Infectious Sample Transport: Evaluating the Use of Parafilm for Sealing Primary Containers

The transport of infectious substances is a highly regulated process. The European Agreement for International Carriage of Dangerous Goods by Road instructs that infectious specimens must be transported in a triple packaging system containing leakproof receptacles. Despite regulatory efforts, leakages occur. Current evidence for Parafilm usage is lacking. This study evaluates the use of Parafilm for preventing leakage from commonly used primary receptacles during ground transport.

Two test methods, manual inversion and a rocker, were used to simulate standard ground transport. Testing was performed with two common receptacles and three differing volumes of test solution. Each test was performed in quintuplicate. Fluorescein solution was used to aid in visual identification of leakage in addition to the weight of the receptacles before and after testing.

Despite lids being correctly applied, 10% of full 30 mL universal tubes leaked as a result of the rocker testing (n = 40). Overall, 92.5% of full 30 mL universals tested with a cross-threaded lid experienced leakage. Two-milliliter Sarstedt tubes did not experience a single leak even while cross-threaded. Clockwise application of Parafilm decreased leakage from receptacles. Wrapping Parafilm over and under the receptacle provided no benefit compared with not using Parafilm.

Clockwise application of Parafilm may decrease leakage in the event of cross-threading. Despite this, receptacles must be opened in the correct containment, as spillage during unwrapping and lid removal is common. Further investigation is required to assess the effects of pressure on modes of transport such as air travel.