HAZWOPER Hazard ID 4 — Questions and Answers
Question 1: Which OSHA standard establishes requirements for hazard communication in the workplace, including labels and SDSs?
- 29 CFR 1910.120
- 29 CFR 1910.1200 (Correct answer)
- 29 CFR 1926.65
- 29 CFR 1910.134
Correct answer: 29 CFR 1910.1200
29 CFR 1910.1200 is OSHA's Hazard Communication Standard (HazCom), which governs chemical labeling, SDSs, and employee training.
Question 2: When assessing a suspicious package during emergency response, which of the following is a key chemical hazard indicator?
- Package is sealed with standard packing tape
- Oily stains, unusual odors, or crystals forming around the container (Correct answer)
- Package weighs more than 10 pounds
- Shipping label is printed rather than handwritten
Correct answer: Oily stains, unusual odors, or crystals forming around the container
Physical clues such as oily residue, crystalline deposits, discoloration, or unusual odors suggest chemical contamination or instability.
Question 3: In the context of HAZWOPER, what does the term 'secondary contamination' mean?
- A second chemical release occurring after the initial event
- Transfer of hazardous substances from a contaminated person or item to an uncontaminated one (Correct answer)
- A hazard identified after the initial site survey is completed
- Contamination found in groundwater below the surface
Correct answer: Transfer of hazardous substances from a contaminated person or item to an uncontaminated one
Secondary contamination occurs when hazardous materials are transferred from a contaminated source to personnel, equipment, or areas previously unaffected.
Question 4: What does a CGI/LEL meter reading of 10% LEL indicate at a HAZWOPER site?
- The atmosphere contains 10% of the chemical by volume
- The flammable vapor concentration is 10% of the lower explosive limit (Correct answer)
- Workers must immediately evacuate because the atmosphere is explosive
- Oxygen levels have dropped to 10%
Correct answer: The flammable vapor concentration is 10% of the lower explosive limit
A CGI reading of 10% LEL means the vapor concentration is 10% of the minimum concentration needed to support combustion — action levels are typically set at 10-25% LEL.
Question 5: Which chemical property helps predict whether a substance will float on or sink below water, affecting spill containment strategy?
- Vapor pressure
- Specific gravity (Correct answer)
- Ionization potential
- Auto-ignition temperature
Correct answer: Specific gravity
Specific gravity compares a substance's density to water; substances with specific gravity less than 1.0 float, while those greater than 1.0 sink.
Question 6: What is the significance of the TLV-STEL value for a chemical?
- The maximum concentration allowed over an 8-hour workday
- The concentration immediately dangerous to life and health
- The maximum concentration allowed for a 15-minute short-term exposure (Correct answer)
- The concentration at which 50% of test animals are killed
Correct answer: The maximum concentration allowed for a 15-minute short-term exposure
The Threshold Limit Value - Short-Term Exposure Limit (TLV-STEL) is the maximum airborne concentration to which workers may be exposed for up to 15 minutes without adverse effects.
Question 7: Which of the following BEST describes a 'reactive' hazardous material as classified under RCRA?
- A material that ignites spontaneously at room temperature
- A material that is normally unstable and may react violently, detonate, or generate toxic gases (Correct answer)
- A material with a pH below 2 or above 12.5
- A material that contains more than 0.5 mg/L of lead
Correct answer: A material that is normally unstable and may react violently, detonate, or generate toxic gases
RCRA defines reactive waste as unstable materials that can detonate, explode, react violently with water, or generate toxic fumes under normal conditions.
HAZWOPER Hazard ID 4
Which OSHA standard establishes requirements for hazard communication in the workplace, including labels and SDSs?