Neutraliser

A substance that stops the antimicrobial activity of a product, preservative or disinfectant residue so that surviving organisms can grow. Common examples are lecithin and polysorbate 80 for quaternary ammonium compounds and parabens, sodium thiosulfate for chlorine and iodine, and histidine for aldehydes. Neutralisers are added to diluents, rinse fluids and contact plates. Their efficacy and lack of toxicity to organisms must be shown in method suitability or disinfectant studies.