Análisis de ciclo de vida de cubrebocas reutilizables y de un solo uso
Authors:   , Tecorralco Bobadilla Ana Laura 
Published: January 2023

The pandemic that started in 2020, because of the spread of the SARS-CoV-2 virus that causes the disease COVID-19, posed a challenge to the production of personal protective equipment to prevent contagion. The use of face masks was one of the measures issued by the World Health Organisation. The compulsory use of coverings to gain access to different areas led to an increase in their manufacture and sale. This fact led to the production of different types of face masks so that a variety of different types are now available on the market. Characteristics that can differentiate them include the number of layers they can have, the filtration efficiency, and the material of manufacture, which can be woven or non-woven polypropylene or cotton fabric. A very relevant feature is the fact that the face mask is reusable or disposable. The Life Cycle Assessment (LCA) methodology was applied to a reusable and a disposable face mask, in both cases stages to be considered in the assessment were identified, as well as the inputs and outputs of raw materials and energy. The stages included in the analysis range from the acquisition of raw materials to the end of life in a landfill, i.e. from cradle to grave. The main sources of information were the companies producing each of these face masks. It is worth mentioning that the life cycle analyses of both types of face masks were carried out independently, with no comparison between them due to the confidentiality that was established with the companies, which were called A and B. For both cases, the functional unit was defined as airway protection with 95% bacterial filtration efficiency for 12 hours per day for 20 days. Regarding the reusable face mask, the reference flow of a reusable face mask is established for 20 days. The production stage is the one that presents the main contribution in all impact categories, this is attributed to the dehydration of natural gas, which is indirectly associated with the ICV due to its applications, such as fuel production. for transport, the transformation of polymers, and the production of electrical energy. The use of antibacterial, which is made from silver salts, is the input that has the main negative contribution to environmental impacts at the production stage, which is associated with freshwater ecotoxicity, the category with the highest environmental impact. In the case of disposable face masks, the reference flow of 20 disposable face masks for 20 days was established. In the same way as the reusable face mask, production is the main stage of environmental impact, which is presented in 10 of 18 categories; the main contribution to the impact categories is attributed to the extraction of natural gas, which is indirectly associated with the ICV due to the activities in which it is applied, such as the production of fuels used in land and sea transport. In the production stage, the raw material acquisition process is the main contributor to the LCA, which can be associated with the indirect processes of polymer production and its emissions affecting human toxicity, which is the impact category that has the main contribution. A sensitivity analysis was carried out for both types of face masks, in which it was possible to observe for both cases that the amount of raw material can be reduced; as in the case of the reusable face mask, the amount of antibacterial used was reduced by 5 %, which is the one with the greatest contribution, and in the case of the disposable one, the amount of fabric (main contributor to the life cycle) used was reduced by 10 % without altering the protective function of both PPE and therefore is reflected in a reduction of the environmental impacts in both cases. Overall, in both cases, the production stage has the highest proportion of associated impacts, which is contrary to the hypothesis of this work where the extraction of raw materials was proposed to be the main contributor. However, some processes associated with LCI such as the extraction of other materials e.g. natural gas and oil for polymer production and some minerals are listed in different impact categories as the main contributing processes.