What type of plastic is used in the Stack capsules?

Stack is held in capsules made from high-grade polypropylene. Many plastics can leach harmful chemicals, especially when exposed to food, heat, or oils. Polypropylene is stable and inert, meaning it doesn’t break down or release unwanted chemicals into food, even when exposed to acids, oils, or high moisture environments. This is crucial for ensuring food safety over time. All plastic used is 100% recyclable.