What is the unit used to express a chemical sanitizer's concentration?

• A. percent
• B. pH
• C. ppm
• D. molarity

Answer: (C)

Parts per million (ppm) is the unit used to express a chemical sanitizer’s concentration. This fits kitchen practice because sanitizers are used in very dilute aqueous solutions, and ppm corresponds to milligrams of active chemical per liter of solution. It also lines up with how test kits and regulatory guidelines measure and specify sanitizing strength. Expressing concentration in percent would describe a much larger proportion and isn’t as practical for these small, precise amounts. pH measures how acidic or basic the solution is, not how much sanitizer is present. Molarity is a lab-focused measure of moles per liter and isn’t how kitchen sanitizers are typically specified or tested. Depending on the sanitizer type, target ppm values are usually in the tens to a few hundred, tailored to the product and surface.