NACAA Comments on Proposed Hydrochloric Acid RTR

March 28, 2019 – NACAA has submitted comments on the proposed “National Emission Standards for Hazardous Air Pollutants: Hydrochloric Acid Production Residual Risk and Technology Review” that was published in the Federal Register on February 4, 2019.  The proposal announces EPA’s determination that the risks remaining after the imposition of the Maximum Achievable Control Technology standards are acceptable and that there are not developments in controls that warrant amending the rule.  The proposal also seeks comment on the use of the updated Integrated Risk Information System (IRIS) risk values for ethylene oxide EtO for regulatory purposes.  NACAA’s comments stated that it is correct and appropriate for EPA to use the updated IRIS risk value for EtO for regulatory purposes.  IRIS has been and should continue to be EPA’s primary source for risk information.  Furthermore, the EtO risk values in IRIS were updated in 2016 following a thorough and comprehensive evaluation and there would be no justification for abandoning their use.  The NACAA letter also commented on certain elements of EPA’s risk assessment methodology, including the use of census tract centroids in determining long-term exposures, consideration of facility-wide risks and strategies for evaluating acute exposures.