What toxic gas is produced when burning wool?

When wool is burned, it produces hydrogen cyanide, which is a highly toxic gas. Wool is a protein fiber primarily composed of keratin, and when it undergoes combustion, especially in conditions with insufficient oxygen, it can decompose into ammonia and hydrogen cyanide.

Hydrogen cyanide is particularly dangerous because it inhibits the body's ability to use oxygen, leading to severe health risks, including unconsciousness and death, when inhaled in sufficient quantities. The production of this gas is a significant concern in fire safety, especially in environments where woolen materials are used, as awareness of potential hazards is crucial during fire inspections and safety planning.

The other options, while potentially hazardous in different contexts or with different materials, do not accurately represent the primary toxic gas produced when burning wool. This highlights the necessity of understanding the combustion products related to specific materials in fire inspection practices.