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