Question # 501

501. How are sulfuric and hydrochloric acid aerosols that are generated over and over again in acid reuse systems to be reported under Section 313?
When solutions of sulfuric acid and hydrochloric acid are aerosolized the manufacture of a listed chemical (sulfuric acid or hydrochloric acid aerosols) has occurred. This is a result of the qualifier to the sulfuric acid and hydrochloric acid listings, which excludes non-aerosol forms and limits the reporting to aerosol forms only. The addition of the acid aerosol qualifier has an impact on certain processes that, prior to the addition of the qualifier, would not have been considered as the manufacturing of a listed chemical. Acid reuse systems that use aqueous solutions of sulfuric acid or hydrochloric acid to generate acid aerosols, use the acid aerosols, condense them back into solution, and then reuse the acid solution again and again are impacted by the addition of the acid aerosol qualifiers. In such processes, the continuous reuse of the acid solutions generates very large quantities of acid aerosols that technically should be counted towards the manufacture (the generation of the acid aerosol is the manufacture of sulfuric or hydrochloric acid (acid aerosol)) and otherwise use thresholds. This may result in many facilities greatly exceeding the manufacture and otherwise use reporting thresholds that, prior to the addition of the qualifier, would not have exceeded thresholds. While it is technically correct to apply all of the quantities of acid aerosols generated in such systems towards the manufacture and otherwise use reporting thresholds, EPA did not intend to increase the reporting burden as a result of the addition of the acid aerosol qualifiers. In addition, under EPA’s general approach to reuse systems, a listed toxic chemical is not counted toward thresholds each time it is reused but only once per reporting period. This approach would apply to sulfuric acid or hydrochloric acid reuse systems were it not for the aerosol qualifiers. Therefore, EPA is providing the following guidance to reduce the reporting burden for covered facilities that operate such processes and to bring the treatment of such systems into alignment with EPA’s general approach to reuse. Rather than having covered facilities count all quantities of acid aerosol generated in such systems towards the manufacture and otherwise use thresholds, EPA will allow facilities to apply the total volume of acid in these systems only once to these thresholds. For example, if an acid reuse system starts the year with 2,000 pounds of acid and 500 pounds is added during the year then the total amount applied towards acid aerosol thresholds would be 2,500 pounds. This reflects a one-time per year counting of all of the acid molecules as being in the acid aerosol form rather than counting them over and over again each time the acid aerosol form is generated and subsequently used. Since in these acid reuse systems the acid aerosols are manufactured and then otherwise used the 10,000-pound otherwise use threshold would be the threshold that triggers reporting from such systems. This guidance applies only to acid reuse systems and the reporting of sulfuric acid and hydrochloric acid aerosols under EPCRA section 313. This guidance does not apply to any other types of processes or to any other listed chemical.