Preservatives in a Selection of Consumer Products Purchased in the United Arab Emirates
Fatima Al Mamari1,2*, Cecilia Svedman2, Lena Persson2, Malin Engfeldt2
1Clinical Dermatology Department, ZayedHospital , Abu Dhabi, UAE
2Department of Occupational and Environmental Dermatology, Skåne University Hospital, Lund University, Malmö
Background: In both Europe and the USA it is mandatory that personal care products are labelled with an ingredient list. This facilitates the possibility to assess exposure to known contact allergens. However, if the products are incorrectly labelled it might pose an obstacle for patients trying to avoid allergens and obstruct the evaluation of clinical relevance for the clinician.
Objectives: To investigate the consistency between labelling and chemically detected amounts of 7 preservatives in consumer products bought on the unregulated market of the United Arab Emirates (UAE) and compare the results with previous studies of the consistency on the European market.
Material/Methods: 64 personal care products and 2 washing-up liquids purchased in the UAE had their ingredient label examined and were analyzed with high-performance liquid chromatography with regard to formaldehyde, methylchloroisothiazolinone/methylisothiazolinone, methyl-, ethyl-, propyl- and butylparaben. Formaldehyde was first screened with the chromotropic acid method.
Results: According to labelling, the most prevalent preservatives were parabens, phenoxyethanol and sodium benzoate. Parabens were detected in 33 (50%) products. Formaldehyde was detected in 16 (24%) products; in 2, a conditioner and a wash-up liquid, the concentration was above 500 ppm. MCI/MI or MI was found in 18 (27%) products. In 4 products, 3 wet wipes and 1 shampoo, the amount of MI was >100 ppm, i.e. higher than allowed within the EU. 23 (36%) products had ingredient labelling that deviated from the analytically detected amounts of the 7 investigated preservatives. In 9 of these labelled preservatives could not be detected, in 14 non-labelled preservatives were found and in 1 both deviations occurred.
Conclusion: The consistency between labelled and detected preservatives on the unregulated market of UAE is similar to that of the European market just as the current regulation came into act. Many products were incorrectly labelled which might affect consumer safety.
Keywords: Allergy Contact Dermitites; Preservatives; Consumer Product Safety; Methylchloroisothaiazolinone/ Methyliosothiazoline;Formaldehyde; Parabens; High-Performance Liquid Chromatography; Chromotropic Acid Method
Preservatives are added to water-containing consumer products to inhibit microbial growth which may destroy or alter the product. However, many preservatives can cause contact allergy and they are, second to fragrances, the most common cause of cosmetic-related contact allergy . Some preservatives, such as those containing methylchloroisothiazolinone (MCI) are strong contact allergens, while others like parabens, relatively rarely cause allergic contact dermatitis . Some, like formaldehyde and formaldehyde donors, are ubiquitous and the extensive exposure contributes to high frequencies of contact allergy . Recently, the association between exposure and allergy frequencies has been illustrated by the much debated rapid increase in the prevalence of contact allergies to methylisothiazolinone (MI) in several European countries [4-9]. This has been attributed to an increased exposure of MI due to the regulation that came into act in 2005 which allowed MI to be used in 100 ppm in cosmetics and personal care products .
Table 1. Chromatographic conditions for HPLC analyses of the 7preservatives as well as data on detection limits, recoveries and manufacturer of reference substances.
*given as a range of quadraple samples for formaldehyde and MCI/MI and as a range of double samples for the parabens
Double samples of approximately 1 g of each product was weighed and placed in graded test tubes to which solvents were added up to the 10 ml grading and stirred in a vortex mixer. This was done for all products with exception for the analyses of wet tissues. Double samples of each tissue brand were prepared by dissolving 1 tissue in 40 ml of solvent. For the analysis of MCI, MI and the 4 parabens the mobile phase was used as solvent (Table 1, 2) while tetrahydrofuran:water (9:1 v/v) was used when preparing samples of formaldehyde (Table 2).
Table 2. Solvents and concentrations used during sample preparation.
*preparations of the standards were made on a stock solution consisting of MCI:MI in the ration 3:1. The two preservatives were analysed in the same runs.
** preparations of the standards were made on a stock solution containing all the listed parabens in the same concentrations. The four parabens were analysed in the same runs.
The paraben samples were diluted another 10-25× before analysis. Samples containing wet tissues were diluted 10× before analysis. Standard solutions were prepared in the concentrations listed in Table 2. The formaldehyde samples were treated according to a method where 2,4-dinitrophenylhydrazine (2,4-DNPH) is used as a derivatizing agent and has been described in detail by Horev et al .
To estimate the recovery of a preservative, quadruple samples were made where a known amount of the preservative was added to products not containing the actual preservative. The preservative was added to the products to give a concentration corresponding to approximately 10 ppm and the spiked samples were then analyzed according to the specific methods. In Table 1 the recoveries are listed.
According to the ingredient labelling 23 products did not contain any of the 7 analyzed preservatives while 41 products were declared to contain at least one of them (Table 3). Parabens were most commonly declared and were listed on 24 of the 66 products followed by phenoxyethanol and sodium benzoate which were also commonly declared (Table 3).
Table 3. The number of products with labelling of preservatives as well as the number of products where the 7 investigated
preservatives were chemically detected together with the found concentration range.
*The cosmetics regulation does not apply to washing up liquids; **detected amount of MCI in products containing the combination, no products contained MCI alone;
*** detected amount of MI (both alone and in combination with MCI); § total amount of MCI/MI in products containing the combination
With regard to the 7 analyzed preservatives the declining order of presence in products according to declaration was methylparaben, propylparaben, MCI/MI, ethylparaben, butylparaben and MI and MCI declared alone. No products were declared to contain formaldehyde, however, 3 formaldehyde donors were found in the ingredient lists; 2-bromo-2-nitropropane- 1,3-diol in1 leave-on product, DMDM hydantoin in 6 rinse-off products and 3 leave-on products and imidazolidinyl urea in 1 rinse-off product and 2 leave-on products (Table 3). No analyses of these preservatives were performed. Instead the content of free formaldehyde was measured in all products. Formaldehyde could be found in 7.7 % (4/52) of the products not declared to contain formaldehyde donors. In two products, 1 declared to contain DMDM hydantoin and one declared to contain imidazolidinyl urea, no formaldehyde could be detected. Overall formaldehyde was detected in 24% (16/66) of the products (Table 3). In 2 products, 1 conditioner and 1 wash-up liquid the amount was above 0.05% with values corresponding to 0.085 and 0.070%, respectively.
According to declaration 2 leave-on products contained only MI and 2 only MCI while 10 rinse-off and 4 leave-on products were declared to contain both MCI and MI. Analyses showed that MI that was not declared on the labelling could be found in 12% (3/25) of these products (including one of the two washing liquids). One wet tissue was labelled to contain only MCI but instead it only contained MI. Overall; MI was detected in 27 % (18/66) of the products (Table 3). In 4 products, 3 wet wipes and 1 shampoo, the amount was higher than allowed within the EU with found concentrations of 201.5, 119.5 and 109 ppm for the wet wipes and 109.5 for the shampoo. MCI was found in 4% (1/25) of the products (one of the washing liquids) without being declared. In three products declared to contain MCI no amounts could be detected.
24 products were declared to contain any of the 4 parabens investigated (Table 3). In 33% (8/24) the content did not match the labelling with regard to which of the four parabens that were present. Furthermore, one or more of the parabens could be found in 17.5% (7/40) of the products lacking declaration of containing parabens.
In total, there were 23 personal care products (36%) where the ingredient labelling of the 7 investigated preservatives was inconsistent with the analytically detected amounts (Table 4). In 10 (16%) the labelled preservatives could not be detected and in 14 (22%) preservatives not declared on the ingredient labelling was found (Table 4). The two washing liquids were only declared “preservatives”. Chemical analysis showed that 1 contained formaldehyde, ethylparaben and MCI/MI while the other contained ethylparaben and methylparaben.
It can be difficult to assess if a contact allergy to a preservative is clinically relevant since the concentration in personal care products often is so low that patch testing with the product itself gives rise to negative patch test results. Still, they might cause allergic contact dermatitis if used for a prolonged time. The mandatory labelling within the EU of personal care products has facilitated the exposure assessment to allergens and thereby enabled to diminish the risk of allergic contact dermatitis. Consequently, it is important that the labelling is correct so that the attentive consumer is not unknowingly exposed to substances that he or she is actively avoiding.
According to labelling, the most commonly declared preservatives amongst the investigated products were parabens followed by phenoxyethanol in different combinations. Furthermore, the number of preservatives used tended to be higher in leave-on than in rinse-off products (Table 3). These findings are in concordance with a recently published study from Germany  where the same pattern was seen. However, a higher rate of products declared to contain MCI/MI was found in the products from UAE compared to those from Germany and the same was seen for formaldehyde releasers.
With regard to the question; can ingredient labelling be trusted? The chemical analysis of the 7 preservatives showed that 25% of the soaps/shower gels, 18% of the moisturizers/facial creams, 42% of the shampoos/ conditioners and 53% of the wet tissues had ingredient labelling that deviated from the chemical analysis (Table 4).
Table 4. Deviations in the consistency between labelled and chemically found data of the 7 investigated preservatives.
This corresponds to figures seen in studies performed just around the time of the regulatory introduction of ingredient lists on consumer products [14-16]. However, there seem to have been an adaptation to a better adherence to the legislation, in at least Sweden, in recent years. Unpublished results from a survey conducted at the Department of Occupational and Environmental Dermatology in Malmö in 2005, where 67 skin care products marketed for use in industrial settings were analyzed 16.7% of the soaps and 3.2% of the moisturizers or protective creams had ingredient labelling that deviated from the chemical analysis and in a survey performed by the Swedish Medical Products Agency in 2012 10.8% of chemically investigated moisturizers were incorrectly labelled. In a recent study 60 Israeli brand cosmetics were investigated with regard to 4 common preservatives (18) and all but one product was within the allowed concentrations by the European directive. Israel is not a part of the European Union, yet, the Israeli ministry of health demands its implementation by Israeli producers . So, it seems that the EU regulation has led to improvements in the trustworthiness of ingredient labelling on the European market and on markets implementing the EU regulation. However, the results of the present study indicates that the concordance between labelling and chemically found preservatives in products on an unregulated market is about the same as it was in Europe in the late 90’s just as the current regulation came into act. This might have significant impact upon how clinical relevance is assessed in the country. It might also affect the possibility to assess clinical relevance in countries on regulated markets; in aglobalized world where people and goods travel long distances products bought on un-regulated markets might end up in the bathroom cabinets in regulated markets.
It is evident that regulatory measurements can affect the contact allergy rates in society as shown by the recent epidemic of MI-allergy . In this study, MI was detected in 27% of the analyzed products (Table 3). In 3 wet wipes and 1 shampoo the amount was higher than allowed within the EU. MCI was found in 4% of the products (one of the washing liquids) without being declared. In three products declared to contain MCI no amounts could be detected. One wet tissue was labelled to contain only MCI but instead it only contained MI. Since MCI is always used in combination with MI in commercially available preservatives it can be assumed that products declared to contain only MCI are incorrectly labelled.
Chemical analysis of the patients’ own products is an important tool in the investigation of allergic contact dermatitis since patch testing with products that contain low concentrations of allergens might give “false negative results”. Recently, Hauksson et al showed that repeated open applications of moisturizers containing such low concentrations of formaldehyde as 2.5-10 ppm can deteriorate or prolong the healing of dermatitis . In the present study, formaldehyde in the range of 6-850 ppm was found in 8% of the products not declared to contain formaldehyde or any formaldehyde donors. In one of these products the content was above 0.05% and thus, if sold on the European market, it should have been labelled “contains formaldehyde”. In two products the content was below 20 ppm, which is not necessarily a sign of incorrect labelling since other substances such as surfactants can release formaldehyde [21, 22]. Notable, is that many of the deviations stemmed from preservatives that were labelled on the package and then not found when analyzed. This might appear as a minor problem but there is a large number of patients who thoroughly work to avoid substances that they are allergic to and who sometimes get very restricted in what they can use. For these patients incorrect labelling leads to further restrain in life but for no reason.
The clinical relevance of preservative contact allergy can be difficult to assess since the concentration in products often is so low that a positive reaction is not elicited when patch testing the product. However, prolonged use of the product can cause allergic contact dermatitis or worsen an existing dermatitis. Therefore, ingredient labelling is an important tool for allergic consumers to be able to actively avoid substances they are allergic too. This study shows that the compliance of labelling and chemically found preservatives on the unregulated market of UAE is similar to that of the European market just as the current regulation in Europe came into act. Many products were incorrectly labelled which might have a significant effect upon consumer safety.
Cite this article: Mamari F. Preservatives in a Selection of Consumer Products Purchased in the United Arab Emirates. J J Exper Derm. 2014, 1(1): 005.