FDA Public Meeting on Testing Methods for Asbestos in Talc & Cosmetic Products Containing Talc

On February 4, 2020, the U.S. Food and Drug Administration (FDA) held a public meeting concerning their proposed standardized testing methods for asbestos and other "biologically active" mineral particles in talc and talc-containing consumer products. FDA's goal is to finalize and publish these recommendations in a "white paper," the date of which has not been specified. The meeting details, including FDA's preliminary recommendations, agenda, slides from presentations by government representatives and the public, and a recording of the event, are available on FDA's website. Although the meeting has concluded, the public can still submit electronic/written comments into the docket until the deadline of March 4, 2020.

Motivation for public meeting

• In 2018, FDA formed the Interagency Working Group on Asbestos in Consumer Products (IWGACP) to support the development of standardized testing methods for asbestos and other "biologically active" mineral particles in talc and talc-containing consumer products.
• FDA believes that standardization is needed due to laboratories differentially adapting published methods for analysis of asbestos in air or building materials, which will result in improved sensitivity, consistency, and inter-laboratory agreement.

Purpose of public meeting

• To present IWGACP's "preliminary recommendations" related to terminology, analytical methods, and reporting, and receive public input on these preliminary recommendations.
• IWGACP's goal is to publish a "white paper" with the finalized recommendations.

IWGACP's "preliminary recommendations"

• Terminology and Definitions
  • IWGACP proposes to adopt the terminology of "elongate mineral particle" (EMP) published in National Institute for Occupational Safety and Health (NIOSH)'s Current Intelligence Bulletin 62 in 2011.
    • IWGACP proposes to define an EMP as any particle, asbestiform or non-asbestiform, with a minimum aspect ratio [i.e., length to width ratio] of 3:1.
  • IWGACP proposes to adopt, with modification, NIOSH's terminology of "covered mineral" and "countable EMP."
    • IWGACP proposes that covered minerals include chrysotile and members of the amphibole group (inclusive; not restricted to the five amphiboles used commercially).
    • IWGACP proposes that countable EMPs have an aspect ratio of >3:1 and a length of ≥0.5 μm.
• Sampling and Sample Handling
  • IWGACP has no specific recommendations for a sampling and handling protocol at this time but generally recommends one that results in confidence in the distribution of potential asbestos in the talc or talc-containing product.
    • IWGACP provided examples of factors to consider such as batch size, homogeneity of asbestos, chain-of-custody, measures against contamination, and collection of reserve samples for future re-testing.
• Sample Preparation
  • IWGACP recommends use of "validated" approaches for sample preparation.
• Analytical Methods
  • IWGACP considered X-ray powder diffraction (XRD), polarized light microscopy (PLM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM), noting that no single method can be regarded as "confirmatory."
  • IWGACP stated that if no EMPs are detected using XRD and PLM, IWGACP recommends using TEM with energy dispersive X-ray spectroscopy (EDS) and selected area electron diffraction (SAED) analyses because PLM is comparatively limited in its sensitivity.
    • IWGACP claims that SEM might be useful as a complementary method, but has significant shortcomings for identification of chrysotile and visualization of the narrowest particles that can only be overcome by using TEM.
• Laboratory Data Reporting
  • IWGACP recommends the counting and reporting of "covered" EMPs as a function of sample mass.
    • IWGACP recommends referring to guidelines such as ISO 10312:2019 to classify "primary" and "secondary" structures (e.g., bundles, clusters, fibers) when counting.
    • IWGACP recommends not reporting results in terms of "mass percent," a unit used to express asbestos content in commercial bulk materials, because mass percent does not correlate with the number of fibers.
    • IWGACP recommends reporting and counting all EMPs of covered minerals under a single classification with additional information that would allow further classification based on measurements such as mineral type and dimensions in the future.

How Can Exponent Help

Exponent has considerable experience in various aspects of asbestos- and talc-related exposure science, toxicology, epidemiology, risk assessment, and risk communication relating to exposures in the occupational, para-occupational, bystander, and domestic environment.

Our consultants can help you navigate the challenges of developing sampling protocols to understand the potential for the presence of asbestos and/or non-asbestiform minerals (e.g., cleavage fragments) in your products, and contextualize potential findings in relation to the state-of-the-science on exposure and health risk.