NSC Chemical Safety 5 — Questions and Answers
Question 1: Which agency must be notified when a reportable quantity of a hazardous substance is released into the environment?
- OSHA only
- The National Response Center (NRC) and local emergency planning committees (Correct answer)
- Only the local fire department
- The chemical manufacturer directly
Correct answer: The National Response Center (NRC) and local emergency planning committees
Under CERCLA and EPCRA, releases of hazardous substances at or above reportable quantities must be reported to the National Response Center and applicable local/state agencies.
Question 2: A 'sensitizer' chemical is hazardous because it can:
- Explode when exposed to heat
- Cause an allergic reaction in subsequent exposures after initial sensitization (Correct answer)
- React with skin oils to produce toxins
- Deplete oxygen in confined spaces
Correct answer: Cause an allergic reaction in subsequent exposures after initial sensitization
Sensitizers cause an allergic immune response; after initial exposure sensitizes a person, even tiny future doses can trigger severe reactions.
Question 3: What is the primary hazard of mixing bleach (sodium hypochlorite) with ammonia-based cleaners?
- Production of flammable hydrogen gas
- Generation of toxic chloramine gases (Correct answer)
- Violent thermal explosion
- Formation of a corrosive acid
Correct answer: Generation of toxic chloramine gases
Mixing bleach with ammonia produces chloramine gases, which are toxic and can cause respiratory damage, chest pain, and at high levels, pulmonary edema.
Question 4: Under OSHA's Globally Harmonized System (GHS), which signal word indicates a LESS severe hazard category?
- Danger
- Caution
- Warning (Correct answer)
- Notice
Correct answer: Warning
GHS uses 'Warning' for less severe hazard categories and 'Danger' for more severe ones; only these two signal words are used on GHS-compliant labels.
Question 5: Which of the following is a key requirement when storing flammable liquids in a safety cabinet?
- The cabinet must be refrigerated
- The cabinet must be grounded and bonded and kept away from ignition sources (Correct answer)
- The cabinet door must remain open for ventilation
- Flammable liquids must be mixed with water before storage
Correct answer: The cabinet must be grounded and bonded and kept away from ignition sources
Flammable liquid storage cabinets must be properly grounded and bonded to prevent static discharge and kept away from ignition sources to prevent fires.
Question 6: What does 'IDLH' stand for in chemical safety, and what is its significance?
- Immediately Dangerous to Life or Health — the concentration posing immediate risk of death or serious health effects (Correct answer)
- Integrated Daily Limit for Hazards — the maximum daily chemical intake
- Inhalation Dose Limit for Humans — the 8-hour average exposure value
- Incident Detection Level for Hazardous materials — the sensor alarm threshold
Correct answer: Immediately Dangerous to Life or Health — the concentration posing immediate risk of death or serious health effects
IDLH (Immediately Dangerous to Life or Health) is the maximum concentration from which a worker could escape within 30 minutes without impairing escape or suffering irreversible health effects.
Question 7: Which of the following best describes 'engineering controls' in chemical safety?
- Written procedures and safety rules for handling chemicals
- Physical changes to the work environment that reduce or eliminate chemical hazards at the source (Correct answer)
- Personal protective equipment worn by the worker
- Training programs that teach safe chemical handling
Correct answer: Physical changes to the work environment that reduce or eliminate chemical hazards at the source
Engineering controls include physical modifications like ventilation systems, enclosed processes, and substitution that reduce hazard exposure at the source without relying on worker behavior.
NSC Chemical Safety 5
Which agency must be notified when a reportable quantity of a hazardous substance is released into the environment?