HMS Copper-Sheathed Naval Vessels

Humphrey Davy's 1836 copper-hull ships for British Navy to prevent barnacle growth — copper as biocide.

They have to have something to eat. In this case some bugs will reduce sulfur compounds and that's what they eat. Don't ask me, I'm not a biologist, but they call them SRBs — sulfur-reducing bacteria. It wasn't something we thought about in the corrosion literature until about 40, 45 years ago, when we saw the stuff in nuclear reactors. Now you read a report on corrosion in a tank, and half the metallurgists in the world say, oh it must be MIC. So now everything is MIC. In fact I had a case once that someone said was MIC on copper. Well wait a second — copper actually kills bugs. If you had a copper-hull ship — in 1836 Humphrey Davy made a copper-hull ship for the British Navy to get rid of all the barnacles that would grow on there. Copper kills organic things at very low concentration. So copper is toxic — you shouldn't be eating lots of copper, but there's not enough copper in copper water pipes; it doesn't corrode fast enough. They worry about the lead in the pipes from the solder. They took lead out of solder in Massachusetts in 1978. But copper is not a problem.