Elaboration of standards in the field of ambient atmospheres excluding the establishment of limit values. The standards are used to determine components of ambient atmospheres that may arise from human activities or occur naturally. These standards are used in legislation, by reference, to determine compliance with limit or reference values, by public or private entities to determine the current components of ambient atmospheres, and in research on the composition, fate, and transport of constituents of the atmosphere. The subcommittee's responsibilities include all ancillary practices and quality assurance procedures necessary to ensure acceptable performance and maintenance of its standards.