Those disposable ink caps is made of 100% PLA material.It’s highly-biodegradable and recyclable, safe for people and the environment.Helps maintain a safe, Hygienic work environment. You can feel good about using these disposable ink caps, as they are made with 100% PLA material. This means they are highly-biodegradable and recyclable, making them safe for both people and the environment. With these ink caps, you can maintain a safe and hygienic work environment without having to worry about harmful materials.