The Occupational Safety and Health Administration is giving industry groups, unions and other parties more time to file comments on its proposal to tighten the exposure standard for airborne silica.

On Oct. 25, OSHA said it is extending the comment-period deadline by 47 days, to Jan. 27. A coalition of construction-industry groups objects to the proposed, more stringent exposure limit.

OSHA announced the proposal on Aug. 23 and published it on Sept. 12.