40 CFR § 721.10119 - Siloxane modified silica nanoparticles (generic).

---
identifier: "/us/cfr/t40/s721.10119"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "40 CFR § 721.10119 - Siloxane modified silica nanoparticles (generic)."
title_number: 40
title_name: "Protection of Environment"
section_number: "721.10119"
section_name: "Siloxane modified silica nanoparticles (generic)."
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"
---


# 721.10119 Siloxane modified silica nanoparticles (generic).

(a) *Chemical substance and significant new uses subject to reporting.* (1) The chemical substance identified generically as siloxane modified silica nanoparticles (PMN P-05-673) 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), (a)(5), (a)(6)(ii), (b) (concentration set at 1 percent), and (c). The following National Institute for Occupational Safety and Health (NIOSH)-approved respirators with an APF of 10-25 meet the minimum requirements for § 721.63(a)(4): Air-purifying, tight-fitting respirator equipped with N100 (if oil aerosols absent), R100, or P100 filters (either half- or full-face); powered air-purifying respirator equipped with a loose-fitting hood or helmet and High Efficiency Particulate Air (HEPA) filters; powered air-purifying respirator equipped with a tight-fitting facepiece (either half- or full-face) and HEPA filters; supplied-air respirator operated in pressure demand or continuous flow mode and equipped with a hood or helmet, or tight-fitting facepiece (either half- or full-face).

(ii) *Industrial, commercial, and consumer activities.* Requirements as specified in § 721.80 (j), (v)(1), (w)(1), and (x)(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), (d), (e), and (i) 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.

(3) *Determining whether a specific use is subject to this section.* The provisions of § 721.1725(b)(1) apply to this section.

[73 FR 65763, Nov. 5, 2008]