Exxon: EPA Should Leverage Existing Chemical Exposure Data

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By Pat Rizzuto

The EPA should partner with chemical and product makers in securing chemical exposure information to improve decisions, an Exxon Mobil scientist said.

The Environmental Protection Agency traditionally has been starved of exposure information when reviewing chemical risks. Yet an amended chemicals law now puts a premium on the agency having exposure data as it weighs regulations to restrict chemical uses.

Without good data, the EPA makes assumptions about human and environmental exposures to chemicals. Whether subsequent regulations are too restrictive—limiting chemical sales and use—or too lax, putting people at risk, often hinges on debates over these assumptions.

“There’s a lot of information out there,” but it can be challenging to get it, said Rosemary Zaleski, who heads the chemical exposure division at Exxon Biomedical Sciences Inc. “No one entity has all the information. We really need to work together,” she said at a recent International Society for Exposure Science conference in North Carolina.

EPA scientists welcomed outside input and said as long as the science meets rigorous criteria, the agency will consider submitted data, exposure models, and other tools to learn how people are exposed to chemicals and at what levels.

Exposure is Critical

Exposure is a critical component of the chemical reviews that the EPA must make as it implements the Toxic Substances Control Act, which was amended in 2016, Richard Becker, a senior toxicologist with the American Chemistry Council, told Bloomberg Environment.

“Decisions will be driven not just by potential toxicity, but also potential exposures,” he said.

Exposure data informs EPA decisions on whether:

  • a chemical is a candidate for initial examination;
  • it’s a low or high priority for closer scrutiny of potential health and environmental risks; and
  • it poses sufficient risks to warrant regulation.
Search Strategies

The EPA has relied on the internet, scientific databases, and other search strategies to obtain information about the “conditions of use” of chemicals and exposures related to how chemicals are made, processed, and disposed of.

“To me, it would be much more efficient to have a dialogue with manufacturers and downstream users/formulators as in combination I would think they could provide this information and in a more current, representative way then what the EPA may be finding on internet searches,” Zaleski told Bloomberg Environment.

Chemical, adhesive, paint, and other manufacturers already have collected exposure information on hundreds of downstream products to comply with chemical regulations around the world, Zaleski said at the conference. Companies have spent a lot of time and money preparing such information, and it could be leveraged to better calibrate upcoming regulations under the amended law.

“How can we maximize information value?,” she asked.

Multinational companies selling chemicals in the European market already have provided European Union authorities with exposure information to register their products. Zaleski said. It could be possible to repurpose for the U.S. some of that data along with submissions to Australian and other regulators, she said.

Cosmetic and personal care product companies in the EU also have teamed up with data management firms to compile chemical use information, said Sarah Tozer, a Procter & Gamble toxicologist. The effort is designed to help calculate “aggregate” exposure to chemicals in personal care products used in Europe, said Filipe Almeida from Cosmetics Europe.

Available Data

Some companies, including Exxon Mobil, have posted detailed information online for chemicals registered in the EU, according to Zaleski. The information is available in what the EU calls an extended Safety Data Sheet. These documents—such as one Exxon Mobil prepared for a type of alcohol called EXXAL™ 13—have more information than those used in the U.S.

That additional information also is available from the European Chemicals Agency database, but it’s hard to access because the searches must be conducted one chemical at a time, Zaleski said.

By working with industries and other parties, the EPA will have an easier time pulling together exposure information. “We want to help with a successful TSCA implementation,” Zaleski said.

As the chemical office continues to work through its first 10 chemical risk reviews, the EPA will examine data available from, and methods used, in other parts of the world such as the EU, Cathy Fehrenbacher, acting deputy director of OPPT’s risk assessment division told Bloomberg Environment.

EPA Seeks Measured Data

Scott Prothero, with the EPA’s Office of Pollution Prevention and Toxics, said the agency wants measurements of worker exposures.

“Breathing zone data is the gold standard,” he said during a conference session. “Monitoring may be an okay substitute.”

Breathing zone measurements are taken with sensors attached near a worker’s face; monitoring measurements track the amount of chemicals in a room or other space. If actual measurements are not available, the agency will use computer-based models, professional judgment, and other methods to predict potential exposures, Prothero said.

Require Data’

But instead of partnering to secure information, Jennifer McPartland—a senior scientist with the Environmental Defense Fund—said the EPA should use new authorities that Congress provided in the amended chemicals law to order companies to generate exposure data.

For example, the agency should require data rather than make untested assumptions as it has in some of its preliminary plans to assess chemicals, she said.

Its initial blueprint to review the risks of the solvent 1-bromopropane, for example, said the agency will consider workers’ dermal exposures. But for asbestos, the agency says dermal exposure is unlikely because workers would wear gloves, even though EPA also acknowledges that workers taking lunch or other food breaks may ingest asbestos that has landed on their skin.

The EPA should use empirical data and analysis to evaluate assumptions such as whether employees are using personal protective equipment and following label warnings and instructions, McPartland said.

Blueprints of Chemical Reviews

Hundreds of academic, corporate, federal agency, and other scientists from 33 countries attended the international conference. Five analysts from the EPA’s chemicals office described near-term efforts to evaluate exposures.

“Problem formulation” documents lay out a blueprint for the health and environmental concerns the agency will examine, specific conditions of those chemicals’ uses, and questions it will seek to answer. These will be released for public comment by the end of this year or early 2018, the EPA’s Fehrenbacher said, and outside parties can provide exposure information to the agency during the comment process.

Along with those documents, the EPA also will publish “living” protocols describing the toxicity and exposure models, processes, and other methods it used to prepare them, Fehrenbacher said. The protocols will evolve as the agency’s chemicals office develops new methods, she told Bloomberg Environment.

Charles Bevington, with the same EPA division, focused on exposure models such as EFAST that the agency plans to use. It also is developing other tools, including as ReachScan. Models are sometimes needed to predict exposures that occur as chemicals get into, move through, and affect the environment and health, according to Bevington .

“We’re open to other models developed by folks outside [the EPA], as long as they meet TSCA’s standards,” he said. That includes internal EPA models, as well as those that chemical companies, consortia, and researchers generate, he said.

Next Steps

The research office developed the web-based Chemistry Dashboard, which quickly pulls together publicly available information on chemical structure, measured and predicted volatility, solubility, toxicity, and other information. Scientists can then use the information to predict the potential health risks of chemicals.

John Wambaugh, co-leader of the EPA’s Rapid Exposure and Dosimetry project, focused on uncertainties.

The exposure information they collect through crawling many websites and databases will be very uncertain, but still useful, Wambaugh said.

If the preliminary—albeit uncertain—information suggests that the exposures to chemicals are vastly lower than any dose that could cause health or ecological harm, then it’s less urgent to evaluate them right away, he said.

Chemicals with uncertain exposures that may be occurring in the range of potentially harmful doses could warrant closer examination, he said.

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