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

EPA has received a specific exemption 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 of the International Space Station to control aerobic/microaerophilic bacteria in the aqueous coolant. The applicant proposes the use of a chemical which is not registered by EPA. Accordingly, as required by the Code of Federal Regulations, EPA is publishing this notice of receipt to allow public comment.