Section 721.10203 - Phosphonium, tetrabutyl-, hydroxide (1:1)(a)Chemical substance and significant new uses subject to reporting.(1) The chemical substance identified as phosphonium, tetrabutyl-, hydroxide (1:1) (PMN P-08-742; CAS No. 14518-69-5) is subject to reporting under this section for the significant new uses described in paragraph (a)(2) of this section.(2) The significant new uses are: (i)Release to water. Requirements as specified in § 721.90 (a)(1), (b)(1), and (c)(1) .(b)Specific requirements. The provisions of subpart A of this part apply to this section except as modified by this paragraph. (1)Recordkeeping. Recordkeeping requirements as specified in § 721.125 (a), (b), (c), and (k) are applicable to manufacturers, importers, and processors of this substance.(2)Limitations or revocation of certain notification requirements. The provisions of § 721.185 apply to this section. 75 FR 57182 , Sept. 20, 2010