Grounding and bonding

When liquids flow through hoses or are poured, static charge can build up on the liquid and on the containers. If the charge is released as a spark in the presence of flammable vapor, a fire or explosion may follow. This is a particular risk with low-conductivity liquids, such as many hydrocarbon solvents, and when the vapor space holds a mixture between the Lower explosive limit (LEL) and Upper explosive limit (UEL).

Bonding is done with a clip-on conductive wire between the dispensing container and the receiving container, so charge cannot jump between them. Grounding then connects the bonded pair to a verified earth ground point. The connections need clean metal contact, since paint, rust or dirt can break the path. Plastic containers cannot be grounded in the same way and need special procedures or approved designs.

The practice applies to filling drums, portable cans, totes and tanks, and to transfers from a Drum or IBC tote. Slow filling rates, bottom or dip-pipe filling to reduce splashing, and avoiding free-falling liquid also help. Static controls complement other measures such as removing ignition sources, ventilation and keeping amounts small.

Inspect the clamps and cables regularly, and connect them before opening containers and before liquid starts to move; disconnect only after flow has stopped. Check the SDS for statements about static discharge, which often appear in Section 7 and in the precautionary statements P240 ("Ground/bond container and receiving equipment.") and P243 ("Take precautionary measures against static discharge."). Relevant materials are Flammable liquid products with a low Flash point.