40 CFR 91.1008 - National security exemption.
(1) Any marine SI engine, otherwise subject to this part, which is used in a vessel that exhibits substantial features ordinarily associated with military combat such as armor and/or permanently affixed weaponry and which will be owned and/or used by an agency of the Federal government with responsibility for national defense, will be exempt from these regulations for purposes of national security. No request for exemption is necessary.
(2) Manufacturers may request a national security exemption for any marine SI engine, otherwise subject to this part, which does not meet the conditions described in paragraph (a)(1) of this section. A manufacturer requesting a national security exemption must state the purpose for which the exemption is required and the request must be endorsed by an agency of the federal government charged with responsibility for national defense.
(b) EPA will maintain a list of models of marine SI engines (and the vessels which use them) that have been granted a national security exemption under paragraph (a)(2) of this section. This list will be available to the public and may be obtained by writing to the following address: Manager, Engine Compliance Programs Group 6403-J, Environmental Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460.