Level A
Level A protection should be used when the hazardous substance requires the highest level of protection for skin, eyes, and the respiratory system.

Level A protection should be used when site operations and work functions involve a high potential for splash, immersion, or exposure to unexpected vapors, gases, or particulates of materials that are harmful to skin or capable of being absorbed through the skin.
 

Level B
Level B protection should be used when the type and atmospheric concentration of substances identified require a high level of respiratory protection, but less skin protection.

Level B protection should be used when vapors and gases are not suspected of containing high levels of chemicals harmful to skin or capable of being absorbed through the skin.
 

Level C
Level C protection should be used when liquid splashes or other direct contact will not adversely affect or be absorbed through any exposed skin.