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Selected tag(s): hypochlorite 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, EPA, FDA, Food, Health Policy, Health Science, perchlorate, Public Health / Also tagged , | Comments are closed

EPA’s latest analysis shows perchlorate risks to fetal brain development

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

Pursuant to a consent decree with the Natural Resources Defense Council (NRDC), the Environmental Protection Agency (EPA) is developing drinking water regulations to protect fetuses and young children from perchlorate, a toxic chemical that inhibits the thyroid’s ability to make the hormone T4 essential to brain development. The rulemaking is part of a long process that began in 2011 when the agency made a formal determination that Safe Drinking Water Act standards for perchlorate were needed. Under the consent decree, EPA should propose a standard by October 2018.

In the latest step in that process, EPA’s scientists released a draft report in September that, at long last, answers questions posed by its Science Advisory Board in 2013: does perchlorate exposure during the first trimester reduce production of T4 in pregnant women with low iodine consumption? Does reduction in maternal T4 levels in these women adversely affect fetal brain development? According to EPA’s scientists, the answers are Yes and Yes.

For several years, EPA and the Food and Drug Administration (FDA) have developed and refined a model that would predict the effect of different doses of perchlorate on levels of T4 in pregnant women. The latest version of the model addresses women during the first trimester, especially those with low iodine intake. This is important because iodine is essential to make T4 (the number four indicates the number of iodine atoms present in the hormone); perchlorate inhibits its transport from the blood into the thyroid. The risk of perchlorate exposure to fetuses in the first trimester is greatest because brain development starts very early and is fully dependent on maternal T4. If the mother gets insufficient iodine to offset the perchlorate inhibition, she will not produce enough T4 for the fetal brain to develop properly. When free T4 (fT4) levels are low but without increase in thyroid stimulating hormone (TSH), the condition is known as hypothyroxinemia. When T4 production is lowered further, the pituitary gland releases TSH to increase T4 production by a feedback loop mechanism.

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Posted in Drinking Water, Emerging Science, EPA, FDA, Food, Health Policy, perchlorate, Public Health, Regulation / Also tagged , , , , , , , , , , | Comments are closed

EPA proposes limits on hypochlorite bleach to reduce degradation to perchlorate

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

Every 15 years, the Environmental Protection Agency’s (EPA) Office of Pesticide Programs (OPP) reviews the safety of registered pesticides. The current cycle ends in 2022. As part of that process, the agency is evaluating the safety of hypochlorite bleaches. In January 2017, EPA decided it would consider the risks posed by degradation of the hypochlorite into perchlorate.

This is important for two reasons: 1) degraded bleach is less effective as a pesticide, and 2) perchlorate is a chemical that interferes with the production of thyroid hormone, a critical hormone for fetal and infant brain development.

On September 22, EPA proposed changes to the pesticide label to minimize the degradation for hypochlorite bleach used to disinfect drinking water, and the agency is accepting comments until November 21, 2017. The label would advise users to:

  • Minimize storage time;
  • Maintain pH of the solution between 11 to 13;
  • Minimize exposure to sunlight;
  • Store at lower temperatures; and
  • If practical, dilute with cool softened water upon delivery.

EDF submitted comments to EPA supporting EPA’s proposal and requesting specific changes to the proposed language, including making the advice to users mandatory. We also asked the agency to extend the label requirements to hypochlorite bleach used to treat produce and to disinfect food handling equipment. Bleach appears to be one of several significant sources of perchlorate contamination of food. Improving management conditions will reduce degradation and preserve effectiveness regardless of the whether the bleach is used in drinking water or to treat vegetables.

EPA’s proposal is an interim decision. We also were pleased to see that OPP is committed to continue working with EPA’s Office of Water (OW) in its assessment of the risks of perchlorate to pregnant women and young children. We asked OPP to incorporate the OW’s findings in additional interim registration decisions for all uses of hypochlorite bleaches.

 

Posted in EPA, Health Policy, Health Science, perchlorate, Public Health, Regulation / Also tagged , , | Comments are closed