Skin is not a surface

In detail

Cleaning objects and cleaning hands are different questions, but they collide constantly: a person with engine oil, paint or adhesive on their hands reaches for whatever removed it from the garage floor. The reason that is a mistake is specific rather than squeamish. The outer layer of skin works because of a lipid matrix between its cells — an oily barrier that holds water in and keeps other things out. Every substance that dissolves oils dissolves that barrier too, and it does not distinguish. White spirit, acetone, petrol, thinners and strong alkaline degreasers all strip it, and the result is not a burn that announces itself but dryness, cracking, and a barrier that admits the next thing more readily. The regulator's sheets say so directly: acetone causes skin irritation, and prolonged or repeated exposure causes drying and cracking with redness. Several are also absorbed THROUGH the skin — oxalic acid, acetone and cresols are all treated as passing through it. Purpose-made hand cleansers use mild surfactants and abrasives rather than solvents. None of this is medical advice; where a substance has reached skin, the label and the poisons service govern.

Why

• Hand cleanser is explained by Skin is not a surface
• Acetone is explained by Skin is not a surface
• White spirit is explained by Skin is not a surface