These black containers are made with up to 40% natural mineral content blended with polypropylene, and fully recyclable, Mineral Filled Polypropylene Containers use far less plastic than other options, offering an earth-friendly solution for service, carryout, or delivery. Keep food secure and fresh inside these liquid and grease resistant containers. Dual lock bars keep containers audibly shut. Green replacement option for foam containers. Textured sidewall ribbing offers durability and better handling. Non-absorbent. Fully microwavable.