chapter 99 is amended by inserting in numerical sequence the following new heading: 9902.06.55 6-Chloro-2-N,4-N-diethyl-1,3,5-triazine-2,4-diamine (Simazine) (CAS No. 122–34–9) (provided for in subheading 2933.69.60) Free No change No change On or before 12/31/2020 . 549. High performance halogen free flame retardant Subchapter II of chapter 99 is amended by inserting in numerical sequence the following new heading: 9902.06.56 1,3,5-Triazinane-2,4,6-trione—1,3,5-triazine-2,4,6-triamine (1:1) (CAS No. 37640–57–6) (provided for in subheading 2933.69.60) Free No change No change On or before 12/31/2020 . 550. Propazine Subchapter II of chapter 99 is amended by inserting in numerical sequence the following new heading: 9902.06.57 6-Chloro-2-N,4-N-di(propan-2-yl)-1,3,5-triazine-2,4-diamine (Propazine) (CAS No. 139–40–2) (provided for in subheading 2933.69.60) Free No change No change On or before 12/31/2020 . 551. Indaziflam Subchapter II of chapter 99 is amended by inserting in numerical sequence the following new heading: 9902.06.58 N-[(1R,2S)-2,6-Dimethyl-2,3-dihydro-1H-inden-1-yl]-6-[(1R)-1-fluoroethyl]-1,3,5-triazine-2,4-diamine (Indaziflam) (CAS No. 950782–86–2) (provided for in subheading 2933.69.60) Free No change No change On or before 12/31/2020 . 552. Phenol,2-(4,6-dIphenyl-1,3,(tinuvin 1577) Subchapter II of chapter 99 is amended by inserting in numerical sequence the following new heading: 9902.06.59 2-(4,6-Diphenyl-1,3,5-triazin-2-yl)-5-(hexyloxy)phenol (CAS No. 147315–50–2) (provided for in subheading 2933.69.60) Free No change No change On or before 12/31/2020 . 553. 2-hydroxyphenyl-s-triazine(tinuvin 1600) Subchapter II of chapter 99 is amended by inserting in numerical sequence the following new heading: 9902.06.60 2-[4,6-Di(4-biphenylyl)-1,3,5-triazin-2-yl]-5-[(2-ethylhexyl)oxy]phenol (CAS No. 204583–39–1) (provided for in subheading 2933.69.60) Free No change No change On or before 12/31/2020 . 554. Terbutryn Subchapter II of chapter 99 is amended by inserting in numerical sequence the following