The record
FDA's December 2024 proposed rule would have required manufacturers to test each batch or lot using BOTH polarized light microscopy with dispersion staining AND transmission electron microscopy with energy dispersive spectroscopy and selected area electron diffraction (TEM/EDS/SAED), and would have deemed a talc-containing cosmetic adulterated if any asbestos were present.
Claim scope
The specific method combination proposed, that it was batch/lot-level, that a supplier certificate of analysis was an allowed alternative provided both PLM and TEM/EDS/SAED were used, and that the rule incorporated ISO 22262-1:2012 Annex D (PLM reference images) and ISO 10312:2019 Annex C Figure C.1 (TEM morphology) by reference. Asbestos was defined as 'amosite, chrysotile, crocidolite; asbestiform tremolite, actinolite, anthophyllite, winchite, and richterite; and other asbestiform amphibole minerals.'
What this source does not establish
It establishes what FDA PROPOSED, not what the law requires. The rule was never finalized and was withdrawn (see below). Nothing in it is currently binding on any manufacturer.
Limitations
Critical framing rule for the page: this is a withdrawn proposal. Any sentence implying manufacturers are required to use PLM+TEM would be false.
Source
Federal Register — 89 FR 105490, 105490-105504 (proposed 21 CFR 730.3(c)); FR Doc. 2024-30544