Production of cotton and synthetic fibres are known to cause negative environmental effects. For cotton, pesticide use and irrigation during cultivation contributes to emissions of toxic substances that cause damage to both human health and the ecosystem. Irrigation of cotton fields cause water stress due to large water needs. Synthetic fibres are questionable due to their (mostly) fossil resource origin and the release of microplastics. To mitigate the environmental effects of fibre production, there is an urgent need to improve the production of many of the established fibres and to find new, better fibre alternatives.

For the first time ever, this reports compiles all currently publicly available data on the environmental impact of fibre production. By doing this, the report illuminates two things:

• There is a glaring lack of data on the environmental impact of fibres – for several fibres just a few studies were found, and often only one or a few environmental impacts are covered. For new fibres associated with sustainability claims there is often no data available to support such claims.
• There are no ”sustainable” or ”unsustainable” fibre types, it is the suppliers that differ. The span within each fibre type (different suppliers) is often too large, in relation to differences between fibre types, to draw strong conclusions about differences between fibre types.

Further, it is essential to use the life cycle perspective when comparing, promoting or selecting (e.g. by designers or buyers) fibres. To achieve best environmental practice, apart from considering the impact of fibre production, one must consider the functional properties of a fibre and how it fits into an environmentally appropriate product life cycle, including the entire production chain, the use phase and the end-of-life management. Selecting the right fibre for the right application is key for optimising the environmental performance of the product life cycle.

The report is intended to be useful for several purposes:

• as input to broader studies including later life cycle stages of textile products,
• as a map over data gaps in relation to supporting claims on the environmental preferability of certain fibres over others, and
• as a basis for screening fibre alternatives, for example by designers and buyers (e.g. in public procurement).

For the third use it is important to acknowledge that for a full understanding of the environmental consequences of the choice of fibre, a full cradle-to-grave life cycle assessment (LCA) is recommended.