Thunderpants might just be the world’s most comfortable pair of sustainable underwear. Celeste Sipes, owner of Thunderpants USA, has been refining the Thunderpants design, materials, and prints for years. Thunderpants makes each pair with fair trade and GOTS certified organic cotton yarn from India. Grown free of synthetic chemicals, fertilizers, pesticides, or AZO dyes, their organic cotton doesn't have any heavy metals, formaldehyde, or chlorine. Thunderpant’s insanely comfortable fabric is dyed and milled in Melbourne, Australia. And a women-owned, minimal-waste factory in Hillsboro, Oregon cuts and sews the organic underwear. Thunderpants works with women illustrators who make their unique, eye-catching prints and designs.