What is a typical sanitizer concentration range for chlorine-based sanitizers on food-contact surfaces?

• A. 10-25 ppm
• B. 25-50 ppm
• C. 50-100 ppm
• D. 100-200 ppm

Answer: (C)

Chlorine sanitizers work by delivering free chlorine to kill microbes on surfaces, so using the right concentration is key to effective sanitation. The usual range for food-contact surfaces is 50 to 100 parts per million (ppm) of free chlorine. This level provides solid antimicrobial action while staying gentle enough for equipment and minimizing residues or odor issues. With proper wetting of the surface and an adequate contact time (often several seconds up to a minute), you can achieve meaningful reductions in common pathogens even when some organic matter is present. If the concentration falls below 50 ppm, disinfection may be incomplete; going much above 100 ppm increases the risk of corrosion, residue taste or odor, and faster sanitizer degradation. Regular testing and refreshing the solution help maintain that effective 50–100 ppm range.