Swig cups are BPA-free and made of polypropylene, a safe material for hot or cold drinks. They’re also manufactured in the United States.
Swig cups are dishwasher-safe and can be thrown into the microwave. They should be hand-washed with warm soapy water after each use to avoid staining; do not soak in water as this can cause damage to your cup’s finish over time (and stains aren’t easy to remove).