Several FDA Warning Letters and Untitled Letters on Asbestos Testing of Talc in OTC Drug Products

The U.S. Food and Drug Administration (FDA) has recently published several Warning Letters and Untitled Letters to OTC drug manufacturers. In these letters, FDA highlights that the affected companies did not have sufficiently robust testing programs and monitoring to control the risk of asbestos contamination in talc.

Background

Talc is a naturally occurring hydrated magnesium silicate and is widely used as an excipient in pharmaceutical formulations.

The United States Pharmacopeia (USP) has recently revised its talc monograph, including updated technical requirements for asbestos testing in talc. The revised monograph is scheduled to become official in June 2026. Further details are provided in the corresponding USP Publication Announcement.

What did FDA criticize?

In the Warning Letters and Untitled Letters published in June 2026, FDA reiterates a key point: "Both talc and asbestos are naturally occurring minerals that may be found in close proximity in the earth. Asbestos is a potential contaminant in talc and is a known human carcinogen when inhaled."

At the core of FDA’s observations is that the companies did not demonstrate appropriate testing of incoming talc components used in drug product manufacturing for identity, purity, strength, and quality. The findings concern companies globally, e.g., Japan, China, the U.S. (including Florida and North Carolina), Canada, Turkey, and India.

The cited deficiencies across the letters are very similar, some are even repeated verbatim. Examples include:

• "QU did not ensure that test procedures and specifications for talc are scientifically sound and appropriate."
• "The tests included in the specification were not performed according to current USP. You did not conduct testing using Atomic Absorption for Calcium and Assay Content of Magnesium as required by USP."
• "Your firm has not demonstrated that you appropriately tested incoming talc drug components or validated and established the reliability of your component supplier’s test analyses at appropriate intervals for talc."
• "You failed to have a specification that includes a test for the absence of asbestos"

FDA also reminds manufacturers that USP-recognized components are generally expected to meet the applicable compendial requirements: "Talc is a USP article, whose specification can be found in the current USP talc monograph. As mentioned above, the specific test for asbestos is included in the talc monograph. Be advised that drugs including components, such as talc, that are recognized in the USP are generally required to meet the current applicable USP monograph under section 501(b) of the FD&C Act".

Overall, companies must not only meet specific analytical requirements, but also demonstrate a risk-based, end-to-end understanding of talc-related hazards within their quality system.

Webinar: "Talc in Pharma"

In response to these developments, ECA has developed a Webinar on Monday, 21 September 2026 from 14:00–16:00 CEST.

During the Webinar, Dr Lance Smallshaw (UCB Biopharma SRL, Belgium), who is also a Board Member of the ECA Analytical Quality Control Group, will cover the following topics:

• Introduction to talc in pharmaceuticals
• ECHA classification and scientific basis
• USP monograph and analytical requirements
• FDA enforcement and compliance implications

A Q&A session will follow the presentation, giving participants the opportunity to ask questions.