Heavy-duty cleaners like Gojo contain less than 30 percent petroleum distillates, which do better in cleaning grease-heavy hands. To put it bluntly: petroleum cleans petroleum.
As weird as it sounds, the science behind it is fascinating. Petroleum distillates are derived from the distillation process, separating substances based on hydrocarbon content. Lighter ones like naphtha and kerosene float, while heavier ones like grease and lube settle at the bottom. Some of the lighter distillates don’t produce as strong of a scent as gasoline, reducing health risk.
Petroleum distillates are better solvents than water, partly due to its low surface tension. If you try to clean greasy hands with plain water, it may only spread the grease further since the two aren’t, on a molecular level, attracted to each other. It would take a lot of rubbing just to get rid of the grease.
Of course, using purely petroleum distillates on your hands isn’t an ideal way of hand washing. That’s why heavy-duty hand cleaners are often found with other cleaning agents such as oleic acid. Also known as omega-9 fatty acid, oleic acid is a common ingredient in hygiene products that facilitate in grime removal. It’s derived from plant and animal fat, making it safe.