Free CIH Exam Questions That Helps Candidates Pass

Air is ~21% oxygen, ~78% nitrogen, ~1% other gases. CIHs monitor oxygen for confined space entry, where <19.5% is deficient and >23.5% is enriched.

Hand-arm vibration exposure is strongly associated with powered tools such as jackhammers, chainsaws, and grinders. Typing and writing do not produce sufficient vibration to cause HAVS. CIHs assess vibration exposure with accelerometers, compare to ACGIH TLVs, and recommend controls (anti-vibration gloves, administrative limits, tool maintenance).

Enclosing hoods, such as glove boxes, fully contain the source and are most effective. Canopy (A) relies on rising currents, slot (B) captures locally, and receiving (D) depends on directed contaminant motion. CIHs prioritize enclosures when feasible.

The EPA’s Lead and Copper Rule sets an action level of 15 ppb under the Safe Drinking Water Act. OSHA PEL (A), NIOSH REL (C), and TLVs (D) apply to workplaces. CIHs consider EPA standards for community lead exposures.

Carbon monoxide binds hemoglobin 200–250 times more strongly than oxygen, forming carboxyhemoglobin and impairing oxygen delivery. SO₂ (B), ozone (C), and NO₂ (D) are irritants but don’t bind Hb. CIHs use CO monitors, biological monitoring, and control strategies in combustion environments.