Best method of sterilizing disposable syringes is -
High-Yield Explanation
Ionizing radiation: commercial plants use gamma radiation for sterilizing items like plastics, syringes, swabs, catheters, animal feeds, cardboard, oils, greases, fabrics, and metal foils REF:Ananthanarayan and Panicker's Textbook of Microbiology 8thEdition pg no:35