of the resources available to complete substitutes
assessment. This guide should be available early in 1996.
For information regarding the CTSA tools
contact Jed Meline at (202) 260-0695
(Internet: meline.jed@epamail.epa.gov).
For more information regarding the
DfE Program contact Irina Vaysman
at (202) 260-1312.
Copies of the draft Executive
Summary are available from the
Pollution Prevention Information
Clearinghouse, (202) 260-1023.
Request for copies of the full report
can be faxed to the National Center
for Environmental Publications and Information
(NCEPI), (513) 489-8695. Ask for report number EPA
744/R-94/005A.
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Chemicals in the Environment
Winter 1995
Communicating Environmental Risk
Susan Hazen, Director, Environmental Assistance Division
Communicating information about risks to human
health is a complicated undertaking. Many
different factors are involved, and these are often
difficult to measure. These factors fall into the general
categories of hazard and exposure, and require scientists
to take into account, among other things, the type of
hazard, the concentration of the chemical, duration of
exposure, and the exposed population. The resulting
rankings are not absolute and require assumptions and
scientific judgements.
To add to this uncertainty, different groups will perceive
risks differently. The regulated community, individuals
living near the source, environmentalists, and elected
officials may have very different views on the problem.
In addition, each of us take different factors into account
when we decide which risks we are willing to accept. For
example, whether or not a risk is voluntary is important
to us. We also take into account who controls the
outcome of risky situations. Most of us have heard that,
statistically, we risk our lives more by driving a car than
by fl>x ig in an airplane. Yet how many of us feel the
same nervousness behind the wheel of a car that we do as
a passenger in a plane?
Because many different factors come together to
determine how serious a risk is in the eyes of the public,
EPA takes pains to ensure that we appropriately
communicate risk. The Agency's seven cardinal rules of
risk communication are listed in the sidebar.
Risk communication is not a one-way street. It is an
interactive process where information and opinions are
exchanged among individuals, groups, and institutions.
EPA recognizes the need not only to inform the public,
but also to provide the public with the opportunity to
become involved in decision making. The purpose of risk
EPA's Seven Cardinal Rules of
Risk Communication
1. Accept and involve the public as a
legitimate partner.
2. Plan carefully and evaluate your
performance.
3. Listen to the public's feelings,
4. Be honest, open and frank.
5. Coordinate and collaborate with other
credible sources.
6. Meet the needs of the media.
7. Speak clearly and with compassion
From The Seven Cardinal Rities of Risk
Communication, EPA, OPPE, May 1992. EPA
Publication No.: EPA 230K92001. Available
from EPA's National Center for Environmental
Publications and Information (NCEPI), FAX:
(513)489-8695.
communication is not to allay the public's concerns, but
to empower the community to participate in the process
and assist in reaching the right decision.
Risk communication objectives include: providing
information to the public, motivating individuals to act,
stimulating a response to emergencies, arriving at the best
possible decision for those involved, helping the public
determine what an appropriate reaction to a particular
risk is, allowing all perspectives to be considered in each
situation, and contributing to the resolution of conflict.
EPA uses different forums to communicate risk
depending the specific situation, the nature of the risk,
and the special needs of the community. Tools EPA can
use to communicate risk include:
IB
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Issue No. 2
Public Access Information
public meetings citizen advisory groups
advisory committees telephone hotlines
press conferences information booths
drop-in hours for citizens to ask questions
informal meetings with interested organizations
direct mailings
advertising and public service
announcements
television or radio
interviews
newspaper or journal
articles
newsletters and other
publications
When EPA intends to hold
a public meeting, the time and
place for the meeting are published
in the Federal Register. EPA's Federal
Register notices are posted on the
Agency's homepage on the World
Wide Web. People with Internet
e-mail can actually subscribe to lists
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containing Federal Register rules and notices for EPA (See
page 20 for more information on accessing EPA Federal
Register information via the Internet.)
There are many ways you can get involved in discussions
about how the environmental risks you face in your life
should be managed. One place to start
might be your local library. Access the
Toxics Release Inventory to find out
about releases of toxic chemicals from
manufacturing facilities in your area.
Find out who is in charge of your local
and state public health and
environmental agencies and give them a
call. Contact the EPA Regional Office
that serves your area. When scientific
understanding is combined with good
risk communication and active public
involvement, much better solutions to
environmental problems emerge.
Federal Register Documents via the internet
Within the "Rule, Regulations and Legislation" section of
the EPA Gopher server (gojfei.epa.gov) are twelve sections
that contain documents extracted from the electronic daily
issue of the Federal Register. These twelve general sections
address various areas of environmental activity by U.S.
Government entities. Not all documents available under
these menus were originally issued by EPA, but they have
been identified as having some environmental impact.
Documents available in these areas are also sent to an
electronic mail listserver. You can subscribe to these
listservs by sending e-mail to the address
listserver@unixmaiLrtpnc.epa,gov and including as the
first non-blank line in the body of the message the command
SUBSCRIBE list-name First Name Last Name
where the list-name is taken from the list of hstserves
available from the EPA listserver. This list can be obtained
by sending as the first non-blank line in the body of the
message to the EPA listserver the command
LISTS
The following lists may be of particular interest to our readers.
Listserve Name
EPA-TOX
EPA-TRI
EPAFR-CONTENTS
EPA-MEETENGS
EPA-SAB
EPA-PEST
Description
Office of Pollution Prevention and Toxics documents excluding Community-Right-To-Know
(Toxics Release Inventory) documents,
Community-Right-To-Know Toxics Release Inventory documents.
The full-text of the table of contents with page number citations.
All meeting notices including those for program-specific meetings.
Material relating to the Science Advisory Board.
All Office of Pesticide Programs documents.
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