The department is proposing Risk Assessment Levels for Cobalt and Cobalt Compounds for use in future air permitting requirements. The department proposes replacing the current risk assessment level (RAL) for cobalt and cobalt compounds (Chemical Abstracts Service Number 7440–48–8) with new RALs. The Missouri Department of Health and Senior Services concurred with the department’s proposal.
On Dec. 11, 2025, the department proposed RALs for cobalt and cobalt compounds for use in future air permitting requirements. The public comment period for this action was originally scheduled to close on Jan. 10, 2025; however, the department extended the comment deadline until Jan. 24, 2025, in response to an extension request. The department received additional stakeholder questions and another extension request for the comment period deadline on this proposal. The comment period still closed on January 24, 2025; however, the department intended to reopen the public comment period at a later date with a supplemented proposal. The department now invites the public to review and offer written comments on the proposal for the next 30 calendar days ending on April 3, 2025. Copies of these documents are available from the Missouri Department of Natural Resources, Air Pollution Control Program, P.O. Box 176, Jefferson City, MO 65102-0172, or by calling 573-751-4817.
Written comments or any relevant information or materials may be submitted by mail to Stephen Hall, Missouri Department of Natural Resources, Air Pollution Control Program, PO Box 176, Jefferson City, MO 65102-0176 or by email to apcppermitspn@dnr.mo.gov. Comments submitted by email are limited to 20 MB in size. Comments larger than 20 MB need to be submitted by mail to the address above.