Textile production includes the use of a large diversity of chemicals, often in high amounts, and their presence in the finished textiles has become a topic of increasing concern. One of the health concerns associated with several of these compounds is skin sensitization, which may lead to the development of textile allergy. This thesis has a special focus on skin allergens and presents analytical methods and workflows to gain a deeper understanding of these chemicals in clothing.

In Paper I, a suspect screening of disperse azo dyes in synthetic clothing was conducted using liquid chromatography/high-resolution mass spectrometry (LC/HRMS). In addition, gas chromatography/mass spectrometry (GC/MS) was applied to screen for volatile/semi-volatile dye components. Various disperse azo dyes and arylamines were identified. Notably, most of the dyes used today to diagnose textile allergy were rarely identified. Further, the well-known skin sensitizer 2,4-dinitrochlorobenzene was shown to occur in garments for the first time. Paper II presents a screening method for textiles with automated thermal desorption (ATD) coupled to GC/MS. This method was used for accurate quantification of more than 30 volatile/semi-volatile compounds in textiles, but is also suitable for a wider range of semi-volatiles. Most analytes had method detection limits below 1 µg/g (26 out of 31 analytes) with a relative standard deviation <15%. The ATD-GC/MS method would allow companies to simultaneously screen for multiple components with a minimum of sample preparation, significantly enhancing efficiency and the ability to comply with regulations. 

Since several compounds identified in Papers I and II are suspected to cause skin sensitization, this was further studied and is the focus of Paper III. A combination of in vitro methods was employed to study the first and third key events of contact allergy as well as mutagenicity. Two hitherto unreported skin sensitizers and two mutagenic compounds were discovered. Despite this, the risks for skin sensitization or other non-carcinogenic health effects from exposure to these compounds in textiles were estimated as acceptable, at least when considering individual compounds and the levels so far reported.

In Paper IV, cellulose nanocrystals (CNCs) produced from upcycling post-consumer garments were screened for textile chemicals using a non-target/suspect screening approach with GC/MS and LC/HRMS. Generally, lower levels were detected in the cellulose nanocrystals. However, phthalates were found to remain mainly in the CNCs. Although the levels of phthalates in this case were below the EU regulation, this emphasizes the need for control of the garments.

In conclusion, this thesis has developed analytical methods and approaches that can be used for the surveillance and screening of chemicals in textiles, facilitating future identification of substances that constitute potential health risks.

As one of the top global industries, textile manufacturing utilizes several thousands of industrial chemicals, many of which end up in the finished garments. These residues constitute a widespread, possibly hazardous, exposure of the general population, yet the long-term health effects remain largely unknown. Skin allergy - a life-long, incurable condition – is one health effect of repeated skin exposure to one or several chemicals. Among the Western population, textile allergy is estimated to have a prevalence of around 1%.

Fast-fashion trends make the chemical content in everyday textile apparel hard to predict, as non-regulated chemicals are rapidly introduced into production. Only a tiny fraction of the used chemicals is hitherto regulated, and there is a lack of oversight regarding the content in everyday garments. A recently introduced EU legislation concerning handling textile waste motivates the development of alternative recycling methods for worn-out textile apparel. Upcycling methods are also important to reduce the environmental burden from incineration and landfilling.

This thesis focuses on developing analytical tools for the quantitative chemical screening of textiles. A novel, fully automated analytical methodology based on thermal desorption - gas chromatography-mass spectrometry (ATD-GC/MS) was developed for polyester, synthetic polyester blends, and cotton, constituting at least 75% of the retail market. The method is especially suitable for detecting semi-volatile compounds capable of skin permeation. Recently, the method was proposed for evaluation as a potential EU standard. Ultimately, the method could help ensure regulatory compliance within the textile industry. 

In addition, a high-resolution mass spectrometry workflow was developed to investigate the fate of hazardous substances during the upcycling of polycotton waste into cellulose nanocrystals. Most hazardous textile chemicals were found to remain in the polyester, while the upcycled product contained much less contaminants. Chemical release into waste streams is correlated with solubility under acidic conditions, highlighting target compounds for removal during upscaling.

Together, the developed methods contribute to a robust analytical toolbox with the potential to improve chemical oversight in textiles, support regulatory expansion, and promote safer, more sustainable fashion.