Safety Trained Supervisor Basic Industrial Hygiene 2 — Questions and Answers
Question 1: What are the four main routes of entry for hazardous substances?
- Inhalation, ingestion, absorption, and injection (Correct answer)
- Inhalation, ingestion, contact, and radiation
- Breathing, swallowing, touching, and smelling
- Airborne, waterborne, foodborne, and bloodborne
Correct answer: Inhalation, ingestion, absorption, and injection
The four routes are inhalation, ingestion, absorption through skin/eyes, and injection through wounds.
Inhalation is the most common occupational exposure route. Understanding these routes is essential for selecting appropriate controls and PPE for each chemical hazard.
Question 2: What is the difference between TLV and PEL?
- TLVs are legally enforceable while PELs are advisory
- TLVs are ACGIH recommended guidelines while PELs are legally enforceable OSHA limits (Correct answer)
- No practical difference
- TLVs for chemicals only while PELs for physical agents
Correct answer: TLVs are ACGIH recommended guidelines while PELs are legally enforceable OSHA limits
TLVs are ACGIH recommended guidelines; PELs are legally enforceable OSHA limits.
Many OSHA PELs have not been updated since 1971 and may be less protective than current TLVs. Best practice recommends following the more protective of the two limits.
Question 3: What type of industrial hygiene hazard is whole-body vibration?
- Chemical hazard
- Biological hazard
- Physical hazard (Correct answer)
- Ergonomic hazard
Correct answer: Physical hazard
Whole-body vibration is a physical hazard along with noise, radiation, and temperature extremes.
Physical hazards include noise, vibration, radiation, temperature, and pressure. Whole-body vibration from heavy equipment can cause lower back disorders and spinal damage.
Question 4: What is the purpose of biological monitoring in industrial hygiene?
- Testing for infectious diseases
- Measuring the actual dose absorbed by a worker through blood, urine, or exhaled air analysis (Correct answer)
- Monitoring mold and bacteria growth
- Tracking attendance and sick days
Correct answer: Measuring the actual dose absorbed by a worker through blood, urine, or exhaled air analysis
Biological monitoring measures actual internal dose through biological specimens for a complete exposure picture.
Unlike air monitoring, biological monitoring accounts for all exposure routes. ACGIH publishes Biological Exposure Indices as reference values. It is especially valuable for substances significantly absorbed through skin.
Question 5: What does IDLH stand for and why is it significant?
- Immediate Danger to Life or Health
- Immediately Dangerous to Life or Health requiring evacuation and specialized respiratory protection (Correct answer)
- Industrial Determination of Lethal Hazards
- Integrated Data on Lifetime Health
Correct answer: Immediately Dangerous to Life or Health requiring evacuation and specialized respiratory protection
IDLH is the maximum concentration from which a worker could escape within 30 minutes without irreversible effects.
At IDLH concentrations, only positive-pressure SCBA or supplied-air respirators with escape bottles provide adequate protection. Air-purifying respirators are never appropriate for IDLH conditions.
Question 6: Which sampling method best determines personal exposure over a full shift?
- Grab sampling at random times
- Area sampling near the process
- Personal sampling with pump and collection media in the breathing zone (Correct answer)
- Direct-reading instrument at the workstation
Correct answer: Personal sampling with pump and collection media in the breathing zone
Personal sampling in the breathing zone provides the most accurate full-shift exposure assessment.
The collection device is positioned within a 10-inch hemisphere around the nose and mouth, capturing concentrations wherever the worker moves. Personal sampling results are what OSHA uses for compliance.
Safety Trained Supervisor Basic Industrial Hygiene 2
What are the four main routes of entry for hazardous substances?