EPA Reaffirms PVC's Negative Health Impacts

Bill Walsh | March 19, 2012 | Materials

EPA Actions Offer More Support for LEED 2012 Approach to Chemicals of Concern: Comment Period Ends 3/20/12

Two actions from the US EPA last month reaffirm the serious and unique negative health impacts of the polyvinyl chloride (PVC) plastic lifecycle. For the green building community, the Agency's latest evaluations of PVC and dioxin affirm both the US Green Building Council's 2007 conclusion that PVC is not a healthy building material, and lend further support for a proposed LEED credit that would reward the avoidance of chemicals of concern, including halogenated plastics. It is clearer than ever why halogenated plastics such as PVC should be avoided in green buildings, and we urge your support for the draft "Chemicals of Concern" credit in LEED 2012. [You can read my colleague Tom Lent's comments on LEED 2012 and add your own here in LEED-user.]

On February 13, 2012, the US EPA issued new restrictions on highly toxic emissions from PVC manufacturing facilities. The rules place new restrictions on two known human carcinogens uniquely associated with the PVC lifecycle: vinyl chloride and dioxin.[1] EPA estimates that total air toxics emissions from covered facilities will be reduced by 238 tons, and that dioxin emissions will be reduced by 0.017 grams.

While dioxin emissions are so toxic that they are measured in hundredths of grams, EPA's studies of dioxin emissions are measured in generations. On February 17, 2012, after 27 years of review, EPA released the first of two much-anticipated reports that reassess dioxin's toxicity. The studies were undertaken in response to industry challenges to the original science, and their release has been held up for years by chemical, plastics and industrial-scale agriculture and food processing interests. (Dioxin accumulates in fatty foods such as meat and dairy products.)

In the report released last month, EPA affirmed the link between dioxin exposure and non-cancer health effects (including developmental and reproductive problems, damage to the immune system, and hormone disruption), concluding that the exhaustive reassessment served to "increase the confidence" in EPA's threshold levels for acceptable dioxin exposure, both qualitatively and quantitatively. These threshold levels are measured in a unit called toxicity equivalency (TEQ), and EPA set the acceptable daily exposure to dioxin at 0.7 picograms per kilogram of body weight.[2] A picogram is a trillionth of a gram.

EPA's press releases stressed anticipated declines in the levels of toxic chemical emissions associated with the PVC lifecycle, but stubborn facts in the actual studies contradict that optimistic spin. For example, the new emissions regulations do not apply to all facilities in the PVC manufacturing chain, just 15 facilities that produce polymers. The rules will not take effect for at least two to three years, and compliance may be delayed at a company's request. Critically, although EPA notes that "children are known to be more sensitive to the cancer risks posed by inhaling vinyl chloride, one of the known carcinogens emitted by this source category," the new emissions standards are not health-based.[3] That is to say, the allowable emissions are still not calibrated to ensure public health, especially children's health. Indeed, EPA did not provide data on how much vinyl chloride or dioxin will continue to be released after the new rules take effect.

Because dioxin is a persistent and bioaccumulative substance, each gram released to the environment accumulates over time in the food chain and in our bodies. Stephen Lester, who as Science Director for the Center for Health Environment & Justice has tracked the dioxin reassessment since it began, says young children may routinely be exposed through their diets to higher levels of dioxin than the 0.7 picogram TEQ set by EPA. According to the National Academies of Sciences, the average 1 to 5 year old's diet contained 1.09 TEQ. Boys and girls 6 to 11 years old averaged .69 TEQ.[4]

This is why the fine print on the new dioxin report is so disturbing. EPA's discussion of reductions in dioxin releases from human activities is based upon what they call "well quantified" sources. HBN's Policy Director, Tom Lent, refers to the phrase "well quantified" as code for ignoring some potentially really big sources that are harder to accurately model. For example, although EPA has data suggesting that landfill fires remain a major source of dioxin, possibly exceeding everything that is "well quantified," and studies have shown that PVC loading may be a significant contributor, the EPA press releases and new reports do not consider landfill fires (or accidental combustion in buildings) as a dioxin contributor.

In the political world, PVC and dioxin remain as contentious as ever. EPA and the PVC industry have put a rosy spin on these developments: dioxin emissions down. Environmental health experts paint a darker picture: a lost generation of avoidable chemical exposures while the chemical and plastics industry tied EPA in knots. But however you color it, you certainly can't color it green. Green building leaders have worked hard to avoid putting this material into their projects for more than a decade, and the latest from EPA proves them right.


[1] Vinyl chloride is an essential component of PVC not used in any other plastic. Dioxin emissions from the PVC lifecycle are higher than other plastics because they are correlated to the halogen content of PVC, in the form of chlorine, which is absent from most other plastics. The EPA regulations also set new limits on hydrogen chloride, which is also widely used both in the production of PVC, and methylene diphenyl diisocyanate (MDI) a chemical essential to polyurethane production. While PVC is by far the most prevalent chlorine-based plastic in use in buildings, there are several others also addressed by the LEED credit, including chlorinated polyethylene (CPE), chlorinated polyvinyl chloride (CPVC), chlorosulfonated polyethylene (CSPE), and Polychloroprene (CR or chloroprene rubber, also brand name Neoprene).

[2] "EPA's Reanalysis of Key Issues Related to Dioxin Toxicity and Response to NAS Comments, Volume 1" U.S. Environmental Protection Agency, Washington, DC February 2012 http://www.epa.gov/iris/supdocs/dioxinv1sup.pdf

[3] The new EPA standards are based upon a determination of maximum achievable control technology (MACT), which sets a performance level based on a technology or other practices already used by the better-controlled and lower emitting sources in an industry. See, http://www.epa.gov/air/caa/peg/toxics.html

[4] CNN Health: http://thechart.blogs.cnn.com/2012/02/22/epa-dioxin-assessment-raises-red-flag-for-some/