Iodine sanitizers are used at what range and contact time?

• A. 12.5-25 ppm; 30-60 seconds
• B. 200-400 ppm; 30-60 seconds
• C. 50-99 ppm; 7 seconds
• D. 5-10 ppm; 5 minutes

Answer: (A)

Iodine sanitizers work by releasing free iodine to inactivate microbes, so the surface must stay wet with the sanitizer long enough for that iodine to act. The effective use on food-contact surfaces is typically 12.5–25 parts per million with a contact time of 30–60 seconds. This range provides reliable microbial reduction without excessive residue, taste or odor issues, or equipment wear.

Choosing a much higher concentration, like 200–400 ppm, isn’t necessary for routine sanitizing and can increase residue and safety concerns. A much shorter contact time, such as 7 seconds, wouldn’t give microbes enough exposure to be reliably killed. Conversely, a very low concentration like 5–10 ppm with a 5-minute contact time is inefficient and may not achieve the required sanitization level.

Remember to start with clean surfaces, because organic matter can reduce iodine effectiveness, and ensure the surface remains visibly wet for the full contact time before air-drying.