Which of the following is an explosive component of sewer gas?

The correct answer is methane, which is a significant component of sewer gas and poses an explosive risk under certain conditions. Methane is highly flammable and can form explosive mixtures with air when concentrations are between approximately 5% and 15%. In sewer systems, it can be produced as a result of the anaerobic decomposition of organic material.

This makes methane a particularly concerning component for safety in sewer systems or wastewater treatment facilities, where proper ventilation is crucial to prevent the accumulation of gas to hazardous levels. The presence of methane is an important consideration in the design and maintenance of sewer systems to mitigate any potential explosion risks that may arise from gas buildup.

In contrast, other components like hydrogen sulfide, although toxic and hazardous, are more known for their poisonous characteristics rather than explosive risks. Carbon monoxide is also poisonous but does not have the explosive properties associated with methane in sewer contexts. Ammonia, while it has its own safety concerns, is not listed as an explosive component in sewer gas mixtures.