On June 17, 2021, the USEPA agreed to reconsider the August 2020 NESHAP: Miscellaneous Organic Chemical Manufacturing (the “MON Rule”). The MON rule is the first USEPA rule to use the 2016 toxicity values from IRIS. Responding to five petitions, the USEPA granted reconsideration that more stringent standards are required for the MON sector, particularly for ethylene oxide (EtO), given more data that EtO may result in a greater carcinogenic risk than previously thought.
EtO is a flammable, colorless gas used to sterilize medical equipment and common in the chemical industry in manufacturing many common products. The revised 2016 IRIS risk assessment for EtO characterized the chemical as a more potent carcinogen for humans by inhalation than previously understood. However, critics claim that the USEPA used improper statistical modeling that resulted in an overestimation of the risk of EtO exposure. Texas, home to many chemical industries, performed an in-depth review of the 2016 assessment and claimed scientific deficiencies and that EtO is a less potent carcinogen than the USEPA estimated in its 2016 report.
The USEPA declared that it would use 2016 IRIS risk values for future rulemaking, including for the December 2019 proposed MON Rule and an Advance Notice of Proposed Rule Making: NESHAP: Ethylene Oxide Commercial Sterilization and Fumigation Operations. The MON Rule was finalized in August 2020 with the USEPA not addressing comments regarding the validity of the 2016 IRIS values. The USEPA will now do a more formal review of the generation of the 2016 IRIS risk values and modify the MON Rule accordingly, if necessary.
Besides the effects on EtO emission regulations, the USEPA’s actions on EtO may suggest how the agency will proceed on other outstanding chemical and toxics issues, such as formaldehyde, a naturally occurring chemical found in a variety of products, such as construction materials, insulation, glues, paints, and in plywood and particleboard used in consumer products like cabinets, flooring, and furniture. Formaldehyde is also used as a preservative in medical laboratories and mortuaries.
Like with EtO, the USEPA issued an IRIS risk assessment for formaldehyde in 2010. It underwent much scientific criticism. 11 years later, the USEPA has still not addressed the formaldehyde IRIS criticisms and confirmed or updated its level of toxicity.
2016 amendments to TSCA require the USEPA to conduct risk evaluations for certain high-priority chemicals to determine whether each presents an unreasonable risk to health or the environment, under the conditions of common use. The USEPA must exclude cost considerations and base decisions on the weight of scientific evidence.
Last year, the Trump Administration issued final TSCA risk evaluations for the first 10 high-priority chemicals. In February 2021, the Biden Administration announced that it will revisit the final TSCA risk evaluations for these 10 chemicals.
CCES has the technical experts to help you assess the quantity and toxicity of air emissions from your various processes and facility. Contact us today at 914-584-6720 or at karell@CCESworld.com.