Testing Totobobo mask against N95 mask

Totobobo mask is the most comfortable and advanced respirator in the non-certified respirator market. In many respects the patented design is revolutionary. The original design cater to the needs of common users, who do not have access to professional fit-test facility and yet need the assurance of a well fitted respirator.

preparing Totobobo mask for test
Preparing Totobobo masks for test

A different approach
To provide assurance of good fit, we made the reusable mask with transparent plastic, so that users can see through it and check the face-seal. We make the mask customizable, so that users can trim it to fit their face. The thin and flexible plastic is highly adaptive and easily follows the contour of the face, require very little force to hold on to the face. The strap is exceptionally flexible and comfortable to use. There is silver ion anti-virus additive in the mask to make reuse more safe. all these sounds great on paper, but how does it perform in real life?

testing Totobobo mask
Testing Totobobo mask

Testing the masks
To validate the protection of Totobobo, we sent the masks to the Prince of Wales Hospital in Hong Kong to test the effectiveness by professional fit-test facilities.
A randomized controlled cross over study was carreid out to compare the efficacy of Totobobo with fitted tested N95 masks (1860 or 1860s or 1862, 3M). The test was conducted in 22 healthy volunteers. The key findings are:

– The pass rate (filtration factor >100) of Totobobo mask was over 73%, while majority of (N95) masks fitting less than 40% of the test population
– The average filtration factor of fitted tested N95 masks is higher (193) then Totobobo mask (135).
– In terms of comfort, 65% subjects preferred Totobobo mask over their fitted tested N95 masks

Quote from the report:

“..Using the Totobobo mask in the panel of masks to be tested may reduce the number of masks that need to be tested before an adequate fit is found. This potential advantage, however, will need to be balanced against the time taken to trim the Totobobo mask to size. Furthermore, in situations where there is insufficient time to carry out fit testing use of the Totobobo mask may be a useful stopgap measure. In addition to this, the fact that the Totobobo mask is designed to be reusable may provide significant advantage. This would minimize the problems associated with the need to stockpile disposable masks and the difficulty of obtaining supplies in an epidemic. However, prior to concluding the mask is re-usable it is necessary to test the effect of sterilization processes on the mask. It is conceivable that such processes may make the mask less pliable and the fit less good. Moreover it is important to ensure that the process of changing the HEPA filters does not contaminate the user with infectious particles.

In terms of comfort 65% of subjects preferred the Totobobo mask over the N95 mask (1860, 1860s 3M). While the confidence interval straddles 50% this may be due to our small sample size. Comfort is an important issue when masks need to be worn for long periods of time. Greater comfort may translate into greater compliance with proper use of the mask and hence greater protection in clinical use. The experience of our ICU during SARS suggests that compliance is an important factor in determining the risk of occupational infection.”

The bottom line
If your have access to fit-test facility and have time to conduct fit test, the best option is fit-tested N95 mask. Otherwise, Totobobo mask provides reasonable good protection even if you don’t have access to fit-test facility or there is no time for fit test.

fit-test result from one of the subject
fit-test result from one of the subject

Source:
A randomized controlled pilot study to compare filtration factor of a novel non fit tested HEPA filtering facemask with a fit-tested N95 mask.
by Dr Sylvia S.W. Au, Dr Charles D. Gomersall, Patricia Leung and Dr Peggy T.Y. Li.
Dept of Anaesthesia & Intensive Care, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong.

How to perform a Visual-Seal-Check (VSC)?

New user seal check of TOTOBOBO mask predicts fit-test success rate

Totobobo masks are able to fit a wide range of large and small faces. However, it is not possible to claim that it will always seal your face perfectly. Sometimes it may require adjustment of the strap and the position of the mask to improve the seal. Sometimes trimming down the mask to a smaller size may help.

The purpose of a Visual-Seal-Check is to provide a fast and reliable method to evaluate the face seal, without the need of fit-test equipment.

User-seal-check of a normal respirator (e.g. N95 mask) involves the steps of cupping the filter area with hands, forcefully inhaling and/or exhaling to sense if there is air-leak. Such method relies on the user’s ability to feel the air movement around the leak area. Several studies have shown that this method is not reliable.

The Totobobo Visual-Seal-Check (VSC) method (patented) is facilitated by a very fine texture moulded on the inside of the transparent mask. In normal condition, the surface is dry and it appears as semi-transparent. The same surface turns transparent if there is water stuck on the surface. Even a tiny amount of water trapped between the mask and the face will make the surface change from semi-transparent to complete transparent.

To do a simple Visual-Seal-Check, you apply a little moisture on your face, than put the mask on. Observe the edge of the mask. Where it is completely transparent, there is a good seal. Where it is semi-transparent, there is no seal. It is considered as a good overall seal if there is a continuous transparent band circle around the nose and mouth.

Our user test using a TSI PortaCount system in a hospital, the gold standard of respirator fit test, shows there is a strong correlation (90%+) between the Visual-Seal-Check (VSC) and the standard fit-test results. In other words, it is possible to predict if the mask will pass or fail the gold standard fit-test by performing a TOTOBOBO VSC. This is particular useful for people who don’t have access to a proper fit-test system.

Milky surface indicates the face seal leak location

Milky surface indicates the face seal leak location

Transparent surface indicates good face seal of Totobobo mask

Transparent surface indicates good face seal of Totobobo mask

Clearly a Better Way to Check for Safety

The protective function of a respirator mask is based on two functions;
(1) the filter media must let in air but stop harmful and unwanted particles from entering the breathing zone.
(2) the mask must fit the user’s face and form a complete seal so that no air bypasses the filter media and enters the breathing zone directly.

Filter + Face seal = good protection

principle of respiratory mask protection

Modern technology has produced highly efficient filter media that can achieve up to an incredible 99.9% filtration efficiency. Ensuring a secure mask-to-face fit, however, is not nearly as simple. Rarely do users achieve a professional-grade fit, and they are surprised when they do.

Fit-testing is a task that requires a trained professional, special equipment, knowledge and skills, and considerable time. There is QUALITATIVE fit test based on subjective senses of the user, and there is QUANTITATIVE fit test based on objective measurement which compares the particle counts inside and outside of a mask. The National Institute of Occupational Safety and Health (NIOSH) recommends that such a fit-test be conducted yearly for each user so as to ensure proper usage. Fit testing can determine if a mask fits the user during the test, but can not tell for sure if the mask still fits the user days or months afterwards. These fit-testing procedures are limited to occupational users and not commonly available. The general public has neither the equipment, nor training, nor expertise, nor regular access to professionals who do in order to conduct professional-grade testing on their protective respiratory masks when they need it.

In a recent study “Respiratory Donning in Post-Hurricane New Orleans” (published on the US CDCwebsite in May 2007), researchers found 76% participants were not able to demonstrate proper donning, resulting in the compromising of their protection. This study group should know a thing or two about proper protective mask use considering the ordeal they went through during the post-Katrina clean-up of New Orleans. Imagine in an emergency situation, what would happen if the public needed to wear respirators to protect themselves? How many of these people will be able to fit their mask properly? Less than 24%, perhaps? CDC has been reluctant to recommend N95 masks for the public use because for 3 out of 4 people the poorly fitted respirator may provide a fault sense of security and encourage risky behavior.
The Prince of Wales Hospital of Hong Kong conducted a study where subjects who had previously passed a fit test were asked to properly don a N95 mask and then check for adequate sealing. These same subjects were then given a TOTOBOBO mask which they have not previous experience and conducted the same test. The results found that although the TOTOBOBO mask performed slightly less than the N95 mask, most test subjects did achieve the appropriate fit and pass the test. How did the non-fit tested Totobobo match the fit-tested N95 mask for this group of users?

Transparent surface indicates good face seal of Totobobo mask
Transparent surface indicates good face seal of Totobobo mask

The TOTOBOBO mask solves the uncertainty about proper fit in a simple but extremely effective way. The transparent mask makes fit checking an easy task. Check around the perimeter of the mask and you can immediately decide if the face seal is good or not. This simplicity, combined with a soft material that comfortably fits your face, makes fitting a lot more intuitive and reliable. Now you can perform a more reliable face-fit check every time before entering a contaminated area. This is certainly more reassuring than relying on once a year fit test.

Reference:
ESICM Annual Congress-Totobobo-mask-1044