Which items are included in Fume Category C?

• A. Kerosene (burned fuel), acid (unburned fuel), bitter.
• B. Water vapor, steam.
• C. Fresh paint scent.
• D. Ethanol and perfume.

Answer: (A)

The idea behind this question is how fumes are classified by hazard to guide action during a flight. Fume Category C includes substances that are known to produce strong irritant fumes from aircraft systems or fuels, and can also leave a bitter taste that signals exposure. The combination of kerosene (burned fuel), acid (unburned fuel), and a bitter sensation fits this higher-hazard group because these fumes are associated with significant airway and irritation risk in cabin air, and they are the kinds of contaminants you’d treat as urgent hazards.

The other odors listed are not considered Category C hazards in this context: water vapor or steam are not hazardous fumes in typical cabin conditions; a fresh paint scent is a transient environmental odor tied to VOCs from paints; and ethanol or perfume are common solvents/fragrances whose exposure risks are handled differently and do not define Category C. Recognizing the presence of fuels and acids (and the bitter-taste warning) helps determine the appropriate, precautionary response.