Which of the following describes the flammable characteristics of hydrogen sulfide?

Hydrogen sulfide (H2S) is recognized for its flammable and potentially explosive characteristics, making the choice of "flammable and explosive" accurate. This gas can ignite and burn in air at concentrations as low as 4.3%, and at higher concentrations, there’s a risk of explosive mixtures forming. Additionally, although it is known for its distinct rotten egg smell and toxicity, the flammable nature is a critical safety consideration in environments where H2S is present.

While hydrogen sulfide may not always present an immediate fire hazard in low concentrations, its behavior as a flammable gas emphasizes the need for caution, particularly in confined spaces or under pressure. It’s essential to monitor for H2S in various industrial and environmental settings to prevent fire and explosion hazards, which is vital for safety protocols concerning handling and storage of this compound.