CFR > Title 40 > Chapter I > Subchapter N > Part 454 > Subpart E CFR > Title 40 > Chapter I > Subchapter N > Part 454 > Subpart E – Essential Oils Subcategory Current as of: 2024 | Check for updates | Other versions § 454.50 Applicability; description of the essential oils subcategory § 454.51 Specialized definitions § 454.52 Effluent limitations and guidelines representing the degree of effluent reduction attainable by the application of the best practicable control technology currently available