What is the difference between OSHA PEL and AIHA REL?

• A. PEL is a recommended exposure limit; REL is enforceable
• B. PEL is an enforceable regulatory limit; REL is a recommended exposure limit; PELs may be outdated
• C. PELs are outdated; RELs are not
• D. REL is legally binding; PEL is optional

Answer: (B)

The main idea here is enforceability versus guidance and how up-to-date the limits are. OSHA PELs are legally enforceable exposure limits set by the government; employers must comply with them or face enforcement actions. AIHA RELs, on the other hand, are recommended exposure limits provided by a professional society to guide exposure assessment and control decisions. They aren’t legally binding, but they reflect current scientific understanding and are often used when no PEL exists or when a REL is more protective than the existing PEL. A key point is that PELs can be outdated because they come from older regulatory processes, whereas RELs are updated more frequently to incorporate newer toxicology data.