A scientific review of colorful textiles

Textiles, especially apparel, play an essential role in our daily life. Given that nearly everybody is in contact with clothes and other textiles 24 h a day, they have to be safe. Today’s manufacturing processes depend on the use of many different chemicals, including dyes. An ideal dye would stay within the fabric during use. However, most textile dyes are prone to leaching and wear-off. Ideally, the industry is trying to keep the respective release of dyestuffs as low as possible. Concomitantly, toxicological risk assessment has to evaluate whether the released amounts are safe based on the substance-inherent characteristics and expected levels of exposure. So far, assessments of the latter are mostly based on what little data is available. Although the use of worst-case scenarios makes systematic overestimation likely and thus warrants a sufficiently high level of consumer protection, existing data gaps should be filled in order to end this unsatisfactory situation. Hence, in a first step this paper compiles and analyzes available data on the migration of dyes from textile materials, dermal dye uptake, and possible reductive cleavage of azo dyes by the skin microbiome as well as the dermal uptake of the resulting cleavage products.