What does TLV stand for?

• A. Threshold Limit Values
• B. Total Limit Values
• C. Transport Limit Vector
• D. Trade Limit Variable

Answer: (A)

TLV stands for Threshold Limit Values. These are exposure guidelines used in occupational safety to indicate the level of a hazardous substance a worker can be exposed to without expected harm, over a defined period. TLVs come from the ACGIH and include forms like TLV-TWA (time-weighted average), TLV-STEL (short-term exposure limit), and TLV-C (ceiling value). They help employers set exposure controls and protective measures, though they are guidance values rather than legally enforceable OSHA limits (which are PELs). The plural form “Values” is the standard usage, which is why this option is correct. The other terms don’t match the established terminology for TLV.