NRDC Comments at The

EPA Workshop on Alternatives and Risk Reduction Approaches to

Trichloroethylene (TCE) Use as a Degreaser

July 29–30, 2014, Washington, DC

These comments are being submitted on behalf of the Natural Resources Defense Council (NRDC). 

NRDC uses law, science, and the support of more than 1.2 million members and on-line activists 

nationwide to protect the planet's wildlife and wild places and to ensure a safe and healthy environment 

for people and all living things. NRDC has no direct or indirect financial or fiduciary interest in the 

deliberations of this committee. 

General Comments

We are pleased that EPA issued its final TSCA Work Plan Chemical Risk Assessment for Trichloroethylene 

(TCE), and not surprised that the science provided that there were unacceptably high health risks from 

TCE exposure when used as a degreasing agent, a spot removal agent in dry-cleaning and as a spray arts 

fixative.1 EPA found that the greatest risks are for developmental effects (fetal cardiac malformations), 

followed by kidney effects and then immunotoxicity (EPA at 69).

The risk assessment clearly supports immediate protective action by EPA to implement risk reduction 

strategies to address the serious potential health effects that are associated with TCE use in the 

assessed exposure scenarios. NRDC believes that an EPA ban of TCE use in small commercial degreasing 

facilities and in consumer aerosol degreasers and protective coating sprays is the most effective risk 

 

1 http://www.epa.gov/oppt/existingchemicals/pubs/TCE_OPPTWorkplanChemRA_FINAL_062414.pdf
reduction strategy. The use of ventilation (general and local exhaust) in commercial degreasing facilities 

is inadequate and does not eliminate the risks of developmental toxicity, cancer, and other TCE-induced 

health effects. The use of consumer general purpose degreaser products that contain TCE are already 

banned in California and safer substitutes are in use. Instead, water-based cleaning systems are 

effective, safe, and economical alternatives for vapor degreasing, cold cleaning, and acetone and soy 

provide safer alternatives for aerosol uses. Water-based cleaners are used extensively in Southern 

California instead of TCE-based vapor degreasing, due to regulations that limit the use of solvents that 

are VOCs.

The non-user risk estimates are an important aspect of the TCE risk assessment. EPA’s assessment

documents serious and largely unexpected potential health problems that are not addressed by 

required preventive measures like the Hazard Communication Standard and precautionary labeling that 

are directed at users of toxic chemicals and consumer products. Cancer and the other potential chronic 

health effects that are identified as risks for bystanders in commercial facilities, and developmental 

toxicity potentially caused by exposure of pregnant non-users in both commercial and residential 

settings to TCE used as a degreaser, would be difficult to detect and would have substantial and costly 

adverse public health impacts.

Therefore, only a full ban will protect the public. EPA must not capitulate to industry arguments that 

voluntary initiatives will be good enough. They won’t. EPA spent twenty-three years trying to finalize its 

hazard assessment of TCE. FDA banned TCE from food uses in 1977, almost four decades ago. Ten years 

later, in 1987, EPA determined that TCE “probably causes cancer”. Since then, EPA has been delayed by 

TCE manufacturers, its lobbying group the American Chemistry Council (ACC), and its allies in Congress. 

Nonetheless, many forward-thinking companies that use TCE in their operations sought out safer 

alternatives, and have since moved completely away from TCE-based cleaners. Safer alternatives are 

readily available and in common use. The hold-out companies that still use TCE have proved by their 

inaction that they will not move away from TCE unless regulation forces them. EPA has already let 

decades of harmful exposures occur. Now that EPA has issued this risk assessment, it needs to cross the 

finish line with enforceable rules. It is decades too late for EPA to claim it is leading the effort to protect 

people from TCE-induced cancer, developmental malformations, and chronic disease, but it can bring up

the rear by pushing the last ‘bad actor’ companies towards safer substitutes. 
EPA must be mindful of not allowing ‘regrettable substitutes’ to TCE onto the market. For example, nhexane is a very hazardous substitute for TCE, used in auto cleaners after the California Air Resources 

Board (CARB) banned TCE, methylene chloride, and perchloroethylene from vehicle repair cleaners.

Another regrettable substitute is 1-bromopropane, which replaced TCE and other ozone-depleting 

solvents. It is linked to severe debilitating nerve damage, reproductive harm, and cancer. EPA must take 

measures to prevent highly hazardous substitutes from coming onto the market.

TCE poses unacceptably high risks to workers, consumers, and bystanders in vapor degreasing, cold 

cleaning, and aerosols. All of these uses have safer alternatives available and in widespread use. EPA 

should ban TCE, using enforceable regulations, so that no more people have to suffer from predicted 

and preventable disease or death from TCE.

Specific Technical Comments 

The final assessment had a number of significant improvements over the earlier draft, consistent with 

scientific understanding of TCE toxicity and EPA risk assessment approaches. We support these 

improvements and discuss them below.

EPA included developmental risks from TCE exposures during fetal development for both acute and 

chronic exposure scenarios. The draft had considered only acute scenarios. This is important because 

the window of developmental vulnerability may occur at any time during child-bearing years – often 

without warning – for an exposed adult.

In another improvement, EPA based its Point of Departure (POD) for developmental toxicity on fetal 

cardiac abnormalities in rodents. The study – Johnson et al 2003 - reported a statistically significant 

increase in severe heart malformations associated with fetal exposure to TCE in the drinking water of 

the pregnant dams. The study findings are supported by similar findings in chick embryos, data 

supporting a possible mode of action, and some weakly positive epidemiologic data (EPA page 97, 

Section 2.6). Fetal cardiac effects – including deformities in the septum and heart valves – are very 

serious and may cause lifelong impairments or death. EPA used this endpoint because it is the most 

sensitive – and, therefore will support the most health-protective assessment – and is consistent with its 
long-standing policy that a single exposure of a chemical at a critical window of fetal development may 

produce adverse developmental effects (EPA, 1991).2

EPA included exposures for spot dry cleaners in its final assessment. These exposures were determined 

to pose unacceptably high risks for both commercial users and for bystanders, based on fetal cardiac 

abnormalities. Spotting chemical formulations that contain high concentrations of TCE are commonly 

used by drycleaners to remove spots from fabrics. Concomitant exposures to tetrachloroethylene 

(perchloroethylene) could result in cumulative adverse health impacts because both chemicals produce 

the same potentially toxic metabolites. Under its Consumer Products Regulation, the California Air 

Resources Board (CARB) banned dry cleaning uses of TCE-containing spot removers in California 

effective December 31, 2012. Safer substitutes to TCE-based spot removers are available, and include 

water-based cleaners, soy based cleaners and acetone based cleaners. The cost analysis indicates that 

the alternatives are less costly than the spotting agents used today.3

Response to Congress

This is the first time EPA has issued an assessment under TSCA since 1986, when it identified the human 

health hazards of asbestos (see blog by Dr. Richard Denison, EDF). EPA’s successful efforts to use its 

existing statutory authorities to inform the public about this hazardous and common chemical did not 

going unnoticed by industrial chemical manufacturers and the chemical-friendly Members of Congress. 

Senator Vitter (R-La.), top Republican on the Environment and Public Works Committee, along with 

Senators Mike Crapo (R-Idaho) and Jim Inhofe (R-Okla.), has since requested the raw data on TCE 

research that supported the EPA TCE assessment, as well as impugning the EPA researcher that coauthored the study. From Senator Vitter’s webpage: “On June 16, 2014, Senator Vitter sent a letter to 

Dr. Francesca Grifo, the Science Integrity Official for EPA requesting their research data, suggesting 

there may be some data-related misconduct.” The letter raises three concerns, for which I offer my 

perspective: 

1. the Johnson et al (2003) study of cardiac malformations is fundamentally flawed; 

 2 Guidelines for Developmental Toxicity Risk Assessment. U.S. Environmental Protection Agency, Risk Assessment 

Forum, Washington, DC, EPA/600/FR-91/001, 1991.

3 http://www.irta.us/reports.htm
2. the EPA scientist, Dr. Stan Barone, that drafted the external charge to peer reviewers had undue 

influence on the outcome of the peer review; and 

3. Dr. Barone may have committed scientific misconduct.4

Senators Vitter, Crapo, and Inhofe will be pleased to know that there concerns are unwarranted. 

First, the Johnson et al (2003) 5 study has undergone extremely rigorous scientific review, including by 

EPA and external experts, public scrutiny and comment, and the peer review that comes with 

publication in a reputable scientific journal. Although it can reasonably be accused of being imperfect, 

an expert consensus to use it for this assessment should be respected. Moreover, the findings in the 

Johnson et al (2003) rodent study are supported by findings in other rodent studies, studies in other 

species, some epidemiologic data, and a plausible mode of action, making EPA’s overall assessment very 

strong. 

Second, the peer review charge questions were developed and reviewed by numerous EPA staff, and 

then vetted for public comment prior to being finalized. I am somewhat sympathetic to the general 

claim in the Senators’ letter that wording of charge questions can limit or constrain the peer review 

feedback, and thereby the outcome of a peer review. However, in this case, the charge questions to the 

peer reviewers resulted from internal discussions among numerous EPA staff, review and comment by 

the public, and then further EPA review to address the public comments. It is reasonable, therefore, that 

Dr. Barone was one among many people – within and outside EPA – that developed the final charge 

questions. 

Third, the suggestion that Dr. Barone may have committed scientific misconduct is simply unfounded. In 

fact, in the situation to which the Senators’ letter refers, he co-published with other authors a paper 

over a decade ago on a completely unrelated chemical – a fungicide – which subsequently underwent 

 4

http://www.epw.senate.gov/public/index.cfm?FuseAction=PressRoom.PressReleases&ContentRecord_id=7D8613

08-98D6-51CA-08FA-85F6CEFB2E95

5 Johnson PD, Goldberg SJ, Mays MZ, Dawson BV. Threshold of trichloroethylene contamination in maternal 

drinking waters affecting fetal heart development in the rat. Environ Health Perspect. 2003 Mar;111(3):289-92. 

Erratum in: Environ Health Perspect. 2014 Apr;122(4):A94.
some re-analysis of the pathology findings that did not change the conclusions of the paper. Both the 

paper and re-analysis were published in a scientific journal.6

The Halogenated Solvents Industry Alliance (HSIA) recently sponsored a review of epidemiologic studies 

examining the association between congenital heart defects and TCE exposure, concluding that overall 

the “literature provides no substantive or consistent evidence linking TCE to CHD [coronary heart 

disease]”.7 The study found that some studies didn’t find a link, some studies did, and all the ones that 

did had design and analytic flaws making them unusable. Although the author spent a good deal more

effort identifying flaws with the studies that found links (the positive studies), he did include a short 

section of “limitations” with the ones that didn’t (the negative studies). He reported that the “negative” 

studies were based on small numbers so increases might have been missed due to low statistical power,

and “each study had substantial potential for non-differential misclassification that might have biased 

toward the null”. In plain-speak, this means that the “negative” studies had flaws that made it more 

likely that they would fail to detect a link between TCE and CHD, and they did fail. Ironically, so did the 

review article. Nonetheless, the conclusions are not inconsistent with EPA’s own review, which also 

determined that the epidemiologic evidence overall was “weakly suggestive” (EPA at 97). However, in 

combination with the animal and mechanistic studies, the science supports the risk assessment.

Conclusion and Recommendations

We commend EPA on its assessment, which identified some significant high health risks for both 

workers and consumers. Since in many cases there are safer alternative materials available, EPA should 

immediately establish more health-protective exposure limits for these unsafe uses, and ban TCE use in 

small commercial degreasing facilities and in consumer aerosol degreasers and protective coating 

sprays.

 6 Barone S Jr, Moser VC. The effects of perinatal tebuconazole exposure on adult neurological, immunological, and 

reproductive function in rats. Toxicol Sci. 2004 Jan;77(1):183.

Moser VC, Barone S Jr, Smialowicz RJ, Harris MW, Davis BJ, Overstreet D, Mauney M, Chapin RE. The effects of 

perinatal tebuconazole exposure on adult neurological, immunological, and reproductive function in rats. Toxicol 

Sci. 2001 Aug;62(2):339-52. 

7 Bukowski, John (06/05/2014). "Critical review of the epidemiologic literature regarding the association between 

congenital heart defects and exposure to trichloroethylene". Critical reviews in toxicology (1040-8444), 44 (7), 1.
In a statement that accompanied the release of its TCE assessment, EPA called on Congress to enact 

legislation that strengthens our current federal toxics law, TSCA. NRDC agrees that it is long past time 

that hazardous chemicals were assessed and regulated so as to prevent unsafe human exposures and 

releases to the environment. Using TSCA to identify unsafe exposures to chemicals already in 

widespread commercial and residential use is too little, too late.

Respectfully,

Jennifer B. Sass, Ph.D.

SENIOR SCIENTIST, NATURAL RESOURCES DEFENSE COUNCIL (NRDC) , AND

PROFESSORIAL LECTURER, GEORGE WASHINGTON UNIV (SEIU LOCAL 500)

NRDC | 1152 15th Street, NW | Washington, DC 20005