Isocyanates are nasty chemicals, including when they are left over as residuals after manufacturing other chemicals. Here are the kinds of risks they pose, according to the National Institute for Occupational Safety and Health (NIOSH):
Isocyanates are powerful irritants to the mucous membranes of the eyes and gastrointestinal and respiratory tracts. Direct skin contact can also cause marked inflammation. Isocyanates can also sensitize workers, making them subject to severe asthma attacks if they are exposed again. There is evidence that both respiratory and dermal exposures can lead to sensitization. Death from severe asthma in some sensitized subjects has been reported.
In prior reviews of new chemicals under the Toxic Substances Control Act, EPA has repeatedly indicated that “[i]socyanate exposure has been identified as the leading attributable cause of work-related asthma, and prevalence in the exposed workforce has been estimated at 1-20 percent.”
Both NIOSH and EPA have raised even greater concern over activities involving spray application of chemicals containing isocyanates. In 2006, NIOSH issued a rare alert calling for workers to undergo medical surveillance and wear high-efficiency respirators and gloves when engaged in such activities.
Even in the recent past, when reviewing new chemicals containing isocyanate residuals, EPA has typically (1) issued a consent order subjecting the company submitting the chemical for review to multiple conditions in order to limit workplace inhalation exposures to the residuals, and (2) followed up with a Significant New Use Rule (SNUR) that extends those conditions to other companies, requiring them to notify EPA prior to engaging in any activity that exceeds those workplace limits. And the only case since TSCA was amended in 2016 where EPA found a new chemical “presents an unreasonable risk” – as opposed to the more common, lower-bar finding that it “may present an unreasonable risk” – involved residual isocyanates present after manufacture of two new chemicals.
In such cases EPA has imposed some combination of three types of conditions on manufacture of such chemicals: prohibitions on activities that could generate inhalable forms of the chemical and result in inhalation exposures; strict requirements for the use of high-efficiency respirators and gloves; and a strict limit on the amount of isocyanate residuals allowed to be present in the new chemical, typically in the range of 0.1% to 0.2%.
So it is quite disturbing to see how EPA has dealt with the most recent such new chemical for which EPA has issued its final decision – which requires that companies employ NONE of these protections.
The notifying company’s identity and its chemical’s specific identity and use are all claimed confidential. The chemical’s generic name is listed only as “Isocyanate terminated polyurethane resin,” and its generic use only as “Adhesive for open, non-descriptive use.”
On June 30 of this year, EPA published its determination that the chemical “is not likely to present an unreasonable risk,” clearing it to enter commerce for its intended use without any conditions. EPA’s final determination was the opposite of what its professional staff recommended when initially reviewing the chemical; staff recommended that EPA issue a section 5(e) Consent Order because the chemical “may present an unreasonable risk of injury to health and to the environment” and presents considerable exposure potential.
The final decision is also difficult to reconcile with EPA’s own findings:
- “Risks were identified for workers for pulmonary effects via inhalation exposure based on quantitative data for a component of the new chemical substance,” with the risks being 46 times higher than EPA’s own “safe” level: “MOE = 0.7; Benchmark MOE = 30; Inhalation fold factor = 46.”
- Irritation and sensitization effects hazards to workers via inhalation and dermal contact were identified based on reactivity and residual isocyanates.
EPA coupled its “not likely” determination with the proposal of a Significant New Use Rule that describes activities involving the manufacture and use of the chemical that, if finalized, would require prior notification and review by EPA. EDF filed comments on EPA’s proposal yesterday.
The proposed SNUR would require notification before commercial or consumer use, but imposes no limits on industrial uses of the chemical. Notably, neither the proposed SNUR nor the “not likely” determination makes any mention of avoiding spray application of the chemical, leaving companies free to use the chemical in such applications.
Unlike in the past, the proposed SNUR says nothing about avoiding activities that could generate inhalable forms of the chemical and result in inhalation exposures. Nor does it require a company to notify EPA if it decides not to provide its employees with and require them to use respirators or gloves. This is quite astounding, given that EPA’s “not likely” determination was based on its “expectation” that “employers will require and that workers will use appropriate PPE [personal protective equipment], including impervious gloves, eye protection, and respiratory protection with an Assigned Protection Factor (APF) of at least 50.”
The only condition that would require notification to EPA if exceeded is this: “manufacture (including import) the substance with isocyanate residuals greater than 7% and polymeric isocyanate residuals greater than 13%.”
These triggers must be compared to those EPA has imposed in the past for similar chemicals, typically set in the range of 0.1% to 0.2%. EPA publicly indicated such limits would be part of its approach in such cases when it proposed an earlier batch of SNURs:
For new isocyanates submitted as PMNs, EPA expects to issue TSCA section 5(e) orders imposing 0.1% limits on total residual isocyanates and greater levels of respiratory protection (at least an APF of 50, or 1000 if used in a process that generates a vapor or particulate), and no consumer use. The Agency would then likely issue a SNUR defining the significant new use as total residual isocyanates exceeding that 0.1% limit and any use in a consumer product.
Nowhere has EPA or the company provided any explanation or basis for these vastly higher limits on isocyanate residuals. There is nothing in the company’s new chemical notice to EPA or any of the attachments to the notice. There is nothing in the proposed SNUR. There is no mention of it in EPA’s “not likely” determination for this chemical. And there is nothing about it in any of the “support documents” EPA has posted to the docket for the proposed SNUR (albeit many of them are heavily redacted).
The only explanation I can see is that the chemical industry has been pressuring EPA to stop imposing limits on isocyanate residuals. In comments the American Chemistry Council (ACC) has submitted on recent prior proposed SNURs, it has made clear it opposes such limits.
It looks like once again the industry’s wishes are being granted, worker health be damned.