The Committee for Risk Assessment (RAC) has adopted an opinion that could radically change how Talc (Mg₃H₂(SiO₃)₄) is regulated in the European Union.
On 20 September 2024, tRAC proposed a harmonized classification of talc as:
- Carcinogen category 1B (H350 – May cause cancer)
- STOT RE 1 (H372 – Causes damage to organs through prolonged or repeated exposure, by inhalation)
This initiative, submitted by the Netherlands, specifically concerns asbestos-free talc, distinguishing it from talc contaminated with asbestos, which is already known to be hazardous.
Talc is widely used across various industrial sectors, from paper and ceramics production to agriculture, and as a filler and anti-caking agent in numerous products, including cosmetics. Previously, the International Agency for Research on Cancer (IARC) classified perineal use of talc as “possibly carcinogenic to humans” (Group 2B) in 2006, while inhalation exposure was not classifiable. However, in June 2024, IARC revised its assessment, concluding that talc is “probably carcinogenic to humans” (Group 2A), without distinguishing between routes of exposure, based on limited human evidence, sufficient animal evidence, and strong mechanistic data.
The initial proposal by the Dossier Submitter (DS) was to classify talc as Carc. 2 (suspected human carcinogen) and STOT RE 1 (target organ toxicity – repeated exposure, category 1) for the lungs via inhalation. However, the RAC’s final opinion proposes a stricter classification: Carc. 1B (presumed human carcinogen) and STOT RE 1 (lungs, inhalation).
Why This Classification?
The RAC’s decision is based on a complex evaluation and combination of animal studies and epidemiological data:
Carcinogenicity:
- Ovarian Tumors (Human Evidence):
The RAC found limited but credible evidence of an association between perineal use of talc and increased ovarian cancer risk (20–60%, stabilized around 20–30% in meta-analyses). This is supported by the detection of talc particles in ovarian tumor tissues and studies suggesting that talc may migrate to the ovaries. - Lung Tumors (Animal Evidence):
Studies in female rats showed the development of lung tumors following talc inhalation. Although these tumors were not observed in males or mice, the RAC considers rats to be a relevant model for humans. Talc demonstrated specific toxicity and inflammatory properties, regardless of “lung overload.”
Specific Target Organ Toxicity – Repeated Exposure (STOT RE):
The STOT RE 1 (lungs, inhalation) classification is supported by consistent human evidence from numerous epidemiological studies on talc miners and workers, showing increased mortality from respiratory diseases, severe lung damage (pneumoconiosis), and impaired lung function. These results are corroborated by animal studies that observed severe and irreversible effects such as inflammation, granuloma formation, and fibrosis in the lungs of rats at relevant exposure levels.
The lungs are considered the target organ for inhalation exposure, while dermal and oral absorption are considered negligible.
The proposed mode of action for both tumor types (lung and ovarian) involves chronic inflammation and oxidative stress, leading to increased cell proliferation and tumor development. The biological plausibility of talc translocating to the ovaries and triggering an inflammatory response is considered robust.
In summary, based on limited but credible human evidence, limited animal evidence, and strong mechanistic support, the RAC concludes that classifying talc as Carc. 1B and STOT RE 1 is justified.
Impact on Chemical Companies
If the European Commission approves this proposal, talc will be included in Annex VI of the CLP Regulation. As a result, companies will need to update:
- Labeling and SDS: Talc will need to carry hazard pictograms (GHS08) and the phrases H350 and H372.
- Usage Restrictions: Companies will need to assess worker exposure and implement technical and organizational measures to reduce risks.
- Authorizations and Substitution: Talc may end up on future restriction or authorization lists. Companies should consider safer alternatives, especially in consumer products.
Conclusion
ECHA’s proposed classification of talc marks a paradigm shift for a material widely used in industrial and cosmetic applications. Companies must be prepared, not only to comply with regulations but also to genuinely protect the health of workers and consumers. Therefore, businesses using talc should act proactively, even though the classification is not yet legally binding.
Source:
https://echa.europa.eu/documents/10162/03b74f7b-10ca-3e74-514b-e7f2b24c98ec
