Hardhat, gloves, respirator as needed, spark-proof tools, flame-retardant jumpsuit. Also, before loading the cargo into empty pre-cleaned compartments, each ca

Hardhat, gloves, respirator as needed, spark-proof tools, flame-retardant jumpsuit. Also, before loading the cargo into empty pre-cleaned compartments, each cargo hold first needs to be physically inspected so it's good to have an oxygen meter reading before you descend into the darkness with your gear using your expolosion-proof flashlight. Otherwise it was typically required for one of the crew to fully enter beforehand to prove survivability. Not as bad as a full oil tanker having strong H2S vapors when you open a hatch, emanating from wherever the crude is not completely sealed from the atmosphere. Now the crude oil is a natural source of PAH compounds which of course the heaviest polycyclics are concentrated into the black fuel oils and asphalts, as the lighter hydrocarbons are removed in the refinery by distillation to largely become LPG, gasoline and diesel fuel. In the fuels the PAHs are mainly significant in the diesel-range products with bicyclics and tricyclics sometimes being prominent. The toluene and benzene are monocyclic aromatic hydrocarbons. Just as dangerous as a gasoline cargo, but you want to take better care of it because it's too expensive to burn. As a reminder, often commodity vegetable oils and animal tallow are loaded into compartments previously containing benzene and things like that, and after the industrial chemicals were exported, the return trip will be with agricultural product. Vessel personnel recognize these strong solvents as leaving their cargo holds spotless after discharge, with no further serious cleaning required before expediting the next load. OTOH in a good US port after these chemical tankers return and discharge the edible oils at nearby agricultural docks, we require some fairly extensive cleaning and verification before risking a load of sensitive chemical raw materials.