;hexachloride (CAS No. 31075–24–8) (provided for in subheading 3824.99.55) Free No change No change On or before 12/31/2024 . 4647. Naphthenic acids Subchapter II of chapter 99 is amended by inserting in numerical sequence the following new heading: 9902.24.59 Naphthenic acids composed of 3-(3-ethylcyclopentyl)propanoic acid (CAS No. 1338–24–5) having an acidic fraction greater than 70 percent (provided for in subheading 3824.99.75) Free No change No change On or before 12/31/2024 . 4648. Hydroxytyrosol powders Subchapter II of chapter 99 is amended by inserting in numerical sequence the following new heading: 9902.24.60 Mixtures containing (2R,3S,4R,5R)-2,3,4,5,6-pentahydroxyhexanal (CAS No. 9050–36–6 (less than 90 percent by weight)) and 4-(2-hydroxyethyl)benzene-1,2-diol (CAS No. 10597–60–1 (less than 25 percent by weight)) (provided for in subheading 3824.99.92) Free No change No change On or before 12/31/2024 . 4649. Secondary alcohol ethoxylates Subchapter II of chapter 99 is amended by inserting in numerical sequence the following new heading: 9902.24.61 Mixtures of C12–14-secondary ethoxylated alcohols with an average of less than 5 ethylene oxide monomer units (CAS No. 84133–50–6) (provided for in subheading 3824.99.92) 2.8% No change No change On or before 12/31/2024 . 4650. Ethylene glycol dimerate Subchapter II of chapter 99 is amended by inserting in numerical sequence the following new heading: 9902.24.62 Mixtures containing fatty acid polymer of a kind used as fuel additives (fatty acids, C18-unsaturated, dimers, polymers with ethylene glycol) (CAS No. 68082–28–0) (provided for in subheading 3824.99.92) Free No change No change On or before 12/31/2024 . 4651. Two-part liquid silicone kits Subchapter II of chapter 99 is amended by inserting in numerical sequence the following new heading: 9902.24.63 Two-part liquid silicone kits (parts A and B) containing 58 to 70 percent by weight aluminum oxide (CAS No. 1344–28–1) treated with tetrapropyl silicate (CAS No. 682–01–9), 10 to 20 percent by weight