Ortho-Phthalaldehyde; Receipt of Application for Emergency Exemption, Solicitation of Public Comment

Official abstract: EPA is announcing a specific exemption reauthorization request from the National Aeronautics and Space Administration (NASA) to use the pesticide ortho-phthalaldehyde (OPA, CAS No. 643-79-8) to treat the coolant fluid of the internal active thermal control system (IATCS) of the International Space Station (ISS) to control aerobic/ microaerophilic bacteria in the aqueous coolant. The applicant proposes the use of a new chemical that has not been registered by EPA. Therefore, in accordance with the Code of Federal Regulations, EPA is soliciting a 15-day public comment before making the decision whether to grant the exemption.