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Regulations for Emissions from Vehicles and Engines

Proposed Rule and Related Materials for Heavy-Duty Highway Program: Revisions for Emergency Vehicles and SCR Maintenance

Rule Summary

On May 23, 2012, the Administrator signed a Notice of Proposed Rulemaking (NPRM) with revisions related to emissions controls on diesel-powered emergency vehicles and revisions related to scheduled maintenance intervals for diesel engines and vehicles using Selective Catalytic Reduction (SCR). The NPRM also included revisions to offer short-term relief from performance inducements related to the emission control system, for general purpose nonroad engines while operating in temporary emergency service.

On June 8, 2012, the NPRM was published in the Federal Register. EPA held a public hearing on the NPRM in Ann Arbor, Michigan on June 27, 2012. At that hearing, oral comments on the NPRM were received and recorded.

In parallel with the NPRM, a direct final rule (DFR) was signed on May 23, 2012, and was published on June 8, 2012. The DFR included only those portions of the NPRM that contained revisions related to emission controls on dedicated emergency vehicles. Because none of the comments on those revisions were deemed adverse, the DFR became effective on August 7, 2012. 

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