This document has been declared "Stabilized" and will no longer be subjected to periodic reviews for currency. Users are responsible for verifying references and continued suitability or technical requirements. New technology may exist. This ARP covers a procedure to be used in the determination of 0.05 to 0.3 ppm of chlorine in oxygen from any type of generator used for emergency or other life-support systems. The methyl orange method described can be considered as a referee technique. Instrumental analysis is also given. This ARP describes a method for rapid and reliable measurement of chlorine in oxygen from a solid chemical oxygen generator. The method