The Office of Environmental Health Hazard Assessment (OEHHA) has revised the cancer inhalation unit risk (IUR) and slope factors for cobalt and water-soluble cobalt compounds to address critical cancer risks linked to cobalt inhalation.

The newly revised cancer inhalation unit risk factors for cobalt sulfate heptahydrate and water-soluble cobalt compounds are emblematic of OEHHA’s commitment to health safety. Initially adopted in October 2020, this initiative seeks to align risk assessments with the latest scientific understanding.

OEHHA has been meticulous in establishing health risk assessment guidelines under the Air Toxics Hot Spots Program. Notably, the development of unit risk factors for carcinogens like cobalt sulfate heptahydrate underscores their dedication to robust health assessments. These unit risk factors serve as critical indicators to evaluate potential lifetime cancer risks associated with inhaling carcinogens. The revised unit risk factors for cobalt sulfate heptahydrate and water-soluble cobalt compounds affirm OEHHA’s commitment to align risk assessment with the current scientific understanding.

While this revision specifically addresses cobalt sulfate heptahydrate and water-soluble cobalt compounds, it’s noteworthy that the IURs for cobalt metal and insoluble cobalt compounds remain unaltered. The comprehensive recalibration and revision process underscores the precision and dedication with which OEHHA approaches health risk assessment, ensuring the currency and accuracy of their findings.

Notable factors for cobalt and cobalt compounds include:

This meticulous revision of inhalation risk factors for cobalt compounds stands as a testament to OEHHA’s commitment to health protection. By ensuring that the latest scientific insights inform risk assessments, OEHHA’s efforts align with its mission of safeguarding public health and fostering a safer environment for all.


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