This standard is formulated for the purposes of enforcing the Environment Protection Law of the People’s Republic of China and Air Pollution Prevention and Control Law of the People’s Republic of China, protecting the environment, safeguarding the human health, and setting standards for the emergency monitoring of ambient air. This standard specifies the length detector tube method used to determine 16 hazardous air pollutants including chlorine, carbon monoxide, hydrogen sulfide, hydrogen chloride, hydrogen cyanide, carbonyl chloride, hydrogen fluoride, ammonia, formaldehyde, phenylethylene, arsenic hydride, ozone, sulfur dioxide, nitrogen oxides, benzene, and toluene. The appendixes A and B to this standard are referential. This standard is the original version.

 Ambient air-Determination of chlorine and other hazardous air pollutants in emergency monitoring-Length detector tube method (HJ 871-2017)