Background: Cinnamic alcohol is a natural compound, widely used in fragrances, which can cause allergic contact dermatitis. Cinnamic alcohol lacks intrinsic reactivity and autoxidation or metabolic activation is necessary for it to act as a sensitizer. Methods: Bioactivation of cinnamic alcohol was explored using human liver microsomes, human liver S9 and SkinEthic™ Reconstructed Human Epidermis. A targeted multiple reaction monitoring mass spectrometry method was employed to study and quantify cinnamic alcohol along with eight potential phase I or phase II metabolites. The reconstructed human epidermis model, treated with cinnamic alcohol, was also analyzed with a non-targeted high-resolution mass spectrometry method to identify metabolites not included in the targeted method. Results: Two metabolites identified with the targeted method, namely, pOH-cinnamic alcohol and pOH-cinnamic aldehyde, have not previously been identified in a metabolic in vitro system. Their reactivity toward biologically relevant nucleophiles was investigated and compared to their sensitizing potency in vivo in the murine local lymph node assay (LLNA). According to the LLNA, the pOH-cinnamic alcohol is non-sensitizing and pOH-cinnamic aldehyde is a moderate sensitizer. This makes pOH-cinnamic aldehyde less sensitizing than cinnamic aldehyde, which has been found to be a strong sensitizer in the LLNA. This difference in sensitizing potency was supported by the reactivity experiments. Cinnamic sulfate, previously proposed as a potential reactive metabolite of cinnamic alcohol, was not detected in any of the incubations. In addition, experiments examining the reactivity of cinnamic sulfate toward a model peptide revealed no evidence of adduct formation. The only additional metabolite that could be identified with the non-targeted method was a dioxolan derivative. Whether or not this metabolite, or one of its precursors, could contribute to the sensitizing potency of cinnamic alcohol would need further investigation. Discussion: Cinnamic alcohol is one of the most common fragrance allergens and as it is more effective to patch test with the actual sensitizer than with the prohapten itself, it is important to identify metabolites with sensitizing potency. Further, improved knowledge of metabolic transformations occurring in the skin can improve prediction models for safety assessment of skin products.

The objective of the present study was to investigate some commonly detected halogenated textile pollutants for their bioavailability and hazardous properties. Release into artificial sweat and skin absorption in vitro were examined as well as mutagenic effects by Ames test, and skin-sensitizing properties from a peptide reactivity assay combined with a cell test.

All investigated compounds were shown to migrate from the textile into sweat and be absorbed by the skin, although to a different extent. The experimental values for migration were found to be up to 390 times higher compared to literature values. Two of the studied compounds, 2,5-dinitrochlorobenzene and 3,5-dinitrobromobenzene, both exhibited mutagenic effects in the Ames test, while both 2,5-dinitrochlorobenzene and 2,6-dichlorobenzene-1,4-diamine were classified as skin sensitizers. The allergenic reactivity of the latter was found to be due to an oxidized transformation product.

Risks for the induction of skin allergy and other non-carcinogenic effects from dermal exposure to the individual compounds were found low, even when considering clothing with the highest reported levels. However, the complex mixtures of chemicals often present in garments may still constitute a health risk, especially when considering the many hours of daily exposure. It is important to further study the toxicity of other frequently occurring chemicals as well as the synergistic effects of chemicals that co-occur in clothing.

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.

The global production of textiles utilizes numerous large-volume chemicals that may remain to some extent in the finished garments. Arylamines, quinolines, and halogenated nitrobenzene compounds are possible mutagens, carcinogens and/or skin sensitizers. For prevention, control of clothing and other textiles must be improved, especially those imported from countries without regulations of textile chemicals. An automated analytical methodology with on-line extraction, separation, and detection would largely simplify screening surveys of hazardous chemicals in textiles. Automated thermal desorption-gas chromatography/mass spectrometry (ATD-GC/MS) was developed and evaluated as a solvent-free, direct chemical analysis for screening of textiles. It requires a minimum of sample handling with a total run time of 38 min including sample desorption, chromatographic separation, and mass spectrometric detection. For most of the studied compounds, method quantification limit (MQL) was below 5 mu g/g for 5 mg of textile sample, which is sufficiently low for screening and control of quinoline and arylamines regulated by EU. Several chemicals were detected and quantified when the ATD-GC/MS method was applied in a limited pilot screening of synthetic fiber garments. A number of arylamines were detected, where some of the halogenated dinitroanilines were found in concentrations up to 300 mu g/g. This is ten times higher than the concentration limit for similar arylamines listed by the EU REACH regulation. Other chemicals detected in the investigated textiles were several quinolines, benzothiazole, naphthalene, and 3,5-dinitrobromobenzene. Based on the present results, we suggest ATD-GC/MS as a screening method for the control of harmful chemicals in clothing garments and other textiles.

From manufacturing to disposal, the textile industry faces multiple challenges to achieve sustainability and reduce its environmental impact. This work investigates the properties and composition of cellulose nanocrystals (CNCs) extracted from clothing waste made of cotton fibers. We isolated CNCs from cotton, polyester/cotton, and acrylic/cotton waste fabrics through acid hydrolysis with sulfuric acid. A yield of 51-62 wt S4, ( co tt on basis) was obtained, and nearly all the polyester and acrylic libers contained in the initial fabrics were recovered in a convenient shape that could allow easier recycling. CNCs extracted from the selected fabrics showed high purity, similar structural, physical, and chemical characteristics, and their properties were comparable to those extracted from virgin sources, although their surface chemistry and elemental composition slightly differed. The chemical components in the waste fabrics and the extracted CNCs were evaluated through a nontarget chromatographic-mass spectrometric screening strategy. Both the recycled textiles and the CNCs contained hundreds of compounds common in postconsumer textiles, including some with health and environmental concerns. However, our initial findings show that their concentrations in the CNCs are negligible. Our results provide insights into the challenges associated with the use of cotton waste textiles for the extraction of cellulose nanoparticles, and into the potential applications of the extracted nanomaterials.

Background: Azobenzene disperse dyes (azo DDs) are well-known as textile allergens, but the knowledge of their occurrence in garments is low. The numerous azo DDs and dye components found in textiles constitute a potential health risk, but only seven azo DDs are included in the European baseline patch test series (EBS).

Objectives: To investigate non-regulated azo DDs and dye components in synthetic garments on the Swedish market.

Methods: High-performance liquid chromatography/mass spectrometry, gas chromatography/mass spectrometry and computerized data mining.

Results: Sixty-two azo DDs were detected, with Disperse Red 167:1 occurring in 67%, and 14 other DDs each found in >20% of the garments. Notably, the EBS dyes were less common, three even not detected, while arylamines were frequently detected and exceeded 1 mg/g in several garments. Also, halogenated dinitrobenzenes were identified in 25% of the textiles.

Conclusion: Azo DDs and dye components, in complex compositions and with large variations, occurred frequently in the synthetic garments. The arylamines were shown to occur at much higher levels compared to the azo DDs, suggesting the former constitute a potentially higher health risk. The role of arylamines and halogenated dinitrobenzenes in textile allergy has to be further investigated.

The global manufacturing of clothing is usually composed of multistep processes, which include a large number of chemicals. However, there is generally no information regarding the chemical content remaining in the finished clothes. Clothes in close and prolonged skin contact may thus be a significant source of daily human exposure to hazardous compounds depending on their ability to migrate from the textiles and be absorbed by the skin. In the present study, twenty-four imported garments on the Swedish market were investigated with respect to their content of organic compounds, using a screening workflow. Reversed-phase liquid chromatography coupled to electrospray ionization/high-resolution mass spectrometry was used for both suspect and non-target screening. The most frequently detected compound was benzothiazole followed by quinoline. Nitroanilines with suspected mutagenic and possible skin sensitization properties, and quinoline, a carcinogenic compound, were among the compounds occurring at the highest concentrations. In some garments, the level of quinoline was estimated to be close to or higher than 50,000 ng/g, the limit set by the REACH regulation. Other detected compounds were acridine, benzotriazoles, benzothiazoles, phthalates, nitrophenols, and organophosphates. Several of the identified compounds have logP and molecular weight values enabling skin uptake. This pilot study indicates which chemicals and compound classes should be prioritized for future quantitative surveys and control of the chemical content in clothing as well as research on skin transfer, skin absorption, and systemic exposure. The results also show that the current control and prevention from chemicals in imported garments on the Swedish market is insufficient.

Textile industry uses a large number of various chemicals in the multi-step production chain. Some of these chemicals are intentionally used to give specific features to textile materials (softness, color, improve fastness, flame resistant etc.). Some other are unintentionally added, such us transformation products (e.g. dye degradation production), impurities of other used compounds and/or biocides. Due to the large number of cloths manufacturing steps, starting from fabric production to clothes trade, information regarding the chemicals used are not always available. Clothes are in close and prolonged contact with the skin, making possible a human exposure to chemicals present in textile material. Furthermore, chemicals, if not removed from wastewater treatment plants, can be released in the environment through the laundry of textile materials. In the present study, reverse phase liquid chromatography coupled to high resolution mass spectrometry was used for screening of suspect and unknown compounds in twenty-four textile samples. Strategies towards suspect and non-target screening are discussed considering the experimental conditions and the subsequent data treatment. Suspect compounds belonging to benzotriazoles, benzothiazoles, nitroanilines, quinolines and phthalates were confirmed in the analyzed samples. The method was able also to successfully identify compounds not included in the suspect list, such as nitrophenols, acridine, and phosphates.