Most band-aids are made from plastic (polyethylene [#1 PET] or polyvinyl chloride [#3 PVC]) or polyurethane. They are, then, toxic single-use items designed to, with luck, end up in a landfill or, without it, in the environment. Have you ever lost a band-aid at the beach or on a hike in the forest? If so, you unintentionally left behind an item that will not biodegrade and will pollute those areas for years after you have ceased to exist.
In the big scheme of things, band-aids are certainly not one of the major sources of plastic pollution, but they do cause damage. So why not switch to compostable band-aids, which are more and more available in the market? Nutricare sells bamboo-based band-aids in different sizes and colors, which you can order online or find in a pharmacy nearby.