EPA’s trichloroethylene (TCE) risk assessment: Will it succeed in protecting workers?

What do these places have in common: Camp Lejeune in North Carolina; Mountain View, California, where Google headquarters are located; Endicott, NY – the birthplace of IBM; and 389 Superfund sites in at least 48 states plus Puerto Rico and the Virgin Islands? All are contaminated by trichloroethylene (TCE), a volatile organic compound classified as a carcinogen that’s been widely used as a solvent and degreaser in large-scale industrial processes, small commercial shops and in some products used by individual consumers. On June 25^th, the Environmental Protection Agency (EPA) released its final risk assessment for TCE, the first such report to be completed for any of the 83 “work plan” chemicals EPA identified in 2012 as sufficiently hazardous to warrant priority assessment. It is the first chemical risk assessment EPA has completed under the Toxic Substances Control Act (TSCA) – the federal law that regulates chemicals in commerce – since it evaluated asbestos in 1986.

EPA’s TSCA risk assessments focus on uses of the chemicals that fall under EPA’s jurisdiction (EPA doesn’t regulate food contact chemicals or those in cosmetics, for example) that have what the agency considers significant potential for human and/or environmental exposure. EPA explains that “If an assessment indicates significant risk, EPA will evaluate and pursue appropriate risk reduction actions.” What those actions may be is not specified. So an EPA risk assessment doesn’t lead directly to specific restrictions, but completion of a TSCA risk assessment is a prerequisite for further EPA action if high hazard is found.

“EPA calls on Congress to enact legislation that strengthens our current federal toxics law,” said Jim Jones, EPA assistant administrator for chemical safety and pollution prevention, in a press release. “Until that time,” said Jones, “we are using the best available science to assess and address chemical risks of TCE that now show that it may harm human health and the environment.” TCE is one of the country’s most common groundwater contaminants and has been detected in ambient air in every state. EPA has noted that virtually all TCE in the environment comes from anthropogenic sources. Given the chemical’s toxicity, the agency has set as a safety goal for TCE in drinking water, zero parts per billion.

The EPA risk assessment does not focus on the widespread environmental exposures to TCE, however, but on health risks to workers in small commercial operations that use TCE-containing products (including dry cleaners where TCE is used as a stain remover) and to consumers using TCE-based degreasers and fixatives in art and other craft, hobby and DIY projects. Nothing regulatory has been announced but the EPA will hold a public workshop on July 29 and 30 to discuss alternatives to these uses of TCE and other “risk reduction approaches.”

“In the meantime, EPA recommends that people 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,” wrote the agency in its June 25th press release.

A volatile and hazardous substance

TCE exposure, primarily through inhalation, has long been linked to cancer of the kidney, liver and immune or lymphatic system. It has also been linked to adverse impacts on development and on immune, neurological and reproductive system health. Exposure, occupational and environmental, has also been linked to low birth-weights and fetal cardiac defects, among other adverse health effects. In the 1980s and earlier, TCE was often used at such volume industrially – including by the electronics industry in circuit board and semiconductor production – that it was stored in underground tanks. Leaks and other unintended releases at many of these tanks sent TCE into surrounding soil and groundwater resulting in ongoing contamination that has lasted for decades. TCE is also used as a chemical intermediate in producing numerous other chemical products including some refrigeration gases, insecticides, flame retardants and polyvinyl chloride (PVC), as well as products that include disinfectants, perfumes, dyes, soaps and pharmaceuticals. Exact current US production figures are not available due to confidential business information claims but the EPA assessment says that 224.7 million pounds were reported to the EPA in 2012 and about 255 million pounds are used here in 2011 when global consumption was 945 million pounds.

TCE is not bioaccumulative and not thought to have high toxicity to aquatic organisms, but it can easily move through soil and groundwater and thus last for years underground. Epidemiologists and public health officials have documented clusters of birth defects and cancers that may be associated with these exposures. Breathing TCE in confined indoor spaces is considered among the most harmful types of exposure.

Because it is so volatile, TCE vapor can rise up from soil under foundations and infiltrate buildings – including homes – as it has done in communities across the US (a process known as vapor intrusion), exposing occupants to toxic but often undetectable fumes. Whole communities have been affected by such vapor intrusion. Endicott, NY sits atop a 300-plus-acre plume of TCE-contaminated groundwater – a situation dating back decades. NIOSH research has found significantly elevated rates of certain cancers including leukemia, non-Hodgkin lymphoma and kidney cancer among workers there exposed to TCE. A 2005 New York State Department of Health study also found high rates of certain birth defects and cancer, including kidney and testicular cancer, among people living in this area. TCE vapor intrusion also recently cropped up at Google’s Mountain View, California campus that is located where electronics industry plants and military aerospace operations spilled TCE into the soil.

Given these hazards, promoting ways to reduce use of TCE-containing products and to eliminate TCE exposure would seem to be a sensible response.

Industry objections

But within hours after EPA released its assessment on June 25^th, Senators David Vitter (R-LA), Mike Crapo (R-ID) and James Inhofe (R-OK) – all members of the Senate Environment and Public Works (EPW) Committee – sent a letter to EPA Assistant Administrator Jim Jones, questioning the EPA’s method of conducting risk assessments, the EPA’s scientific standards and suggesting that lead scientists on the assessment had committed “scientific misconduct” and “fraud,” and that EPA “mismanagement” had compromised studies used in the assessment.

“As there continue to be significant challenges with your Agency's ability to produce credible sound science in a transparent manner, we will continue to investigate OCSPP [Office of Chemical Safety and Pollution Prevention], its scientific findings, and the processes used for promoting individuals to senior-level positions, who ultimately have decision-making authority on chemical risk assessments,” wrote the senators who – with other Republican colleagues in the House and Senate – have previously questioned EPA’s assessment of formaldehyde, inorganic arsenic and endocrine disruptors. Vitter’s defense of formaldehyde has taken a similar tack

In the past year, the American Chemistry Council (ACC), whose members include companies that manufacture TCE (Dow Chemical and Axiall), has also written to the EPA, outlining its criticisms of the agency’s approach to its TCE TSCA risk assessment. Among these, spelled out in a March 2013 letter from ACC’s Director of Regulatory Affairs to EPA, is that EPA’s assessment should “explicitly address the authority of the Occupational Safety and Health Administration (OSHA) to regulate occupational exposures” and coordinate with OSHA to avoid any conflict or confusion.

The Halogenated Solvents Industry Association (HSIA), a trade association whose members also include TCE manufacturers, wrote in its comments to EPA on the draft assessment: “…it would be a clear overreach of EPA’s authority for it to assert the power to regulate to protect workers in occupational settings when this responsibility has been delegated by Congress to the Occupational Safety and Health Administration…” The HSIA also takes issue with the entire premise of the EPA assessment, saying that EPA has not met the standard of showing there is “unreasonable risk” to health from the TCE exposures under consideration and therefore would be lacking authority to act as it is doing under TSCA.

The HSIA also questioned EPA’s authority to consider products that might be used in art projects – spray fixatives for example – saying that no further action is warranted given the warning labels issued under the Federal Hazardous Substances Act (FHSA) and by the Consumer Product Safety Commission. That EPA is also considering the risks of TCE to “bystanders” who might be exposed by the use of the products covered in the assessment, HSIA found to be without merit, saying this wouldn’t apply to products used occupationally.

Ongoing effort to cast doubt

Center for Progressive Reform senior policy analyst Matt Schudtz sees the Senate EPW Republicans’ and industry response to the TCE assessment as part of an ongoing pattern of action to stall and question EPA and other federal agency science on widely used but toxic chemicals. The EPA Integrated Risk Information System (IRIS) assessment of formaldehyde has come under similar attack as have the National Toxicology Program’s (NTP) assessments of formaldehyde and styrene in its Report on Carcinogens. He characterized the June 25th letter from Sens. Vitter, Crapo and Inhofe to EPA as a “short term” effort in a “long game” aimed at casting doubt on now well-established science on these chemicals, including TCE.

As the salvo of criticism of EPA’s chemical risk assessments and accusations against EPA continue, those losing out are workers and other individuals who continue to be exposed and the thousands of “by-standers” exposed to TCE environmentally as its large-scale use persists.

Elizabeth Grossman is the author of Chasing Molecules: Poisonous Products, Human Health, and the Promise of Green Chemistry, High Tech Trash: Digital Devices, Hidden Toxics, and Human Health, and other books. Her work has appeared in a variety of publications including Scientific American, Yale e360, Environmental Health Perspectives, Ensia, The Washington Post, Salon and The Nation.