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'Safe Harbor' Level Generation

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SAFE HARBOR LEVEL

Companies are required to provide “clear and reasonable warnings” and terminate discharges one year after a chemical is listed under Proposition 65 if exposures exceed the Safe Harbor Level. If OEHHA has not published a default Safe Harbor Level, companies must establish their own Safe Harbor Level as described in regulations.

California 's Office of Environmental Health Hazard Assessment (OEHHA) establishes threshold levels, often called “Safe Harbor Levels”, that trigger warning and discharge prohibition requirements under Proposition 65. OEHHA has published default Safe Harbor Levels for many listed chemicals, but others lack default values, even many years after the compounds have been added to the list.

TSG has the toxicology expertise required to independently establish Safe Harbor Levels (NSRL and MADL) that companies can use with confidence in risk assessments until defaults are published by OEHHA.

Safe Harbor Levels are described as follows:

  • Carcinogen Safe Harbor Levels are termed No Significant Risk Levels (NSRL). They are based on the most sensitive study meeting certain requirements and calculations described in regulations to calculate an exposure level that results in 1 excess cancer in an exposed human population of 100,000.
  • Reproductive Toxin Safe Harbor Levels are termed Maximum Allowable Dose Level (MADL). They are based on the most sensitive study meeting certain requirements at a level that is 1,000 fold below the no observable effect level (NOEL) for the study.

TSG is experienced at calculating NSRL and MADL using regulations and underlying documentation. Companies have used TSG's independent NSRL and MADL to comply with Proposition 65 until default values are published by OEHHA.

TSG's State Affairs Division and Toxicology Division staff routinely prepare independent NSRL and MADL with underlying documentation for use in risk assessments until default values are published by OEHHA. TSG's values and documentation along with appropriate risk assessments establish a record of Proposition 65 compliance that would strongly deter any litigation under the Act.