Ask a RIFM Scientist: What is genotoxicity, and why study it?


From soaps and hand sanitizers to household cleansers, fragrance is an indispensable part of our lives, especially now amid the COVID-19 pandemic. For more than 50 years, the scientists at the Research Institute for Fragrance Materials (RIFM) have studied fragrance-producing ingredients to help ensure that consumers can enjoy the safe use of these essential products.

RIFM’s robust Safety Assessment program covers all known fragrance-producing ingredients in commercial use. RIFM’s scientists identify whether the ingredient poses any hazard, and how much, how often, and through which parts of the body a person may be exposed to it. Both exposure and hazard are needed to determine the risk.

Post-doctoral researcher Holger Moustakas, PhD, is part of the genotoxicity team at RIFM that evaluates the potential genetic impact of fragrance ingredients.

Q: What is genotoxicity, and why does RIFM study it?

A: Genotoxicity is the potential of a substance to alter or damage genetic material (DNA). Genetic integrity is paramount to our health because alterations in DNA can increase the possibility of more serious effects, including cancer.

Any fragrance ingredient found to be genotoxic will be banned for use by the Fragrance Industry through the International Fragrance Association (IFRA) Standards.

Q: How do you know if something is genotoxic?

A: To investigate this, we test for two properties of an ingredient: “mutagenicity” and “clastogenicity.”

Mutagenicity refers to an 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 refers to 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, including in humans.

Q: What happens if one of the tests is positive?

A: RIFM adheres to a rigorous follow-up protocol when we observe a positive result.

Mutagenicity: If the screening test for genetic mutation in bacteria delivers a positive result, we follow up with a more focused Petri dish test using mammalian cells that are more representative of those in humans, along with an analysis in a 3D human skin model.

Clastogenicity: If the Petri dish screening test for broken DNA in human cells is positive, 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.

Read more about the RIFM Safety Assessment process.