This direct final rule the removes chemical substances phosphorotrithious acid, tributyl ester, CAS No. 150-50-5, and phosphorodithioic acid, O,O-diethyl ester, sodium salt, CAS No. 3338- 24-7, which were inadvertently added to the list of voluntary High Production Volume (HPV) Challenge Program orphan (unsponsored) chemical substances by EPA. As a result, these chemical substances were inadvertently added to two final rules: The Preliminary Assessment Information Reporting (PAIR) rule (Toxic Substances Control Act (TSCA) section 8(a)) and the Health and Safety Data Reporting rule (TSCA section 8(d)), both published in the Federal Register issue of August 16, 2006. With this removal action, persons who manufacture (including import) either of these two chemical substances are no longer subject to the reporting requirements imposed by these TSCA section 8(a) and 8(d) rules.