Speaking of dangerous chemicals used in the painting of aircraft Boeing has a special facility where they strip all of the contaminants on the airframe prior to painting using MEK, which is sprayed on the skin. I believe all of the MEK is then collected, strained and reused.
For paint removal a firm has come up with a system where dry ice crystals are sprayed on the painted surface under high pressure much like sand blasting. The localized cold fractures the paint bond with the skin surface and it is blown away.
