Rust removers you buy over the counter may contain phosphoric acid and oxalic acid. These chemicals are poisonous and corrosive. The rust removers also contain solvents, which are flammable. Do not use on silk, wool or rayon; you'll rot the fabric.
Alternative
Treat rust stains on clothes with lemon juice and then rinse. Use neat vinegar on baths and basins. Rust can be removed from cast-iron furniture by rubbing it with wire wool dipped in paraffin. Remove the paraffin by wiping it with cotton wool soaked in white spirit. Dry thoroughly, then paint with an oil-based paint to prevent the piece from going rusty again.
