Development of a novel positive pressure protective suit for Biosafety Level 4 laboratory in Japan.

Biosafety Level 4 (BSL-4) laboratories are necessary to study microorganisms that are highly pathogenic to humans and have no prevention or therapeutic measures. Currently, most BSL-4 facilities have suit-type laboratories to conduct experiments on highly pathogenic microorganisms. In 2021, the first Japanese suit-type BSL-4 laboratory was constructed at Nagasaki University. Positive pressure protection suit (PPPS) is a primary barrier that protect and isolate laboratory workers from pathogens and the laboratory environment. Here, we developed a novel PPPS originally designed to be used in the Nagasaki BSL-4 laboratory. We modified several parts of the domestic chemical protective suit, including its front face shield, cuff, and air supply hose, for safe handling of microbiological agents. The improved suit, PS-790BSL4-AL, showed resistance to several chemicals, including quaternary ammonium disinfectant, and did not show any permeation against blood and phages. To validate the suit's integrity, we also established an airtight test that enabled the elimination of individual differences for quantitative testing. Thus, our developed suit is sufficient as a primary barrier and allows for the safe handling of pathogens in our new BSL-4 laboratory.