A decrease in the flash point of diesel engine lube oil indicates the lube oil has become __________.
Official USCG Answer & Rule Citation
Correct Answer: Option C — diluted with fuel oil
Fuel oil dilution lowers the flash point of crankcase lubricating oil because volatile lighter ends from diesel fuel mix with the sump oil, presenting a severe operational fire and explosion hazard.
100% Free & Open Access — No daily limits, paywalls, or gated answers on BrightMariner.