PFAS are fluorinated compounds found in many everyday products, such as outdoor clothing and cookware like Teflon pans. This is because PFAS are durable, heat-resistant and dirt-repellent. Their stability is precisely what leads to problems: although potentially harmful to our health, these substances are scarcely broken down at all in the environment and are regarded as "forever chemicals." PFAS are also found in wastewater. Although they can be removed by filtration, this is a laborious process.