IARC Upgrades Talc Classification
On July 5, 2024, the International Agency for Research on Cancer (IARC), part of the World Health Organization, classified talc as Group 2A: probably carcinogenic to humans.
This represents an upgrade from talc’s previous Group 2B classification (“possibly carcinogenic”), reflecting growing scientific evidence of cancer risks.
Evidence Behind the Classification
The IARC working group based its decision on:
Limited evidence in humans:
- Increased ovarian cancer rates in women exposed to talc occupationally
- Studies of women who used talcum powder for personal hygiene
- Occupational studies in pulp, paper, and cosmetics industries
Sufficient evidence in animals:
- Laboratory studies demonstrating carcinogenic effects
Strong mechanistic evidence:
- Inflammation pathways linked to cancer development
- Potential asbestos contamination during talc mining
The Asbestos Connection
A critical factor in the classification is that talc and asbestos form in the same geological deposits. During mining:
- Asbestos fibers can contaminate talc ore
- Complete separation is not always possible
- Contaminated talc carries the same cancer risks as asbestos
Asbestos-contaminated talc is classified as Group 1 (carcinogenic to humans), the highest classification level.
The FDA has stated there is no safe level of asbestos exposure.
What Group 2A Means
IARC classifications indicate the strength of evidence that a substance causes cancer:
| Group | Classification | Examples |
|---|---|---|
| 1 | Carcinogenic to humans | Asbestos, tobacco, processed meat |
| 2A | Probably carcinogenic | Talc, red meat, night shift work |
| 2B | Possibly carcinogenic | Gasoline, pickled vegetables |
| 3 | Not classifiable | Caffeine, cholesterol |
Group 2A means there is strong evidence of carcinogenicity but not quite enough to reach the “definite” threshold of Group 1.
Implications for Consumers
The classification reinforces concerns about talc-based products:
- Baby powders: J&J discontinued talc-based formula globally in 2023
- Body powders: Many brands have switched to cornstarch
- Cosmetics: Talc remains in some makeup products
Consumers can check product labels for:
- Talc
- Talcum
- Magnesium silicate
Relevance to Mesothelioma
A 2023 study in the Journal of Occupational Medicine and Toxicology examined 166 mesothelioma patients with talc exposure:
- 122 (73.5%) had talc as their only known asbestos source
- 74.7% of patients were women
- Average talc use: 40.8 years
Without documenting talc exposure history, these cases would have been classified as “idiopathic” (unknown cause) mesothelioma.
Industry Response
Industry groups, including the Essential Minerals Association, have disputed the classification, maintaining that pure talc does not cause cancer. However, the IARC classification reflects the real-world reality that talc contamination with asbestos has occurred and poses health risks.
Ongoing Litigation
The classification comes amid over 90,000 pending lawsuits against Johnson & Johnson related to talc products. Courts have awarded billions of dollars to plaintiffs who developed mesothelioma or ovarian cancer after using talc-based products.
The FDA has stated there is no safe level of asbestos exposure. Asbestos-contaminated talc carries the same cancer risks as asbestos and is classified as Group 1 (carcinogenic to humans)—the highest classification level.
What does Group 2A carcinogen mean?▼
IARC’s Group 2A classification means there is strong evidence of carcinogenicity but not quite enough to reach the “definite” threshold of Group 1. Other Group 2A carcinogens include red meat and night shift work. Group 1 includes asbestos, tobacco, and processed meat.
Why is talc linked to cancer?▼
Two reasons: (1) Talc forms in the same geological deposits as asbestos, and mining contamination can occur. Asbestos-contaminated talc carries known cancer risks. (2) Even pure talc shows evidence of carcinogenicity, with increased ovarian cancer rates in exposed women.
Is talc the same as asbestos?▼
No, but they’re related. Talc and asbestos are both silicate minerals that often form together. During mining, asbestos can contaminate talc ore. Pure talc is classified as Group 2A (“probably carcinogenic”), while asbestos-contaminated talc is Group 1 (“carcinogenic”).
What should consumers do?▼
Check product labels for talc, talcum, or magnesium silicate. Consider switching to talc-free alternatives like cornstarch-based products. J&J discontinued talc-based baby powder globally in 2023, and many brands have switched to cornstarch.