Summary of the Public Health Goal for Picloram

A Public Health Goal (PHG) of 500 ppb is developed for picloram in drinking water. The U.S. Environmental Protection Agency’s (U.S. EPA’s) Maximum Contaminant Level (MCL) for picloram is 500 ppb. This is based on a no-observed-adverse-effect-level (NOAEL) of 7 mg/kg-day from a six month dog feeding study in which the critical health endpoint was increased liver weights. There is no new scientific information that would justify a change in the toxicological endpoint of concern, or the assumptions and uncertainty factors used in the calculation of the PHG. Therefore, the Office of Environmental Health Hazard Assessment (OEHHA) calculates a PHG of 0.5 mg/L (500 ppb) which is expected to be sufficiently health-protective to prevent adverse effects in the general population and in potential sensitive subpopulations based on the data currently available for this chemical.