Ask a RIFM Scientist

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Headshot of Yax Thakkar

What is genotoxicity, and why study it?

Yax Thakkar, MS

Genotoxicity is the potential of a substance to alter or damage the genetic material (DNA). Genetic integrity is paramount to our health because alterations in DNA can increase the possibility of more serious effects, including cancer. Therefore, the fragrance industry will ban for use any fragrance ingredient found to be genotoxic via the International Fragrance Association (IFRA) Standards.

RIFM tests for two properties to determine whether an ingredient is genotoxic: “mutagenicity” and “clastogenicity.”

Mutagenicity refers to a fragrance ingredient’s potential to cause mutations in DNA that may result in permanent change. The Ames test is the most common screen for mutagenicity. The Ames test exposes bacterial strains of Salmonella and E. coli to the fragrance ingredient. We can tell if the ingredient has a mutagenetic effect by the number of mutated bacteria caused by the exposure.

Clastogenicity is an ingredient’s potential to cause breaks that lead to deleted or rearranged chromosome sections. The most common test for clastogenicity involves exposing human cells in a test tube or Petri dish to a fragrance ingredient and observing whether or not this results in chromosomal damage.

If both tests are negative, we know that the ingredient does not pose a risk for genotoxicity in humans.

RIFM adheres to a rigorous follow-up protocol when we observe a positive result. For example, suppose the screening test for genetic mutation in bacteria delivers a positive result for mutagenicity. In that case, we follow up with a more focused Petri dish test using mammalian cells more representative of those in humans, along with an analysis in a 3D human skin model.

If the Petri dish screening test for broken DNA in human cells is positive for clastogenicity, RIFM conducts a more refined 3D skin micronucleus test to verify the results.

IF RIFM concludes on a sound scientific basis that a fragrance ingredient is genotoxic, it will be banned.

Senior Scientist Yax Thakkar, MS, leads RIFM’s genotoxicity research and safety assessment programs.