As little as 1 percent of hydrochloric acid in solution can cause pink or orange spots in carpets. Stomach acid is essentially 10 percent hydrochloric acid. Some toilet bowl cleaners contain as much as 10 percent hydrochloric acid. Corn and callous removers contain phosphoric and glacial acetic acid. Tile cleaners also contain acid which can cause color changes as do certain foot preparations.
Hydrochloric acid can cause some red dyestuffs to turn bright blue.
Strong alkaline substances are equally damaging when they come in contact with carpets and other textile products. Oven cleaners may get their cleaning power from sodium hydroxide. Strong alkalis will destroy the fabric itself, as well as cause spots and stains. Urine Stains Urine from children and pets can cause permanent stains to some fabrics if not promptly removed. The characteristic ammonia-like odor will be replaced by a musty odor.