A common quaternary ammonium compound (quat) sanitizer concentration for food-contact surfaces is within which range?

• A. 10–50 ppm
• B. 200–400 ppm
• C. 400–600 ppm
• D. 50–99 ppm

Answer: (B)

The main idea is choosing a sanitizing concentration that reliably lowers microbes on food-contact surfaces without creating excess residue. Quaternary ammonium compound sanitizers are typically used at about 200–400 parts per million. This range provides effective sanitizing action within the usual contact time while keeping residues and costs reasonable. Concentrations much lower than this often don’t fully sanitize, and higher concentrations offer little extra benefit and can lead to more residue or regulatory concerns. So the 200–400 ppm range is the appropriate, practical target for quat sanitizers on food-contact surfaces.