Research suggests shampoo ingredient causes abnormalities in baby mice

The project, which was headed up by Dr. Steven Zeisel saw DEA applied to the skin of pregnant mice. The experiment used a formula that included 80mg/kg of DEA - claimed to be a relatively low formulation ratio.

According to Dr. Zeisel, the results showed that due to perturbed choline metabolism in the liver the ingredient prevented cell growth and increased cell death in an area of the brain used for memory, known as the hippocampus.

Likewise, the results also showed that the number and size of the litters was reduced for the mice after exposure to DEA under laboratory conditions.

In its conclusion regarding DEA exposure in mice, the UNC research team said that, "our work suggests that it may have adverse effects on pregnancy outcome and on brain development."​

The results of the study were made public in a presentation given by Dr. Zeisel during a teleconference held at the University last Thursday.

Although he stressed that the research was still incomplete and that the evidence did not pose any immediate risk to pregnant women exposed to normal levels of DEA found in shampoo and other personal care products, he did say that more research work would have to be carried out in the field before full conclusions can be drawn.

Dr. Zeisel also said the team's research found that triethanolamine (TEA), a substance that manufacturers sometimes substitute for DEA, also perturbed choline metabolism, a matter the research team also plans to explore further.

Currently over 100,000 tonnes of DEA are produced in the US each year. It is mainly used in consumer products, where it is most commonly found in personal care products, but is also found in pharmaceutical and agricultural products.

In cosmetic products it is used as a surface-active or wetting agent in lotions and creams, together with shampoos and often represents up to 25 per cent of a formulation's ingredients. In the case of shampoos it is said to add a rich lather to formulations.

According to the US-based International Agency for Research on Cancer, the ingredient is also said to be a known carcinogen. This only happens when it combines with other cosmetic ingredients to form nitrosodiethanolamine (NDEA).

The cancer agency says that NDEA is readily absorbed through the skin and has been linked with stomach, esophagus, liver and bladder cancers.