Three methods for strategic product toxicity assessment—the case of the cotton T-shirt

Abstract

Purpose The use and emission of chemicals and the intrinsic toxic properties of some of these chemicals are an important topic in the textile industry. Quantitative evaluation of toxic impacts is a life cycle assessment (LCA) approach, termed Btoxic footprint^in this article. We ask whether calculation of toxic footprints is a useful method to steer the textile industry towards more sustainable use of chemicals. Methods Three different methods by which strategic product toxicity assessment can be performed within the context of LCA are illustrated and compared using a wet treatment process for a cotton T-shirt as the basis of a case study. The methods are the USEtox model chosen for the European Product Environmental Footprint work, the Score System presented in the European Commission's Reference Document on Best Available Techniques for the Textiles Industry, and the Strategy Tool presented by Askham. The methods are compared in terms of their ease of use and whether the results give a consistent evaluation of a set of chemicals. Results and discussion New USEtox characterisation factors for textile chemicals were calculated and used for this article. The results show that the three methods do not give a consistent evaluation of the different wet treatment chemicals. Both the Score System and the Strategy Tool are very concerned with persistent contaminants such as the optical brightener in this case study, which is deemed to be less important by USEtox. The calculations also show how the results generated by the USEtox model depend on whether users apply (1) only the recommended characterisation factors or (2) these and the interim characterisation factors or (3) these and the new characterisation factors calculated for this article.Conclusions and recommendations With current policy initiatives such as the Product Environmental Footprint now being applied for textile products, toxicity assessment will by default be performed in the LCA of textiles. It is important that the results are relevant and representative as the intended users are supposed to take actions based on them. Confidence in the results is crucial for a scientific method, and therefore, this exploratory comparison exercise shows how benchmarking can be a tool to make the differences in background assumptions explicit, to better understand the differences in the results, and help create such confidence.

The environmental price of fast fashion

“…As there is a wide variety of chemical pollutants emanating from the fashion and textile industries, life-cycle analysts have attempted to aggregate their impacts into an indicator that reflects both the relative rate of emission of the chemicals and their potential for harm 61 . The latest European approach to aggregate impacts is based on the USEtox model, a nested, multicompartment transport and fate model that has been applied to over 4,000 substances 42 .…”

Advances, Norms, and Perspectives in Product Chemical Footprint Research

“…USEtox provides a concise and transparent tool for human health and ecosystem assessment and is based on a reference database, which is used in calculating CFs for thousands of substances and forms the basis of the UNEP-SETAC recommendations of the Life Cycle Initiative on the characterization of toxic effects in life cycle assessment [ 36 ]. The scoring system developed in the 1990s by the federation of Danish textile and clothing [ 37 ] is a semi-quantitative multi-criteria analysis method [ 38 ] for describing the properties of chemical substances and determining the scale of their use in the production process [ 39 ]. A score of 1–4 was assigned to each substance according to the following criteria: A-mass of weekly discharge, B-biodegradability, C-bioconcentration factor, and D-toxicity.…”

“…The strategy tool was developed by Askham et al [ 40 ] to make strategic decisions about product development. It assesses the chemical composition of a product in a simplified way based on information available in Safety Data Sheets (SDS) [ 39 ]. Ping Hou et al developed a neural network model with an architecture optimized by a genetic algorithm to efficiently predict the ecotoxicity of chemicals (HC50 values in USEtox) [ 41 ].…”

“…These methods have advantages and disadvantages. The advantage of USEtox is that it is a quantitative evaluation method for simulating and assessing the toxicity of actual substances emitted to different compartments [ 39 ]. It is useful in determining where and how different assumptions, scenarios, and decision choices give rise to differences among model outputs [ 42 ].…”

“…The advantage of the scoring system is its simplicity, and the time frame for its implementation and use ranges from days to weeks; the disadvantage of the scoring system is that it is limited in scope, as it only deals with the release of environmentally harmful substances to water. The strategy tool has the advantage of being simple and including exposures in the work environment; it has the disadvantage of not being universally applicable throughout the life cycle [ 39 ]. The scoring system and strategy tool are qualitative calculation methods with some subjective limitations.…”