Reviewers Say EPA’s Draft Musk Analysis Needs Changes Before Use in Decisions

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By Pat Rizzuto

Jan. 9 --The Environmental Protection Agency must clarify, expand and revise many aspects of its draft environmental risk assessment of a widely used polycyclic musk fragrance ingredient before the document can be used for regulatory or other decisions, an agency peer review panel said Jan. 9.

Seven ecological scientists met by telephone to critique a draft assessment of 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta-γ-2-benzopyran (HHCB; CAS 1222-05-5), which the EPA released in January 2013. The agency concluded the fragrance ingredient posed a low concern for the environment .

The peer reviewers said they would compile their recommendations prior to their final meeting Feb. 6.

The HHCB assessment is part of an initiative the EPA's Office of Pollution Prevention and Toxics (OPPT) announced in 2012. That office is evaluating specific uses of dozens of what it calls “work plan” chemicals in U.S. commerce .

Six companies made or imported more than 3.1 million pounds of HHCB in 2011, according to information they provided the EPA under the Chemical Data Reporting rule.

The companies were SC Johnson & Son Inc., International Flavors& Fragrances Inc., Symrise Inc., Berje Inc., Firmenich Inc., and a company that told the EPA its name was confidential business information.

HHCB's Uses

HHCB can be one of hundreds of chemicals used to make fragrances for detergents, fabric softeners, shampoos, cleaners and other consumer products, and it is being released to the environment continuously, the EPA said in information staff presented at the panel's Dec. 4 meeting.

The draft document is really a draft screening level or hazard evaluation, not a draft risk assessment, said panel member Duane Huggett, an associate professor of biological sciences at the University of North Texas, summarizing a perspective stated by several other peer reviewers.

The difference between a screening level assessment and a risk assessment goes to the types of decisions for which the document could be used.

Screening level assessments can be used to decide a chemical isn't a problem, because even worst case assumptions found no risk. They also are useful for helping agencies decide what chemicals warrant additional data or analysis.

Screening level assessments also aren't intended for regulatory decisions because their rough estimates could result in overly stringent or inadequately protective regulations.

Peter Chapman, a senior environmental scientist at the Vancouver-based consulting firm Golder Associates Ltd., was among the peer reviewers who said the agency's draft environmental risk assessment never clearly said what its purpose was.

Problem Formulation Lacking

The document didn't include the problem formulation information that ecological risk assessments are supposed to contain, Chapman said.

The problem formulation stage of an ecological assessment is supposed to define the ecological entity--species, group of species, or ecosystem, for example--the assessment is intended to protect, the EPA said in a description of that stage.

Robert Gensemer, a vice president and senior ecotoxicologist with GEI Consultants, said he couldn't be sure the assessment would meet the agency's needs because it lacked a problem formulation statement.

Chapman described a variety of analytical concerns he had with the EPA's analysis.

For example, in some cases the agency focused on no-observed-adverse-effect-levels (NOAELs) and lowest-observed-adverse-effect-levels (LOAELs), Chapman said, referring to concentration levels that caused no or few problems.

Ecological risk assessments generally do not use those types of concentrations because their accuracy depends on the concentration of a chemical the researchers used, he said.

The preferred approach is to use an effect concentration (EC) that caused some kind of change or problem in 10 percent or perhaps 20 percent of the animals or plants exposed in a particular test, he said.

New Zealand Mud Snails

Chapman further questioned the agency's use of a study that found 3.2 milligrams HHCB per kilogram dry weight of sediment harmed the reproduction of New Zealand mud snails. Those snails are an invasive species that pose a risk to native species, Chapman said. Tests with a common algae-eating shell species called hyalella azeca might be more appropriate, he said.

The EPA also used test data from a marine copepod, yet the test used was a draft--not final--protocol being developed by the Organization for Economic Cooperation and Development (OECD), he said. “It may not matter that much, but it should be noted.”

Other peer reviewers asked the agency to be sure to use terms consistently throughout the document, to clarify the meaning of terms, to provide information so readers could know what measures researchers took to verify the quality of their data and to provide the criteria it used to decide what studies it would include and exclude.

Trade associations commenting on the HHCB assessment included the International Fragrance Association North America, the American Cleaning Institute and the American Chemistry Council. No industry or other parties spoke during the public comment session provided during the Jan. 9 peer review.

Prior to the meeting, however, the trade associations said they supported the agency's conclusion that HHCB posed little risk.

They provided additional data, analytic approaches and other recommendations to improve the final assessment.

To contact the reporter on this story: Pat Rizzuto in Washington at

To contact the editor responsible for this story: Larry Pearl at

EPA's draft assessment, public comments and other materials regarding the HHCB assessment are available at

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