Assessing Chemicals | April 30, 2012 Issue - Vol. 90 Issue 18 | Chemical & Engineering News
Volume 90 Issue 18 | pp. 28-30
Issue Date: April 30, 2012

Assessing Chemicals

New EPA effort targets dozens of substances already on the market for in-depth scrutiny
Department: Government & Policy
Keywords: TSCA, risk assessment, EPA
Credit: Cheryl Hogue/C&EN
A photo of the Environmental Agency Sign, outside of the EPA East Building.
Credit: Cheryl Hogue/C&EN

When it comes to commercial chemicals, the Environmental Protection Agency’s main gig is reviewing industry-submitted notices about new substances—those that are about to be introduced to the market. In comparison, the agency’s chemical control program has historically conducted limited scrutiny of what are called existing substances—those that are already in commerce.

But the agency broke new ground in March when its Office of Pollution Prevention & Toxics announced that it will subject dozens of chemicals in commerce to risk assessment (C&EN, March 12, page 11). Using its authority under the Toxic Substances Control Act (TSCA), EPA selected 83 chemicals or categories of related substances for its initial efforts, called a work plan, which will take place from 2012 through 2014.

Seven of those 83 were selected as the first group for review in 2012: 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta-γ-2-benzopyran (a fragrance compound commonly called HHCB); long-chain chlorinated paraffins; medium-chain chlorinated paraffins; antimony and antimony compounds; methylene chloride; N-methylpyrrolidone; and trichloroethylene.

EPA expects the reviews could result in regulation or other action on substances that pose a significant risk. Or the agency may simply close its books, for now, on a compound. A lack of regulatory action could imply that a chemical is safe for its current use.

In principle, environmental groups and the chemical industry welcome EPA’s action. But EPA’s plan faces criticism from industry groups.

Expressing concerns about potential health effects, environmentalists for many years have pushed EPA to review chemicals on the market, particularly those made in large volumes or to which consumers—especially babies and children—are exposed. Industry is critical of some of the details about how work plan substances and categories were selected, but it generally sees the reviews as a potential way of obtaining an EPA imprimatur that their products are safe.

“Prioritization of chemicals in commerce is critical to addressing one of the most fundamental criticisms of TSCA,” which is that the law does not mandate EPA review of chemicals on the market, the Society of Chemical Manufacturers & Affiliates (SOCMA) said in a statement to C&EN. This industry group represents primarily small and medium-sized companies.

“While there is more to be done, we’re encouraged that EPA is moving forward on establishing a process to prioritize chemicals” for risk assessment, says Scott Jensen, a spokesman for the American Chemistry Council, an industry group that represents mainly large chemical manufacturers.

“It’s about time,” Richard Denison, senior scientist for the Environmental Defense Fund, an environmental group, says of EPA’s new work plan for existing chemicals.

In selecting the 83 chemicals or classes, EPA zeroed in on substances that meet one or more criteria it outlined. One criterion is that the substances are potentially of concern to children’s health because of reproductive, developmental, or other effects. Others include toxicity to the nervous system; designation as probable or known carcinogens; detection in biomonitoring programs that test people’s blood, urine, or tissue; use in children’s products; and persistence, bioaccumulation, and toxicity.

At least two-thirds of the 83 chemicals or classes are, or have been, manufactured commercially in large amounts, Denison says. Called high-production-volume substances, these chemicals are made or imported in amounts of at least 1 million lb per year.

Although EPA describes on its website how it selected the 83, the agency has not laid out publicly how it will assess them, some industry representatives note. A description of the process would help companies determine how their products might come out at the end of an assessment, says Paul C. DeLeo, senior director of environmental safety at the American Cleaning Institute, a trade association representing the cleaning products industry. If they know how EPA will assess substances, manufacturers would have a chance to provide the agency with more detailed information about their chemicals, or time to shift to alternative substances.

Industry representatives are also asking whether a substance or a category of related chemicals can get off the work plan list.

For instance, Derek D. Swick, senior policy adviser for the American Petroleum Institute (API), a group representing the oil and natural gas industry, cites tert-amyl methyl ether. This compound was formerly used to boost the oxygen content of gasoline. It’s listed in the work plan, but the chemical is no longer in U.S. commerce, Swick says.

“You would think that if something is no longer being manufactured and used that EPA would focus resources on higher priority chemicals,” Swick tells C&EN. For this reason, he adds, “there needs to be a mechanism to remove chemicals off that list.” The list needs to be dynamic, with EPA reviewing it regularly, taking into account new information, he says.

For its part, EPA tells C&EN that it does not plan to add or remove chemicals from the work plan “in the immediate term.”

Another point of contention for some industry groups is EPA’s estimation of how people are exposed to work plan chemicals and how much exposure they receive.

For instance, some of the chemicals in EPA’s work plan have consumer uses, but the greatest human exposure to them may be through personal care products applied to skin, DeLeo says. Examples of chemicals used both in consumer products and personal care products are some fragrances and 1-hexadecanol, also known as cetyl alcohol, DeLeo says.

DeLeo points out that the Consumer Product Safety Commission regulates chemicals in many consumer goods, while FDA has jurisdiction over substances in personal care products. DeLeo wonders why EPA would spend its resources studying chemicals whose main uses fall under the control of other agencies.

Plus, the primary use of 1-hexadecanol, a high-production-volume chemical, is as a precursor to surfactants, DeLeo continues. Thus, the production volume of this chemical is not a good indicator of consumer exposure to it, he says.

Meanwhile, API is concerned that in selecting candidates for the work plan EPA used data from the annual Toxics Release Inventory (TRI) to estimate exposure to substances, Swick says. But TRI releases can include disposal of chemicals in regulated landfills as well as air emissions and discharges to water, he says, and do not equate to human exposure from use of a particular compound.

New information that should help the agency refine exposure estimates is soon coming EPA’s way, says Lynn L. Bergeson, managing principal of Bergeson & Campbell, a Washington, D.C., law firm that works with chemical manufacturers and processors. By the end of June, chemical makers must submit data to the agency about 2011 production levels and uses of their compounds. Reporting of this type of information is periodically required under TSCA. Data will be submitted electronically, so EPA should be able to access it quickly, she says.

Bergeson, nevertheless, questions the inclusion in EPA’s work plan of chemicals that have undergone rigorous review in other parts of the agency not associated with the administration of TSCA. “There is some redundancy,” she tells C&EN.

As an example, she cites the category of arsenic and arsenic compounds. For years EPA’s Office of Research & Development has been assessing the health hazards of inorganic arsenic. And the agency’s Office of Pesticide Programs in recent years has acted on organic arsenical pesticides under the Federal Insecticide, Fungicide & Rodenticide Act. Other metals and metal-containing compounds in the work plan—notably antimony, lead, cadmium, and cobalt—have also been subject to considerable review within the agency, she says.

SOCMA is also taking issue with how EPA selected the chemicals for the work plan. The industry association faults EPA for including chemicals ranked as suspected carcinogens along with substances that are known or presumed carcinogens.

Beyond questions regarding overall selection, SOCMA is critical of how EPA chose the first round of substances for review. “After all the rigorous work EPA did to get the list of 83 chemicals, its process of winnowing that list down to seven is subject to political considerations,” SOCMA contends.

In the agency’s screening effort, each substance received a score of between 1 and 3 in each of three categories: hazard, exposure, and persistence and bioaccumulation. That means the top score a chemical could receive is 9. SOCMA complains that the agency did not select chemicals with the highest score to work on this year. Some chemicals with total scores of 7 are in the initial group for 2012, SOCMA points out, but other substances with a score of 9 are deferred until another year.

Those deferred include two classes—cadmium and its compounds and cobalt and its compounds—and two individual ethanones used as scents in consumer products such as laundry detergents. Each of the ethanone’s score of 3 for hazard is based solely on aquatic toxicity, not on concerns about health, according to EPA’s list of chemicals.

“This is very frustrating and undermines the credibility of the earlier work,” SOCMA says.

Despite these criticisms, Bergeson says the launching of the work plan is a noteworthy step for EPA’s Office of Pollution Prevention & Toxics, which has had limited experience in conducting risk assessments for existing chemicals. This office, which regulates commercial chemicals, would likely have to assess a great many existing substances if, as many in industry and public interest groups are hoping, Congress modernizes the 35-year-old TSCA, she points out. The office’s efforts on the work plan should help it hone skills for conducting risk assessments and develop tools that are defensible and yield reproducible results, she says.

Regardless of EPA’s new work plan on existing chemicals, most of the agency’s efforts on commercial substances will remain focused on new compounds, Denison says. Most of EPA’s budget for work under TSCA supports scrutiny of new chemicals because that law requires the agency to conduct those reviews. Although the agency has authority to examine chemicals already on the market, TSCA does not explicitly require EPA to do so, he points out.

The lack of a mandate combined with federal budget-cutting, Denison says, means that the resources that EPA will be able to focus on assessing the risk of existing chemicals, including those in the work plan, are likely to be limited.

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Bob Buntrock (May 8, 2012 10:06 PM)
Interesting article. It would appear that organizations such as the EDF continue to be misinformed about the TSCA list. Elsewhere, they imply that all ca. 80,000 compounds on the list are currently item of commerce. That is obviously not true for many compounds, especially methyl tert-amyl ether. In addition, many are natural products. Also, they state that none of the compounds of been trested for toxicity. Also not true. Of the seven compounds selected for 2012 review, all specific compounds have HSDB records including human toxicity data (the two classes of chlorinated hydrocarbons, and antimony compounds represent several specific compounds. In addition, it’s pointed out in “Toxic Chemicals: Risk Prevention Through Use Reduction” (Higgins, Sachdev, and Engleman, CRC, 2011), that TRI data is not as meaningful as ETF doses (Effective Toxicity Factors).

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