United States Government Accountability Office

GAO Testimony

Before the Committee on Environment 

and Public Works, U.S. Senate 

TOXIC CHEMICALS 

EPA’s New Assessment 

Process Will Increase 

Challenges EPA Faces in 

Evaluating and Regulating 

Chemicals 

Statement of John B. Stephenson, Director 

Natural Resources and Environment 

For Release on Delivery 

Expected at 10:00 a.m. EDT 

Tuesday, April 29, 2008

 

GAO-08-743T 
What GAO Found

United States Government Accountability Office

Why GAO Did This Study

Highlights

Accountability Integrity Reliability

April 29, 2008

TOXIC CHEMICALS

EPA’s New Assessment Process Will Increase 

Challenges EPA Faces in Evaluating and Regulating

Highlights of GAO-08-743T, a testimony Chemicals

before the Committee on Environment and 

Public Works, U.S. Senate 

The Environmental Protection 

Agency’s (EPA) mission includes 

evaluating and regulating toxic

chemicals. EPA’s Integrated Risk 

Information System (IRIS) program 

is a chemical evaluation program 

that is a critical component of

EPA’s capacity to support 

scientifically sound environmental 

regulations and policies. The IRIS 

database contains EPA’s scientific 

position on the potential human

health effects of exposure to more

than 540 chemicals. 

This testimony highlights GAO’s 

work on toxic substances, focusing

on (1) its March 2008 report, 

Chemical Assessments: Low 

Productivity and New Interagency 

Review Process Limit the 

Usefulness and Credibility of 

EPA’s Integrated Risk Information 

System and (2) key changes to the

IRIS assessment process EPA 

included in its revised IRIS 

assessment process released on 

April 10, 2008. It also highlights the

findings of two GAO reports on 

EPA’s regulation of toxic 

chemicals. For the IRIS report,

GAO analyzed EPA data and 

interviewed officials at relevant 

agencies, including the Office of

Management and Budget (OMB).

For this testimony, GAO 

supplemented the IRIS report with

a review of EPA’s revised IRIS 

assessment process announced 

earlier this month. 

Given the importance of the IRIS

program to EPA’s ability to protect 

public health and the environment, 

Congress should consider requiring 

EPA to suspend its new process 

and develop one that is responsive

to GAO’s recommendations. 

The IRIS database is at serious risk of becoming obsolete because EPA has 

not been able to routinely complete timely, credible assessments or decrease

its backlog of 70 ongoing assessments—a total of 4 were completed in fiscal 

years 2006 and 2007. In addition, recent assessment process changes, as well

as other changes EPA was considering at the time of GAO’s review, further 

reduce the timeliness and credibility of IRIS assessments. 

• Although EPA has taken steps to improve the IRIS program since 2000 and 

has developed a number of draft assessments for external review, its 

efforts to finalize assessments have been thwarted by a combination of 

factors, including two new OMB-required reviews of IRIS assessments by 

OMB and other federal agencies; EPA management decisions, such as 

delaying some assessments to await new research; and the compounding 

effect of delays—even one delay can have a domino effect, requiring the 

process to essentially be repeated to incorporate changing science and 

methods. 

• The OMB/interagency reviews of draft assessments involve other federal

agencies in EPA’s IRIS assessment process in a manner that limits the 

credibility of IRIS assessments and hinders EPA’s ability to manage them. 

For example, the OMB/interagency reviews lack transparency, and OMB 

required EPA to terminate five assessments EPA had initiated to help it 

implement the Clean Air Act. 

• The changes to the IRIS assessment process that EPA was considering, 

but had not yet issued at the time of GAO’s review, would have added to 

the already unacceptable level of delays in completing IRIS assessments 

and further limited the credibility of the assessments. 

On April 10, 2008, EPA issued a revised IRIS assessment process, effective 

immediately. In its February 2008 comments on GAO’s draft report, EPA said

it would consider the report’s recommendations, which were aimed at 

streamlining the process and better ensuring that EPA has the ability to 

develop transparent, credible assessments. However, EPA’s new process is 

largely the same as the draft GAO evaluated, and some key changes also are 

likely to further exacerbate the productivity and credibility concerns GAO 

identified. For example, while the draft process would have made comments 

on IRIS assessments from other federal agencies part of the public record, 

EPA’s new process expressly defines such comments as “deliberative” and 

excludes them from the public record. GAO continues to believe it is critical

that input from all parties—particularly agencies that may be affected by the 

outcome of IRIS assessments—be publicly available. As recommended in 

GAO’s March 2008 report, to effectively maintain IRIS, EPA must, among 

other things, streamline its lengthy assessment process and adopt 

transparency practices that provide assurance that IRIS assessments are

appropriately based on the best available science and that they are not 

inappropriately biased by policy considerations. Since EPA’s new process is 

not responsive to GAO’s recommendations, the viability of this critical 

database has been further jeopardized. 

To view the full product, including the scope 

and methodology, click on GAO-08-743T. 

For more information, contact John B. 

Stephenson at (202) 512-3841 or

stephensonj@gao.gov. 
Madam Chairman and Members of the Committee: 

I am pleased to be here today to discuss issues associated with the 

Environmental Protection Agency’s (EPA) evaluation and regulation of 

toxic chemicals. Over the past few years, GAO has issued a number of 

reports on this topic. Today I will focus primarily on our most recent 

report in this area that examined EPA’s Integrated Risk Information 

System (IRIS)—one of the most significant tools that EPA has developed

to effectively support its mission of protecting people and the environment 

from harmful chemical exposures. IRIS contains EPA’s scientific position 

on the potential human health effects that may result from exposure to 

more than 540 chemicals in the environment and is a critical component of 

EPA’s capacity to support scientifically sound environmental decisions, 

policies, and regulations. It is also relied upon by state and local 

environmental programs and some international regulatory bodies for 

managing their environmental protection programs. 

The toxicity assessments in the IRIS database fulfill the first two critical 

steps of the risk assessment process—providing hazard identification and

quantitative dose-response assessments. IRIS information can then be 

used with the results of exposure assessments (typically conducted by 

EPA’s program or regional offices) to provide an overall characterization 

of the public health risks for a given chemical in a given situation. The 

development of health risk assessments is thus directly dependent on the 

development of toxicity assessments such as those developed in the IRIS

program. With risk assessment information, decision makers can make 

informed risk management decisions on how to protect public health,

reflecting other important data and considerations, such as the costs and

benefits of mitigating identified risks, the technological feasibility of 

managing risks, and the concerns of various stakeholders. Examples of 

risk management decisions include deciding how much of a chemical a

company may discharge into a river, determining the extent to which a 

hazardous waste site must be cleaned up, and setting allowable levels of 

contamination in drinking water. Thus, as EPA has recognized, although

IRIS assessments are not regulatory in nature, the quantitative IRIS values 

may influence many risk management decisions and serve as a basis for 

regulatory consideration. However, EPA’s productivity in finalizing IRIS 

assessments is poor, and EPA has a significant backlog of incomplete IRIS 

assessments and a growing number of outdated assessments. Importantly, 

EPA has not been able to complete assessments of key chemicals of 

concern to public health, including dioxin, formaldehyde,

trichloroethylene (TCE), naphthalene, and tetrachloroethylene (perc) (see 

app. I). 

Page 1 GAO-08-743T Toxic Chemicals 
In the last several years, GAO issued a number of reports on EPA’s toxics 

programs, highlighting program shortcomings and recommending 

management improvements. My testimony today addresses (1) the 

highlights of our March 2008 report, Chemical Assessments: Low 

Productivity and New Interagency Review Process Limit the Usefulness

and Credibility of EPA’s Integrated Risk Information System,

1

 being 

released today, and (2) key changes to the IRIS assessment process that 

EPA included in its revised process released on April 10, 2008. We are also 

providing information on two of our prior reports on EPA’s regulation of

toxic chemicals (see app. II).2

 For our March 2008 report, we examined the 

outcome of steps EPA has taken to ensure that IRIS contains current, 

credible chemical risk information; to address the backlog of ongoing 

assessments; and to respond to new requirements from the Office of 

Management and Budget (OMB). We also examined the potential effects of

planned changes to the IRIS assessment process on EPA’s ability to ensure

that IRIS provides current, credible risk information. In conducting our 

work, we obtained and analyzed information on EPA’s productivity and 

the resources provided to the program for fiscal years 2000 through 2007,

user needs, and EPA’s assessment completion goals. We also interviewed 

EPA’s National Center for Environmental Assessment officials who 

manage the IRIS assessment program; officials from other EPA program 

offices and federal science and health agencies involved in the IRIS 

assessment process; and officials from the Department of Defense, the 

Department of Energy (DOE), the National Aeronautics and Space 

Administration (NASA), and OMB. For this testimony, we supplemented 

our report with an analysis of the IRIS assessment process that EPA 

released on April 10, 2008. We conducted this work from April 16 to April 

29, 2008, in accordance with generally accepted government auditing 

standards. Those standards require that we plan and perform the audit to

obtain sufficient, appropriate evidence to provide a reasonable basis for 

our findings and conclusions based on our audit objectives. We believe 

that the evidence obtained provides a reasonable basis for our findings 

and conclusions based on our audit objectives. 

 1

GAO-08-440 (Washington, D.C.: Mar. 7, 2008).

2

GAO, Chemical Regulation: Options Exist to Improve EPA’s Ability to Assess Health

Risks and Manage Its Chemical Review Program, GAO-05-458 (Washington, D.C.: June 13, 

2005); and GAO, Chemical Regulation: Approaches in the United States, Canada, and the

European Union, GAO-06-217R (Washington, D.C.: Nov. 4, 2005). 

Page 2 GAO-08-743T Toxic Chemicals 
IRIS was created in 1985 to help EPA develop consensus opinions within 

the agency about the health effects of chronic exposure to chemicals. Its 

importance has increased over time as EPA program offices and the states 

have increasingly relied on IRIS information in making environmental 

protection decisions. Currently, the IRIS database contains assessments of 

more than 540 chemicals. According to EPA, national and international 

users access the IRIS database approximately 9 million times a year. EPA’s 

Assistant Administrator for the Office of Research and Development has 

described IRIS as the premier national and international source for 

qualitative and quantitative chemical risk information; other federal 

agencies have noted that IRIS data are widely accepted by all levels of 

government across the country for application of public health policy, 

providing benefits such as uniform, standardized methods for toxicology 

testing and risk assessment, as well as uniform toxicity values. Similarly, a 

private-sector risk assessment expert has stated that the IRIS database has 

become the most important source of regulatory toxicity values for use 

across EPA’s programs and is also widely used across state programs and 

internationally. 

Background 

A typical IRIS assessment contains a qualitative hazard identification 

description and quantitative dose-response assessments. Historically and 

currently, the focus of IRIS toxicity assessments has been on the potential

health effects of long-term (chronic) exposure to chemicals. According to 

OMB, EPA is the only federal agency that develops qualitative and 

quantitative assessments of both cancer and noncancer risks of exposure 

to chemicals, and EPA does so largely under the IRIS program. Other 

federal agencies develop quantitative estimates of noncancer effects or 

qualitative cancer assessments of exposure to chemicals in the 

environment. While these latter assessments provide information on the 

effects of long-term exposures to chemicals, they provide only qualitative 

assessments of cancer risks (known human carcinogen, likely human 

carcinogen, etc.) and not quantitative estimates of cancer potency, which 

are required to conduct quantitative risk assessments. 

EPA’s IRIS assessment process has undergone a number of formal and 

informal changes during the past several years. While the process used to 

develop IRIS chemical assessments includes numerous individual steps or 

activities, major assessment steps include (1) a review of the scientific 

literature; (2) preparation of a draft IRIS assessment; (3) internal EPA 

reviews of draft assessments; (4) two OMB/interagency reviews, managed 

by OMB, that provide input from OMB as well as from other federal 

agencies, including those that may be affected by the IRIS assessments if 

they lead to regulatory or other actions; (5) an independent peer review 

Page 3 GAO-08-743T Toxic Chemicals 
conducted by a panel of experts; and (6) the completion of a final 

assessment that is posted to the IRIS Web site. 

The IRIS database is at serious risk of becoming obsolete because the 

agency has not been able to routinely complete timely, credible 

assessments or decrease a backlog of 70 ongoing assessments. 

Specifically, although EPA has taken important steps to improve the IRIS 

program and productivity since 2000 and has developed a number of draft 

assessments for external review, its efforts to finalize the assessments

have been thwarted by a combination of factors including the imposition 

of external requirements, the growing complexity and scope of risk 

assessments, and certain EPA management decisions. In addition, the 

changes to the IRIS assessment process that EPA was considering at the

time of our review would have added to the already unacceptable level of 

delays in completing IRIS assessments and further limited the credibility 

of the assessments. 

Findings and 

Recommendations 

from Our March 2008 

Report on the 

Productivity and 

Credibility of EPA’s 

Integrated Risk 

Information System 

EPA’s Efforts to Improve 

the IRIS Assessment 

Program Have Not 

Produced the Desired 

Results 

EPA has taken a number of steps to help ensure that IRIS contains current, 

credible chemical risk information; to address its backlog of ongoing 

assessments; and to respond to new OMB requirements. However, to date, 

these changes—including increasing funding, centralizing staff conducting 

assessments, and revising the assessment process—have not enabled EPA 

to routinely complete credible IRIS assessments or decrease the backlog.

That is, although EPA sent 32 draft assessments for external review in 

fiscal years 2006 and 2007, the agency finalized only 4 IRIS assessments 

during this time (see fig. 1). 

Page 4 GAO-08-743T Toxic Chemicals 
Figure 1: Number of Completed IRIS Assessments, Draft Assessments to OMB, and 

IRIS Staff in Full-Time Equivalents, Fiscal Years 2000-2007 

0

5

10

15

20

25

30

35

40

2000 2001 2002 2003 2004 2005 2006 2007

Source: GAO analysis of EPA data.

Fiscal year

IRIS staff levels in full-time equivalents

IRIS assessments completed

Draft IRIS assessments to OMB for OMB/interagency review

(Year OMB/interagency

review initiated)

Several key factors have contributed to EPA’s inability to achieve a level

of productivity that is needed to sustain the IRIS program and database:

new OMB-required reviews of IRIS assessments by OMB and other federal 

agencies; the growing complexity and scope of risk assessments; certain

EPA management decisions and issues, including delaying completion of 

some assessments to await new research or to develop enhanced analyses 

of uncertainty in the assessments; and the compounding effect of delays. 

Regarding the last factor, even a single delay in the assessment process 

can lead to the need to essentially repeat the assessment process to take 

into account changes in science and methodologies. 

A variety of delays have impacted the majority of the 70 assessments being 

conducted as of December 2007—48 had been in process for more than 5 

years, and 12 of those for more than 9 years. These time frames are 

problematic because of the substantial rework such cases often require to

take into account changing science and methodologies before they can be 

completed. Further, because EPA staff time continues to be dedicated to

completing these assessments, EPA’s ability to both keep the more than 

Page 5 GAO-08-743T Toxic Chemicals 
540 existing assessments up to date and initiate new assessments is 

limited. Importantly, EPA program offices and state and local entities have

requested assessments of hundreds of chemicals not yet in IRIS, and EPA 

data as of 2003 indicated that the assessments of 287 chemicals in the 

database may be outdated—that is, new information could change the risk 

estimates currently in IRIS or enable EPA to develop additional risk 

estimates for chemicals in the database (for example, developing a cancer 

potency estimate for assessments with only noncancer estimates). In 

addition, because EPA’s 2003 data are now more than 4 years old, it is 

likely that more assessments may be outdated now. 

One of the factors that has contributed to EPA’s inability to complete 

assessments in a timely manner—the new OMB-directed OMB/interagency

review process—also limits the credibility of the assessments because it

lacks transparency. Specifically, neither the comments nor the changes 

EPA makes to the scientific IRIS assessments in response to the 

comments made by OMB and other federal agencies, including those 

whose workload and resource levels could be affected by the assessments, 

are disclosed. In addition, the OMB/interagency reviews have hindered 

EPA’s ability to independently manage its IRIS assessments. For example, 

without communicating its rationale for doing so, OMB directed EPA to 

terminate five IRIS assessments that for the first time addressed acute, 

rather than chronic exposure—even though EPA initiated this type of 

assessment to help it implement the Clean Air Act.

The Expansion of 

Agencies’ Roles in IRIS 

Assessments That EPA 

Was Considering at the 

Time of Our Review Would 

Have Caused Further 

Delays and Limited the 

Assessments’ Credibility 

For our March 2008 report, we reviewed the additional assessment 

process changes EPA was planning and concluded that they would likely 

exacerbate delays in completing IRIS assessments and further affect their

credibility. Specifically, despite the OMB/interagency review process that 

OMB required EPA to incorporate into the IRIS assessment process in 

2005, certain federal agencies continued to believe they should have

greater and more formal roles in EPA’s development of IRIS assessments. 

Consequently, EPA had been working for several years to establish a 

formal IRIS assessment process that would further expand the role of 

federal agencies in the process—including agencies such as DOD, which 

could be affected by the outcome of IRIS assessments. For example, some 

of these agencies and their contractors could face increased cleanup costs 

and other legal liabilities if EPA issued an IRIS assessment for a chemical

that resulted in a decision to regulate the chemical to protect the public. In

addition, the agencies could be required to, for example, redesign systems 

and processes to eliminate hazardous materials; develop material 

substitutes; and improve personal protective clothing, equipment, and 

Page 6 GAO-08-743T Toxic Chemicals 
procedures. Under the changes that EPA was planning at the time of our 

review, these potentially affected agencies would have the opportunity to 

be involved, or provide some form of input, at almost every step of EPA’s 

IRIS assessment process. Most significantly, the changes would have

provided federal agencies, including those facing potential regulatory 

liability, with several opportunities during the IRIS assessment process to 

subject particular chemicals of interest to additional process steps. These 

additional process steps, which would have lengthened assessment times 

considerably, include 

• giving federal agencies and the public 45 days to identify additional 

information on a chemical for EPA’s consideration in its assessment or to 

correct any errors on an additional assessment draft that would provide 

qualitative information;3

• giving potentially affected federal agencies 30 days to review the public 

comments EPA received and initiate a meeting with EPA if they want to 

discuss a particular set of comments; 

• allowing potentially affected federal agencies to have assessments 

suspended for up to 18 months to fill a data gap or eliminate an 

uncertainty factor that EPA plans to use in its assessment; and 

• allowing other federal agencies to weigh in on (1) the level of independent

peer review that would be sought (that is, whether the peer reviews would 

be conducted by EPA Science Advisory Board panels, National Academies’ 

panels, or panels organized by an EPA contractor); (2) the areas of 

scientific expertise needed on the panel; and (3) the scope of the peer 

reviews and the specific issues they would address. 

EPA estimated that assessments that undergo these additional process 

steps would take up to 6 years to complete. While it is important to ensure

that assessments consider the best science, EPA has acknowledged that 

waiting for new data can result in substantial harm to human health, 

safety, and the environment. Further, although coordination with other 

 3

This represents an additional review of a new draft product and comment period that had 

not existed previously. 

Page 7 GAO-08-743T Toxic Chemicals 
federal agencies about IRIS assessments could enhance their quality,4

increasing the role of agencies that may be affected by IRIS assessments in 

the process itself reduces the credibility of the assessments if that 

expanded role is not transparent. In this regard, while EPA’s proposed 

changes would have allowed for including federal agencies’ comments in 

the public record, the implementation of this proposal was delayed for a 

year, in part, because of OMB’s view that agencies’ comments about IRIS 

assessments represent internal executive branch communications that 

may not be made public—a view that is inconsistent with the principle of 

sound science, which relies on, among other things, transparency. 

To address the productivity and credibility issues we identified, we 

recommended that the EPA Administrator require the Office of Research

and Development to re-evaluate its draft proposed changes to the IRIS 

assessment process in light of the issues raised in our report and ensure 

that any revised process, among other things, clearly defines and 

documents an IRIS assessment process that will enable the agency to 

develop the timely chemical risk information it needs to effectively 

conduct its mission. One of our recommendations—that EPA provide at

least 2 years’ notice of IRIS assessments that are planned—would, among 

other things, provide an efficient alternative to suspending assessments 

while waiting for new research because interested parties would have the 

opportunity to conduct research before assessments are started. 

In addition, we recommended that the EPA Administrator take steps to 

better ensure that EPA has the ability to develop transparent, credible IRIS

assessments—an ability that relies in large part on EPA’s independence in 

conducting these important assessments. Actions that are key to this 

ability include ensuring that EPA can (1) determine the types of 

assessments it needs to support EPA programs and (2) define the 

appropriate role of external federal agencies in EPA’s IRIS assessment 

process and manage an interagency review process in a manner that 

enhances the quality, transparency, timeliness, and credibility of IRIS 

assessments. In its February 21, 2008, letter providing comments on our 

Recommendations Made in 

Our March 2008 Report 

 4

We recommended in our 2006 report on human health risk assessment that EPA 

consistently involve stakeholders as appropriate to the risk assessment. We made this 

recommendation in the context of improving the overall quality, consistency, and 

transparency of risk assessments. GAO, Human Health Risk Assessment: EPA Has Taken 

Steps to Strengthen Its Process, but Improvements Needed in Planning, Data

Development, and Training, GAO-06-595 (Washington, D.C.: May 31, 2006). 

Page 8 GAO-08-743T Toxic Chemicals 
draft report, EPA said it would consider each of our recommendations in

light of the new IRIS process the agency was developing. 

On April 10, 2008, EPA issued a revised IRIS assessment process, effective 

immediately (see app. III for a flow chart of the process). Overall, EPA’s 

revised process is not responsive to the recommendations made in our 

March 2008 report. While the revised process is largely the same as the 

draft proposed process we evaluated in our March 2008 report, there are 

several key differences that are likely to further exacerbate the 

productivity and credibility issues we identified in our report. These 

changes are as follows. 

Key Changes to the 

IRIS Assessment 

Process That EPA 

Implemented in 

April 2008 

• While the draft process we reviewed provided that comments on IRIS 

assessments from OMB and other federal agencies would be part of the 

public record, under the recently implemented process, comments from 

federal agencies are expressly defined as “deliberative” and will not be 

included in the public record. (Making these comments public would have 

been a change from the OMB/interagency review process that has been in

place since 2004.) Given the importance and sensitivity of IRIS 

assessments, we believe it is critical that input from all parties, particularly 

agencies that may be affected by the outcome of IRIS assessments, be 

publicly available. Thus, under EPA’s new process, input from some IRIS 

assessment reviewers—representatives of federal agencies, including 

those facing potential regulatory liability, and private stakeholders 

associated with these agencies—will continue to receive less public 

scrutiny than all other comments. 

• The newly implemented IRIS assessment process broadens EPA’s 

characterization of IRIS assessments from “the Agency’s scientific 

positions on human health effects that may result from exposure to 

environmental contaminants” to “the Agency’s science and science policy 

positions” on such effects. As we highlighted in our report, under the 

National Academies’ risk assessment and risk management paradigm, 

policy considerations are relevant in the risk management phase—which 

occurs after the risk assessment phase that encompasses IRIS 

assessments. EPA’s new, broader characterization of IRIS raises concerns 

about the agency’s intent to ensure that scientific assessments are 

appropriately based on the best available science and that they are not 

inappropriately impacted by policy issues and considerations. 

• The new process includes several revisions to the time frames associated 

with various process steps. Most notably, while EPA has estimated that 

under the new process assessments may take up to 6 years to complete, 

Page 9 GAO-08-743T Toxic Chemicals 
the estimated time frames do not factor in the time needed for peer 

reviews conducted by the National Academies, which can take 2 years to 

plan and complete.5 EPA typically uses reviews by the National Academies 

for highly controversial chemicals or complex assessments. Therefore, 

assessments reviewed by the National Academies are likely to take at least 

8 years to complete. However, as discussed in our report, when 

assessments take longer than 2 years, they can become subject to 

substantial delays stemming from the need to redo key analyses to take 

into account changing science and assessment methodologies. As a result, 

we concluded that it was critical that EPA streamline its process to 

routinely support timely completion of assessments and avoid being 

caught in an endless cycle of delays. Further, EPA’s lengthy assessment 

time frames must be considered in light of OMB’s view that health 

assessment values in IRIS are out of date if they are more than 10 years old 

and if new scientific information exists that could change the health 

assessment values. EPA’s new process institutionalizes time frames that 

could essentially require the agency to start assessment updates as soon as 

2 years after assessments are finalized in order to keep the IRIS database 

current. Such time frames are not consistent with our recommendation 

that EPA clearly define and document a streamlined IRIS process that can 

be conducted within time frames that minimize the need for wasteful 

rework. Further, the agency would need a significant increase in resources 

to support such an assessment cycle.

In addition, EPA had previously emphasized that, in suspending 

assessments to allow agencies to fill in data gaps, it would allow no more 

than 18 months to complete the studies and have them peer reviewed. 

However, under the new process, EPA states that it generally will allow no 

more than 18 months to complete the studies and have them peer 

reviewed. As we concluded in our report, we believe the ability to suspend 

assessments for up to 18 months would add to the already unacceptable 

level of delays in completing IRIS assessments. Further, we and several 

agency officials with whom we spoke believe that the time needed to plan, 

conduct, and complete research that would address significant data gaps,

and have it peer reviewed, would likely exceed 18 months. Therefore, the 

less rigid time frame EPA included in its new process could result in 

additional delays. 

 5

It is not clear whether the time frames exclude reviews conducted by EPA’s Science 

Advisory Board, which can also add considerably more time than the most basic level of 

peer review used by the IRIS program—panels organized by an EPA contractor. 

Page 10 GAO-08-743T Toxic Chemicals 
• The new process expands the scope of one of the additional steps that 

initially was to apply only to chemicals of particular interest to federal 

agencies.6 Specifically, under the draft process we reviewed, EPA would 

have provided an additional review and comment opportunity for federal 

agencies and the public for what EPA officials said would be a small group 

of chemicals. However, under EPA’s new process, this additional step has 

been added to the assessment process for all chemicals and, therefore, will 

add time to the already lengthy assessments of all chemicals. 

• Finally, EPA and OMB had planned for EPA to release a draft revised IRIS 

assessment process to the public, hold a public meeting to discuss EPA’s 

proposed changes, and seek and incorporate public input before finalizing 

the process. For example, in its letter commenting on our draft report, 

OMB emphasized that EPA had not completed the development of the IRIS 

assessment process, adding: “Indeed, the process will not be complete 

until EPA circulates its draft to the public for comments and then releases 

a final product that is responsive to those comments.” However, as stated 

above, EPA released its new assessment process without obtaining public

input and made it effective immediately. 

The new IRIS assessment process that EPA implemented in April 2008 will 

not allow the agency to routinely and timely complete credible 

assessments. In fact, it will exacerbate the problems we identified in our 

March 2008 report and sought to address with our recommendations—all 

of which were aimed at preserving the viability of this critical database, 

which is integral to EPA’s mission of protecting the public and the 

environment from exposure to toxic chemicals. Specifically, under the 

new process, assessment time frames will be significantly lengthened, and 

the lack of transparency will further limit the credibility of the 

assessments because input from OMB and other agencies at all stages of 

the IRIS assessment process is now expressly defined as deliberative and

therefore not subject to public disclosure. To effectively maintain IRIS, 

EPA must streamline its lengthy assessment process and adopt 

transparency practices that provide assurance that IRIS assessments are 

appropriately based on the best available science and that they are not 

Conclusions 

 6

The new IRIS assessment process refers to such chemicals as “mission critical.” A missioncritical chemical is one that is an integral component to the successful and safe conduct of 

an agency’s mission in any or all phases of its operations. Impacts on the use of missioncritical chemicals include cessation or degradation of the conduct of the mission and/or

unacceptable resource constraints. 

Page 11 GAO-08-743T Toxic Chemicals 
inappropriately biased by policy issues and considerations. Federal 

agencies may appropriately participate in policy dialogues through the 

rule-making process and other interagency working groups, which are risk 

management activities that should occur after the risk assessment process 

that encompasses IRIS assessments. Finally, suspending assessments is 

inefficient; alternatively, with longer-term planning, EPA could provide 

agencies and the public with more advance notice of assessments, 

enabling them to complete relevant research before IRIS assessments are 

started. 

In light of the importance of the IRIS program to EPA’s ability to protect 

the public health and the environment, the Congress should consider 

requiring EPA to suspend implementation of its new IRIS assessment 

process and develop a process that is responsive to our recommendations 

for a streamlined process that is transparent and otherwise responsive to 

our recommendations aimed at improving the timeliness and credibility of 

IRIS assessments. In addition, the Congress should consider requiring EPA 

to obtain and be responsive to input from the Congress and the public 

before finalizing a revised IRIS assessment process. 

Madam Chairman, this concludes my prepared statement. I would be 

happy to respond to any questions that you or other Members of the 

Committee may have at this time. 

For further information about this testimony, please contact John B. 

Stephenson on (202) 512-3841 or stephensonj@gao.gov. Contact points for 

our Offices of Congressional Relations and Public Affairs may be found on

the last page of this statement. Contributors to this testimony include 

Christine Fishkin (Assistant Director), Laura Gatz, Richard P. Johnson, 

Nancy Crothers, David Bennett, and Crystal M. Huggins. 

Matter for 

Congressional 

Consideration 

GAO Contact and 

Staff 

Acknowledgments 

Page 12 GAO-08-743T Toxic Chemicals 
Page 13 GAO-08-743T Toxic Chemicals 

Appendix I: Examples of Key IRIS 

Assessments That Have Been Delayed 

Some key IRIS assessments have been in progress for a number of years, 

in part because of delays stemming from one or more of the key factors we 

identified that have hindered EPA’s productivity.1

 Examples include the

following: 

Naphthalene. EPA started the IRIS assessment of cancer risks stemming 

from the inhalation of naphthalene in 2002. Naphthalene is used in jet fuel

and in the production of widely used commercial products such as moth 

balls, dyes, insecticides, and plasticizers. According to a presentation 

delivered at the 2007 annual meeting of the Society for Risk Analysis by an

Army Corps of Engineers toxicologist,

2

 “The changing naphthalene 

regulatory environment includes a draft EPA risk assessment that if/when 

finalized, will change naphthalene’s status from ‘possible’ to ‘likely’ human 

carcinogen.”3

 Thus, according to this presentation, one potential impact of 

this IRIS assessment on DOD is that DOD would need to provide many 

employees exposed to naphthalene with equipment measuring their 

exposure to the chemical. In addition, because many military bases are 

contaminated with naphthalene, a component of jet fuel (approximately 1 

percent to 3 percent) used by all DOD services, DOD could face extensive 

cleanup costs. By 2004, 2 years after starting the assessment, EPA had 

drafted a chemical assessment that had completed internal peer reviews 

and was about to be sent to an external peer review committee. Once it 

returned from external review, the next step, at that time, would have

been a formal review by EPA’s IRIS Agency Review Committee. If 

approved, the assessment would have been completed and released. 

 1

The factors we identified that have hindered EPA’s efforts to improve productivity are the

OMB/interagency review process managed by OMB, the growing complexity and scope of 

risk assessments, certain management decisions and issues regarding the IRIS program,

congressional action that has delayed some assessments with potentially significant 

economic effects, and the compounding effect of delays. 

2

Presentations at the Society for Risk Analysis meeting reflect the views of the authors and 

“do not necessarily reflect the views of any other organization or agency.”

3

Using its 1996 Proposed Guidelines for Carcinogen Risk Assessment, EPA concluded in

the 1998 IRIS assessment of naphthalene that its human carcinogenic potential could not

be determined at that time, but noted that there was suggestive evidence of potential 

human carcinogenicity. (EPA also noted that under its 1986 cancer guidelines, EPA 

classified naphthalene as a possible human carcinogen.) Subsequently, in 2002, the

International Agency for Research on Cancer (IARC), part of the World Health 

Organization, concluded that naphthalene is possibly carcinogenic to humans; in 2004, the 

Department of Human Health and Services’ National Toxicology Program concluded that 

naphthalene can reasonably be anticipated to be a human carcinogen. EPA’s current 

assessment will be subject to the agency’s 2005 cancer guidelines. 
However, in part because of concerns raised by DOD, OMB asked to 

review the assessment and conducted an interagency review of the draft. 

In their 2004 reviews of the draft IRIS assessment, both OMB and DOD 

raised a number of concerns about the assessment and suggested to EPA 

that it be suspended until additional research could be completed to 

address what they considered to be significant uncertainties associated 

with the assessment. Although all of the issues raised by OMB and DOD 

were not resolved, EPA continued with its assessment by submitting the 

draft for external peer review, which was completed in September 2004.4

However, according to EPA, OMB continued to object to the draft IRIS 

assessment and directed EPA to convene an additional expert review 

panel on genotoxicity to obtain recommendations about short-term tests 

that OMB thought could be done quickly.5

 According to EPA, this added 6 

months to the process, and the panel, which met in April 2005, concluded 

that the research that OMB was proposing could not be conducted in the 

short term. Nonetheless, EPA officials said that the second expert panel 

review did not eliminate OMB’s concerns regarding the assessment, which 

they described as reaching a stalemate. In September 2006, EPA decided, 

however, to proceed with developing the assessment. By this time, the 

naphthalene assessment had been in progress for over 4 years; EPA 

decided that the IRIS noncancer assessment, issued in 1998, was outdated 

and needed to be revisited. Thus, EPA expanded the IRIS naphthalene 

assessment to include both noncancer and cancer assessments. As a 

result, 6 years after the naphthalene assessment began, it is now back at 

the drafting stage. The assessment now will need to reflect relevant 

research completed since the draft underwent initial external peer review 

in 2004, and it will have to undergo all of the IRIS assessment steps again, 

including additional internal and external reviews that are now required. 

This series of delays has limited EPA’s ability to conduct its mission. For 

example, the Office of Air and Radiation has identified the naphthalene

assessment as one of its highest-priority needs for its air toxics program. 

In addition, the Office of Solid Waste and Emergency Response considers 

the naphthalene assessment a high priority for the Superfund program—

naphthalene has been found in at least 654 of Superfund’s current or 

 4

According to DOD, EPA did not specifically ask the peer reviewers to address some of the

technical questions DOD had raised and wanted the peer review to address. 

5

Genotoxic substances are a type of carcinogen, specifically those capable of causing 

genetic mutation and of contributing to the development of tumors. This includes both 

certain chemical compounds and certain types of radiation. 

Page 14 GAO-08-743T Toxic Chemicals 
former National Priorities List sites.6

 Although EPA currently estimates 

that it will complete the assessment in 2009, meeting this revised estimate 

will be challenging, given all of the steps that are yet to be completed and 

the extensive external scrutiny to which it will continue to be subjected. 

Royal Demolition Explosive. This chemical, also called RDX or 

hexahydro-1,3,5-trinitrotriazine, is a highly powerful explosive used by the 

U.S. military in thousands of munitions. Currently classified by EPA as a 

possible human carcinogen, this chemical is known to leach from soil to 

groundwater. Royal Demolition Explosive can cause seizures in humans 

and animals when large amounts are inhaled or ingested, but the effects of

long-term, low-level exposure on the nervous system are unknown. As is 

the case with naphthalene, the IRIS assessment could potentially require 

DOD to undertake a number of actions, including steps to protect its 

employees from the effects of this chemical and to clean up many 

contaminated sites. Although EPA started an IRIS assessment of Royal 

Demolition Explosive in 2000, it has made minimal progress on the 

assessment because EPA agreed to a request by DOD to wait for the 

results of DOD-sponsored research on this chemical. In 2007, EPA began 

to actively work on this assessment, although some of the DOD-sponsored

research is still outstanding. 

Formaldehyde. EPA began an IRIS assessment of formaldehyde in 1997

because the existing assessment was determined to be outdated.7

Formaldehyde is a colorless, flammable, strong-smelling gas used to 

manufacture building materials, such as pressed wood products, and used 

in many household products, including paper, pharmaceuticals, and 

leather goods. While EPA currently classifies formaldehyde as a probable 

human carcinogen, the International Agency for Research on Cancer 

(IARC), part of the World Health Organization, classifies formaldehyde as 

a known human carcinogen. Since 1986, studies of industrial of workers 

have suggested that formaldehyde exposure is associated with 

nasopharyngeal cancer, and possibly with leukemia. For example, in 2003 

and 2004, the National Cancer Institute (NCI) and the National Institute of 

Occupational Safety and Health (NIOSH) released epidemiological studies

following up on earlier studies tracking about 26,000 and 11,000 industrial

workers, respectively, exposed to formaldehyde; the updates showed 

 6

The National Priorities List is EPA’s list of seriously contaminated sites. 

7

The cancer portion of the formaldehyde assessment was originally issued in 1989 and 

updated in 1991; the noncancer assessment was added in 1990. 

Page 15 GAO-08-743T Toxic Chemicals 
exposure to formaldehyde might also cause leukemia in humans, in 

addition to the cancer types previously identified. According to NCI 

officials, the key findings in their follow-up study were an increase in 

leukemia deaths and, more significantly, an exposure/response 

relationship between formaldehyde and leukemia—as exposure increased, 

the incidence of leukemia also rose. As with the earlier study, NCI found 

more cases of a rare form of cancer, nasopharyngeal cancer, than would 

usually be expected. The studies from NCI and NIOSH were published in

2003 and 2004,8

 around the time that EPA was still drafting its IRIS 

assessment. In November 2004, the Chairman of the Senate Environment 

and Public Works Committee requested that EPA delay completion of its

IRIS assessment until an update to the just-released NCI study could be

conducted, indicating that the effort would take, at most, 18 months. EPA 

agreed to wait—and more than 3 years later, the NCI update is not yet 

complete. As of December 2007, NCI estimates that the study will be 

completed in two stages, one in mid-2008 and the second one later that 

year. An NCI official said that the additional leukemia deaths identified in 

the update provide “greater power” to detect associations between 

exposure to formaldehyde and cancer. EPA’s inability to complete the IRIS 

assessment it started more than 10 years ago in a timely manner has had a 

significant impact on EPA’s air toxics program. Specifically, when EPA 

promulgated a national emissions standard for hazardous air pollutants 

covering facilities in the plywood and composite wood industries in 2004,

EPA’s Office of Air and Radiation took the unusual step of not using the 

existing IRIS estimate but rather decided to use a cancer risk estimate 

developed by an industry-funded organization, the CIIT Centers for Health 

Research (formerly, the Chemical Industry Institute of Toxicology) that 

had been used by the Canadian health protection agency. The IRIS cancer

risk factor had been subject to criticism because it was last revised in 1991

and was based on data from the 1980s. In its final rule, EPA stated that 

 8

NCI published the results of its study in two publications. The first study, published in

November 2003, focused on the association between formaldehyde exposure and leukemia. 

M. Hauptmann, J. H. Lubin, P. A. Stewart, R. B. Hayes, A. Blair, “Mortality from 

Lymphohematopoietic Malignancies among Workers in Formaldehyde Industries,” Journal 

of the National Cancer Institute (2003). The second study, published in June 2004,

evaluated the association between formaldehyde exposure and other cancers—including 

nasopharyngeal cancer. M. Hauptmann, J. H. Lubin, P. A. Stewart, R. B. Hayes, A. Blair, 

“Mortality from Solid Cancers among Workers in Formaldehyde Industries,” American 

Journal of Epidemiology (2004). The results of the NIOSH study were described in one 

publication, dated March 2004, which assessed mortality from all causes and all cancers. L. 

E. Pinkerton, M. J. Hein, L. T. Stayner, “Mortality among a Cohort of Garment Workers 

Exposed to Formaldehyde: an Update,” Occupational and Environmental Medicine

(2004). 

Page 16 GAO-08-743T Toxic Chemicals 
“the dose-response value in IRIS is based on a 1987 study, and no longer 

represents the best available science in the peer-reviewed literature.” The 

CIIT quantitative cancer risk estimate that EPA used in its health risk 

assessment in the plywood and composite wood national emissions 

standard indicates a potency about 2,400 times lower than the estimate in 

IRIS that was being re-evaluated and that did not yet consider the 2003 and 

2004 NCI and NIOSH epidemiological studies. According to an EPA 

official, an IRIS cancer risk factor based on the 2003 and 2004 NCI and 

NIOSH studies would likely be close to the current IRIS assessment, which 

EPA has been attempting to update since 1997. The decision to use the 

CIIT assessment in the plywood national emissions standard was 

controversial, and officials in EPA’s National Center for Environmental 

Assessment said the center identified numerous problems with the CIIT 

estimate. Nonetheless, the Office of Air and Radiation used the CIIT value,

and that decision was a factor in EPA exempting certain facilities with 

formaldehyde emissions from the national emissions standard. In June 

2007, a federal appellate court struck down the rule, holding that EPA’s 

decision to exempt certain facilities that EPA asserted presented a low 

health risk exceeded the agency’s authority under the Clean Air Act.9

Further, the continued delays of the IRIS assessment of formaldehyde—

currently estimated to be completed in 2010 but after almost 11 years still 

in the draft development stage—will impact the quality of other EPA 

regulatory actions, including other air toxics rules and requirements. 

Trichloroethylene. Also known as TCE, this chemical is a solvent widely

used as a degreasing agent in industrial and manufacturing settings; it is a 

common environmental contaminant in air, soil, surface water, and 

groundwater. TCE has been linked to cancer, including childhood cancer, 

and other significant health hazards, such as birth defects. TCE is the most 

frequently reported organic contaminant in groundwater, and 

contaminated drinking water has been found at Camp Lejeune, a large 

Marine Corps base in North Carolina. TCE has also been found at 

Superfund sites and at many industrial and government facilities, including 

aircraft and spacecraft manufacturing operations. In 1995, the 

International Agency for Research on Cancer classified TCE as a probable

human carcinogen, and in 2000, the Department of Health and Human 

Services’ National Toxicology Program concluded that it is reasonably 

 9

Natural Resources Defense Council v. E.P.A., 489 F.3d 1364, 1372-73 (D.C. Cir, 2007). The

court did not specifically address EPA’s reliance on the CIIT study, holding instead that the

Clean Air Act prohibited establishment of the exemptions at issue. 

Page 17 GAO-08-743T Toxic Chemicals 
anticipated to be a human carcinogen. Because of questions raised by peer

reviewers about the IRIS cancer assessment for TCE, EPA withdrew it 

from IRIS in 1989 but did not initiate a new TCE cancer assessment until 

1998. In 2001, EPA issued a draft IRIS assessment for TCE that proposed a 

range of toxicity values indicating a higher potency than in the prior IRIS 

values and characterizing TCE as “highly likely to produce cancer in 

humans.” The draft assessment, which became controversial, was peer 

reviewed by EPA’s Scientific Advisory Board and released for public 

comment. A number of scientific issues were raised during the course of 

these reviews, including how EPA had applied emerging risk assessment 

methods—such as assessing cumulative effects (of TCE and its 

metabolites) and using a physiologically based pharmacokinetic model—

and the uncertainty associated with the new methods themselves.10 To 

help address these issues, EPA, DOD, DOE, and NASA sponsored a 

National Academies review to provide guidance. The National Academies 

report, which was issued in 2006, concluded that the weight of evidence of 

cancer and other health risks from TCE exposure had strengthened since 

2001 and recommended that the risk assessment be finalized with 

currently available data so that risk management decisions could be made

expeditiously. The report specifically noted that while some additional 

information would allow for more precise estimates of risk, this 

information was not necessary for developing a credible risk assessment. 

Nonetheless, 10 years after EPA started its IRIS assessment, the TCE 

assessment is back at the draft development stage. EPA estimates this 

assessment will be finalized in 2010. More in line with the National 

Academies’ recommendation to act expeditiously, five senators introduced 

a bill in August 2007 that, among other things, would require EPA to both 

establish IRIS values for TCE and issue final drinking water standards for 

this contaminant within 18 months. 

Tetrachloroethylene. EPA started an IRIS assessment of 

tetrachloroethylene—also called perchloroethylene or “perc”—in 1998.

Tetrachloroethylene is a manufactured chemical widely used for dry 

cleaning of fabrics, metal degreasing, and making some consumer 

products and other chemicals. Tetrachloroethylene is a widespread 

groundwater contaminant, and the Department of Health and Human 

Services’ National Toxicology Program has determined that it is 

 10Physiologically based pharmacokinetic models are a class of dosimetry models that are

useful for predicting internal doses to target organs. With the appropriate data, these 

models can be used to extrapolate across species and exposure scenarios and address 

various sources of uncertainty in risk assessments. 

Page 18 GAO-08-743T Toxic Chemicals 
reasonably anticipated to be a carcinogen. The IRIS database currently 

contains a 1988 noncancer assessment based on oral exposure that will be

updated in the ongoing assessment. Importantly, the ongoing assessment 

will also provide a noncancer inhalation risk and a cancer assessment. The 

IRIS agency review of the draft assessment was completed in February 

2005, the draft assessment was sent to OMB for OMB/interagency review 

in September 2005, and the OMB/interagency review was completed in 

March 2006. EPA had determined to have the next step, external peer 

review, conducted by the National Academies—the peer review choice 

reserved for chemical assessments that are particularly significant or 

controversial. EPA contracted with the National Academies for a review 

by an expert panel, and the review was scheduled to start in June 2006 and 

be completed in 15 months. However, as of December 2007, the draft 

assessment had not yet been provided to the National Academies. After 

verbally agreeing with both the noncancer and cancer assessments 

following briefings on the assessments, the Assistant Administrator, Office 

of Research and Development, subsequently requested that additional 

uncertainty analyses—including some quantitative analyses—be 

conducted and included in the assessment before the draft was released to

the National Academies for peer review. As discussed in our March 2008 

report on IRIS (GAO-08-440), quantitative uncertainty analysis is a risk 

assessment tool that is currently being developed, and although the agency 

is working on developing policies and procedures for uncertainty analysis, 

such guidance currently does not exist. The draft tetrachloroethylene 

assessment has been delayed since early 2006 as EPA staff have gone back

and forth with the Assistant Administrator trying to reach agreement on 

key issues such as whether a linear or nonlinear model is most appropriate 

for the cancer assessment and how uncertainty should be qualitatively and 

quantitatively characterized. EPA officials and staff noted that some of the 

most experienced staff are being used for these efforts, limiting their 

ability to work on other IRIS assessments. In addition, the significant delay 

has impacted the planned National Academies peer review because the 

current contract, which has already been extended once, cannot be 

extended beyond December 2008. The peer review was initially estimated 

to take 15 months. As a result, a new contract and the appointment of 

another panel may be required. 

Dioxin. The dioxin assessment is an example of an IRIS assessment that 

has been, and will likely continue to be, a political as well as a scientific 

issue. Often the byproducts of combustion and other industrial processes, 

complex mixtures of dioxins enter the food chain and human diet through

emissions into the air that settle on soil, plants, and water. EPA’s initial 

dioxin assessment, published in 1985, focused on the dioxin TCDD 

Page 19 GAO-08-743T Toxic Chemicals 
(2,3,7,8-tetrachlorodibenzo-p-dioxin) because animal studies in the 1970s 

showed it to be the most potent cancer-causing chemical studied to date.

Several years later, EPA decided to conduct a reassessment of dioxin 

because of major advances that had occurred in the scientific

understanding of dioxin toxicity and significant new studies on dioxins’ 

potential adverse health effects. Initially started in 1991, this assessment 

has involved repeated literature searches and peer reviews. For example, a 

draft of the updated assessment was reviewed by a scientific peer review 

panel in 1995, and three panels reviewed key segments of later versions of 

the draft in 1997 and 2000. In 2002, EPA officials said that the assessment 

would conclude that dioxin may adversely affect human health at lower 

exposure levels than had previously been thought and that most exposure 

to dioxins occurs from eating such American dietary staples as meats, fish, 

and dairy products, which contain minute traces of dioxins. These foods 

contain dioxins because animals eat plants and commercial feed and drink 

water contaminated with dioxins, which then accumulate in animals’ fatty 

tissue. It is clear that EPA’s dioxin risk assessment could have a 

potentially significant impact on consumers and on the food and 

agriculture industries. As EPA moved closer to finalizing the assessment, 

in 2003 the agency was directed in a congressional appropriations 

conference committee report to not issue the assessment until it had been

reviewed by the National Academies. The National Academies provided 

EPA with a report in July 2006. In developing a response to the report, 

which the agency is currently doing, EPA must include new studies and 

risk assessment approaches that did not exist when the assessment was 

drafted. EPA officials said the assessment will be subject to the IRIS 

review process once its response to the National Academies’ report is 

drafted. As of 2008, EPA has been developing the dioxin assessment, 

which has potentially significant health implications for all Americans, for 

17 years. 

Page 20 GAO-08-743T Toxic Chemicals 
Page 21 GAO-08-743T Toxic Chemicals 

Appendix II: Summary of Two GAO Reports 

on EPA’s Toxic Substances Control Act and 

Chemical Control Regulations in the EU 

This appendix summarizes information presented in two prior GAO 

reports and related work on EPA’s regulation of toxic chemicals. In 1976, 

Congress passed the Toxic Substances Control Act (TSCA) to authorize 

the Environmental Protection Agency (EPA) to obtain information on 

chemicals and regulate chemicals that pose an unreasonable risk to 

human health or the environment. In 2005, we reviewed EPA’s efforts to 

assess the risks of new chemicals—those not yet in commerce—and the 

risks of existing chemicals—those already being used in commerce.1

 In 

summary, EPA faces challenges in obtaining the information necessary to

assess the human health and environmental risks of chemicals. 

Like the United States, the European Union has laws governing the 

production and use of chemicals. The European Union has recently 

revised its chemical control policy through legislation known as 

Registration, Evaluation and Authorization of Chemicals (REACH). In 

another report, we provided comparative information on TSCA and 

REACH.2

 In summary, REACH generally requires that chemical companies 

develop and provide government regulators with information on 

chemicals’ effects on human health and the environment, while TSCA 

generally does not. REACH is based on the principle that chemical 

companies have the responsibility to demonstrate that the chemicals they 

place in the market, distribute, or use do not adversely affect human 

health or the environment, while TSCA generally requires EPA to 

demonstrate that chemicals pose risks to human health or the

environment prior to controlling risks related to their production, 

distribution, or use. The findings of these reports are summarized below. 

Overall, we found that EPA has limited information on the health and 

environmental risks of chemicals. EPA does not routinely assess the 

human health and environmental risks of existing chemicals and faces 

challenges in obtaining the information to do so. TSCA’s authorities for 

collecting data on existing chemicals do not facilitate EPA’s review 

Key Findings in GAO’s 

2005 Report and 

Related Testimony 

 1

GAO, Chemical Regulation: Actions Are Needed to Improve the Effectiveness of EPA’s

Chemical Review Program, GAO-06-1032T (Washington, D.C.: Aug. 2, 2006); and GAO,

Chemical Regulation: Options Exist to Improve EPA’s Ability to Assess Health Risks and

Manage Its Chemical Review Program, GAO-05-458 (Washington, D.C.: June 13, 2005). 

2

GAO, Chemical Regulation: Comparison of U.S. and Recently Enacted European Union

Approaches to Protect against the Risks of Toxic Chemicals, GAO-07-825 (Washington, 

D.C.: Aug. 17, 2007); and GAO, Chemical Regulation: Approaches in the United States,

Canada, and the European Union, GAO-06-217R (Washington, D.C.: Nov. 4, 2005).
process because they generally place the costly and time-consuming 

burden of obtaining data on EPA, rather than requiring chemical 

companies to develop and submit such data to EPA. Consequently, EPA 

has used its authorities to require testing for few of the over 60,000

chemicals already in commerce when EPA began reviewing chemicals 

under TSCA in 1979. Recognizing the need for additional information on 

existing chemicals, EPA has initiated voluntary programs. While these 

programs are a laudable effort to develop data on these chemicals, several

problems remain, including that the chemical industry may not provide 

testing results in a timely manner for all chemicals in these programs and 

that even with additional test data, EPA would need to demonstrate that 

the chemicals pose unreasonable risks in order to control their production 

or use under TSCA. While TSCA does not define what risk is unreasonable, 

EPA has found it difficult to meet this standard. In order to withstand 

judicial scrutiny, a TSCA rule must be supported by substantial evidence 

in the rule-making record. In this regard, EPA officials say the act’s legal 

standards are so high that they have generally discouraged EPA from using 

its authorities to ban or restrict the manufacture or use of chemicals. 

Further, EPA’s reviews of new chemicals can provide only limited 

assurance that health and environmental risks are identified before the 

chemicals enter commerce because TSCA does not require chemical 

companies to test new chemicals before notifying EPA of their intent to 

manufacture a chemical. Furthermore, chemical companies generally do

not voluntarily perform such testing. Because of a general lack of data, 

EPA has developed scientific models to predict the potential exposure and

toxicity levels of new chemicals. However, the use of these models can 

present weaknesses in the assessment because the models are not always

accurate in predicting physical chemical properties and the evaluation of 

general health effects is contingent on the availability of information on 

chemicals with similar molecular structures. Additionally, chemical 

company estimates of a chemical’s production volume and anticipated 

uses provided in the premanufacture notices that EPA uses to assess 

exposure can change substantially after EPA completes its review and 

manufacturing begins. However, these estimates do not have to be 

amended by companies unless EPA promulgates a rule determining that a 

use of a chemical constitutes a significant new use, which EPA has done 

for only a small percentage of new chemicals. Despite limitations in the 

information available on new chemicals, EPA’s reviews have resulted in 

some action being taken to reduce the risks of over 3,600 new chemicals 

submitted for review. 

Page 22 GAO-08-743T Toxic Chemicals 
EPA’s ability to provide the public with information on chemical 

production and risk has also been hindered by strict confidential business 

information provisions of TSCA, which generally prohibits the disclosure 

of confidential business information. According to EPA officials, about 95 

percent of the premanufacture notices for new chemicals contain some 

information that is claimed as confidential. While EPA has the authority to

evaluate the appropriateness of confidentiality claims, these efforts are 

time and resource-intensive, and the agency does not have the resources 

to challenge a significant number of claims. State environmental agencies 

and others have expressed interest in obtaining information claimed as 

confidential business information for use in various activities, such as 

developing contingency plans to alert emergency response personnel to 

the presence of highly toxic substances at manufacturing facilities. 

Chemical companies recently have expressed interest in working with 

EPA to identify ways to enable other organizations to use the information 

given the adoption of appropriate safeguards. 

In our June 2005 report, we recommended that Congress consider 

providing EPA with additional authorities under TSCA to improve its 

ability to assess chemical risks, such as providing the EPA Administrator 

with the authority to require that chemical companies develop test data 

when production volumes reach certain levels. We also recommended that 

the EPA Administrator take several actions to improve EPA’s management 

of its chemical program, including revising its regulations to require that 

companies reassert confidentiality claims under TSCA within a certain

time period after the information is initially claimed as confidential. EPA

did not disagree with the report’s findings and is in the process of 

implementing several of our recommendations. 

Overall, we found that REACH, the legislation through which the 

European Union has recently revised its chemical control policy, requires

chemical companies to develop more information than TSCA on the 

effects of chemicals on human health and the environment. REACH 

generally requires that chemical companies develop and provide 

government regulators information on chemicals’ effects on human health

and the environment, while TSCA generally does not. For example, under 

REACH, chemical companies provide, and in some cases develop, 

information on chemicals’ physical/chemical properties and health and

environmental effects for both new and existing chemicals produced over

specified volumes. REACH also provides regulators the general authority 

to require chemical companies to provide additional test data and other 

information when necessary to evaluate a chemical’s risk to human health

Key Findings in GAO’s 

2007 Report and 

Related 

Correspondence 

Page 23 GAO-08-743T Toxic Chemicals 
and the environment. In contrast, TSCA places the burden on EPA to 

demonstrate that data on health and environmental effects are needed 

before requiring chemical companies to develop the data. In this regard, 

while TSCA requires chemical companies to notify EPA before producing 

or importing a new chemical, it does not require chemical companies to 

develop and provide data on health and environmental effects unless EPA 

promulgates a rule requiring them to do so. In promulgating such a rule, 

EPA must demonstrate that data already available are insufficient and that 

either (1) the chemical may present an unreasonable risk or (2) the 

chemical is or will be produced in substantial quantities and that there is 

or may be substantial human or environmental exposure to the chemical.

REACH is based on the principle that chemical companies have the 

responsibility to demonstrate that the chemicals they place in the market, 

distribute, or use do not adversely affect human health or the 

environment, while TSCA generally requires EPA to demonstrate that 

chemicals pose risks to human health or the environment prior to 

controlling risks related to their production, distribution, or use. Under 

REACH, chemical companies must obtain authorization to continue to use 

a chemical of very high concern, such as a chemical for which there is 

scientific evidence of probable serious health or environmental effects. 

Generally, to obtain such authorization, each chemical company needs to

demonstrate that it can adequately control risks posed by the chemical, 

such as by requiring that workers wear safety equipment when working 

with the chemical or otherwise ensuring that the chemical is produced 

under safe conditions. If the chemical company cannot provide evidence 

of adequate control, authorization would be granted only if the 

socioeconomic advantages of a specific use of the chemical are greater 

than its potential risks, and if there are no suitable alternatives or 

technologies. 

Under TSCA, EPA has differing authorities to control the risks posed by 

new and existing chemicals. For new chemicals, EPA can restrict a 

chemical’s production or use if the agency determines that insufficient 

information exists to permit a reasoned evaluation of the health and 

environmental effects of the chemical and that, in the absence of such 

information, the chemical may present an unreasonable risk to human 

health or the environment; the chemical is or will be produced in 

substantial quantities and either enters or may reasonably be anticipated 

to enter the environment in substantial quantities; or there is or may be 

significant or substantial human exposure to the substance. For existing 

chemicals, EPA may regulate those chemicals for which it finds a 

reasonable basis exists to conclude that they present or will present an 

Page 24 GAO-08-743T Toxic Chemicals 
unreasonable risk to human health or the environment. In this regard, EPA 

can promulgate a rule that bans or restricts the chemical’s production, 

processing, distribution in commerce, use, or disposal, or that requires 

warning labels be placed on the chemical. However, TSCA requires EPA to 

choose the least burdensome requirement on the chemical industry that 

will adequately protect against the risk. 

TSCA and REACH both have provisions to protect information claimed by 

chemical companies as confidential or sensitive business information; 

however, REACH requires greater public disclosure of certain information, 

including information about (1) basic chemical properties such as melting 

and boiling points and (2) analytical methods that make it possible to 

detect a dangerous substance when discharged into the environment and 

to determine the effects of direct exposure to humans. In addition, REACH 

places greater restrictions on the kinds of information companies may 

claim as confidential or sensitive. For example, REACH generally does not

allow confidentiality claims to apply to the chemical’s trade name, and it 

does not allow such claims to apply to guidance on the chemical’s safe 

use. 

Page 25 GAO-08-743T Toxic Chemicals 
Page 26 GAO-08-743T Toxic Chemicals 

Appendix III: EPA’s IRIS Assessment Process 

as of April 10, 2008 

Annual request for 

nomination of IRIS chemicals 

for assessment

Determine the annual 

agenda and publish it in the 

Federal Register

Scientific literature search

Federal Register 

notice/data call-in

Development of a draft 

qualitative assessment

Federal agency and public 

review of draft qualitative 

assessment

EPA and federal agency

review of comments

Interagency evaluation to 

close data gaps

Federal agency 

development of new studies

Is the

chemical mission

critical?

Is there

interest in

conducting research

to close data

gaps?

Yes, it is mission critical.

No, it is not mission critical.

No, there is no

interest in conducting

new research to

close data gaps.

Yes, there is interest in conducting

research to close data gaps.
Development of a complete 

draft IRIS assessment 

(qualitative and quantitative), 

including internal peer 

consultation

Internal agency review by 

the 18-member IRIS Agency 

Review Committee

Revised draft IRIS 

assessment

OMB/interagency review 

coordinated by OMB

Revised draft IRIS 

assessment

Independent external peer 

review and public comment

Revised draft IRIS 

assessment

Second internal agency 

review by the 18-member 

IRIS Agency Review 

Committee

Second 

OMB/interagency 

review coordinated by 

OMB

Completion of IRIS 

assessment, EPA 

management review 

and approval, and 

posting on IRIS

Darker shaded boxes are additional steps under EPA’s changes to its assessment 

process and indicate where EPA has provided additional opportunity for input

from potentially affected federal agencies for mission-critical chemicals.

Lighter shaded boxes with dotted lines indicate steps where EPA has provided additional

opportunity for input from potentially affected federal agencies for all chemicals.

White boxes with heavy lines indicate steps where potentially affected federal agencies already

had an opportunity for input.

Is the chemical

mission critical?

EPA consults

with federal

agencies to

determine level

and scope of

peer review

EPA determines

the level and

scope of the

peer review

Yes No

Source: GAO analysis of EPA information.

(360955) Page 27 GAO-08-743T Toxic Chemicals 
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