The use of protective equipment
1、The use of filtered gas mask requirements
When the oxygen content in the air of the workplace is greater than or equal to 19%, and the concentration of hydrogen sulfide is less than 10mg/m³, the filtered gas mask with gray tank (hydrogen sulfide) can be used.

Notes on the use of filtered gas masks.
Gas tightness check before use (after the user puts on the mask, block the air inlet with your hand and inhale hard at the same time. If you feel the occlusion is not breathable, the mask is basically airtight)
must remember to remove the rubber plug of the air inlet hole at the bottom of the canister in advance when using, otherwise it is prone to asphyxiation accidents.
pay attention to prevent the ventilation hole at the bottom of the canister and the hood exhalation valve from being blocked by foreign objects.
Emergency wear: In case of an accident, the user should immediately hold his breath, quickly take out the hood and put it on, when confirming that the edge of the hood fits tightly with the head, then exhale the remaining air in the body, and then make a simple airtightness test before putting it into use.
2、The use of air respirator requirements
When the oxygen content in the air of the workplace is less than 19%, or the concentration of hydrogen sulfide is greater than or equal to 10mg/ m³. Must use isolated gas mask, currently commonly used for self-contained air respirator.

Precautions for the use of air respirators:
Pressure test before use, the cylinder pressure should not be less than 28MPa (open the cylinder valve, turn the cylinder handwheel in the counterclockwise direction, at least 2 turns. Also observe the pressure gauge reading, the cylinder pressure should be no less than 28MPa, otherwise it should be replaced with a cylinder filled with compressed air).
The pressure gauge should be fixed at the shoulder strap of the air respirator, so that it is easy to observe the pressure indication value at any time to determine the remaining air in the cylinder.
Checking the seal of the mask, which must ensure that there is no hair or whiskers, etc. between the rubber sealing surface and the skin.
When you hear the alarm sound, you should immediately prepare to end working in the danger zone and leave the danger zone as soon as possible (when air is consumed in the cylinder to 5.5MPa ± 0.5MPa, the alarm will sound to remind the user that there is at most 16% air left in the cylinder).