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Section 302 notification requirements and mixtures with unknown components

Are facilities exempt from Section 302 notification requirements if they produce, use, or store mixtures whose extremely hazardous substance component information is not available on the MSDS provided by the manufacturer?

If the facility which produces, uses, or stores mixtures knows or reasonably should know the components of the mixture, the facility owner or operator must notify under Section 302 if the extremely hazardous substance component is more than one percent of the total weight of the mixture and equal to or more than the threshold planning quantity.