40 CFR 87.21 - Exhaust emission standards for Tier 4 and earlier engines.

REGULATIONS

Regulations last checked for updates: Feb 06, 2026

Title 40 - Protection of Environment last revised: Dec 22, 2026

§ 87.21 - Exhaust emission standards for Tier 4 and earlier engines.

Exhaust emission standards apply to new aircraft engines as described in 40 CFR 1031.40 through 1031.90.

authority: 42 U.S.C. 7401

source: 87 FR 72350, Nov. 23, 2022, unless otherwise noted.

cite as: 40 CFR 87.21

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