Originally Posted by
unworthy1
Most CLR brands contain a "blend of acid" that includes phosphoric and/or muriatic. Should be fine and effective if you follow the advice above.
CLR has been reformulated to avoid dumping P ions into the water. CLR ingredients are a blend of organic acids that are less likely to harm the item you're trying to derust/descale: Lactic acid, citric acid, and gluconic acid.