---
kind: "section"
citation: "40 C.F.R. § 91.1"
title: "40"
number: "91.1"
heading: "Applicability."
url: "https://uscodex.org/cfr/40/91.1"
---

# §91.1. Applicability.


The Environmental Protection Agency adopted emission standards for model year 1998 and later marine spark-ignition engines under this part, except that the standards of this part did not apply to sterndrive/inboard engines. EPA has migrated regulatory requirements for these engines to [40 CFR part 1045](/cfr/40/part1045.md), with additional testing and compliance provisions in 40 CFR parts [1065](/cfr/40/part1065.md) and [1068](/cfr/40/part1068.md). The standards originally adopted in this part are identified in [40 CFR part 1045](/cfr/40/part1045.md), appendix I. See [40 CFR 1045.1](/cfr/40/1045.1.md) for information regarding the timing of the transition to [40 CFR part 1045](/cfr/40/part1045.md), and for information regarding regulations that continue to apply for engines that manufacturers originally certified or otherwise produced under this part.


## Notes

### Authority

Authority: 42 U.S.C. 7401-7671q.

### Source

Source: 86 FR 34372, June 29, 2021, unless otherwise noted.