Totobobo demo in Beijing and Shanghai

Next week Tuesday (2014/09/16 to 18) I will be conducting life demo of customizing the Totobobo mask to fit individual users in Beijing and Shanghai. Here is a quick preview of what I intended to share:

The essential factors to determine protection against PM2.5 is:

  • (1) if a tight fit can be achieved between the respirator mask and the user’s face (mask-to-face seal)
  • (2) the quality of the filter
  • - Quality of filter can be achieved by technology and tested in laboratory
    - Quality of mask-to-face seal is the biggest issue for ensuring the protection for individual, because each individual is different

  • Fit-testing is a process to determine the quality of the face-to-mask seal for individual. This is essential because the protection against PM 2.5 is hugely affected by the quality of the seal.
  • Totobobo special approach: (1) ReShape or trim to fit most people, (2) Easy fit-check through the transparent mask
  • To validate our approach, we sent Totobobo mask to Prince of Wales Hospital in Hong Kong for fit-test. The resulting Fit-Factor is 135, which is better than the minimum requirement for N95 mask.
  • For normal N95 mask, a proper fit-test is necessary during the first use by a new user. This is to determine if a good seal is achievable.
  • - if a good seal is not achievable, the user has to choose a different mask
    - In case of Totobobo, if a good seal is not achievable (by see-through method), the mask can be ReShape or cut smaller to get a better fit

    All those who participated in the demo fit-test will get a free, customized Totobobo mask!
    email us as totobobomask(at) if you are interested to join.


    Martie’s Totobobo filter in London

    Martie use her Totobobo mask for cycling in London traffic

    Martie use her Totobobo mask for cycling in London traffic (Southampton Row, London)

    Why do you choose cycling to work?

    I realised cycling is a cheaper, more reliable and (even) enjoyable mode of transport compared to the unreliable, overcrowded & expensive public transport. I’m least interested in cycling sports, but I’m glad that I made the decision to cycle for my everyday transport.

    Adding all the bicycle-related cost (bike, locks, mask, clothes etc. altogether) is equivalent of buying a 4-month travel ticket in London. Even including maintenance cost, I’m financially better-off cycling than using public transport.

    Another factor is reliability. Cycling may take a bit longer and require more physical effort, but at least its duration is predictable. Commuting on a public transport is always full of confusion and frustration due to unreliable service and overcrowding. But once I started cycling, to my surprise the whole set of travel-related stress has disappeared and I discovered happier me.

    When I started cycling I was scared my socks off for the first 2-3 months, but if you take it as a small adventure for the first time and repeat the route carefully, the nervous excitement will wear off and cycling will become everyday activity after a while.

    To cycle safely amongst large vehicles, you just need to know the DOs and DON’Ts around those vehicles. As long as you adhere to it, those big guys won’t harm you. If you respect other general traffic rules, the motorists will respect your presence in return. You cycle alone but you share the space with everyone else.

    How is your experience of using Totobobo mask in London?

    Martie at Kingsway, London, WC2B

    Martie at Kingsway, London, WC2B

    filters facing outside of the mask.

    Totobobo mask after cycling in London about a week, the distance covered is approx 80km.

    I use Totobobo mask all the time as I cycle everywhere in London.

    Since I began commuting to the centre of London where traffic pollution is worst, I started using double 96% filter for my mask.

    With single filter I get discomfort in my throat after every journey because of the heavy traffic, but with double filter I can clearly feel the improvement. Previously I keep producing small amount of sputum for a couple of hours after every journey, whereas with double filter, I don’t get that ‘ahem…ahem, ahem…’ phase, virtually none.

    Obviously using double filter limits my inhalation, but I’m happy to take this trade-off for greatly reducing discomfort caused by pollution.

    I have been using double filter nearly every day for about 4 months, and so far there’s no lasting respiratory impact, only short period of breathlessness immediately after a journey.

    filters facing outside of the mask.

    filters facing outside of the mask.

    With the mask, I’m more willing to travel longer distance without worrying about the level of pollution, it also allows me to cycle safely as I’m not compelled to move away from the rear of a vehicle when it is unsafe to do so.

    I do intensive exercise regularly so I know my respiration capacity is stronger than the average person, but I’m also aware that there might be a long term negative impact of having double filter.

    (Note: Double layer of filter may cause discomfort and can be damaging for special group of user. Consult your doctor before applying double filter on your mask.)

    Have you try other brands (of mask) before?

    No, but other products didn’t look so air-tight while Totobobo taking less space to carry around. Other product looked either too elaborate or too flimsy. Totobobo seemed to me hitting the right balance.

    The rather clinical look of the mask sometimes raise eyebrows, but I think it’s just an outcome of that famous principle ‘form follows function’.

    1 comment

    Latest filter test report from Nelson Labs

    Recently we received the final test report regarding F96 and F94 filters from Nelson Labs. The result summary (and link to the pdf):

    F96 filter
    Latex Particle Challenge Final report
    Test particle size: 0.1μm
    Filtration efficiency %: 99.86

    F96 filter
    Bacterial Filtration Efficiency.
    Test particle size: 3 μm
    Delta P: 11.4 Pa/cm2
    Flow rate: 8 L/min
    Filtration efficiency %: 99.9*

    F96 filter
    Viral Filtration Efficiency (VFE) Final report
    Test particle size: 3 μm
    Filtration efficiency %: 99.9*

    F94 filter
    Latex Particle Challenge Final report
    Test particle size: 0.1μm
    Filtration efficiency %: 99.71


    Fit testing Totobobo mask with 5.5 years old

    Happy Lucas wearing a well fitted Totobobo mask

    Happy Lucas wearing a well fitted Totobobo mask

    Conducting a fit-test with Lucas

    Conducting a fit-test with Lucas

    Lucas is the youngest fit-tester ever tested by our Portacount Pro fit-tester machine so far!

    Lucas was born in the year of rat 2008, making him 5 years 6 months old when he visited us for a fit-test. Not long ago Yixuan, Lucas’ mother, send us a photo of Lucas wearing a Totobobo mask and explained that she couldn’t get it to fit him perfect enough. After checking the photo it is obvious that the mask was too big for Lucas. I offered to to conduct a fit-test help to customize the mask for the little boy.

    At first the mask was too big for Lucas..

    Help! Lucas’ Totobobo mask is way too big. Large gaps can be seen below the chin and around the nose bridge. Photo credit: Yixuan

    Lucas’ mum told us he is a very active boy and makes friends easily with both adults and peers. It was fun to have Lucas since he is very playful and active. However the fit-test part was a bit challenging since Lucas has to keep still and perform certain specific action, such as deep breathing, moving the head steadily side to side and up-and-down. The most difficult action turn out to be “breathing normally”, (that sounds so boring for Lucas) and the easiest was “Talking loudly”.

    Optimized Totobobo mask after the fit test

    Optimized Totobobo mask after the fit test

    We were unable to obtain an uninterrupted routine to pass overall “Fit-factor” of 100. On the other hand, although the result during “Normal breathing” was a poor 20, incidental results of over 100 means that it is possible for Totobobo mask to achieve N95 level performance on a 5 and a half years old. For example, during the task “Head side to side” the fit factor was 107, and another task “Head Up and Down” the fit factor was beyond 200!

    Partial result during the fit test

    Partial result during the fit test


    How do we test Totobobo mask?

    We have not yet figure out what were the causes of the relatively poor results from the CCA (China Consumer Association) test report last month. What we can do now is to share how we conduct our own test to ensure a high level of protection is achievable with Totobobo mask. Even Though Totobobo mask is not a certified N95 mask, we make use of an OSHA-compliant fit-tester called PortaCount® Pro+, which is manufactured by TSI in USA.

    由于资料不足我们还没法弄清楚为什么Totobobo在上月中国消费者协会(CCA)的测试报告中表现较差。但我们可以公开我们是如何测试Totobobo口罩,以确定它对PM2.5的高度防护作用。Totobobo不是一个N95认证的口罩,但我们采用符合OSHA标准,由美国TSI公司制造的定量测试仪,PortaCount® Pro+。

    Theory of operation of a PortaCount Pro + Image credit: TSI

    The PortaCount® Respirator Fit Tester works by measuring the concentration of microscopic dust particles in the ambient air and then measuring the concentration of those dust particles that leak into the respirator. The ratio of these two concentrations is called the fit Factor.

    PortaCount® Pro+ 的工作原理为何?它是如何进行口罩测试仪工作?
    PortaCount® Pro+ 有两根导管,一根通往口罩测量口罩内的微小颗粒的浓度。另外一根在口罩外测量周围空气的微小颗粒的浓度。PortaCount® Pro+ 根据这两个浓度的比值计算出总保护率(Fit Factor),这包括过滤效率和泄漏性.

    A fit factor is a measure of how well a particular face piece seals against a person’s face. It is expressed as a ratio of the concentration of challenge aerosol outside a respirator to the concentration of aerosol that leaks into the respirator through the face seal. A fit factor of 100 means the air inside the mask is 100 times cleaner than the air outside.

    什么是总保护率-Fit Factor?
    总保护率-Fit Factor是指一个口罩对某一个使用者人的总体保护程度。以口罩内外空气中两个颗粒的浓度的比值计算。总保护率-Fit Factor =100 即是表示面罩内的空气比外面的空气清洁器100倍。N95口罩的总保护率-Fit Factor必虽达到100。

    The PortaCount® Pro is a Quantitative fit tester (QNFT). QNFT is a better test because it eliminates the subjectivity of QLFT. A quantitative fit test is not affected by the person’s sense of smell, taste or sensitivity to irritant chemicals. One of the most appreciated aspects of QNFT is that the test subject cannot deceive the test operator, as often happens with QLFT.

    PortaCount® Pro+是一款定量测试仪。 定量测试比定性测试更好,因为它消除了定性测试中会影晌结果的一些主观因素。例如受试者的嗅觉,味觉或对刺激性化学品的敏感度。在定量测试中测试受试者不可能欺骗测试仪。

    Below is a 9 minutes video showing the entire process of a Quantitative fit test. The final result shows the Totobobo mask with a pair of F96 filters is able to reduce ambient particles by 142 times (Video @ 8:48), or a fit-factor of 142.

    以下是一段9分钟的视频显示PortaCount® Pro+定量测试的全个过程。最终的结果显示Totobobo口罩可以提供142的总保护率(Fit Factor)。面罩内的空气比外面的空气清洁器142倍,即总过滤效率=1-1/142=99.3%。(视频@8:48)

    Fit-test-Totobobo Mask with TSI Portacount Pro 8038 from Francis Chu on Vimeo.

    Intro to Quantitative Fit Testing (TSI)

    Totobobo mask in NIOSH site for “No Fit Test Respirator”

    Clearly a Better Way to Check for Safety


    CCA report: Totobobo mask performs not as good as $1 disposable mask?

    2014-03-21 Beijing, China
    China Consumer’s Association (CCA) published a major test report of 37 types of anti-pollution masks purchased from open market in China. These includes sources from both physical shops and online stores. The test was conducted according to Chinese standard GB2626-2006 《呼吸防护用品自吸过滤式防颗粒物呼吸器》, or 《Particulate Filtering Facepiece Respirators》. Majority of the test samples are disposable respirator, a few cloth mask (permeable material) with exchangeable filters. Only Totobobo mask is “rubber mask” (non permeable material) with exchangeable filters. According to the results, at a rating from poor (1 star, to best, 5 stars) Totobobo mask rated 3.5 stars for filtration efficiency, 4 stars for breathing resistance and “POOR” for face fit. This result compares to a few of the much cheaper disposable mask (e.g. Maskin 61750) is not impressive at all.

    Link to the CCA test result here:

    We were quite surprised by the poor result because there is a big differences from an earlier study done in the Prince of Wales hospital, Chinese University in Hong Kong. That study compared the performance of Totobobo mask against several N95 masks previously fit tested. The results shown that Totobobo mask was able to achieve reduction of airborne particles by 132 fold while those previously fitted 3M masks were able to achieve 193 fold of reduction. In terms of comfort 65% of subjects preferred the Totobobo mask
    over the N95 masks (1860, 1860s 3M).

    Link to the hospital test in Hong Kong:

    Since there is a large gap between the two tests, we are now trying to find out more information about the CCA test, for example what kind of tests have been performed on the mask, and how it was conducted. Perhaps the reason will be more clear about our investigation. We will update this post at we find out more.

    If you have any idea/theory to explain this performance gaps, please leave a comment below.


    How to improve the locking power of the new filter cap?

    How to improve the locking of the filter cap?
    The filter cap can be reshaped to improve the locking power.
    Follow the following steps :


    How to improve locking power of Totobobo filter cap?


    Totobobo on WSJ and CCTV

    Totobobo mask was recently featured in The Wall Street Journal and CCTV. Below are the links:

    Totobobo featured in The Wall Street Journal!8947A308-3A68-4689-AA5E-B741B9FF5927

    Totobobo mask featured in CCTV


    Nanjing University experiment with used Totobobo filters

    Nanjing University Totobobo filter experiment

    Would you like swop your used TOTOBOBO filters with new one?
    We are helping a research group in Nanjing University to study the harmful material in the filter. Two sub-groups will be analysing the organic material as well as the heavy metal trapped in the used filters.
    If you are using Totobobo mask in China, this is your chance to help.
    What we need you to do is to send your used filter to Totobobo China in Beijing, along with the following details:

    Details of used filter pair (example)
    Date: 2013-12-12 ~ 2013-12-14
    Duration: 7 hours
    Location: Beijing, Haiding
    PM2.5 range: 200 ~ 300

    The research team will publish the result at the end of the study. To support this meaningful study, we will issue 60 pairs of F96 filter to swop with the first 60 pairs of useful filter samples.

    Below is more detail instruction in Chinese:
    Nanjing University Totobobo filter experiment


    There is a large gap around the filter holder! (2014 design)

    Some user feedback that the filter holder of the 2014 new design is not as tightly seal as the old design. There is a large gap around the filter holder and the filter inside is clearly exposed. (pic. 1)

    Does this gap cause a problem with the seal?

    Does this gap cause a problem with the seal?

    First the large gap around the filter holder is our design intent. It is designed to allow more air to go through the filter. More air opening means lower resistance and easier breathing. This is an important benefit relates to the comfort of mask wearing.
    Now, does this large gap also indicates the new 2014 model is less protective?
    Certainly NOT. To understand, you need to check the inside of the mask (pic. 2) Here you can see clearly, all the air has to go through the opening. The seal is valid, as long as the filter makes good contact with the edge of the opening.

    The seal is good , as long as the inside of the filter is properly fitted.

    The seal is good , as long as the inside of the filter is properly fitted.

    To demonstrate the above is true, we use a TSI PortaCount device to perform a fit test of a user using the 2014 new design. The overall fit-factor in this case is 165, clearly above the pass rating of 100.

    Fit test result from one of the 2014 design users.

    Fit test result from one of the 2014 design users.