The purpose of this action is to make minor revisions and corrections affecting recently-promulgated rules. First, a regulatory provision included in the health effects testing requirements for fuel and fuel additive registration (at 40 CFR part 79) is revised to ensure sufficient scheduling flexibility when test laboratories encounter technical problems. Second, a provision inadvertently omitted from both the Interim Detergent Program and the Detergent Certification Program is added to the regulations (at 40 CFR part 80). The new provision will allow a detergent additive manufacturer to apply one set of performance demonstration tests to multiple detergent additive products containing the same active ingredients. Finally, a regulatory numbering error and a syntactical error affecting the Detergent Certification rule are corrected. These changes are being implemented without prior notice because EPA believes that they are not controversial. Both of the affected programs serve the public health and environmental protection goals of the Clean Air Act (CAA). The detergent certification program is intended to ensure the emission reduction and fuel efficiency benefits of gasoline detergent additives. The fuel and fuel additive (F/FA) health effects testing program is designed to determine if the emissions of certain gasoline or diesel F/FAs present an unacceptable risk to the public health. The corrections implemented by today's action will facilitate attainment of these program objectives by simplifying the regulatory requirements which might otherwise pertain to some regulated parties.