Which hazard category is explicitly listed under double barrier protection?

• A. Hazardous gases/ liquids
• B. Non-hazardous solids
• C. Clean water
• D. Food items

Answer: (A)

Double barrier protection relies on two independent containment layers to prevent a release of hazardous material. This approach is explicitly applied to materials that pose real danger if they escape, such as hazardous gases and liquids, because their potential to vent, ignite, or contaminate the environment requires redundancy, continuous monitoring, and quick isolation. The other categories—non-hazardous solids, clean water, and food items—do not typically call for two separate barriers in the same safety sense, as they are not associated with the same level of hazard or containment risk. Therefore, the category explicitly listed under double barrier protection is hazardous gases and liquids.