They use it in swimming pools where people get it on there skin. Wear gloves if you have to put your hand in it, in other words use your brain. I've used every form of rust remover, I have vats of molasses, electrolysis tanks, muriatic acid tanks and I use osfo stuff. If you have a little or delicate part use the evoporust product $$$$. If you need fast, muriatic is the one, what you buy now is diluted but I still cut in half. Wash good when removed then spray with Crud Cutter, sold in paint stores, it will keep it from rusting back. Did my lca about three weeks ago, still no rust back, in about two months I'll paint. Remember, they all have there good points and bad points. After the muriatic been used awhile and lost its power I mix it with weed killer to get the stubborn grass out of my driveway. The ph just burns it up. I can hear the tree huggers now.