The record
The IWGACP — subject-matter experts from eight federal agencies convened by FDA in fall 2018 — recommended that laboratories report all elongate mineral particles at least 0.5 micrometres in length with an aspect ratio of at least 3:1, count and report them as a function of sample mass, and use both PLM and TEM.
Claim scope
The government's technical counting criteria, and the reason a bulk-materials method is the wrong instrument: 'testing methods pertaining to asbestos in articles of commerce were developed for analyzing "bulk materials" containing at least 1% asbestos as an intentional ingredient.' The 2020 executive summary further recommends 'Testing laboratories report all EMPs having length ≥ 0.5 µm (500 nm)', that covered minerals include 'chrysotile (but not other serpentine minerals) and members of the amphibole group (inclusive; not restricted to the five amphiboles used commercially)', and 'Use of TEM at nominally 20,000x magnification'. The 0.5 µm floor is stated to be 'consistent with the counting rules for fibers established by the global standard for TEM sampling and analysis, ISO 10312:2019'. The final 2022 white paper adds reporting all such particles 'greater than or equal to (≥) 0.5 µm in length with a length to width aspect ratio (AR) ≥ 3:1'.
What this source does not establish
The IWGACP document carries an explicit disclaimer and is NOT agency policy: 'These recommendations do not represent proposed changes to any regulations of the U.S. Government' and 'do not necessarily reflect the opinions or policies of their agencies.' FDA's own page states the executive summary and public-meeting presentations 'do not represent proposed or preliminary recommendations or policies of the FDA or any other federal agency.' Critically, the IWGACP 'EMP' criteria are DELIBERATELY BROADER than 'asbestos' — they count non-asbestiform particles too. Do not equate an EMP count with an asbestos count.
Limitations
Two documents, two dates: the January 6, 2020 preliminary executive summary and the January 13, 2022 final peer-reviewed white paper. Cite the correct one for the correct claim. The IWGACP adopts the NIOSH Bulletin 62 term 'elongate mineral particle' precisely to sidestep the asbestiform/non-asbestiform naming fight — which is why defense-aligned literature contests it (see the cleavage-fragment findings).
Source
Gov Report — IWGACP, 'Preliminary Recommendations on Testing Methods for Asbestos in Talc and Consumer Products Containing Talc' (Executive Summary, January 6, 2020); final: 'IWGACP Scientific Opinions on Testing Methods for Asbestos in Cosmetic Products Containing Talc (including Talc Intended for Use in Cosmetics)', released January 13, 2022 (docket FDA-2020-N-0025); FDA Constituent Update January 13, 2022