EDF Health

Selected tag(s): Bleach

EPA sets interim limits on hypochlorite bleach to reduce degradation to perchlorate

Tom Neltner, J.D.is Chemicals Policy Director and Maricel Maffini, Ph.D., Consultant

On May 1, 2018, Environmental Protection Agency’s (EPA) Office of Pesticide Programs (OPP) made an interim pesticide registration decision[1] for hypochlorite bleach used to disinfect drinking water. The office decided to require the “Precautionary Statements” section of the bleach’s pesticide label to include advisory best management practices to minimize the formation of chlorate and perchlorate. The new label will state:

“The following practices help to minimize degradant formation in drinking water disinfection:

  • It is recommended to minimize storage time.
  • It is recommended that the pH solution be in the range of 11-13.
  • It is recommended to minimize sunlight exposure by storing in opaque containers and / or in a covered area. Solutions should be stored at lower temperatures. Every 5º C reduction in storage temperature will reduce degradant formation by a factor of two.
  • Dilution significantly reduces degradant formation. For products with higher concentrations, it is recommended to dilute hypochlorite solutions with cool, softened water upon delivery, if practical for the application.”

EDF submitted comments in November 2017 supporting OPP’s proposed label changes and requesting specific changes to the language including making the advice to users mandatory. We also asked the agency to extend the changes to hypochlorite bleach used to treat produce and to disinfect food handling equipment.

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Posted in Drinking water, FDA, Food, Health policy, Health science, Perchlorate, Public health / Also tagged , , | Comments are closed

EPA to consider perchlorate risks from degradation of hypochlorite bleach

Tom Neltner, J.D.is Chemicals Policy Director and Maricel Maffini, Ph.D., Consultant

Virtually all types of food contain measurable amounts of perchlorate. Young children are the most highly exposed, and they consume levels that may be unsafe. Reducing exposure to perchlorate is of public health importance because it presents a risk to children’s brain development

One potentially significant source of the toxic chemical in food is hypochlorite bleach that, when not well managed, degrades to perchlorate. Bleach is used to sanitize food manufacturing equipment or to wash or peel fruits and vegetables. Thanks to a recent decision by Environmental Protection Agency’s (EPA) Office of Pesticide Programs, we will better understand the risk posed by perchlorate-contaminated bleach and whether standards are needed to improve the management of bleach.

Reduce perchlorate exposure by improving bleach management

In 2011, an excellent report by the American Water Works Association (AWWA) and the Water Research Foundation documented that hypochlorite bleach degrades into perchlorate. The report also included guidelines on better management of hypochlorite to preserve its effectiveness for drinking water utilities using it to disinfect water.

Most of AWWA’s recommendations are equally relevant to food manufacturers and anyone using bleach to disinfect food contact surfaces. The key recommendations are:

  • Dilute hypochlorite solutions on delivery. Cutting the concentration in half decreases the degradation rate by a factor of 7.
  • Store hypochlorite solutions at lower temperatures. Reducing temperature by 5oC decreases degradation rate by a factor of 2.
  • Keep pH between 11 and 13 even after dilution.
  • Avoid extended storage times, and use fresh hypochlorite solutions when possible.

The objective is not to reduce the use of bleach. Rather it is to preserve its effectiveness by preventing degradation to perchlorate through careful management.

Bleach: a food additive and a pesticide

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Posted in Drinking water, Emerging science, FDA, Food, Perchlorate, Regulation / Also tagged , , , , , | Authors: / Comments are closed