DTSC Requests Public Comment on Another Draft of the Green Chemistry Regulations

California Green Chemistry Regulations:

The saga of California’s nascent Green Chemistry program continues. Last week, the Department of Toxic Substances Control (DTSC) released the revised text (PDF) of its proposed Safer Consumer Product Regulations. The comment period for the revisions started on January 29 and closes on February 28, 2013.

Notably, the revised rules significantly pare down the list of potential Chemicals of Concern (COCs), which are now referred to as “Candidate Chemicals,” from over 3,000 to approximately 1,200. The Candidate Chemicals  are drawn from lists of substances which exhibit one or more hazard trait. The revisions also clarify that the list of Priority Products to be regulated will be developed and updated through the Administrative Procedure Act rulemaking process.

In addition, DTSC modified the applicability of upfront exemptions for certain products, providing an exemption for products already regulated by other laws that provide comparable health and environmental protections. However, products which are manufactured, stored, or transported through California solely for use outside of the state, or used in California solely for the manufacture of non-consumer products will no longer be exempted, although these factors will be considered in the product prioritization process.

Requirements for the certification and accreditation of assessors involved in developing Alternatives Analyses (AA) have been relaxed in favor of a public review and comment process for AA reports, a choice that seems likely to increase the administrative burden and place confidential business information at greater risk. The scope of evaluating economic impacts for AA reports has also been limited to “a monetized comparison of public health and environmental costs, and costs to governmental agencies and nonprofit organizations that manage waste, oversee environmental cleanup and restoration efforts, and/or are charged with protecting natural resources, water quality, and wildlife.”

Finally, DTSC’s ability to make regulatory responses has been further refined and clarified. For example, the revised proposal requires DTSC to provide notice (with accompanying public comment period) of its proposed regulatory response determination no later than 90 days after it issues a notice of compliance or disapproval for a submitted AA report. The revised proposal also limits the agency’s ability to impose certain regulatory responses on manufacturers only, and not on retailers or importers.

More details on the revised proposed regulations, including how to submit comments and a comprehensive summary of changes from the agency’s last proposal, are available on the DTSC’s website.

IRIS Remains Under Fire

Risk Assessment/IRIS:

EPA’s Integrated Risk Information System (“IRIS”), which assesses the human health risks associated with chemical exposure, has come under fire from the head of the scientific panel charged by Congress to review the program.

In recent years, IRIS has been the subject of much criticism, causing Congress to direct a panel of the National Research Council (“NRC”), an arm of the National Academies, to review EPA’s assessment of arsenic and other chemicals and issue recommendations to improve “scientific and technical performance.” NRC is also currently conducting a review of the overall IRIS process for developing assessments and the current methods available for weight-of-evidence analyses, with the goal of recommending “approaches for weighing scientific evidence for chemical hazard and dose-response assessments.”

In 2011, NRC found fault with the agency’s IRIS assessment of formaldehyde, and EPA is in in the process of implementing some of the panel’s recommendations from that review.

However, EPA’s attempts to improve the program have provoked criticism from the very panel whose recommendations the agency is trying to adopt. At a December 18, 2012 meeting with EPA officials, the head of the NRC review panel, Professor Jonathan Samet of the University of Southern California Keck School of Medicine, raised concerns that EPA’s ongoing changes to the IRIS process presented the panel with a difficult “moving target.” Samet noted that “it seems like literally every aspect of the IRIS assessment process” is changing, complicating NRC’s review.

EPA’s newly revised IRIS process will be on display in its assessment of benzo[a]pyrene, which is expected to be released in coming months.

In another example of overlapping agendas, both EPA and NRC have planned upcoming events on weight-of-evidence assessments. Vince Cogliano, head of the IRIS program, told meeting attendees that EPA would coordinate with NRC so that the two events would be complementary and further strengthen weight-of-evidence analyses.

Meanwhile, EPA has also announced that it is “restarting” its IRIS assessment of arsenic. The new assessment process is expanded to include inhalation risks and will also combine studies of cancer and non-cancer effects for a broader overview of the chemical’s health risks. EPA held a January 8-9, 2013 workshop to gather public input on the assessment, the first meeting of its kind. The NRC panel reviewing the arsenic assessment will also collect public input and provide EPA with an interim report prior to EPA’s release of the draft assessment, which the panel will also peer review.

EPA Releases First Set of Draft Risk Assessments Under Existing Chemicals Work Plan Effort

On January 4, EPA  released for public comment draft risk assessments, for particular uses, on five chemicals found in common household products. The draft risk assessments were developed as part of the agency’s Toxic Substances Control Act (TSCA) Work Plan, which identified common chemicals for review over the coming years to assess any impacts on people’s health and the environment. Following public comment, the agency will seek an independent, scientific peer review of the assessments before beginning to finalize them in the fall of 2013.

“The draft risk assessments released today for public review and comment highlight the agency’s ongoing commitment to ensure the safety of chemicals we encounter in our daily lives,” said James J. Jones, acting assistant administrator of EPA’s Office of Chemical Safety and Pollution Prevention. “The public and scientific peer review will ensure use of the best science to evaluate any impacts of these substances on people’s health and the environment.”

The five assessments address the following chemical uses: methylene chloride or dichloromethane (DCM) and n-methylpyrrolidone (NMP) in paint stripper products; trichloroethylene (TCE) as a degreaser and a spray-on protective coating; antimony trioxide (ATO) as a synergist in halogenated flame retardants; and 1,3,4,6,7,8-Hexahydro-4,6,6,7,8,8,-hexamethylcyclopenta-[γ]-2-benzopyran (HHCB) as a fragrance ingredient in commercial and consumer products. The draft assessments focus either on human health or ecological hazards for specific uses which are subject to regulation under TSCA. Three of the draft risk assessments— DCM, NMP, and TCE— indicate a potential concern for human health under specific exposure scenarios for particular uses. The preliminary assessments for ATO and HHCB indicate a low concern for ecological health.

EPA recommends the public follow product label directions and take precautions that can reduce exposures, such as using the product outside or in an extremely well ventilated area and wearing protective equipment to reduce exposure. If EPA concludes in finalizing the risk assessments that there is a potential for concern, the agency will take action as appropriate to address possible risks.

The draft assessments were undertaken as part of EPA’s efforts to identify chemicals for review under the TSCA Work Plan, which EPA released in March 2012. At that time, EPA identified 83 chemicals as candidates for review over the coming years and outlined the data sources and other information the agency would use in the reviews. This initiative is part of EPA’s comprehensive approach to enhance the current chemicals management program within the limits of existing TSCA authorities. EPA continues to support updating TSCA to strengthen and modernize the law.

Additional information on the TSCA Work Plan effort and the specific draft risk assessments can be found at: http://www.epa.gov/oppt/existingchemicals/pubs/workplans.html


EPA Publishes the Peer Review Plans for the Risk Assessments on the Seven 2012 Work Plan Chemicals


Today, August 17, 2012, EPA published the Peer Review Plans for the risk assessments on the seven 2012 work plan chemicals. The plans, which form part of the Agency’s Peer Review Agenda, describe the focus of the risk assessment being conducted on each chemical, indicate how peer reviewers will be selected and how the peer review will be conducted, and provide the time line for the reviews. As indicated in the plans, EPA will publish a notice in the Federal Register when the External Review Drafts of the assessments become available, and will provide a 60-day period for public comment on the drafts before the peer review begins. The public will also be able to present comments at the teleconference panel review meetings. You can access and submit comments on the individual peer review plans for each chemical by using the following links:

New TSCA Work Plan Chemicals

TSCA/Work Plan for Existing Chemicals/Chemical Risk Assessment

June 1, 2012 EPA announced the addition of 18 chemicals to its work plan for existing chemicals risk assessment. The 18 chemicals include flame retardants, fragrance chemicals, and chlorinated hydrocarbons.  Many of these chemicals are potentially carcinogenic, or pose reproductive or developmental toxicity.  In addition, some of these chemicals present persistent, bioaccumulative, and toxic potential or are found in consumer products.  New and existing work plan chemicals are listed on EPA’s website.

As part of the Agency’s strategy to manage existing chemicals (see EPA’s Existing Chemicals Program Strategy (PDF), EPA has been screening chemicals against risk criteria (see e.g., Identifying Priority Chemicals for Review and Assessment).  Chemicals are likely to be flagged for further review and assessment if screening indicates:

  • children’s health effects (e.g., chemicals with reproductive or developmental effects);
  • persistence, bioaccumulation, and toxicity (PBT);
  • carcinogenic effect ;
  • presence in children’s products;
  • presence in consumer products; and
  • detection by biomonitoring programs. 

In the June 1 announcement, EPA solicited unpublished health and safety studies on these chemicals.  Research should be submitted to docket EPA-HQ-OPPT-20110-516 by August 31, 2012. Health and safety studies comprise “any study of any effect of a chemical substance or mixture on health or the environment or on both,” including but not limited to:

  • Epidemiological or clinical studies;
  • Studies of occupational exposure;
  • In vivo and in vitro toxicological studies; and
  • Ecotoxicological studies;

Risks assessments on the new work plan chemicals will be conducted in 2013 and 2014.

European Chemical Industry Debuts Chemical Combination Screening Tool – Concludes Regulating Individual Chemicals is Usually Adequate

Chemical Mixture Risk Assessment:

May 31, the European Chemical Industry Council (Cefic) unveiled a tool for assessing the risks posed by chemical combinations: the Maximum Cumulative Ratio (MCR) (see e.g., news release, combination effects tools).  MCR compares the toxicity of individual chemicals to the cumulative toxicity of all chemicals in an exposure scenario.  Cefic argues that in most exposure scenarios the risk of one or two chemicals contribute nearly all risk of harm.  The organization notes that prioritization of chemical combinations is necessary to identify combinations of concern that warrant full risk assessment. 

Cefic references Maximum Cumulative Ratio (MCR) as a Tool for Assessing the Value of Performing a Cumulative Risk Assessment (in International Journal of Environmental Research and Public Health) for full discussion of the application of MCR.  The article comprises an investigation of the magnitude of toxicity from multiple chemical exposure that is missed in scenarios where no cumulative risk assessment is conducted.  U.S. Geological Survey water quality data were used for the evaluation. From 5 to 81 chemicals were present in the 3,000 samples analyzed.  The authors estimate that approximately 20 percent of cumulative toxicity –compared to component chemical toxicity– is missed where cumulative risk assessments are not conducted.  However, mixture toxicities were dominated by only a fraction of chemical compounds present.

Because risk is usually driven by one or two chemicals in a combination, Cefic believes that controlling individual substances through the current regulatory schemes will often control the risk from combination exposures.

Cefic notes that MCR is based on the WHO risk assessment framework (see e.g., Combined Exposure Risk Assessment Workshop Report) and relies on cumulative risk assessment theories from the European Scientific Committees (see e.g., Environmental Risk Assessment of Mixtures Symposium).

EPA Draft (IRIS) Ammonia Assessment Available for Public Comment

Integrated Risk Information System (IRIS):

Today, EPA released for a 60-day public comment period the draft IRIS assessment for ammonia.   Excerpts from the agency’s press release are provided below, and a copy of the draft assessment is avaialble here

IRIS is a human health assessment program that evaluates information on health effects that may result from exposure to environmental contaminants. Through the IRIS Program, EPA attempts to provide the highest quality science-based human health assessments to support the Agency’s regulatory activities.  The IRIS database is web-accessible and contains information on more than 550 chemical substances.  Readers familiar with IRIS will recall the various criticisms of the agency’s evaluation process, which EPA has been attempting to address, as described in further detail here.  General background information on IRIS is available here.



June 1, 2012 

EPA Draft Ammonia Assessment Available for Public Comment

Draft assessment continues agency’s responsiveness to NAS recommendations 

WASHINGTON – The U.S Environmental Protection Agency today announced the release of its draft Integrated Risk Information System (IRIS) health assessment for ammonia. The draft assessment will be available for public comment for 60 days and will be sent for independent expert peer review.

Ammonia is used in agricultural fertilizers, the manufacture of pharmaceuticals and explosives, water purification, household cleaners, as a refrigerant, and in many industries. Scientific studies show that ammonia can affect the respiratory system. The draft assessment includes an estimate of the amount of ammonia a person can inhale daily throughout a lifetime that is not likely to cause harmful health effects, which is less stringent than the current value for ammonia on IRIS.

 The draft IRIS assessment for ammonia represents major progress for EPA in implementing the April 2011 National Academy of Sciences (NAS) recommendations for improving IRIS assessments. The draft assessment uses a new streamlined document structure that is more transparent and clear; includes a template for describing the literature search approach; identifies the strengths and weaknesses of analyzed studies; and describes how EPA applied their guidance, methods, and criteria in developing the assessment.

 When the assessment is final it will be posted to the IRIS database. IRIS is a publicly available online database that provides high quality science-based human health assessments used to inform the agency’s decisions on protecting public health and the environment.

  The IRIS database contains crucial information on more than 550 chemical substances and their impacts on human health. Governments and private entities use data from IRIS in conjunction with exposure information to help characterize the public health risks of chemical substances. These characterizations are then considered in risk management decisions to protect public health. 

NRDC Recommends Improvements to Chemical Risk Assessment Methods

Chemical Risk Assessment: 

Readers following efforts to improve chemical management and control in the United States may be interested in a recent National Resources Defense Council (NRDC) White Paper, Strengthening Toxic Chemical Risk Assessments to Protect Human Health.  In the White Paper, NRDC reaches several conclusions in reliance on National Academy of Sciences (NAS) findings that significant improvements in both chemical testing and risk assessment are needed to protect people from toxic chemicals.  NRDC emphasizes the need to address the following:

  • the range of human exposures and vulnerabilities,
  • data gaps and uncertainties, and
  • impacts of exposure to multiple chemicals.

NRDC also argues that risk assessment should not presume that a zero effect exposure level exists, unless there are sufficient data to support this assumption.

Each of NRDC’s points is discussed further below.

Citing the NAS findings, NRDC concludes that differences among human exposures and individual vulnerabilities are important determinants of risk.  NRDC therefore recommends that risk assessment consider vulnerable individuals and those who are more highly exposed.  NAS had noted that a broad variety of factors, including nutrition, health status, and psychosocial stress, can increase and individual’s vulnerability to toxic chemicals, and these factors—and their variability—need to be incorporated into risk assessments so that adequate measures can be employed to protect public health.  NRDC also cites an NAS recommendation that risk assessments incorporate analyses that address the uncertainty and variability inherent in a risk assessment—including uncertainty and variability in the measurement of chemical releases into the environment, environmental fate and transport, exposure assessment, dose-response assessment, and risk characterization.  

To address data gaps and uncertainties, NRDC stresses the need for agencies to develop robust risk assessments by updating default factors and assumptions.  It cites the NAS recommendation that agencies update risk assessment protocols based on the best current science.  NAS had identified significant missing default assumptions.  For example, most chemicals are not tested for their potential interference with the hormone systems that govern growth and development, learning, and behavior; the assumption being that chemicals have no effect on hormones—an implicit default assumption that may or may not be true.  And, NRDC noted, allowing such assumptions does not protect health.

NRDC emphasizes the need to address the impacts of multiple chemical exposures.  It faults risk assessment methodologies that focus on only single chemical exposure, rather than endeavoring to model the actual complexity of the world.  NRDC relies on a NAS finding that stressed the need for cumulative risk assessments that address the combined risks posed by aggregate exposure to multiple agents or stressors.  

And finally, the NRDC challenges the standard assumption that there is a safe level of exposure to most chemicals.   NRDC notes that NAS recommends risk assessments assume that all exposures, even low level, are associated with some level of risk, unless there are sufficient data to the contrary.  NRDC explains that science has found many examples of chemicals that increase the risk of various non-cancer health effects—such as reproductive harm and neurological effects—at low doses, without any scientifically-identifiable threshold.

For more information see the NAS reports: