(Shown above: a new test method using a special chamber, left, and a robotic arm, right, could help PPE manufacturers test new products for leakages at the glove-gown interface. Photo by NIOSH.)
During recent disease outbreaks, most notably the 2014 Ebola epidemic, the importance of effective personal protective equipment (PPE) was emphasized once again. When designed and used properly, PPE can protect healthcare workers from potentially deadly infectious diseases and viruses, such as hepatitis B, hepatitis C, Ebola, and HIV.
In addition to proper use of PPE, especially while putting it on and taking it off, PPE must fit together seamlessly to protect the wearer. The problem is that the many parts of an ensemble—face and shoe coverings, gown, and gloves—are typically manufactured separately, often by different companies. A particularly vulnerable area is where the glove and gown meet: the glove-gown interface. This interface is considered one of the weakest areas because gaps can occur, allowing infectious fluids to seep through to the skin. Despite this concern, the glove-gown interface has received little research attention, so minimal guidance is available on how to prevent gaps. Furthermore, no standardized test currently exists to evaluate leakages in new products.
Recently, National Institute for Occupational Safety and Health (NIOSH) investigators developed a chamber, pictured above, outfitted with four nozzles to simulate exposures in healthcare activities and test for leakages, according to research published in the Journal of the American College of SurgeonsExternal.
Within this chamber, they placed a novel robotic arm, developed by the Johns Hopkins University Applied Physics Laboratory. The robotic arm’s realistic shoulder and elbow joints move much like a human arm, enabling the investigators to simulate common movements that healthcare providers perform when treating a patient.
The investigators dressed the arm in different gowns and gloves made from various materials, and then tested each under a range of conditions, including spraying and soaking in a container of fluid, for varying lengths of time. The surface tension of the fluid plays an important role in leakage. To simulate body fluids, researchers used water mixed with a substance that decreases the surface tension between two compounds. After each test, they measured the fluid that leaked through the gowns and glove cuffs by weighing the gown cuffs and inner sleeves.
Compared to spraying, soaking resulted in considerably more leakage. Specifically, the average amount of fluid leakage during spraying was 6.08 grams, compared to soaking’s 30.44 grams. Other conditions linked to greater leakage were longer spraying or soaking durations, rigorous arm movement, and pressure applied to the wrist area.
According to the investigators, this method could help PPE manufacturers test the performance of new products for leakages at the glove-gown interface, and help in developing testing standards and guidelines. An important next step is to design customized tests with PPE for specific activities, such as surgical, patient isolation, and decontamination.
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