Ultra One Safest Rust Remover SRR.C Attacks rust only nothing else. SSR.C Will not affect your skin, clothing, plastics, wood, rubber, wiring, etc. SSRC. Is used as a dipping solution or as a recycling spray for rusted parts. SSR.C Can be filtered and reused til spent. SSRC. Is water based, biodegradable and safe for the environment when filtered.