Cosmetic Ingredient Review Expert Panel. Final report of the safety assessment of methacrylate ester monomers used in nail enhancement products

Methacrylate Ester Monomers

The Expert Panel for Cosmetic Ingredient Safety reviewed newly available studies since their original assessment in 2005, along with updated information regarding product types and concentrations of use, and confirmed that these 22 methacrylate ester monomers are safe as used in nail enhancement products in the practices of use and concentration as described in this report, when skin contact is avoided.

2-Hydroxyethyl methacrylate (HEMA): A clinical review of contact allergy and allergic contact dermatitis-Part 1. Introduction, epidemiology, case series and case reports

2-Hydroxyethyl methacrylate (HEMA) has been increasingly recognised as a contact allergen and was added to the European baseline series in 2019. In this article (2 parts), the results of an extensive literature review of the clinical aspects of contact allergy/allergic contact dermatitis to HEMA are presented. In part 1, the epidemiology of HEMA contact allergy is discussed and detailed information on published case series and case reports presented. HEMA is an important cause of contact allergy/allergic contact dermatitis in North America and Europe with recent prevalences of >3% in the USA + Canada and 1.5%-3.7% in Europe. Currently, most cases are caused by nail cosmetics, both in consumers and professional nail stylists. In our literature review, we have found 24 studies presenting case series of patients with allergic contact dermatitis attributed to HEMA and 168 case reports. However, the presence of HEMA in the products causing ACD was established in only a minority. Part 2 will discuss cross- and co-sensitisation, and other skin reactions to HEMA, will assess whether HEMA is the most frequent (meth)acrylate allergen and how sensitive HEMA as a screening agent is, investigate the presence of HEMA in commercial products and provide practical information on patch testing procedures.

N-acetyl cysteine inhibits IL-1α release from murine keratinocytes induced by 2-hydroxyethyl methacrylate

The hydrophilic compound 2-hydroxyethyl methacrylate (HEMA) is a major component of dental bonding materials, and it enhances the binding of resin-composites to biomolecules. However, HEMA is a well-known contact sensitizer. We reported previously that intradermal injection of HEMA induces the production of IL-1 locally in the skin. Keratinocytes are the first barrier against chemical insults and constitutively express IL-1α. In this study, we analyzed whether HEMA induces the production of inflammatory cytokines from murine keratinocyte cell line Pam212 cells. We demonstrated that HEMA induced the release of 17-kDa mature IL-1α and caused cytotoxicity. The activity of calpain, an IL-1α processing enzyme, was significantly higher in HEMA-treated cells. The thiol-containing antioxidant N-acetyl cysteine (NAC) inhibited HEMA-induced IL-1α release but not cytotoxicity. NAC inhibited intracellular calpain activity and reactive oxygen species (ROS) production induced by HEMA. NAC post-treatment also inhibited IL-1α release and intracellular ROS production induced by HEMA. Furthermore, HEMA-induced in vivo inflammation also inhibited by NAC. NAC inhibited polymerization of HEMA through adduct formation via sulfide bonds between the thiol group of NAC and the reactive double bond of HEMA. HEMA-induced IL-1α release and cytotoxicity were also inhibited if HEMA and NAC were pre-incubated before adding to the cells. These results suggested that NAC inhibited IL-1α release through decreases in intracellular ROS and the adduct formation with HEMA. We concluded that HEMA induces IL-1α release from skin keratinocytes, and NAC may be a promising candidate as a therapeutic agent against inflammation induced by HEMA.

Assessment of work-related symptoms, perceived knowledge, and attitude among nail salon technicians

OBJECTIVES

Beauty is a Lebanese stereotype, as Lebanese women often feel urged to decorate themselves. Recent studies have raised concerns about nail salon technicians' (NSTs) health and safety issues. The aim of our study was to evaluate the occupational symptoms reported by NSTs, to assess their knowledge and document their awareness regarding hazardous chemicals found in nail cosmetics.

METHODS

NSTs completed a researcher-administered questionnaire. Data were gathered on sociodemographic characteristics, perceived knowledge, and safety issues. Work-related symptoms reported by NSTs were evaluated, and their responses were compared to those of the office employees.

RESULTS

A total of 120 NSTs and 120 office employees were interviewed. Compared to the control group, NSTs reported a higher prevalence of work-related respiratory, dermal, and irritative symptoms, all significantly associated with smoking and a poor ventilation system. In addition, musculoskeletal complaints were common among NSTs and significantly linked to a poor ventilation system, an increased number of customers per day, and a longer service duration. Furthermore, a longer career duration was significantly associated with an increased prevalence of irritative symptoms. When a binary logistic regression was carried out, it demonstrated a 25 times higher prevalence of work-related symptoms among NSTs compared to the office employees. Interestingly, 84% of the respondents had an inaccurate knowledge of nail cosmetics' risks with their educational level acting as key factor.

CONCLUSIONS

Based on these findings, it is warranted to perform a clinical assessment, implement a stringent regulatory framework, and improve knowledge toward nail cosmetics' risk.

Use of Protective Gloves in Nail Salons in Manhattan, New York City

Objectives:

Nail salon owners in New York City (NYC) are required to provide their workers with gloves and it is their responsibility to maintain healthy, safe working spaces for their employees. The purpose of this study was to determine the frequency with which nail salon workers wear protective gloves.

Methods:

A Freedom of Information Law request was submitted to New York Department of State’s Division of Licensing Services for a full list of nail salons in Manhattan, NYC. A sample population of 800 nail salons was identified and a simple random sample (without replacement) of 30% (n=240) was selected using a random number generator. Researchers visited each nail salon from October to December of 2015, posing as a potential customer to determine if nail salon workers were wearing gloves.

Results:

Among the 169 salons in which one or more workers was observed providing services, a total of 562 workers were observed. For 149 salons, in which one or more worker was observed providing services, none of the workers were wearing gloves. In contrast, in six of the salons observed, in which one or more workers was providing services, all of the workers (1 in 2 sites, 2 in 1 site, 3 in 2 sites, and 4 in 1 site) were wearing gloves. Almost three-quarters of the total number of workers observed (n=415, 73.8%) were not wearing gloves.

Conclusions:

The findings of this study indicate that, despite recent media attention and legislation, the majority of nail salon workers we observed were not wearing protective gloves when providing services.

Assessment of occupational symptoms and chemical exposures for nail salon technicians in Daegu City, Korea

OBJECTIVES

This study aimed to evaluate occupational symptoms and chemical exposures of nail salon technicians.

METHODS

Work-related symptoms of nail salon technicians in Daegu City were surveyed using a researcher-administered questionnaire, and responses were compared to those of non-exposed office workers as controls. Personal exposure level of airborne volatile organic compounds was also monitored using passive samplers.

RESULTS

A total of 159 subjects in 120 salons were interviewed. Average work-shift concentrations of 13 chemicals were measured for 50 workers from 30 salons using personal passive samplers. The most frequently reported respiratory or neurologic symptoms by nail shop technicians compared to controls were nose irritation (odds ratio [OR], 54.0; confidence interval [CI], 21.6 to 134.8), followed by headache (OR, 9.3; CI, 4.7 to 18), and throat irritation (OR, 4.3; CI, 2.2 to 8.5). For eyes and skin, 92% of respondents complained eye irritation (OR, 13.1; CI, 5.7 to 30.1). In musculoskeletal symptoms, workers reported pain or discomfort in shoulders (OR, 20.3; CI, 7.7 to 54) and neck (OR, 19.7; CI, 8.9 to 43.6). From personal measurements, the proportion of exceeding the Korean Occupational Exposure Limit was the highest for acetone with 64%, followed by toluene (50%), butyl acetate (46%), and methyl methacrylate (12%). However, the service was being provided without a proper ventilation system in most surveyed shops.

CONCLUSIONS

Based on these findings, it is warranted to have appropriate local exhaust ventilation place to ensure adequate health protection of nail shop technicians as well as customers. At the same time, greater policy interests are warranted in nail care business to protect health of both workers and customers.