CFR › Title 40 › Part 1042 › §1042.63540 CFR §1042.635Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗Copy linkEngines qualify for a national security exemption as described in 40 CFR 1068.225. This applies to both freshly manufactured and remanufactured engines.