40 CFR § 721.9662 - Thieno[3,4-b]-1,4-dioxin, 2,3-dihydro- (9CI).

---
identifier: "/us/cfr/t40/s721.9662"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "40 CFR § 721.9662 - Thieno[3,4-b]-1,4-dioxin, 2,3-dihydro- (9CI)."
title_number: 40
title_name: "Protection of Environment"
section_number: "721.9662"
section_name: "Thieno[3,4-b]-1,4-dioxin, 2,3-dihydro- (9CI)."
chapter_name: "ENVIRONMENTAL PROTECTION AGENCY"
subchapter_number: "R"
subchapter_name: "TOXIC SUBSTANCES CONTROL ACT"
part_number: "721"
part_name: "SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES"
positive_law: false
currency: "2026-03-24"
last_updated: "2026-03-24"
format_version: "1.1.0"
generator: "[email protected]"
authority: "15 U.S.C. 2604, 2607, and 2625(c)."
regulatory_source: "49 FR 35018, Sept. 5, 1984, unless otherwise noted."
cfr_part: "721"
---


# 721.9662 Thieno[3,4-b]-1,4-dioxin, 2,3-dihydro- (9CI).

(a) *Chemical substance and significant new uses subject to reporting.* (1) The chemical substance identified as thieno[3,4-b]-1,4-dioxin, 2,3-dihydro- (9CI) (PMN P-95-1825; CAS No. 126213-50-1) 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) *Protection in the workplace.* Requirements as specified in § 721.63 (a)(1) and (a)(2)(i).

(ii) *Industrial, commercial, and consumer activities.* Requirements as specified in § 721.80(f).

(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), (d), (e), 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.

[63 FR 3439, Jan. 22, 1998; 63 FR 9441, Feb. 25, 1998]