When transferring flammable or combustible liquids, what precaution must be taken to prevent static electricity?

• A. Wet the floor with water.
• B. Insulate the containers.
• C. Provide a bonding wire between the containers.
• D. Use only a non-metallic transfer hose.

Answer: (C)

Preventing static electricity during transfer of flammable liquids hinges on equalizing electrical potential between containers. When liquids flow, charges can separate and build up on surfaces and within hoses. If there isn’t a conductive path for these charges to flow to the same potential, a spark can occur and ignite vapors. A bonding wire between the containers provides that path, allowing the charge to move freely and equalize, which minimizes the risk of a discharge igniting the vapors. Grounding the system enhances this protection by directing any charges to earth. The other options don’t address charge equalization: wetting the floor doesn’t guarantee a continuous conductive path between containers; insulating the containers would trap static charges; and a non-metallic transfer hose reduces conductivity and cannot reliably balance charges.