October 24, 2019

European Chemicals Agency Proposes OEL for Lead, Notations for Diisocyanates

New scientific reports published by the European Chemicals Agency include ECHA’s recommendations regarding occupational exposure limits for lead and its compounds and for diisocyanates. The agency proposes a biological limit value, or BLV, of 150 µg Pb/L in blood for inorganic and for organic lead compounds. To help achieve blood lead levels below the proposed BLV, ECHA proposes to establish an OEL for inorganic compounds and organic compounds—or alkyl lead compounds—of 30 μg/m3 as an 8-hour time-weighted average. For comparison, OSHA’s permissible exposure limit and NIOSH’s recommended exposure limit for lead are both 50 µg/m3 as an 8-hour TWA. OSHA also has an action level for lead of 30 µg/m3, at which an employer must begin specific compliance activities. ECHA’s report concludes that no 15-minute short-term exposure limit can be derived.

“ECHA does not propose a STEL because the leading toxic effects for lead and inorganic compounds are chronic systemic effects and there is no evidence of acute effects at these levels,” the report (PDF) states.

ECHA is not proposing an OEL for diisocyanates, which the agency says are the most common group of isocyanates used in the workplace. Instead, ECHA recommends that the Committee for Risk Assessment, which supports the European Commission by giving scientific opinions on OELs, focus on “further [developing] the approach to derive an exposure response and then establish an OEL.”

“ECHA considers that the data available do not allow identification of a threshold average exposure concentration below which no cases of asthma would occur among those workers where the induction of respiratory sensitization to diisocyanates has already taken place,” the agency’s report (PDF) explains.

ECHA is proposing skin sensitization, respiratory sensitization, and skin notations for diisocyanates.

The agency will accept public comments on its OEL proposals until Dec. 16, 2019. More information on submitting comments is available on ECHA’s website.