All of the following are considered hazardous gas materials EXCEPT:

Diesel fuel is not classified as a hazardous gas material like the other options listed. Chlorine, hydrogen, and anhydrous ammonia are all recognized as hazardous gases due to their properties and potential health risks when released into the environment.

Chlorine is a highly reactive and toxic gas, often used in water treatment, but it can cause severe respiratory problems and other health issues upon exposure. Hydrogen is flammable and can form explosive mixtures in air, leading to hazards during leaks or spills. Anhydrous ammonia is also a gas at room temperature and is known for its strong irritant properties, causing burns to the skin and respiratory tract.

On the other hand, diesel fuel primarily exists as a liquid and does not possess the same immediate gas-related hazards as the other substances listed. While diesel fuel can pose fire and environmental risks, it is not classified under hazardous gases, which often require specific handling protocols in emergency situations.