What is secondary containment?

• A. A device to monitor air quality
• B. The primary containment for a chemical
• C. A spill pad and absorbent system
• D. An additional containment system to contain spills/leaks from primary containers, preventing environmental release

Answer: (D)

Secondary containment is an extra containment system that surrounds or sits beneath the primary container to catch spills or leaks, preventing them from reaching the environment. It acts as a backup layer so if the container leaks, the liquid is held long enough to prevent soil, water, or air contamination. Examples include spill containment pallets, trays or basins, berms, or double-walled vessels that create a built-in space to collect leaks.

The other ideas don’t fit because monitoring air quality isn’t containment, the primary container is the main container that actually holds the chemical, and a spill pad or absorbent system is used for cleanup after a spill rather than preventing release in the first place.