Muriatic (hydrochloric) acid is not effective as a degreaser, and should not be used to clean metal because it causes rapid rusting.


Lye (sodium hydroxide) is nontoxic. It is even used in food products. Just because something is caustic doesn't make it toxic.

Sodium hydroxide is an environmentally-friendly alternative to solvents for degreasing and methylene chloride (aircraft remover) for paint stripping.

The environmental/disposal issue encountered when using sodium hydroxide is caused by presence of the crud being removed in the waste liquid, not by the presence of sodium hydroxide.

One could dispose of the waste by first neutralizing the sodium hydroxide with hydrochloric acid. Sodium hydroxide + hydrochloric acid = table salt + water. The neutral liquid could then be evaporated to produce solid waste that could be disposed of in your regular trash.