There are two ways of providing respiratory protection against dusts, fumes and gases through activated carbon system.
These respirators purify the air using filters. The choice of filters depends on the level of contaminants in the air. Sometimes a combination of gas and dust filters is necessary. There are two types of air purifying respirators. One is non-powered and relies on the wearer to draw in air by inhaling. The other is powered and relies on a battery-powered motor to draw in the air.
This method delivers clean air from an uncontaminated source. Types of supplied air respirators include; air hose – air delivered through a hose by natural breathing or a pump; air-line – air delivered through an airline via a compressor or compressed air cylinders; and self-contained breathing apparatus (SCBA) – compressed air comes in cylinders strapped to the user’s body.