Biological and Chemical Processes that Lead to Textile Malodour Development

Abstract

The development of malodour on clothing is a well-known problem with social, economic and ecological consequences. Many people still think malodour is the result of a lack of hygiene, which causes social stigma and embarrassment. Clothing is washed more frequently due to odour formation or even discarded when permastink develops. The malodour formation process is impacted by many variables and processes throughout the textile lifecycle. The contact with the skin with consequent transfer of microorganisms, volatiles and odour precursors leads to the formation of a distinctive textile microbiome and volatilome. The washing and drying processes further shape the textile microbiome and impact malodour formation. These processes are impacted by interindividual differences and fabric type as well. This review describes the current knowledge on the volatilome and microbiome of the skin, textile and washing machine, the multiple factors that determine malodour formation on textiles and points out what information is still missing.

Keywords: malodour; permastink; skin microbiome; textile odour; volatilome.

Figure 1

Schematic overview of different processes (wearing, storing, washing, drying, re-wearing) during two wear-wash-dry cycles affecting metabolites and microorganisms from different sources attaching to clothing. During the wearing (1), the clothing is in contact with the skin where a transfer of e.g., microorganisms and sebum occurs (indicated in red). When the clothing is stored before washing (2), a cross-over of these microorganisms and metabolites between clothing from another individual (indicated in blue) can take place. The washing process (3) reduces the amount of microorganisms and metabolites on the clothing, with an efficiency dependent on temperature, wash time and type of detergent. Furthermore, bacteria and metabolites present in the washing machine and in the wash water as well as fragrances and enzymes and other ingredients from the detergent/softener attach to the clothing. The effect of the drying process (4) is dependent on humidity, temperature and drying time, although relatively unstudied. In subsequent wear cycles (5) these processes are repeated and microorganisms and malodour volatiles accumulate to a situation of excessive malodour build-up or permastink.