The floss, plastic spools and flip-top containers can’t be recycled easily because of their size, and floss filament easily tangles up recycling machinery. In landfills, their toxins leak into the soil; in waterways, floss can entangle and even kill sea creatures. And washing and reusing floss isn’t a good option because it runs the risk of introducing bacteria into new areas of the mouth, warns the American Dental Association.

However, a handful of new eco-options in flosses have emerged, primarily with silk and bamboo, which are biodegradable and free of chemicals. Blogger Beth Terry at My Plastic-Free Life rates Dental Lace, a floss made of 100 percent silk coated with candelilla wax from Mexican trees, as her favorite product. It’s packaged without a plastic coil in a refillable glass container, making it a 99 percent zero-waste product. In addition, the company, based in Cape Elizabeth, Maine, offers a vegan bamboo version.

Bamboo flosses in eco-friendly containers are also made by Los Angeles-based Terra & Co. (with activated charcoal, coconut oil, peppermint oil and no synthetic fragrances, sweeteners or artificial colorings, in a cardboard box); and Altoona, Florida-based Lucky Teeth (activated charcoal, candelilla plant wax, organic peppermint oil and tea tree oil, in a glass jar). Two other easy-to-find flosses, by Eco-Dent and Tom’s of Maine, are made of nylon, but are covered in natural vegan waxes rather than beeswax or petroleum-based waxes. They come in compostable cardboard boxes but include plastic spools.

Advice columnist Umbra of Grist recommends switching to an oral irrigator or water flosser that plugs into the wall or runs on a battery—sometimes rechargeable—because it effectively removes plaque, is reusable, produces no trash, lasts for years and uses relatively little water and electricity.