A vapor tight suit which resists permeation by most chemicals is a:

• A. Level A
• B. Level B
• C. Level C
• D. Level D

Answer: (A)

A vapor-tight, fully encapsulating chemical-protective suit with its own air supply provides the highest level of protection against chemical vapors. “Vapor-tight” means the suit blocks vapors from diffusing through the material and reaching the skin or entering the breathing zone, so it resists permeation by most chemicals. Because it includes a self-contained breathing apparatus, the wearer has an independent source of clean air, which is crucial when unknown or highly toxic vapors are present. This level is chosen for unknown hazards or highly concentrated vapor exposures, where dermal and inhalation protection must be maximized. Other options may protect against splashes or rely on external air supplies, but they do not seal the body or provide the same level of vapor protection, making them inappropriate for high-risk vapor environments.