Despite of progress in medicine, iatrogenic (gr. ἰατρός means physician) infections are important problem in all countries. Even single cells or spores can form health hazards and can potantially generate hygienic problems, diseases and even epidemics. One of the contamination ways can be universally used disposable syringes.

Approximately 30 000 000 000 disposable syringes are produced in the world each year. We want to pay attention to mechanism of contamination connected with construction and injection practices of commonly used types of disposable syringes: contact of plunger with sterile surface of syringe barrel. Two (or more) strokes of the plunger can transport a contaminant from the external compartment into the sterile compartment. It is common practise to use the same syringe to draw up sterile water, add this to lyophilized drugs and recover the reconstituted fluid into the same syringe for injection to a patient.

Some sources on the application of aseptic technique to the preparation and dispensing of sterile medications admonish health-care professionals not to touch or grasp the plunger rod of sterile disposable syringe during use. However many practitioners are not physically coordinated enough to be capable of complying with this while efficiently transferring volumes of approximately 10 ml or greater.