Washable Period Pants. Help save up to 420 tampons per year going into landfill with our washable period pants. These pants are designed to be worn for up to 10-12 hours, day or night. These brief style pants are made for heavy flows and hold the equivalent of 4-5 tampons. They can be washed repeatedly by hand or machine without the colour fading and are quick to air dry. Waist size: 30 inch.