40 CFR § 1090.260 - Gasoline deposit control standards.
(a) Except as specified in subpart G of this part, all gasoline that is sold, offered for sale, dispensed, supplied, offered for supply, or transported to the ultimate consumer for use in motor vehicles or in any off-road engines, or that is transported to a gasoline retailer or WPC must be treated with a detergent that meets the requirements of paragraph (b) of this section at a rate at least as high as the detergent's LAC over the VAR period.
(b) The LAC of the detergent must be determined by the gasoline detergent manufacturer using one of the following methods:
(1) The detergent must comply with one of the deposit control testing methods specified in § 1090.1395.
(2) The detergent must have been certified prior to January 1, 2021, under the intake valve deposit control requirements of 40 CFR 80.165(b) for any of the detergent certification options under 40 CFR 80.163. Di-tertiary butyl disulfide may have been used to meet the test fuel specifications under 40 CFR 80.164 associated with the intake valve deposit control requirements of 40 CFR 80.165(b). A party compliant with this paragraph (b)(2) is exempt from the port fuel injector deposit control requirements of 40 CFR 80.165(a).
(3) A gasoline detergent manufacturer must produce detergents consistent with their detergent certifications for detergents certified prior to January 1, 2021, and with the specific composition information submitted as part of the registration of detergents under 40 CFR 79.21(j) thereafter.