Emergency Vehicle Rule-SCR Maintenance and Regulatory Flexibility for Nonroad Equipment

This rule consists of three parts. First, the Environmental Protection Agency (EPA) is adopting minimum maintenance intervals for replenishment of consumable chemical reductant (commonly known as diesel exhaust fluid, or DEF) in connection with the use of selective catalytic reduction (SCR) technologies. Second, EPA is adopting provisions allowing manufacturers of nonroad engines to give operators the means to obtain short-term relief from emission controls while operating in emergency situations, such as those where operation of a nonroad engine or equipment is needed to protect human life, and where obtaining short-term relief from emission controls enables such operation. Third, EPA is adopting minor revisions to the direct final rule for emergency vehicles that became effective August 7, 2012, in response to comments received on the parallel Notice of Proposed Rulemaking.