Using chlorine bleach as a packing and washwater sanitizer

New factsheet outlines use of chlorine bleach as a sanitizer on fresh produce, the effective concentration based on the produce type and potential factors that can reduce bleach’s effectiveness.

Chlorine bleach is both an inexpensive and effective disinfectant if it is used properly. Improper use of bleach could lead to incomplete sanitization or contamination of produce with excess chlorine. Bleach is not the only sanitizing agent on the market, but it is by far the least expensive and most widely accessible. The principles of sanitizing produce, monitoring sanitizer concentrations and documenting these concentrations remain the same, irrespective of the sanitizer used.

To understand the reasons for monitoring, it is important to explain a bit about chlorine’s chemistry. Chlorine bleach is essentially chlorine gas dissolved in a liquid. Gases dissolved in liquids dissipate out of them based on many factors, including temperature, pH and particulate matter. Therefore, these factors can radically alter the concentration of chlorine in a sanitizer over time.

Chlorine bleach may not be the best sanitizer for some jobs. Another sanitizer will be much less corrosive when sanitizing metal surfaces or using metal spray nozzles to distribute sanitizer. If chlorine bleach is used with spray nozzles, you may wish to substitute ceramic nozzles in place of brass.

It is also important to pay attention to what you are buying when you buy chlorine bleach. Fragrances and thickeners can alter the effectiveness of chlorine bleach from a food safety perspective. In addition, concentrations of chlorine bleach may vary by brand. Always choose household bleach with no fragrances or thickeners and a base concentration of 5.25% Sodium Hypochlorite.

If a grower has specific questions or has difficulty tailoring Good Agricultural Practices (GAPs) to their farm, they are welcome to contact the Agrifood Safety Work Group at or (517) 788-4292. For more information on chlorine as a sanitizer, ask for AFSM029-01.

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