Two drums were pulled from the Chauga River in Oconee County on Thursday.
County hazardous materials chief Bobby Williams says the two 35-gallon drums were carrying labels saying they contained sodium hydrosulfite.
Emergency Management Director Rodney Burdette says sodium hydrosulfite is used in some industrial dying processes, in water treatment, leather processing, cleaning, some food processing and printing.
Burdette says the river would have diluted any spilled chemical. Westminster officials are monitoring their water supply.
The drums were turned over to Phillips Recovery Company of West Pelzer for decontamination and disposal.