HSE Occupational Health and Hygiene 2

Question 1

What is the primary purpose of Threshold Limit Values (TLVs) established by ACGIH?

Accepted Answer

To define airborne concentrations of substances to which workers may be repeatedly exposed without adverse health effects

Answer

To set legal enforcement limits for OSHA inspectors

Answer

To establish the minimum exposure needed to trigger medical surveillance

Answer

To determine acceptable skin absorption rates for all chemicals

Question 2

Biological monitoring differs from air monitoring in occupational hygiene because it:

Accepted Answer

Assesses the actual absorbed dose in the worker's body

Answer

Measures contaminants only in the breathing zone

Answer

Only applies to physical hazards like noise

Answer

Replaces the need for engineering controls

Question 3

Which type of ventilation is most appropriate for controlling a highly toxic chemical released at a localized point source?

Accepted Answer

Local exhaust ventilation (LEV)

Answer

General dilution ventilation

Answer

Supply-only mechanical ventilation

Answer

Natural convection ventilation

Question 4

A worker is exposed to two chemical solvents simultaneously. Solvent A is at 60% of its TLV and Solvent B is at 50% of its TLV. What is the combined exposure index, and is it acceptable?

Accepted Answer

1.10 — not acceptable

Answer

0.55 — acceptable

Answer

0.60 — acceptable

Answer

1.10 — acceptable because each is below its own TLV

Question 5

What does the term 'permissible exposure limit' (PEL) refer to in the context of OSHA regulations?

Accepted Answer

A legally enforceable maximum airborne concentration of a substance

Answer

A voluntary guideline recommended by NIOSH

Answer

A short-term exposure limit applied only during peak tasks

Answer

The lowest concentration detectable by industrial hygiene instruments

Question 6

In the hierarchy of controls for occupational health hazards, which control is considered most effective?

Accepted Answer

Elimination of the hazard at the source

Answer

Administrative controls such as job rotation

Answer

Personal protective equipment

Answer

Warning signs and labels

Question 7

Work-related musculoskeletal disorders (WMSDs) are primarily caused by which combination of ergonomic risk factors?

Accepted Answer

Force, repetition, awkward postures, contact stress, and vibration

Answer

Extreme temperatures, ultraviolet radiation, and shift work

Answer

Noise exposure, chemical absorption, and poor lighting

Answer

High altitude, confined spaces, and excessive workload