Although lube oils used in the main lubricating service systems should have a relatively high flash point to avoid ignition, they can create smoke and fire hazards when they __________.

In USCG Marine Engineering General Subjects, for engine room systems involving 'Although lube oils used in the main lubricating service systems should have a relatively high flash point to avoid ignition, they can create smoke and fire hazards when they', the standard operating requirement is: 'come in contact with extremely hot surfaces'.