Mass of components and material distribution in lateral flow assay kits.

Objective: To assess the type and amount of materials used in commercial lateral flow tests.

Methods: We collected and weighed the components of 21 commercial coronavirus disease 2019 (COVID-19) lateral flow tests from the European Union, the United Kingdom of Great Britain and Northern Ireland, the United States of America and the World Health Organization's emergency use listing procedure. We took test kits apart manually, classified components and weighed them individually.

Findings: We found large variations in the total average weights of the lateral flow kits ranging from 13.7 g per test to 84.6 g. The average weight of standard housing in the kits was 4.1 g per casing (range: 2.8-6.5). The packaging made up between 34% and more than 89% of the whole kit and was found to be a large source of weight variations. In the standard kits, plastics made up on average 36% of the total weight, while paper and cardboard accounted for 52% on average. In the non-standard kits, which had newer cassette designs, the opposite was observed.

Conclusion: Wide variation in the weight of components in COVID-19 tests suggests there is scope for manufacturers to reduce the amount of materials, including plastic, in these products. We propose that a quantitative baseline of material usage be introduced in target product profiles for lateral flow tests to limit the large volume of plastic from reaching the market, and reduce the burden of plastic waste from diagnostic testing on local waste management systems.