The "Grading Code" of Chemical Protective Suit: Protection Options for Different Risk Scenarios

NFPA 1991 (National Fire Protection Association Standard) and GB 24540-2020 (Chinese Personal Protective Equipment Standard) clearly define the core basis for classifying chemical protective clothing from Grade A to Grade D—the type, concentration, and exposure risk of hazardous media—and establish a professional framework for subsequent selection.

In high-risk scenarios (leaks of highly toxic gases, nuclear, biological and chemical contamination, splashes of high concentrations of strong acids and alkalis), Class A fully sealed airtight chemical protective suits must be used. The fabric should preferably be made of fluororubber or polytetrafluoroethylene composite material, which has strong corrosion resistance and impermeability. It must be used with a positive pressure self-contained breathing apparatus (SCBA) and must pass an airtightness test to ensure that there are no leaks at the joints of zippers, gloves and boot covers. This type of suit is commonly used in emergency rescue, nuclear industry maintenance and other scenarios.

For medium-risk scenarios (routine inspections of chemical workshops, concentrated pesticide spraying, and mild solvent contact), Class B or Class C breathable chemical protective suits are recommended. The fabric is mostly nitrile rubber coated fabric, which can block harmful substances while ensuring moisture permeability and avoid the stuffiness and discomfort of wearing it for a long time. Class C suits require a filter respirator and are suitable for environments with known harmful media and controllable concentrations.

For low-risk scenarios (minor chemical operations in the laboratory, inventory of ordinary chemical storage), Class D chemical protective suits are selected. They are mostly made of disposable non-woven fabric, which can block small amounts of liquid splashes. They are low in cost and easy to use.