40 CFR Part 1074 Subpart A
Preemption of State Standards and Procedures for Waiver of Federal Preemption for Non-road Engines and Non-road Vehicles - Applicability and General Provisions.
40 CFR Part 1074 Subpart B
Preemption of State Standards and Procedures for Waiver of Federal Preemption for Non-road Engines and Non-road Vehicles - Procedures for Authorization.