# 721.10941 Carbon silicon oxide.
(a) *Chemical substance and significant new uses subject to reporting.* (1) The chemical substance identified as carbon silicon oxide (PMN P-15-28; CAS No. 39345-87-4) 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), (a)(2)(i), (a)(3), (a)(4) (respirators must provide a National Institute for Occupational Safety and Health (NIOSH) assigned protection factor of at least 10), (a)(6)(v), (a)(6)(vi), (a)(6) (particulate or a combination gas/vapor and particulate), (b) (concentration set at 1.0 percent), and (c). When determining which persons are reasonably likely to be exposed as required for § 721.63(a)(1) and (a)(4), engineering control measures (*e.g.,* enclosure or confinement of the operation, general and local ventilation) or administrative control measures (*e.g.,* workplace policies and procedures) shall be considered and implemented to prevent exposure, where feasible.
(A) As an alternative to the respirator requirements in paragraph (a)(2)(i) of this section, a manufacturer or processor may choose to follow the new chemical exposure limit (NCEL) provision listed in the TSCA section 5(e) consent order for this substance. The NCEL is 6 mg/m
<sup>3</sup> as an 8-hour time weighted average. Persons who wish to pursue NCELs as an alternative to § 721.63 respirator requirements may request to do so under § 721.30. Persons whose § 721.30 requests to use the NCELs approach are approved by EPA will be required to follow NCELs provisions comparable to those contained in the corresponding TSCA section 5(e) consent order.
(B) [Reserved]
(ii) *Hazard communication program.* Requirements as specified in § 721.72(a) through (e) (concentration set at 1.0 percent), (f), (g)(1)(i), (g)(1)(ii), (g)(2)(i), (g)(2)(ii), (g)(2)(iv), (g)(2)(v), and (g)(5).
(iii) *Industrial, commercial, and consumer activities.* It is a significant new use to manufacture the PMN substance other than specified in the TSCA section 5(e) consent order. Requirements as specified in § 721.80(p) (within 24 months of submission of a Notice of Commencement of Manufacture).
(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) through (i) are applicable to manufacturers and processors of this.
(2) *Limitations or revocation of certain notification requirements.* The provisions of § 721.185 apply to this section.
(3) *Determining whether a specific use is subject to this section.* The provisions of § 721.1725(b)(1) apply to paragraph (a)(2)(iii) of this section.
[81 FR 81268, Nov. 17, 2016]