Filter facepiece respirator (FFR) is a critical equipment to prevent the transmission of respiratory tract infection disease especially the dreadful corona virus 2(SARs-CoV-2).The N95 mask is the prototype of high efficiency protective device and can effectively protect airborne pathogens of less than 0.3 μm by more than 95%. It is tightly fit and had high filtration capacity. The widespread pandemic of COVID-19 leads to greater requirement of FFR. A rising in demand would greatly exceed current productive capabilities and stockpiles and would almost certainly result in a robust shortage.

In order to solve these problems, our team had invented a new type of half-piece respirator made from silicone and assembled with hepa or elastostatic filter . A variety of methods have been used to evaluate this new device, including qualitative fit test with Bitrex® test kit and filtration test.

As required by Occupational Safety and Health Administration OSHA)[7], the halfpiece respirators need to pass the fittestto identify those individuals who do not achieve the good fit necessary for adequate protection. The performance of this respirator was also determined by measuring percent leakage under constant airflow[8]. The purposes of this study was to evaluate the fitting characteristicof our newly invented silicone N99 respirator and the performance against 30 µm particles using NaCL aerosols. The study was conducted to achieve two specific research objectives

1. To investigate the fit characteristic of the novel silicone mask and whether the strap adjustment can help reduce the face-seal leakage
2. To determine the level of performance by measure the inward leakage of the generated aerosolswith the new filter and used filter for up to 24 hours.

Inclusion Criteria:

• Healthcare workers

Exclusion Criteria:

• Intolerance to exercise
• cannot taste bitter sensation