These masks prototypic samples for evaluation. Using these free samples exempts us (VitaFlex and its staff) from any responsibility on product performance. Shipped by USPS First Class Mail.

The main purpose of the Soft-stretch mask is to contain saliva droplets from the wearer.The masks have been tested to have a bacterial filtration efficiency (BFE) of >99.5% (ASTM F2101). However, due to wearers’ faces varying in shape and nose-bridge height, our Soft-stretch mask may not tightly cover the nose and mouth to provide the filtering protection. They should not be used as surgical masks.

“Surgical Masks” are not always higher quality. Calling disposable surgical masks “medical grade” is misleading. Registration of premarket notification 510 (k) is to notify the FDA of a company’s intention of marketing a facemask that is equivalent to an existing surgical mask in effectiveness and safety. FDA does not test to certify “Surgical Masks”; rather, they grant permission to label “Surgical Mask” based on company provided barrier properties statement.

Although the filing process is not complicated, the cost is significant. We did not file 510 (k) for our Soft-stretch Masks because we do not intend to promote them to be worn by healthcare professionals in surgical procedures.

The Problem with Masks is Leakage

Dr. De-Sheng Tsai

Respirable particles of 1 to 15 µm are considered industrial health concerns. Although disease bacteria and virus require a critical mass to trigger an infection, many particles such as asbestos fibers and silica dust can cause irreversible damage to the lungs when inhaled even at a low concentration.

Generally, smaller particles have higher penetration rate through a filter. However, sub-micron particulates are charged and more easily trapped on mask fibers. While the bacteria and particle filtration efficiency of surgical masks are tested at a flow rate of 28.3 L/min (ASTM F2101 and ASTM F2299), a normal adult’s breathing is only about 8 L/min. Higher air flow would create more force to push particles through the filter. Therefore, any mask capable of blocking 90% of 1-µm particles in a filtration test should be able to block 99% of a particle mix of 1-15 µm at normal breathing.

The problem with masks is leakage. Because faces vary in shape and nose-bridge height, there are many gaps between a wearer’s face and the edges of a flat facemask. Also, their elastic ear-loops are either too loose or too tight for proper fit. Masks often fall from the nose to cover only wearer’s mouth or even hang under the chin protecting nothing. Meanwhile, the elastic straps of the rigid dome-shaped masks have to be uncomfortably tight to seal at all. Even then, the mask moves and leaks when the wearer talks or sweats.

As a material scientist with over 20 years’ experience in developing protective equipment, I have seen no low-cost cure to this leakage problem. It is fair to conclude that workers cannot rely on disposable masks for respiratory protection. However, the convenience and usefulness of masks to contain saliva droplets are well recognized. They are useful in public places and in congested environments- meetings, concerts, conventions, stadiums, lines, buses, trains, airports etc. We are offering free prototypic samples of my Soft-stretch masks at our E-store.