CDS Safety Standards & Hazardous Material Handling 3 — Questions and Answers
Question 1: Which NFPA standard specifically addresses the control of flammable and combustible liquids during demolition operations?
- NFPA 10
- NFPA 30 (Correct answer)
- NFPA 72
- NFPA 101
Correct answer: NFPA 30
NFPA 30 (Flammable and Combustible Liquids Code) governs the handling and storage of these liquids, including during demolition.
Question 2: A demolition crew finds vermiculite insulation in a building's attic. What is the primary safety concern and required action?
- Treat it as a fire hazard and wet it down before removal
- Presume it contains asbestos and follow asbestos abatement protocols (Correct answer)
- Remove it with standard PPE as it contains only naturally occurring minerals
- Test only if the material is friable; otherwise proceed normally
Correct answer: Presume it contains asbestos and follow asbestos abatement protocols
Vermiculite from Libby, Montana is associated with asbestos contamination; it must be presumed to contain asbestos and handled accordingly.
Question 3: Under the EPA's RRP Rule, what is the required clearance testing threshold for lead dust on floors after demolition disturbs lead-based paint?
- 10 μg/ft²
- 40 μg/ft² (Correct answer)
- 100 μg/ft²
- 250 μg/ft²
Correct answer: 40 μg/ft²
EPA's RRP Rule requires post-work floor clearance of 40 μg/ft² or less for lead dust to confirm adequate cleanup.
Question 4: What type of fire extinguisher is appropriate for a Class D fire involving combustible metal swarf from demolition cutting operations?
- CO₂ extinguisher rated for Class C fires
- Dry chemical (ABC) extinguisher
- Dry powder extinguisher rated for Class D metals (Correct answer)
- Water mist extinguisher
Correct answer: Dry powder extinguisher rated for Class D metals
Class D fires involving combustible metals (e.g., magnesium, titanium) require a dry powder extinguisher specifically rated for Class D fires.
Question 5: What is the OSHA-required minimum frequency for air monitoring of silica dust when a demolition supervisor establishes that a task is on the Table 1 control list?
- Monitoring is required at least once per shift
- Monitoring is required at least once per month
- No air monitoring is required if Table 1 controls are fully implemented (Correct answer)
- Monitoring is required before each new task begins
Correct answer: No air monitoring is required if Table 1 controls are fully implemented
OSHA's silica standard allows employers who fully implement Table 1 engineering controls to skip air monitoring for those tasks.
Question 6: When demolishing a building with a wet sprinkler system, what must be done with the system before structural demolition begins?
- The system can remain active to suppress dust during demolition
- The system must be drained and properly disabled to prevent accidental discharge (Correct answer)
- Only the main riser valve needs to be shut off
- Sprinkler heads must be individually capped before work begins
Correct answer: The system must be drained and properly disabled to prevent accidental discharge
Active sprinkler systems must be fully drained and disabled before structural demolition to prevent uncontrolled water discharge that can cause structural instability.
Question 7: Under OSHA standards, what is the maximum permissible exposure limit (PEL) for mercury vapor in an 8-hour workday?
- 0.01 mg/m³
- 0.05 mg/m³ (Correct answer)
- 0.1 mg/m³
- 1.0 mg/m³
Correct answer: 0.05 mg/m³
OSHA sets the PEL for mercury vapor at 0.05 mg/m³ (50 μg/m³) as a ceiling limit for an 8-hour workday.
CDS Safety Standards & Hazardous Material Handling 3
Which NFPA standard specifically addresses the control of flammable and combustible liquids during demolition operations?