CIH Toxicology and Chemical Hazards 3

Question 1

When two chemicals together produce a toxic effect greater than the sum of their individual effects, this interaction is called:

Accepted Answer

Synergism

Answer

Synergism occurs when the combined toxic effect of two chemicals exceeds the sum of their individual effects (greater than additive).

Question 2

The IDLH (Immediately Dangerous to Life or Health) value for a substance represents:

Accepted Answer

The maximum concentration from which a worker could escape within 30 minutes without irreversible harm

Answer

IDLH is the maximum airborne concentration from which an unprotected worker could escape within 30 minutes without irreversible health effects or escape impairment.

Question 3

Which mechanism explains how carbon monoxide causes toxicity?

Accepted Answer

High affinity binding to hemoglobin preventing oxygen transport

Answer

Carbon monoxide binds to hemoglobin with approximately 200-240 times the affinity of oxygen, forming carboxyhemoglobin and preventing oxygen delivery to tissues.

Question 4

Methemoglobin-forming agents like aniline cause toxicity primarily by:

Accepted Answer

Oxidizing ferrous (Fe2+) iron in hemoglobin to ferric (Fe3+) form

Answer

Methemoglobin-forming agents oxidize the iron in hemoglobin from the ferrous (Fe2+) to ferric (Fe3+) state, which cannot carry oxygen.

Question 5

A substance classified as a 'sensitizer' is one that:

Accepted Answer

Induces an allergic response after prior sensitization exposure

Answer

A sensitizer causes an allergic response upon re-exposure after an initial sensitization period, not on first contact.

CIH - Certified Industrial Hygienist Exam Practice Test

CIH - Certified Industrial Hygienist Exam Practice Test

CIH Toxicology and Chemical Hazards 3