Cosmetic Talc Should Not Be Listed as a Carcinogen: Comments on NTP's Deliberations to List Talc as a Carcinogen

Abstract

Concerns that cosmetic talc might be carcinogenic are addressed and shown to lack persuasive scientific support. These concerns are based (1) on several, but not all, retrospective epidemiological, statistically barely significant case-control studies of questionable biological import (Their results lack dose-response relationships, are inconsistent and ambiguous, and are therefore inconclusive. Whether inanimate talc particles can translocate from the perineum to the ovaries, a precondition if they were to cause ovarian cancer, remains unresolved.); (2) on one inhalation study in animals whose results, according to a panel of experts, “cannot be considered as relevant predictors of human risk,” a position shared by other experts in the field; and (3) on elevated incidence of lung cancer in pottery workers. These workers were occupationally exposed several decades ago to nowadays impermissible concentrations of aerosols comprising a multitude of industrial dusts. To construe a risk for the consumer of pure cosmetic or pharmaceutical-grade talc under consumer conditions, based on these findings, lacks scientific support. Talc is not genotoxic, is not carcinogenic when injected into ovaries of rats, does not cause cancer decades after pleurodesis, and induces apoptosis in vitro in human mesothelioma cells but not in normal mesothelial cells. There is no credible evidence of a cancer risk from inhalation of cosmetic talc by humans. Considering talc a carcinogen lacks convincing scientific documentation.