The 2010 regulation's limits for mercury, hydrocarbons and hydrogen chloride would not be altered.

EPA said the proposed revisions are a response to portland-cement industry petitions and to a December 2001 federal appeals court ruling.

Among other results, the decision by the Court of Appeals for the District of Columbia Circuit stayed the 2010 rule’s standards for clinker storage piles and directed EPA to reconsider it.

EPA's new proposal does not include a clinker-pile emissions level but instead calls for various work practices to deal with them. The emissions are in the form of dust, for which “measurement was not feasible,” the agency said.

The proposed work practices for dealing with dust when clinker is added to a pile include such measures as using a water spray,  tarp or wind barrier.

Comments on the proposed regulation are due 30 days after their publication in the Federal Register. The rule had not appeared in the paper as of June 27.