Free CRST Industrial Hygiene and Occupational Health Questions and Answers

Question 1

What is the primary purpose of a Local Exhaust Ventilation (LEV) system in an industrial setting?

Accepted Answer

To capture and remove contaminants at their source.

Answer

LEV systems are designed to capture airborne contaminants at or near their point of generation, preventing them from entering a worker's breathing zone. This is a highly effective engineering control because it removes the hazard before it can spread throughout the workplace. General ventilation, by contrast, only dilutes the contaminant.

Question 2

Which of the following is the best example of an administrative control for reducing noise exposure?

Accepted Answer

Rotating workers through high-noise and low-noise areas during a shift.

Answer

Administrative controls involve changing work practices or procedures to limit exposure. Job rotation moves workers out of high-noise areas after a set period, limiting their total daily dose of noise. Providing earplugs is PPE, enclosing machinery is an engineering control, and replacing equipment is substitution.

Question 3

The term 'Threshold Limit Value' (TLV) refers to which of the following?

Accepted Answer

A guideline published by the ACGIH for recommended occupational exposure levels.

Answer

TLVs are guidelines established by the American Conference of Governmental Industrial Hygienists (ACGIH) for airborne substance exposure. While many Canadian jurisdictions adopt or refer to TLVs in their regulations, making them legally enforceable, the term itself originates from the ACGIH as a recommended guideline, not a law.

Question 4

What are the three primary routes of entry for chemical contaminants into the human body in a workplace?

Accepted Answer

Inhalation, skin absorption, and ingestion.

Answer

The three main pathways for industrial chemicals to enter the body are inhalation (breathing), absorption (through skin or eyes), and ingestion (swallowing). While injection is a possible route, it is far less common in most occupational settings compared to the other three.

Question 5

A direct-reading instrument is most suitable for which of the following sampling applications?

Accepted Answer

Obtaining an instantaneous measurement of a gas concentration in a specific area.

Answer

Direct-reading instruments provide immediate, real-time measurements of a contaminant's concentration. This is ideal for tasks like checking for gas leaks, assessing conditions before entering a confined space, or identifying peak exposure tasks. They are generally not used for collecting samples for later analysis or calculating official 8-hour TWA exposures.

CRST - Canadian Registered Safety Technician Practice Test

CRST - Canadian Registered Safety Technician Practice Test

Free CRST Industrial Hygiene and Occupational Health Questions and Answers