Use of Bleach as a Disinfectant in Post-Harvest Washing Systems
Posted: July 14, 2014
USDA has indicated that if an auditor observes a grower using an unapproved disinfectant for washing produce or food contact surfaces, that grower will fail the audit.
Instead, growers should contact a reputable chemical supply company that sells sodium or calcium hypochlorite labeled for that purpose. The Penn State fact sheet "Using Chlorine Sanitizers in Produce Wash Tanks" provides further details on the different types of chlorine sanitizers, as well as factors that influence their effectiveness. (To request a copy of this factsheet, contact Lee Stivers at firstname.lastname@example.org.)
Question: Didn't there used to be a formulation of Clorox that was registered with EPA for use as a sanitizer for fruits and vegetables? Answer: Clorox Brand Ultra Regular Bleach appears to have been registered for this use, but it is no longer manufactured by Clorox. However, recently Clorox registered "Chlorox Germicidal Bleach" (EPA Reg. No 5813-100) for washing fruits and vegetables at 25 ppm or less.
Question: Are there other hypochlorite products on the market that are currently registered for washing fruits and vegetables? Answer: Yes, there are products that are legal alternatives for non-labeled bleach. For example, AFCO Chemical Company sells a 12% sodium hypochlorite labeled for this use. There are other manufacturers as well.
Question: Many organic growers use hydrogen peroxide as a disinfectant. Must hydrogen peroxide products used for disinfecting wash water also be registered with EPA? Answer: Although it is listed on the USDA Organic website as approved for use, hydrogen peroxide must also be EPA registered for use as a disinfectant.
Question: Are there other alternatives? Answer: Yes. SaniDate 5 or 12 are alternatives that have EPA approval and are sold by BioSafe Systems. These consist of peroxyacetic (PAA) acid and hydrogen peroxide, and break down to acetic acid (vinegar), water and oxygen. They are less affected by organic matter and pH than hypochlorite products. SaniDate 5 complies with USDA organic standards because the formulation PAA level is below 6%.
Question: How can I find products approved for fruit and vegetable washing or for other uses? Answer: Search the National Pesticide Information Retrieval System for EPA registered products.