Reference

Most OSHA PELs derive from 1968 ACGIH TLVs and have not been updated since 1971 — ACGIH updates TLVs annually. For many chemicals the TLV is 5–20× lower than the PEL, requiring a higher APF respirator. ANSI/ISEA Z88.2 directs employers to use the most protective OEL. This guide covers the practical selection implications.

NIOSH vs. OSHA Explained (2026 Guide): NIOSH (National Institute for Occupational Safety and Health) is a research and certification agency within the CDC that approves PPE and sets recommended exposure limits.