More generically known as respirators, gas masks are also an important part of industrial safety on a daily basis. They protect workers against everything from flour dust in a grain elevator to the damaging organic chemicals in paint spray.
When most people think about gas masks or respirators, what they usually envision is a tight-fitting plastic or rubber face mask with some sort of filter cartridge. The mask covers the nose and mouth. These are called half-mask air-purifying respirators.
Depending on the chemical or biological agents in the environment, a half mask may not be sufficient because the eyes are very sensitive to chemicals and offer an easy entry point for bacteria. In this case, a full-face respirator is called for. It provides a clear face mask or clear eye pieces that protect the eyes as well.
The problem with air-purifying respirators is that any leak in the mask makes them ineffective. The leak could come from a poor fit between the mask and the user’s face, or from a crack or hole somewhere on the mask. Two other types of respiratory systems solve the leak problem. The supplied-air respirator uses the same sort of filter cartridge found in an air-purifying respirator. However, instead of placing the filter directly on the mask and requiring the user’s lungs to suck air through it, the filter attaches to a battery-operated canister.