How this calculator works
Disposable masks, gloves and rapid tests are made mostly of plastic. The calculator multiplies the number of each item your household uses in a week by 52 weeks and by the number of people where the item is personal, then by a typical mass: about 3.5 g for a surgical mask, 5 g for a respirator, 5 g for a nitrile glove and 20 g for a rapid test kit with its cassette, swab and tube. The total mass is converted to greenhouse gas emissions at about 2 kg of carbon dioxide equivalent per kilogram of polypropylene and similar commodity plastics. Worn masks should go in the garbage rather than the recycling bin, so the mass is treated as landfill waste. The estimate does not cover packaging, distribution or the medical waste incineration used in hospitals, which adds emissions for the same items.
Formula
items per year = items per week x 52, multiplied by the number of people for masks, respirators and gloves. mass per year = sum of items per year x grams per item / 1000. emissions per year = mass per year x 2.0 kg CO2e per kg.
Worked example
Two people using two surgical masks and one respirator each week, with no gloves and no tests. That is 2 x 2 x 52 = 208 masks at 3.5 g, or 0.728 kg, and 2 x 1 x 52 = 104 respirators at 5 g, or 0.52 kg. The total is 1.248 kg a year, and at 2 kg CO2e per kg it carries about 2.5 kg CO2e.
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Frequently asked questions
Can used masks be recycled?
Generally no. They are tangled, contaminated and made of mixed materials, so municipal programs reject them. Some hospitals use specialist recycling for clean packaging, but household masks belong in the garbage.
Do reusable masks really help?
They remove almost all of the mask waste, leaving only washing. A cloth mask washed with a normal laundry load has a small footprint compared with hundreds of disposables, provided it is actually worn many times.
Is 2 kg CO2e per kg of plastic accurate?
It is a mid-range figure for commodity plastic production. Recycled content, bio-based plastics and the local electricity mix all change it. The mass of waste is the more reliable part of the estimate; use it in preference to the emissions figure if you need a defensible number.
Why is a rapid test so heavy?
The kit is dominated by the rigid plastic cassette, plus a plastic tube, cap and swab. At roughly 20 g per kit, a household testing weekly generates about 1 kg of plastic a year.
Sources
- Peng et al. (2021), Plastic waste release caused by COVID-19 and its fate in the global ocean, PNAS
- World Health Organization (2022): global analysis of health care waste in the context of COVID-19
- Plastics Europe: eco-profiles and life cycle data for polypropylene production
- Environment and Climate Change Canada: emission factors and reference values for greenhouse gas quantification (national inventory edition, updated annually)