First drain the used sump oil from warm engine, the drain plug should be reinserted and the engine refilled to the minimum oil level, then run the engine for 2 to 3 minutes under tick-over conditions, in order to circulate the oil and effectively wash the inner surfaces of the engine.

But the engine should not be run under load conditions while flushing oil is in use.

These products produce no adverse effects on health when properly handled and used. No special protections are suggested beyond attention to good personal hygiene including laundered oil-stock clothing and washing skin-contact areas with soap and water.