being designed and tailored for very particular uses. Hypodermic needles remain essential to large volume administration or exchange in settings of trauma or dialysis. The trend of needle specification for use began in the 1920s, particularly for the administration of insulin to diabetics. The onset of World War II spurred the early development of partially disposable syringes for the administration of morphine and penicillin on the battlefield. Development of the fully disposable hypodermic needle was spurred on in the 1950s for several reasons. The Korean War created blood shortages and in response disposable, sterile syringes were developed for collecting blood. The widespread immunization against polio during the period required the development of a fully disposable syringe system. The 1950s also saw the rise and recognition of cross-contamination from used needles. This led to the development of the first fully disposable plastic syringe by New Zealand pharmacist Colin Murdoch in 1956. This period also marked a shift in interest from needle specifications to general sterility and safety. The 1980s saw the rise of the HIV epidemic and with it renewed concern over the safety of cross-contamination from used needles. New safety controls were designed on disposable needles to ensure the safety of medical workers in particular. These controls were implemented on the needles themselves, such as retractable needles, but also in the handling of used needles, particularly in the use of hard-surface disposal receptacles found in every medical office today. By 2008, all-plastic needles were in production and in limited use. One version was made of Vectra (plastic) aromatic liquid crystal polymer tapered from 1.2 mm at the hub to 0.72 mm at the tip (equivalent to 22 gauge metal needle), with an ID/OD ratio of 70%. Manufacture Hypodermic needles are normally made from a stainless-steel or Niobium tube through a process known as tube drawing where the tube is drawn through progressively smaller dies to make the needle. The end of the needle is bevelled to create a sharp pointed tip, letting the needle easily penetrate the skin. Gauge The main system for measuring the diameter of a hypodermic needle is the Birmingham gauge (also known as the Stubs Iron Wire Gauge); the French gauge is used mainly for catheters. Various needle lengths are available for any given gauge. Needles in common medical use range from 7 gauge (the largest) to 33 (the smallest). 21-gauge needles are most commonly used