In Vivo Evaluation of the Protective Capacity of Different Gloves Against Hair Dyes

Hairdressers are taught to use gloves when dyeing hair. We wanted to study what gloves are recommendable for other common hair dye substances than p - phenylenediamine, such as toluene - 2,5 - diamine sulphate and 2‐ methoxymethyl ‐ p ‐ phenylenediamine. The gloves used in professional salons and the gloves commonly sold with hair dyes for home - use were investigated. 7 volunteers previously allergic to - 2,5 - diamine sulphate


Introduction
Hair dresser is a risk occupation due to wet-work and exposure to a multitude of chemical  [1,2]. However, a recent report has shown that, despite educational programs, hairdresser apprentices are still at increased risk of acquiring hand eczema [3]. Furthermore the hairdressers seem to acquire hand dermatitis after only a few years work.
According to Lysdal et al. [4], in Denmark hairdressers remain in the profession on average for 8.4 years and where hand dermatitis is a common reason for leaving the trade [4].
Gloves are usually evaluated with regard to the protective quality in in vitro studies [5]. However the hairdressers wear the gloves in their daily work, the glove is exposed to wear and tear, water and a multitude of chemicals. A more realistic evaluation of skin protection provided by a glove would be achieved by performing in vivo provocation tests with commonly used hair dyes, comparing different glove materials. In a previous in vivo study [6] we have shown that with regard to hair-colouring products containing p-phenylenediamine (PPD) the nitrile glove was superior.
In this study we wanted to test the protective effect of gloves further since not only PPD is used as hair colouring substance and hair dyeing also is performed at home where exposure conditions and glove recommendations may be different.

Aims of the Study
We wanted to verify the protective capacity of both nitrile and polyvinyl chloride gloves against hair dyes containing PPD, and investigate the capacity when

Hair dyes
Three permanent hair dyes (Table II) (Table II). The analysis with regard to PPD and 2,5-TDA content was performed also in the ME-PPD-containing hair dye, the two chemicals were not detected given the quantification limit of 0.05% w/w. The ME-PPD content of the hair dye was not analysed since the reference substance could not be purchased at the time. were scored according to the ICDRG criteria [8,9].
In Vivo "Provocation Test" The in vivo provocation test was carried out with an open chamber test system ( Figure 1) developed at the DOED in Malmö to evaluate in vivo the permeation through gloves of different chemicals [6,10]. The procedure of testing has been described elsewhere [6,10]. During the provocation the subject lies in the supine position exposing the back. The chambers with the substance to be tested are applied to the back for fixed periods of time. The procedure is carried out with standardised humidity and temperature.
The chambers are prepared with the glove material to be tested fixed with metal clips the bottom of the chamber ie where the chamber is fixed to the skin of back, thus acting as a membrane between hairdye and skin, simulating the actual effect of a glove in the same material (Fig 1,2).
In the study, the hair dye mixtures (prepared to simulate ordinary use, see above) was prepared within   with HDp-ME-PPD ( Figure 3, Table 3).
With the open chamber test with the 4H ® glove (negative control) and when the 4 hair dyes were tested with the 2 nitrile gloves there were no positive.
The polyvinyl chloride glove did not give any protection in 6 volunteers when used with the hair dye HDp-TDA-S, and neither in 5 volunteers when used with HDp-PPD and HDhu-TDA-S. Regarding the hair dye HDp-ME-PPD however no reactions were noted with the polyvinyl chloride glove (Table III). Statistically, the 4H ® glove gave better protection than the polyvinyl chloride glove for all hair dyes except HDp-ME-PPD (Table IV) (Table III).
Comparing the negative control with the polyethylene glove concerning the protection against the HDp-TDA-S, a statistical significance was indicated (p= 0.062) ( Table   IV) Table   3.  Table   4. Thus, the 4H ® and nitrile gloves gave complete protection regardless of what hair dye was used. For the polyethylene and polyvinyl chloride gloves, respectively, complete protection was obtained against the HDp-ME-PPD but not against the other three hair dyes (Table III, Figure 3).

Results
No association was found for the polyvinyl chloride glove concerning the individual degree of patch test reactivity to PPD and the protective capacity, whereas with regard to 2,5-TDA-S reactivity, a numerical but not statistical association was indicated.

Discussion
In a profession such as the hairdressers' where there is a huge exposure to both irritants and potentially contact allergic chemicals, the choice of gloves is of course important, and if advices can be based on evaluation simulating real life this is an obvious advantage. A method to evaluate the performance of glove material could thus be through in vivo studies mimicking the workplace exposure. In order to improve the advice given to hairdressers regarding protective gloves, we performed a study a few years ago [6] comparing the protective capacity of glove materials commonly used among hairdressers when exposed to a hair dye containing PPD. A good protection from nitrile gloves was noted. An interventional workplace-based study [11] concluded that when used correct, gloves can be protective in real work situations. Geens et al. [11] investigated the systemic exposure of hairdressers to 2,5-TDA-S and PPD using urine diamine biomarkers before and after ordinary work with permanent hair dyes the first week and again after providing nitrile gloves to hairdressers in the second week. Through the biomonitoring of PPD and 2,5-TDA-S a significant decrease of systemic exposure to 2,5-TDA-S but not to PPD was noted explained by the adequate use of nitrile gloves.
With regard to the exposure to hair dye ingredients, they vary qualitatively and quantitatively in different regions of the world. It is known that hair dyes in northern Europe more often contain 2,5-TDA or 2,5-TDA-S than PPD, or these dye ingredients combined [12][13][14]. Furthermore, products bought in non-European countries usually contain higher concentrations of PPD [12]. subjects) and polyethylene (tested in 5 subjects) with the HDp-ME-PPD, excellent protection was shown. On the other hand considering that the hair dye containing ME-PPD has recently been introduced on the market, we do not really know which reactivity pattern patients primarily sensitized to the ME-PPD would have.
Therefore a larger group of individuals should be tested to verify if the good protection provided by the gloves tested with this hair dye is due to a lower allergenic potential of the hair dye-ME-PPD-based. Previous patch testing with ME-PPD showed that there is decreased strength of elicitation response to this hair dye containing ME-PPD in PPD/TDA allergic subjects [17] and it has been shown that the hair dye products containing ME-PPD were tolerated by 29/43 PPD/TDA allergic individuals throughout continued hair dyeing with repeated treatments [18]. In our study we could not patch test with dilution series of the substance as such and thus we have no knowledge of the actual reactivity pattern with regard to ME-PPD. The two nitrile gloves gave complete protection with the three professional hair dyes at 45 minutes and with the home use hair dye at 30 minutes, comparable to the 4H ® glove ( Figure 3, Figure 4, 5), known to have excellent performance with regard to protection against chemicals [6,10].
In term of advice to hairdressers the study has shown that the nitrile glove must be the preferred choice during the hair dye procedures with the permanent hair dyes currently available. Also with regard to ME-PPD, nitrile gloves is easiest to advice since we know that these will protect the consumer. However limited, the study indicates that the use of hair dye for home use the gloves supplied in the package can be considered safe in term of hand exposure during the at-home dyeing procedure, taken into consideration that the exposure time is limited to 30 minutes. Of course this does not prevent the at-home dye consumer or the person visiting the hairdresser from the risk of sensitization since the major risk is the actual hair dyeing in the individual case.