From US EPA. Circulated on 5/6/2005.

In the 5/6/2005  Federal Register: 

EPA published a Final Rule on Transportation Conformity Rule Amendments for the New PM2.5 Precursors.

This final rule adds several transportation-related PM2.5 precursors to the transportation conformity regulations.
	
This final rule also makes a technical correction to a cross-reference of the U.S. DOT planning regulations in the public consultation procedures of the conformity rule.

The effective date is 6/6/2005.

The Notice can be found at the Link below: 

http://a257.g.akamaitech.net/7/257/2422/01jan20051800/edocket.access.gpo.gov/2005/pdf/05-9086.pdf