EPA is proposing a rule to address certain persistent, bioaccumulative, and toxic chemicals identified pursuant to section 6(h) of the Toxic Substances Control Act (TSCA). These five chemicals are: Decabromodiphenyl ether; phenol, isopropylated phosphate (3:1), also known as tris(4-isopropylphenyl) phosphate; 2,4,6-tris(tert- butyl)phenol; hexachlorobutadiene; and pentachlorothiophenol. This proposed rule would restrict or prohibit manufacture (including import), processing, and distribution in commerce for many uses of four of these five chemical substances. EPA has evaluated the uses of hexachlorobutadiene and is proposing no regulatory action. For the other four, this proposal includes recordkeeping requirements. Additional downstream notification requirements are proposed for phenol, isopropylated phosphate (3:1).