Which NFPA standard primarily focuses on vapor-protective ensembles?

The correct answer centers on NFPA 1991, which specifically addresses vapor-protective ensembles designed for use in environments where toxic chemicals or hazardous materials may be present. This standard sets forth the requirements for materials, construction, and performance testing of protective clothing intended to guard against the penetration of vapors. The focus on vapor protection is critical for ensuring the safety of personnel working in hazardous conditions, making understanding this standard fundamental for safety officers.

Other NFPA standards listed address different types of protective gear or applications. For instance, NFPA 1990 pertains to chemically impermeable protective clothing, but it is not exclusively focused on vapor protection. NFPA 1971 is aimed at structural firefighting protective clothing and does not address vapor-specific guidelines. NFPA 1977, on the other hand, is relevant to wildland firefighting and protective clothing suitable for that environment, rather than specifically for vapor protection. Understanding these nuances helps in recognizing the importance of selecting the appropriate standards for various safety needs.