Some towels are advertised as super absorbent and are made of ‘microfiber’. This means they are synthetic and will shed microfiber plastics when washed and dried. These plastic fibers are bad news for wildlife as they can lead to disease and death in fish, birds, amphibians, and other small animals. Some towels are also advertised as antimicrobial, meaning they’ve been treated with biocides. While this sounds great for anyone who has had to deal with a smelly gym towel, it’s far better to just launder towels regularly as these biocide chemicals can be highly damaging to wildlife and contribute to antibiotic resistance. If you can, it’s best to avoid towels (which are a regularly washed item) that are made from polyester, viscose, rayon, or polyamide. These types of materials are also not biodegradable and are harder to recycle, meaning they end up in landfill where they may pose further risks to the environment. In general, avoid anything advertised as microfiber and instead choose towels made from: Organic cotton Hemp Select types of bamboo (see below). In addition to choosing more eco-friendly materials for towels, consider how these materials are treated after they’re harvested. This means checking that the towels are not bleached using chlorine bleach and are not dyed with carcinogenic azo dyes. Ironically, natural fibers treated with azo dyes and other harsh chemicals such as chlorine tend to leach more of these chemicals when used and washed as the fibers are less effective at holding onto the chemicals compared to some synthetic fibers. One startling report found that a whopping 4.44 tons of hazardous dyes are likely released every year into wastewater in the European Union just from washing cotton and polyamide textiles during manufacturing. By following good manufacturing practices, companies can reduce this effluent impact around five-fold.