749R96001a
SERA,
                     United States
                     Environmental Protection
                     Agency
                        Pollution Prevention
                        and Toxics
                        (7407)
                                                                            Winter 1995/1996
                                                                            EPA 749-R-96-0013
Chemicals in the  Environment
Public Access Information
The Three R"s 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 Scoring
  System
integrated Risk
  information System
Exposure Assessment
Estimating Exposure: The
  Graphicaf Exposure
  Modeling System
  (GEMS)
TRf Environmental
  Indicators
Using Genen'c 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

                                 ?       Exposure
                        The Three R's of Risk
                           Odelia Funke, Chief, Information Access Branch
                                                                         8
                                                                         *-*
                                                                         CD
                                                                         b>
                              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 by EPA's Office of Palkttion 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) ami Web server {http://www.epa.gav}.
  It is located «nder JEPA Offices and Regions  f OJficeof
  Prevention, Pesticides and Toxics f Toxic Substances I
  Chemicals m ike Environment: Public Access Bulletin.

  Payeet Manager Georglanne McDonald
  Editor Randall Brinkhuis
        Internet: brinkfauis.randail@eparnail.epa.gov
  Publisher: Chuck Freeman
        Internet: freeman.charles@epamail.epa.gav
  Assistant Editor/Publisher: Gwen Shepard

  Advisory Board
  OPPT Divisional Representatives:
    David Di Korei, CCD         Ted Jones, CSRAD
    Dan Fort. JSEED              Mike McDondl BAD
   Ode1ia]?unke,IMD           foe Merenda, HERD
    RuthHeiickinert>£4Z>(^rPPD>  Tim Torma, CMD

  Mailing Address:
    Chemicals in lite Environment: Public Access Information
   U.S, EPA
   Office of Foliation Prevention and Toxics {7407}
   4QlMSt,,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
~*C  A  TTiile  all  substances   are  hazardous   or
 \/\/ potentially    harmful    under    some
  V   T  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 comer
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 lie 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 OPPTs 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 (continuedfrom 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 (continuedfrom 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 tfie 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
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 "dusters"  of
      chemicals. A duster is simply a group of diemicals
      related  by  denned  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 diemicals are:

  1)   The Use Ouster 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.
                                                 6

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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 Dorr 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,
       toxicologists, 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
           Cl
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 the system can modify the cancer
concern level for a chemical based upon additional
biological testing data that correlate with carcinogenitity
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. Phase contact Ernest V. Falke (202) 260-3433
(Internet: Falke.Ernest@epamail.epa.gpv) for more information.
 The Use  Cluster  Scoring  System:  A Use-Based  Approach  to Setting
    Priorities
    Daniel Fort, Economics, Exposure, and Technology Division
                             EPA'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 dusters"
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 agendes.   Also,  the system  uses
predictive methodologies  to  determine  hazard  and
exposure for chemicals lacking specific  data.  Beyond
duster 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 fay 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 dted
studies and pertinent sdentific 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
                                                  1O\

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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 Homines and
   Clearinghouses referred to
   in this issue

   EPA Programs

   Emergency Planning and Community
     RighMo-Know Act Hotline, (800) 535-
     0202; in the Washington, O.C.t
     metropolitan ama, (703) 920-9877

   Integrated Risk Information System (tRIS)
     Information Hotfine, (513) 569-7254

   National Center for Environmental
     Publications and Information (NCEPf),
     FAX (513} 489-8695

   Pollution Prevention information
     Clearinghouse (PPIC), (202) 260-1023

   Toxic Substances Control Act Assistance
     Information Service (TSCA Hotline),
     (202) 554-1404

   TR1 User Support, (202) 260-1531

   Other numbers

   National Library of Medicine,
     tRIS Representative,  (301) 496-6531

   National Technical information Service
     (MTtS), (703) 487-4650
For an overview of the GEMS program or to reauest a copy of
the GEMS User's Guide, contact Cathy Turner at (202) 260-
3929. far further information, contact Lynn Delpire, (202)
260-3928, or Patricia Harrigan, (202) 260-8479.
                                              11

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Chemicals in the Environment
                                                                                  Winter 1995/1996
TRl  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
(TRl) chemical emissions over time.  OPPT is planning
to develop four indicators of potential acute and chronic
health and ecological impacts.
            a  Microsoft  Windows-based computer
             uses   chemical   data  submitted  by
The  model,
application,
manufacturers to EPA's TRl.  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 TRl Environmental Indicator.

Each year's indicator will provide one perspective on how
the potential impact of TRl 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
                                                     80-
                                                   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@epamailepa.gov
      Emergency Planning and Community Right to Know Act (EPCRA): Release
      Information Required by Section 313

      Under Section 313 of EPCRA, certain manufecturing 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 Toxks Release
      Inventory {TRl). To find out how to access TRl data submitted by industries, call TRl 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 Washington, B.C., metropolitan
      area.

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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
                              «PPT  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 clear 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.

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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 management—for 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.
                                                 15\

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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   \1 G
(Post-RM2),  the  Program    **1
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
C H O C JHT ( f W  T>   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.
                                                1B\

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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      infer
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 flying 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 evaiuate your
       performance.

   3.   Usien 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  Rules  of Risk
   Comammcati&n, EPA, QPPE, May 1992. EPA
   Publication.]*).:  EPA 230K920QL  Available
   ftom 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:
                                                18'

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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
                          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 {gopher,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 Sstserves
                          available from the EPA listserver. Tins list can be obtained
                          by sending as the 8rst 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-TKl
      EEAfR-CONTENTS
      EPA-MEETINGS
      EPA-SAB
      EPA-PEST
Description
Office of Pollution Prevention and Toxics documents excluding Cfommunity-Right-To-SKnow
(Toxics Release Inventory) documents.
Conrfnanxty-Right-To-ICnow Toxics Release Inventory documents.
The full-text of the table of contents with page number citations,
Afl meeting notices including those for program-specific meetings.
Material relating to die Science Advisory Board,
All Office of Pesticide Programs documents.
                                                    19'

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Chemicals in the Environment                                                              Winter 1995
   United States
   Environmental Protection
   Agency
   (7407)
   Washington DC 20460

   Official Business
   Penalty for Private Use
   $300

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