2009 study posted for filing
FECYT – Spanish Foundation for Science and Technology
Baby bathwater contains fragrance allergens
A group of chemists from the University of Santiago de Compostela (USC) has developed a method to quantify the fragrance allergens found in baby bathwater. The researchers have analysed real samples and detected up to 15 allergen compounds in cosmetics and personal hygiene products.
A team of scientists from the Department of Analytical Chemistry, Nutrition and Bromatology at the USC has developed a method to detect and quantify the 15 most common fragrance allergens included in soap, gel, cologne and other personal hygiene products.
“Applying the method to eight real samples obtained from the daily baths of a series of babies aged between six months and two years old, we discovered the presence of all the compounds under study in at least one of the samples,” co-author of the study published this month in Analytical and Bioanalytical Chemistry, María Llompart, explained to SINC.
The scientists found at least six of the 15 compounds in all the samples. In some cases, concentrations were “extremely high”, exceeding 100ppm (parts per million = nanograms/millilitre). Some of the substances that appeared were benzyl salicylate, linalol, coumarin and hydroxycitronellal.
“The presence and levels of these chemical agents in bathwater should be cause for concern,” Llompart said, “bearing in mind that babies spend up to 15 minutes or more a day playing in the bath and that they can absorb these and other chemicals not only through their skin, but also by inhalation and often ingestion, intentional or not.”
New Method to Detect Fragrances
Allergens were able to be detected due to the high level of sensitivity of the method, which for the first time applies the Solid-Phase Micro Extraction (SPME) technique to determining the ingredients of cosmetics and child hygiene products. This technique makes it possible to concentrate and isolate chemical components from a sample by absorbing them into fibres with a certain coating.
The researchers have also employed gas chromatography to separate compounds and mass spectrometry to identify and measure the abundance of each of the fragrances.
European regulations stipulate that the presence of such substances should be indicated on the label of the product when levels exceed a certain limit (0.1 or 0.01%, depending on the type of compound), but some associations believe these limits are excessively tolerant, particularly where child hygiene and baby and child care products are concerned.
J. Pablo Lamas, Lucia Sánchez-Prado, Carmen Garcia-Jares y María Llompart. “Solid-phase microextraction gas chromatography-mass spectrometry determination of fragrance allergens in baby bathwater”. Analytical and Bioanalytical Chemistry 394 (5): 1399-1411, julio de 2009.
Considerably more people than previously believed are allergic to the most common fragrance ingredient used in shampoos, conditioners and soap. A thesis presented at the Sahlgrenska Academy, University of Gothenburg, Sweden found that over 5% of those who underwent patch testing were allergic to the air oxidized form of the fragrance ingredient linalool.
“I would suspect that about 2% of the complete population of Sweden are allergic to air oxidized linalool. That may not sound very much, but it is serious since linalool is so widely used as a fragrance ingredient. Linalool is found in 60-80 percent of the perfumed hygiene products, washing up liquids and household cleaning agents that can be bought in the nearest supermarket, and it can be difficult for people who are allergic to avoid these products”, says dermatologist Johanna Bråred Christensson, author of the thesis.
Around one person in five in Sweden has some form of contact allergy. Nickel is by far the most common substance that causes eczema, but the thesis shows that oxidized linalool occupies third place in the list, after nickel and cobalt.
In the study, oxidized linalool was added at patch testing for more than 3,000 patients who wanted to find out what was causing their eczema. Between 5% and 7% proved to be allergic to the oxidized form of the fragrance ingredient.
“Linalool is present in many products around us, and this is probably the reason that contact allergy to this material is so common. Some people can shower with shower cream that contains linalool but never develop contact allergy, but we know that the risk increases as the exposure to t! he substance increases”, says Johanna Bråred Christensson.
Linalool is a fragrance ingredient found naturally in lavender, mint, and other plants. Linalool breaks down when it comes into contact with oxygen, it becomes oxidized and can cause allergy. Manufacturers do include other substances in the products to delay this oxidation process, but allergenic substances can st! ill be formed from linalool when it is stored.
“One way of trying to minimize exposure to oxidized linalool is to avoid buying large packs of soap and shower cream, and always to replace the top after using a bottle”, says Johanna Bråred Christensson.!
EU legislation states that manufacturers must specify on the labels of hygiene products whether they contain linalool. Previous studies have shown that oxidized linalool may cause contact allergy in about 1% of patients with eczema.
BRIEF FACTS: COMMON CONTACT ALLERGENS
Around 10-15% of all Swedes are allergic to nickel, and this is the ! most common form of contact allergy. Another substance that may be present in imitation jewellery is cobalt, to which around 2 3% of the population is allergic. Linalool occupies third place in the list after nickel and cobalt. It has been estimated that 2% of all Swedes are allergic to linalool. Other substances that can cause contact allergy include various perfumes and preservatives.
The Sahlgrenska Academy
The Sahlgrenska Academy is the faculty of health sciences at the University of Gothenburg. Education and research are conducted within the fields of pharmacy, medicine, odontology and health care sciences. About 4000 undergraduate students and 1000 postgraduate students are enrolled at Sahlgrenska Academy. The staff is about 1500 persons. 850 of them are researchers and/or teachers.
This thesis is based on the following papers:
I. Air oxidation increases skin irritation from fragrance terpenes Bråred Christensson J, Forsström P, Wennberg A-M, Karlberg A-T, Matura M.Contact Dermatitis: 2009: 60: 32-40.
II. Oxidized linalool – a significant contact sensitizer Bråred Christensson J, Matura M, Gruvberger B, Bruze M, Karlberg A-T. Manuscript.
III. Hydroperoxides form specific antigens in contact allergy. Bråred Christensson J, Matura M, Bäcktorp C, Börje A, Nilsson JLG, Karlberg A-T.Contact Dermatitis: 2006; 55(4): 230-7.
IV. Limonene hydroperoxide analogues differ in allergenic activity. Bråred Christensson J, Johansson S, Hagvall L, Jonsson C, Börje A, Karlberg A-T.Contact Dermatitis: 2008; 59(6): 344-52