Chemical Assessments: EPA's New Assessment Process Will Further Limit the Productivity and Credibility of Its Integrated Risk Information System
Released: 2008-05-21T00:00:00

Letter

Background

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.

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 conducted by a panel of experts; and (6) the completion of a final assessment that is posted to the IRIS Web site.

Unlike many other EPA programs that have statutory requirements, including specific time frames for completing mandated tasks, the IRIS program is not subject to statutory requirements or timeframes. In contrast, the Department of Human Health and Services’ Agency for Toxic Substances and Disease Registry (ATSDR), which develops quantitative estimates of the noncancer effects of exposures to chemicals in the environment, is statutorily required to complete its assessments within certain timeframes.

Findings and Recommendations from Our March 2008 Report on the Productivity and Credibility of EPA’s Integrated Risk Information System

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.

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. 2).

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. For example, EPA’s assessment of the cancer risks stemming from exposure to naphthalene—a chemical used in jet fuel and in the production of widely used commercial products such as moth balls, dyes, insecticides, and plasticizers—was nearing completion in 2006. However, prior to finalizing this assessment, which had been ongoing for over 4 years, EPA decided that the existing noncancer assessment had become outdated and essentially restarted the assessment to include both cancer and noncancer effects. 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 the additional internal and external reviews that are now required (see app. I).

Further, because EPA staff time continues to be dedicated to completing assessments in the backlog, EPA’s ability to both keep the more than 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.

The consequences of not having current, credible IRIS information can be significant. EPA’s inability to complete its assessment of formaldehyde, which the agency initiated in 1997 to update information already in IRIS on the chemical, has had a significant impact on EPA’s air toxics program. Although in 2003 and 2004, the National Cancer Institute and the National Institute of Occupational Safety and Health (NIOSH) had released updates to major epidemiological studies of industrial workers that showed a relationship between formaldehyde and certain cancers, including leukemia, EPA did not move forward to finalize an IRIS assessment incorporating these important data. Instead, EPA opted to await the results of another update to the National Cancer Institute study. While this additional research was originally estimated to take, at most, 18 months to complete, at the time of our report (more than 3 years later) the update was not complete. In the absence of this information, EPA’s Office of Air and Radiation decided to use risk information developed by an industry- funded organization—the CIIT Centers for Health Research—for a national emissions standard. This decision was a factor in EPA exempting certain facilities with formaldehyde emissions from the national emissions standard. The CIIT risk estimate 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 National Cancer Institute and NIOSH epidemiological studies. According to an EPA official, an IRIS cancer risk factor based on the 2003 and 2004 National Cancer Institute and NIOSH studies would likely be close to the current IRIS assessment, which EPA has been re-evaluating since 1997. The discrepancy between these two risk estimates raises concerns about whether the public health is adequately protected in the absence of current IRIS information. For example, in 1999, EPA published a national assessment that provided information about the types and amounts of air toxics to which people are exposed. The assessment, which also used the CIIT risk estimate for formaldehyde, concluded, for example, that formaldehyde did not contribute significantly to the overall cancer risk in the state of New Jersey. However, in carrying out its own risk assessment on formaldehyde, the New Jersey Department of Environmental Protection opted to use the risk information that is currently in IRIS (dating back to 1991) and found that the contribution from formaldehyde to overall cancer risk in New Jersey is quite significant, second only to diesel particulate matter. (App. I provides additional information on EPA’s IRIS assessment for formaldehyde.)

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 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; 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 federal agencies about IRIS assessments could enhance their quality, 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. (App. II and III provide flow charts of the IRIS process that was in place at the time of our review and EPA’s draft proposed process being considered at the time of our review, respectively).

Recommendations Made in Our March 2008 Report

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 (3) 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 draft report, EPA said it would consider each of our recommendations in light of the new IRIS process the agency was developing.

Key Aspects of the Revised IRIS Assessment Process Implemented in April 2008 Which Is Not Responsive to GAO’s Recommendations

On April 10, 2008, EPA issued a revised IRIS assessment process, effective immediately. Overall, EPA’s revised process is not responsive to the recommendations made in our March 2008 report—it is largely the same as the draft proposed process we evaluated in our March 2008 report (see app. III and IV). Moreover, changes EPA did incorporate into the final process are likely to further exacerbate the productivity and credibility issues we identified in our report.

We recommended that EPA ensure that, among other things, any revised process clearly defines and documents a streamlined IRIS assessment process that can be conducted within time frames that minimize the need for wasteful rework.

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. However, EPA’s revised process institutionalizes a process that the agency estimates will take up to 6 years to complete. Further, the estimated time frames do not factor in the time for peer reviews conducted by the National Academies, which can take 2 years to plan and complete. EPA typically uses reviews by the National Academies for highly controversial chemicals or complex assessments. Therefore, assessments of key chemicals of concern to public health that are reviewed by the National Academies are likely to take at least 8 years to complete. These time frames must also 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. Thus, 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 develop, 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.

Finally, 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. 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.

We also 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.

Contrary to our recommendation, EPA has formalized a revised IRIS process that is selectively, rather than fully, transparent, limiting the credibility of the assessments. Specifically, 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. 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. However, 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 comments from all others.

In commenting on a draft of our March 2008 report, and in a recent congressional hearing, EPA’s Assistant Administrator, Office of Research and Development, stated that the IRIS process is transparent because all final IRIS assessments must undergo public and external peer review. However, as we stated in our report, the presence of transparency at a later stage of IRIS assessment development does not explain or excuse its absence earlier. Under the new process, neither peer reviewers nor the public are privy to the changes EPA makes in response to the comments OMB and other federal agencies provide to EPA at several stages in the assessment process—changes to draft assessments or to the questions EPA poses to the peer review panels. Importantly, the first IRIS assessment draft that is released to peer reviewers and to the public includes the undisclosed input from federal agencies potentially subject to regulation and therefore with an interest in minimizing the impacts of IRIS assessments on their budgets and operations.

In addition, EPA’s revised process does not provide EPA with sufficient independence in developing IRIS assessments to ensure they are credible and transparent. We made several recommendations aimed at restoring EPA’s independence. For example, we recommended that the EPA Administrator ensure that EPA has the ability to, among other things, define the appropriate role of external federal agencies in the IRIS assessment process and determine when interagency issues have been appropriately addressed. However, under the newly implemented IRIS assessment process, OMB continues to inform EPA when EPA has adequately addressed OMB’s and interagency comments. This determination must be made both before EPA can provide draft assessments to external peer reviewers and to the public and before EPA can finalize and post assessments on the IRIS database. While EPA officials state that ultimately IRIS assessments reflect EPA decisions, the new process does not support this assertion given the clearances EPA needs to receive from OMB to move forward at key stages. In fact, we believe the new IRIS assessment process may elevate the goal of reaching interagency agreement above achieving IRIS program objectives. Further, as discussed above, because the negotiations over OMB/interagency comments are not disclosed, whether EPA is entirely responsible for the content of information on IRIS is open to question.

In our report, we also emphasized the importance of ensuring that IRIS assessments be based solely on science issues and not policy concerns. However, under the new IRIS assessment process, EPA has further introduced policy considerations into the IRIS assessment process. That is, 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. EPA’s new, broader characterization of IRIS raises concerns about the agency’s stated 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. For example, in discussing science and science policy at a recent Senate hearing, EPA’s Assistant Administrator of Research and Development described science policy considerations as including decisions about filling knowledge gaps (e.g., whether and to what extent to use default assumptions) and assessing weight-of-the-evidence approaches to make scientific inferences or assumptions. We believe that these are scientific decisions that should reflect the best judgment of EPA scientists who are evaluating the data, using the detailed risk assessment guidance the agency has developed for such purposes. We have concerns about the manner and extent to which other federal agencies, including those that may be affected by the outcome of assessments, are involved in these decisions as well as the lack of transparency of their input. As we highlighted earlier, 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. The National Academies recently addressed this issue as follows: “The committee believes that risk assessors and risk managers should talk with each other; that is, a ‘conceptual distinction’ does not mean establishing a wall between risk assessors and risk managers. Indeed they should have constant interaction. However, the dialogue should not bias or otherwise color the risk assessment conducted, and the activities should remain distinct; that is, risk assessors should not be performing risk management activities.”

Concluding Observations

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. The position of the Assistant Administrator, Office of Research and Development, that the IRIS process is transparent because all final IRIS assessments must undergo public and external peer review is unconvincing. Transparency at a later stage of the IRIS assessment process—after OMB and other federal agencies have had multiple opportunities to influence the content of the assessment without any disclosure of their input—does not compensate for its absence earlier.

We continue to believe that 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 inappropriately biased by policy issues and considerations. As discussed in our April 29, 2008, testimony before the Senate Environment and Public Works Committee, we believe that the Congress should consider requiring EPA to suspend implementation of its new IRIS assessment process and develop a streamlined process that is transparent and otherwise responsive to our recommendations aimed at improving the timeliness and credibility of IRIS assessments. For example, suspending assessments to obtain additional research 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 addition, as discussed in our April 2008 testimony, 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. We note that while EPA and OMB initially 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, EPA released its new assessment process without obtaining public input and made it effective immediately. This was inconsistent with assertions made in OMB’s letter commenting on our draft report, which emphasized that EPA had not completed the development of the IRIS assessment process and stated: “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.”

Finally, if EPA is not able to take the steps we have recommended to effectively maintain this critical program, other approaches, including statutory requirements, may need to be explored.

Mr. Chairman, this concludes my prepared statement. I would be happy to respond to any questions that you or other Members of the Subcommittee may have at this time.

Contacts and Acknowledgments

For further information about this testimony, please contact John B. Stephenson on (202) 512-3841 or stephensonj@gao.gov. Contact points for our Congressional Relations and Public Affairs Offices may be found on the last page of this statement. Contributors to this testimony include Christine Fishkin (Assistant Director), Laura Gatz, Richard P. Johnson, and Nancy Crothers.

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. 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, “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.” 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.

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. 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. 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 former National Priorities List sites. 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. 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 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, 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 “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. 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 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. 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 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 (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.

Appendix II: EPA’s IRIS Assessment Process Being Implemented at the Time of Our Review (Includes OMB Requirements as of 2005)

Appendix III: EPA’s Draft Proposed IRIS Assessment Process Being Considered at the Time of Our Review (Dated March 2007)

No, it is not mission critical.

Development of a draft qualitative assessment critical?

Yes, it is mission critical.

No, there is no new research to close data gaps. gaps?

Ye, there is interest in conducting research to close data gaps.

Is the chemical mission critical?

Darker shaded boxes are additional steps, under EPA’s planned changes, to its assessment process and indicate steps 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.

Appendix IV: EPA’s IRIS Assessment Process as of April 10, 2008

No, it is not mission critical. critical?

Ye, it is mission critical. new research to close data gaps. gaps?

Ye, there is interest in conducting research to close data gaps.

Is the chemical mission critical?

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.

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