8 Conclusion

Survey and safety assessment of Chemical substances in artificial nails and nail hardeners

8.1 Recommendations to the consumers

The objective of this survey was

To make a survey of allergy causing chemicals in nail hardeners and products for manufacture of artificial nails to be sold to private persons from the retail trade, the internet and beauty shops.
Analyse selected products for their content of e.g. acrylic compounds
To perform health risk assessment of selected chemicals found during the analyses
To suggest a safe concentration of formaldehyde in nail hardeners.

A wide selection of products was purchased. Nail hardeners were purchased from the retail trade, while products for artificial nails could only be purchased from the internet.

The purchased products were examined for ingredients and their labelling was assessed. Many of the examined products appeared not to be in accordance with the demanded labelling requirements. Most significant was the insuffiently prepared ingredient declaration and the lacking directions for use. As shown in this survey, directions for use are imperative especially for artificial nail products to secure a correct application of the products on the nails, which is extremely important to avoid allergy health risks.

Nail hardeners were examined for free formaldehyde while the artificial nails were examined for different acrylic compounds.

None of the examined nail hardeners contained more than the permitted 5% formaldehyde. For only one product, formaldehyde was not on the list of ingredients, even if the content was greater than the demanded labelling requirement of 0.05%.

The investigations showed that the content of acrylates is very different from product to product. Within the framework of this project it was not possible to identify the complete composition of the products.

The health assessment of the products showed that especially contact allergy is the critical effect of the examined ingredients of the products.

A realistic worst-case scenario was set up for nail hardeners and the risk of systemic effects when using nail hardeners was calculated. The calculation showed that there is no risk of systemic effects when using nail hardeners containing the permitted amount of formaldehyde which is 5%. As formaldehyde can evaporate during the process, it is recommended to let in some air after application of nail hardeners to limit the exposure most possible by inhalation and deposition of vapour on the skin.

Formaldehyde may cause allergy and is classified as allergenic. Elicitation of allergy has been observed in formaldehyde sensitive persons in concentrations down to 0.05% formaldehyde, while induction of allergy in animal studies is seen at about 0.4 – 0.96% formaldehyde. The greatest risk of allergy is expected to develop if the nail hardener comes into contact with the skin. Exposure of the skin through application of nail hardener is expected to be limited, but application of nail hardener on the cuticle and the skin around the cuticle is hazardous and may cause allergic reactions. Irritation and allergy may also occur, if nail hardeners are applied on broken nails. In this case, formaldehyde may come into contact with the tissue under the nail and the risk of irritation and allergy will increase.

On the basis of the material generated in this project the permitted concentration of 5% is assessed to constitute a risk of allergy induction in healthy persons and a high risk of elicitation of allergy in formaldehyde sensitive persons. Based on the literature presented in this report, a maximum concentration of 0.01% formaldehyde in nail hardeners is assessed to be a safe concentration compared with the risk of allergy when applied both by healthy persons and persons already suffering from allergy. If the objective is to prevent healthy persons from developing formaldehyde allergy, a higher limit of concentration may be argued. However, this is difficult to set as there is no existing clear limit value for induction of formaldehyde allergy for this type of exposure. Formaldehyde is permitted as preservative in cosmetic products in a concentration of 0.2%. It can be argued that the concentration in nail hardeners as a minimum should not exceed this limit to diminish the risk of induction of allergy in healthy persons. A warning to already sensitive persons should appear on the product about the content of formaldehyde in a concentration above 0.05%. The Scientific Committee of Consumer Products (SCCP) of EU has been requested to assess a safe limit value of the content of formaldehyde in nail hardeners. This survey showed that several nail hardeners on the Danish market contains below 1% formaldehyde (4 out of 6 tested). Therefore, there are alternatives to the products containing larger amounts of formaldehyde. One of the six tested products only contains 0.01% formaldehyde.

The health assessment of products for building up artificial nails showed that there is no health risks of systemic effects related to the use. On the other hand, the risk of contact allergy by applying these products is assessed to be significant. This assessment was due to the amount of acrylates found in the products compared with the allergenic potential. Skin contact will result in a risk of contact allergy, if the products contain allergenic acrylate monomers in concentrations of up to 15%. This applies specifically for the gel nails that contain high concentrations (up to 8%) of particularly 2-hydroxyethyl acrylate, which is considered to be the ingredient with the highest allergenic potential of the tested ingredients. In patch tests with acrylate sensitized persons elicitation of allergy at concentrations of 0.1% 2-hydroxyethyl acrylate was observed. The acrylic nails (liquid and powder) appeared to produce a lower risk of contact allergy, as these products contain lower concentrations of the most allergy potent acrylates in these products. However using the products still constitutes a significant risk of allergy.

The conclusion of this survey project is that the products contain chemical substances in concentrations so high that they constitute a significant risk of contact allergy. The survey also demonstrates how important the application of this type of product is. It is suggested that professional and competent personnel builds up artificial nails instead of the consumer. This survey project does not comprise the working environment for personnel in beauty clinique’s etc., but it is important to emphasize that these products contain substances that may give rise to concern within the working environment. Many of the purchased products are marketed for professional use, but the private consumer is assessed not to have difficulty in obtaining the products for private use. However, the risk of contact allergy increases considerably by use, if the products come into contact with the skin. It is also assessed that the risk of skin contact decreases with the increasing experience in building up artificial nails.

8.1 Recommendations to the consumers

Be careful when applying nail hardener so that it only covers the nail and not the skin. This decreases the risk of formaldehyde.

To reduce the amount of formaldehyde that is inhaled and deposited on the skin, the room should be well aired when using nail hardeners

Do not use nail hardeners containing formaldehyde on broken nails. If the nail is broken, the ingredients can come into contact with the tissue under the nail and increase the risk of allergy.

Use qualified nail technicians for building up ”powder + liquid nails”, ”gel nails”, ”wrapping nails” and ”dip on nails”. These products should not be applied by private consumers, due to the increasing risk of exposure of allergenic substances when misused.