Single-use syringes are typically made of polypropylene, which is transparent, durable, and chemical-resistant. The plungers and needles are made of stainless steel or other metals, ensuring strength and sharpness for effective injections (need to be changed). Typically syringes are made up of three parts: barrel, plunger, and needle. The barrels and plungers are made up of non-toxic, medical-grade polypropylene and the needle is made up of stainless steel.