OEHHA Proposes Revised Public Health Goal for Perchlorate


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SACRAMENTO – The Office of Environmental Health Hazard Assessment (OEHHA) today released a draft public health goal (PHG) of 1 part per billion (ppb) for perchlorate in drinking water.

The proposed goal would revise the existing PHG for perchlorate, which was set at 6 ppb in 2004.  Release of the proposed revision begins a 45-day public comment period.

A public health goal is not an enforceable regulatory standard. Its purpose is to provide scientific guidance to the California Department of Public Health (CDPH) in reviewing the existing state drinking water standard for perchlorate. There is no current federal standard for perchlorate in drinking water. The current state standard, officially known as a maximum contaminant level (MCL), is set at 6 ppb.

The proposed new PHG is lower than the existing goal because it incorporates new information about the effects of perchlorate on infants.

“New research about perchlorate’s potential to affect the health of California babies has led OEHHA’s scientists to develop this revised public health goal for drinking water,” said OEHHA Director Joan Denton, Ph.D. “The revised goal reflects infants’ enhanced susceptibility to the health effects of this chemical.”

Perchlorate is a chemical that can occur naturally and also may be released by fireworks, rocket fuel, and various industrial processes. Exposure to perchlorate can affect infant brain development, growth, and other key body functions. Perchlorate is known to damage the thyroid’s ability to take in and process iodide, which is a nutrient essential to brain development, growth, heart function, and other systems.

Studies conducted by OEHHA scientists and others revealed that perchlorate harms the health of babies at lower levels than healthy adults. At the same time, a recent study of Boston-area new mothers indicates that nearly half of all infants may not receive enough iodide from their mothers’ milk.

OEHHA’s draft PHG also incorporates new data on how much water infants consume per pound of body weight. It also considers infants’ intake of perchlorate from infant formula.

A public health goal is not a boundary line between a “safe” and “dangerous” level of a contaminant.  It is not considered the highest level of a chemical that is safe to drink.

A PHG is a stringent health-protective goal that CDPH will use to develop an enforceable regulatory standard. CDPH must set its drinking water standards as close to the corresponding PHGs as is economically and technically feasible.

A copy of the draft perchlorate PHG document can be viewed or downloaded from OEHHA’s web site at www.oehha.ca.gov.  OEHHA will hold a public workshop on the PHG from 10 a.m. to noon on February 23, 2011 in Room 11 of the Elihu Harris Building at 1515 Clay St. in Oakland. Written comments may be submitted to  oehha@oehha.ca.gov or sent to OEHHA at 1515 Clay St., 16th Floor, Oakland, CA 94612 until 5 p.m. on February 23.  OEHHA will review all comments and make any appropriate revisions before finalizing the PHG.