CIH Toxicology & Health Risk Assessment

Question 1

LD50 is defined as the dose that causes death in what percentage of a test population?

Accepted Answer

50%

Answer

25%

Answer

75%

Answer

100%

Question 2

Which dose-response model assumes there is NO safe threshold for carcinogenic chemicals?

Accepted Answer

Linear non-threshold (LNT) model

Answer

Hormesis model

Answer

Threshold model

Answer

Sigmoid model

Question 3

What does the term 'carcinogen' specifically describe?

Accepted Answer

A substance capable of causing cancer

Answer

A substance that causes birth defects

Answer

A substance that causes liver damage

Answer

A substance that causes respiratory sensitization

Question 4

OSHA Permissible Exposure Limits (PELs) are based on which exposure duration?

Accepted Answer

8-hour time-weighted average (TWA)

Answer

15-minute short-term exposure

Answer

Instantaneous ceiling value

Answer

24-hour continuous exposure

Question 5

Which route of chemical exposure is most common in occupational settings?

Accepted Answer

Inhalation

Answer

Dermal absorption

Answer

Ingestion

Answer

Injection

Question 6

What does IDLH stand for in industrial hygiene?

Accepted Answer

Immediately Dangerous to Life or Health

Answer

Industrial Dose Limit for Hazardous materials

Answer

Integrated Daily Limit for Health

Answer

Instantaneous Detection Level for Hazards

Question 7

Acute toxicity is best characterized as an adverse effect resulting from:

Accepted Answer

A single or short-term high-level exposure

Answer

Low-level repeated exposure over years

Answer

Cumulative exposure over a lifetime

Answer

Exposure below the NOAEL repeatedly