What is it?
An extract of Asparagopsis armata, a red seaweed native to Western Australia that has spread along European coasts, including Portugal and the Azores, and has been farmed in Ireland since the 1990s for cosmetic extracts. The seaweed is rich in bromine and makes halogenated compounds that help it fend off bacteria and crowd out other algae. In cosmetics, including eye creams, the extract is listed as a skin-protecting and skin-conditioning ingredient.
Key information
- In 2021 the CIR Expert Panel found the data insufficient to conclude that Asparagopsis Armata Extract is safe in cosmetics and asked for systemic toxicity data.
- Human tests of products containing 0.325 percent, and of a mixture with 0.3 to 2 percent, of the extract found no allergic reactions.
- The extract was reported in 18 cosmetic products, at concentrations of 0.031 to 0.33 percent.
- Asparagopsis seaweeds make bromoform, which IARC considers not classifiable as to its carcinogenicity in humans; a 2024 laboratory analysis did not detect it in a water-ethanol extract.
More information
Asparagopsis seaweeds are best known for making bromoform, a small brominated compound that cuts methane production when the dried seaweed is added to cattle feed. Batches used in livestock feeding trials have contained about 1.3 to 7.8 milligrams of bromoform per gram of seaweed. Bromoform is also a by-product of chlorinating drinking water. The International Agency for Research on Cancer (IARC) places it in Group 3, not classifiable as to its carcinogenicity to humans, and the World Health Organization’s drinking-water guideline is 100 micrograms per liter.
Whether bromoform ends up in skin care extracts is not well documented. A 2024 study of a water-ethanol extract of A. armata found high levels of bromine but did not detect bromoform, and the crude extract was toxic to skin cells in the laboratory at higher concentrations.
The Cosmetic Ingredient Review (CIR) Expert Panel’s 2021 review of red algae ingredients, which does not discuss bromoform, found the data insufficient to support the extract’s safety. The tests that exist were reassuring: products containing 0.325 percent, and a mixture with 0.3 to 2 percent, caused no allergic reactions in people, in vitro skin irritation and bacterial mutagenicity tests were negative, and the oral median lethal dose in rats was above 2,000 mg/kg. One in vitro eye test showed slight irritation. The Panel asked for systemic toxicity data, which it does not require for algae that are eaten as food, and asked manufacturers to limit arsenic, heavy metals and pesticide residues. The extract was reported in 18 products, at 0.031 to 0.33 percent.
Reality check: this extract is not the dried seaweed fed to cattle. It is used at a fraction of a percent; what is missing is the systemic toxicity data CIR asked for. On labels, look for Asparagopsis Armata Extract.
Sources: CIR: Safety Assessment of Red Algae-Derived Ingredients as Used in Cosmetics (final report, 2021); Marine Drugs (2024): Exploring the therapeutical potential of Asparagopsis armata biomass: a novel approach for acne vulgaris treatment; New Zealand Journal of Agricultural Research (2023): Methane reduction, health and regulatory considerations regarding Asparagopsis and bromoform for ruminants
