A scavenger comprising a formaldehyde sulfoxylate may be used to scavenge hydrogen sulfide (H2S) from systems that are brine or mixed production. Suitable formaldehyde sulfoxylates include, but are not necessarily limited to, sodium formaldehyde sulfoxylate, zinc formaldehyde sulfoxylate, and calcium formaldehyde sulfoxylate, potassium formaldehyde sulfoxylate, magnesium formaldehyde sulfoxylate, iron formaldehyde sulfoxylate, copper formaldehyde sulfoxylate, alkene aldehyde sulfoxylates, and combinations thereof.