HSE Occupational Health and Hygiene 3

Question 1

A short-term exposure limit (STEL) is defined as the maximum concentration a worker may be exposed to for up to how long without suffering irritation, tissue damage, or narcosis?

Accepted Answer

15 minutes

Answer

A STEL is the airborne concentration to which workers can be exposed for up to 15 minutes, no more than 4 times per day, with at least 60 minutes between exposures.

Question 2

Which type of respirator provides the highest level of respiratory protection for IDLH (immediately dangerous to life or health) atmospheres?

Accepted Answer

Self-contained breathing apparatus (SCBA) in positive-pressure mode

Answer

A positive-pressure SCBA provides the highest protection factor and is the required respirator for IDLH atmospheres because it supplies its own air supply.

Question 3

Noise-induced hearing loss (NIHL) is classified as which type of hearing loss?

Accepted Answer

Sensorineural hearing loss affecting the cochlea's hair cells

Answer

NIHL is a sensorineural hearing loss caused by permanent damage to the hair cells in the cochlea from excessive sound pressure levels.

Question 4

OSHA's Hearing Conservation Amendment requires hearing protection and audiometric testing when an employee's 8-hour TWA noise exposure equals or exceeds what level?

Accepted Answer

85 dBA

Answer

The OSHA action level is 85 dBA as an 8-hour TWA, at which point employers must implement a hearing conservation program including audiometric testing and hearing protection.

Question 5

What is the primary health risk associated with chronic inhalation of crystalline silica dust?

Accepted Answer

Silicosis (irreversible fibrotic lung disease)

Answer

Chronic inhalation of respirable crystalline silica causes silicosis, an irreversible and potentially fatal fibrotic lung disease, and also increases lung cancer risk.

(HSE) Certified Health Safety Environment Practice Test

(HSE) Certified Health Safety Environment Practice Test

HSE Occupational Health and Hygiene 3