Common Hazardous Gases

Carbon Monoxide

Carbon monoxide is an odorless, colorless, and toxic gas. Because it is impossible to see, taste, or smell, carbon monoxide can kill you before you are aware of your exposure. At lower levels of exposure, carbon monoxide causes mild effects that are often mistaken for the flu. These symptoms include headaches, dizziness, disorientation, nausea, and fatigue. The effects of carbon monoxide exposure can vary greatly from person to person depending on age, overall health, and the concentration and length of exposure.

Carbon monoxide is found in combustion exhaust, such as those produced by cars, trucks, and small gasoline engines (generators).

Hydrogen Sulfide

Hydrogen sulfide is a colorless, very poisonous, flammable gas with the characteristic foul odor of rotten eggs. It often results from the bacterial breakdown of organic matter in the absence of oxygen, such as in swamps and sewers (manholes).

Just a few breaths of air containing high levels of hydrogen sulfide gas can cause death. Lower, longer-term exposure can cause eye irritation, headache, and fatigue.

Diesel Exhaust

Diesel exhaust is a pervasive airborne contaminant in workplaces where diesel-powered equipment is used. Due to expanding use of diesel equipment, more and more workers are exposed to diesel exhaust. More than one million workers are exposed to diesel exhaust and face the risk of adverse health effects, ranging from headaches and nausea to cancer and respiratory disease.

To learn more about Construction Chemical Hazards visit our Construction Chemical Hazards & Toxic Substances Online Training web page.