CATER Mask Decisions

December 23, 2020

The Pandemic is Like a Football Game Where the Head Covering is a Life and Death Decision

CATER 95 Mask Suppliers Have a Responsibility to Provide Fit Testing Advice

Hong Kong Masks Performance Evaluated

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The Pandemic is Like a Football Game Where the Head Covering is a Life and Death Decision

Most of  the regulations  now require wearing of masks. But this is like saying every football player must wear a head covering. The difference is that the risk of death is much greater by wearing a less protective mask than it is a less protective helmet.  It is therefore of highest importance to wear an efficient tight fitting mask.

ASTM is taking a big first step by preparing to create standards based on 20% and 50% efficiency. These proposed standards communicate the important parameters and the methods by which the level of protection is achieved. This work and the ASTM 50 rating can be used for what might be called the ASTM 50 plus rating.  One of the plus ratings would be CATER 95.  It would use all the tools and protocols set up by ASTM but be able to demonstrate not only the high efficiency but also the tight fit with various face sizes.

CDC could provide information on reliable fit testing procedures for  public masks. They can include use of the same qualitative and quantitative fit testing technologies required for industrial and medical use.  But they would also provide advice on frequency of testing and generic testing by mask size.

CATER mask suppliers with five different mask sizes are in a better position to provide low leakage masks than are suppliers with just two sizes. At one level suppliers should provide  leakage results through detailed testing of each different size mask when applied to appropriate  face sizes. This should include talking, walking, bending etc.  (Practical Performance Tests on sample test subjects).

Most masks are worn in such a manner that air leakage is as much as 40% of the total exhaled. The biggest challenge will be to create a system which keeps leakage below 10%. If both emitter and recipient have leakage limited to 10 % the net virus transmission is only 1%.  Rating of net efficiency (capture efficiency less leakage) will be useful. There are CATER 95 masks with 95% efficiency and an average of 4% leakage for a net efficiency of 91%.

The concept of CATER 95 bubbles is being proposed. If everyone entering this bubble has a CATER 95 or better mask then the school, fitness center, or office building in the bubble could operate normally. 

It is proposed that fit testing for the public be accomplished by one of the following

·         Existing industrial fit testing services with mobile vans or  on site measurement capabilities

·         New groups of fit testers such as physical therapists at fitness centers

·         Retail stores who can sell masks and provide fitness testing and advice

·         Schools and large institutions

·         Local fit testing centers (could be the fitness center or retail store)

It is further proposed that there be limitation of entry to the bubble based on some sort of proof (if only visual) that the individual is wearing a properly fitted CATER 95 mask.

In the Alert yesterday we provided details on the fitness centers and how they could reopen and even generate extra revenue from fit testing. We are forecasting that CATER Mask sales will be greater than gym shoes, hoodies, or for that matter any other clothing item. 

So the department store with a shoe section to help customers obtain the right shoes could generate more revenues by helping people choose the right mask.

CATER 95 Mask Suppliers Have a Responsibility to Provide Fit Testing Advice

Consumer mask manufacturers should  provide clear instructions on how to perform a Self-Fit Test:  Here are the instructions provided by Vogmask.

Place your fingers on the cheekbones and thumbs on sides of chin to do inhale and exhale fitting check. 

"General use respirators are not fit tested in a Workplace Safety Program, so it is recommended that you self-check how the mask fits by this method. In some regulatory regions, Vogmask is fit tested on human test subjects to confirm filtering efficiency under a variety of motions such as walking, and talking, head side to side, and head up and down.

1. Inhale slowly. Check to see if the facepiece suctions slightly towards your face. No air should leak in between your face and mask.
2. Exhale slowly. The facepiece should be bulging slightly outwards as exhale exits back through facepiece.
3. Check again for leaks between your face and the facepiece of the respirator.
4. If you detect any leaks, readjust the ear loops or head straps and check again for fit.
5. If you cannot get a good seal around nose and mouth, the mask is not correct size and we request you contact us.

Hong Kong Masks Performance Evaluated

An evaluation of masks available in Hong Kong has valuable information but misses the mark because it reports criteria of value to a surgeon who wants to avoid blood spurts but does not address the biggest factor which is mask air leakage.

In tests on 30 models of surgical masks for sale in the city, the consumer watchdog finds all but one meets basic infection prevention standards

But 70 percent fall short in other measures relating to bacteria levels, bodily fluid resistance and comfort.

The vast majority of surgical masks on sale in Hong Kong meet minimum standards for protecting against infections, but 70 per cent of models have flaws in other areas such as hygiene and durability, according to a Consumer Council study.

The watchdog’s findings, released on Tuesday as the city battled its fourth wave of Covid-19, revealed high levels of bacteria on some disposable masks, and one type did not reach basic requirements for resisting bodily fluids.

The Consumer Council oversaw tests on 30 different types of surgical, single-use masks.

Photo: Handout

Pharmacy chain Watsons, owned by city tycoon Li Ka-shing, was the most vocal of those disputing the findings, insisting its masks attained the highest American standards of protection. The firm said it used the same laboratory as the one commissioned by the council to perform the tests but found discrepancies between both sets of results.

All but one of the 30 models of single-use masks that the council tested reached 95 per cent or above for average bacterial filtration efficiency (BFE) and particle filtration efficiency (PFE).

By doing so they were judged satisfactory in terms of guarding against infection, reaching the basic level one requirement under the American ASTM F2100 standard.

To obtain ASTM level two or three certification, which is the top standard available, BFE and PFE readings must hit at least 98 per cent.

The price of each mask ranged from HK$2 to HK$9, with 18 marked as made in Hong Kong, eight in mainland China, and others from Taiwan and Vietnam.

The one model found in the study not to reach level one for countering infections was produced by Perfetta, a medical supplies manufacturer from Vietnam. Its average PFE was only 86.64 per cent, failing to meet ASTM level two as claimed as well as falling far short of the most basic standard for protective efficacy.

Lui Wing-cheong, vice-chairman of the council’s research and testing committee, said in general the masks sold in the city should be able to offer basic protection to consumers for daily use. However, he warned that 70 per cent of the models performed poorly in other tests.

For example, three models were detected with relatively high levels of bioburden, referring to the number of bacteria living on a given surface. The ear straps of about a third of the models broke in stress tests, and one failed to meet the level one resistance requirement against penetration by bodily fluid.

“The council stresses that as face masks are crucial daily necessities against the pandemic, manufacturers should strictly monitor the quality and ensure all important information on the labelling is comprehensive and accurate, so as to ensure the best protection to consumers,” he said.

The tests showed the PFE readings on all five samples from each of four models were lower than the producers claimed. Two of those – from Tempo as well as Perfetta – also had a lower BFE than they had stated.

However, Lui noted instances of blood or bodily fluid splashing on masks were relatively rare in daily life.

For hygiene standards, the study showed 90 per cent, or 27 models, met the European Union standard for levels of coliform forming, which is set at less than 30 units per gram.

The three models failing in this standard were Artec Med, Pure Living and Powecom, which recorded levels under the hygienic indicator ranging from 41.7 to above 159.4.

According to the council, the 159.4 reading from Powecom, from China, also exceeded the 100 limit of its home country’s “bacterial detection implement standard”.