Lab grade polypropylene Hinged Vials are leak-proof and airtight. The containers are manufactured in FDA approved Class 10,00 and Class 100,000 clean rooms. The containers are physically closed in the mold as part of the manufacturing process in clean rooms using Hepa-Filtration systems, guaranteeing zero particulates larger than one half micron. They are non-absorptive and non-aersoling. The flip-top is integrally hinged to the container, allowing the user to open and close the container with one hand.