Exam Questions And Correct Answers

FDNY W42 Supervision of Handling and Use of Corrosives and Oxidizers Practice Exam Questions And Correct Answers (Verified Answers) Plus Rationales 2026 Q&A | Instant Download Pdf

Q1. According to FDNY regulations, which document must be available on- site for every corrosive or oxidizer container?

• DOT Shipping Manifest
• Safety Data Sheet (SDS)
• Vendor Purchase Order
• Transporter Certification

Rationale: SDS sheets are required for all hazardous materials to provide

hazard, handling, and emergency information.

Q2. Corrosive liquids are primarily defined by their ability to: 1 / 4

• React with nitrogen
• Burn when exposed to flame
• Destroy living tissue or metal through chemical action
• Produce flammable vapors

Rationale: Corrosives cause destruction of materials or tissue upon contact.

Q3. Oxidizers are hazardous primarily because they:

• Freeze rapidly
• Neutralize acids
• Support or accelerate combustion
• Become inert when heated

Rationale: Oxidizers release oxygen or similar agents, increasing fire

intensity.

Q4. The W42 Certificate of Fitness holder must be present:

• Only during shipping
• Only during storage
• During handling, dispensing, and use of corrosives or oxidizers
• Only during emergencies

Rationale: FDNY requires supervision during all active operations involving

these materials.

• / 4

Q5. Corrosive storage rooms must be equipped with:

• Carbon monoxide alarms
• Class K extinguishers
• Secondary containment and spill control materials
• Natural gas shutoff valves

Rationale: Secondary containment mitigates leaks and accidental releases.

Q6. What pH range typically defines corrosive liquids?

A. 4–6

B. 6–10

• ≤2 or ≥12.5
• 7 only

Rationale: Extremely high or low pH values classify corrosive substances.

Q7. Which class of extinguishers is required where oxidizers are used?

• Class K
• Class D
• Class ABC
• Class B only

Rationale: ABC extinguishers handle most oxidizer-related fires.

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Q8. Mixing acids and bases may result in:

• The creation of flammable solids
• Violent heat release and splattering
• Rapid cooling
• Material becoming inert

Rationale: Neutralization reactions produce heat that may cause

splashing.

Q9. When transporting corrosive containers on-site, they must be:

• Dragged carefully
• Secured on a corrosion-resistant cart
• Carried by hand
• Stacked in tall piles

Rationale: Proper carts prevent spills and protect the handler.

Q10. Oxidizers must never be stored near:

• Clean glassware
• Organic materials or combustibles
• Fire extinguishers
• First aid kits

Rationale: Oxidizers can react dangerously with organic or combustible

materials.

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