Migration and penetration of a fluorescent textile dye into the skin--in vivo versus in vitro methods

The amount of textile dye migration from the textile and penetration into the skin is relevant when assessing the risk of textile dyes. In this paper, in vivo methods were developed using a harmless textile dye with a strong fluorescence and were then compared with in vitro methods. For the in vivo method, the textile was applied to the lower back of six volunteers wearing the textile 12 h and to the lower back of 12 volunteers during 30 min active sport. The maximum skin absorption of 55 +/- 17 ng/cm(2) was obtained in the group engaged in sports. The in vitro methods, which involved the application of the textile to the pig ear skin, was shown to yield similar results to the 12 h in vivo group (31.2 +/- 9.6 ng/cm(2) vs 27 +/- 14 ng/cm(2)). The migration of the textiles into artificial sweat resulted in approximately 20 microg/cm(2). The disadvantage of such textile extract applications on pig ear skin is discussed. It could be demonstrated that the absorption of the dye is strongly correlated to the amount of sweat, whereas the contact time was less important.