Washing and drying clothes requires lots of energy and contributes to water pollution—and no garment is more culpable than underwear. Generally speaking, underwear has a very short life cycle and needs constant washing. That’s why a Danish entrepreneur has created a line of underwear that uses silver-infused yarn that can’t be washed away, meaning the underwear has a long lifespan. What makes this underwear extra special is that it uses the same technology that NASA uses for purifying water in order to neutralize the ability of bacteria to form, which is where the smell from underwear comes from.