Tolcide is a phosphonium salt-based biocide

It is typically used to control biofouling, souring and microbiologically induced corrosion (MIC) issues often encountered by the oil and gas industry. Tolcide excels over other biocides because it exhibits lower environmental toxicity, is very effective across a broader pH range, displays excellent efficacy against both sulfate reducing bacteria (SRB) and acid producing bacteria (APB), and can dissolve iron sulfide regardless of iron sulfide scale form.