When there is no refill option, choose a can over a plastic bottle, and put it in the recycling. Better still, carry your own bottle.
Global aluminium can recycling reached 75 percent in 2023, and about 75 percent of all aluminium ever made is still in use. A 500 ml PET bottle is about 12 g of plastic; two a week swapped to cans avoids around 1.2 kg a year.
The catch: making aluminium takes a lot of energy, and National Association for PET Container Resources (NAPCOR)’s 2023 industry life-cycle assessment (LCA) found single-use PET lower on greenhouse gas (GHG), energy and water than aluminium or glass per single use, and cans have a thin plastic lining inside, so they are not plastic-free; the case for cans is about recyclability and litter, not carbon.