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Pollution inside – Bus vs Plane

“It’s the best mask I’ve tried so far.”

Allan Hansen – Califonia, USA

Allan Hansen, CA, USA

Allan Hansen, CA, USA

Allen travel a lot and want to protect himself when he is in cities with heavy air pollution. He tried the TOTOBOBO mask and it appears to be the best mask he has tried so far. He ordered a bunch for his family because TOTOBOBO mask can fit the small faces of his children too.

As a traveler, pollution can exit in the most unexpected place. If it is not because of my previous research for a post (Say no to to pollution in school bus). I wouldn’t suspect there can be polluted air circulating inside a deluxe, aircond tourist coach.

Two weeks ago I took a SVIP coach from Singapore to Cameron Highlands. The seats inside this coach are large and the back can be lowered to almost flat- just nice for a good night sleep. The soft velvet feels comfy but I was curious to find out the air quality inside the bus.

I put on my mask during the overnight trip. We were required to get off the bus when crossing the border, and there were a couple of pee-stops during the night. I took off my mask when I need to get out of the bus and put it back on when I am getting back in.

After 6 hours of use

After 6 hours of use

When we reach Cameron Highland it was 7am in the morning, I was shocked to discover the gray patch collected on the filters- a clear indication of air pollution inside the coach, most likely from it’s own engine! The air quality along the route up Cameron Highlands at that time should be very clean.

To make sure I was not making this up, I decided to compare the result on a plane trip. I put on the mask with a clean set of filters on a business trip to Frankfurt. When I reach there after 12 hours, I can not see any noticeable sign of dirt. To be very sure about this, I put the same mask on during my flight back. Now it accumulated a total 24 hours of use in the plane. Judging from the color of the filter it is still very clean.

My conclusion? The air inside that coach is MUCH worst than the air inside the plane. It seems the air filter on plane is much more effective than those on buses, if the buses have any air filter at all.

24 hours of use in a plane

24 hours of use in a plane

Read more:
TOTOBOBO, the fitting mask for children
How to customize TOTOBOBO mask?
Advanced features of TOTOBOBO mask


Say No to Pollution in School Bus

School bus in USA

School bus in USA

Every day, half a million school buses safely carry 24 million American children to school, field trips and athletic events.

Unfortunately, most buses are powered by diesel engines that actually pollute the air inside the bus. Studies show the pollution gets trapped inside the bus, where kids breathe it in.
Soot from two sources

Pollution come from emissions from the tailpipe and from the engine. Engine emissions (also referred to as crankcase emissions) enter the school bus cabin mostly through the door and the floorboard.

Because the door is right near the engine, engine emissions get sucked into the school bus, every time the door opens.
Unhealthy diesel exhaust

Diesel engines spew out nearly 40 toxic substances, smog-forming emissions and particulate matter (PM), better known as soot. Coarse and fine particles (PM10 and PM2.5) are breathed deeply into the lungs where they can lodge, creating serious, even life-threatening health problems (more on the health effects of soot and the problem with diesel).

Children are at particular risk because their lungs are still developing. Kids also breathe two times more air per pound of body weight than adults do. The damage to young lungs can result in reduced lung function by adulthood and other dangerous health problems.

Particle Pollution Health Risks

• aggravated asthma
• lung inflammation
• heart problems
• possible cancer
• premature death

Children receive an extra dose of pollution twice a day

pollution in school bus

pollution in school bus

Children riding buses older than 2007 models receive an extra dose of pollution on each ride: monitoring shows that the diesel pollution inside a typical school bus can be up to five times higher than the outside air.

Unless your child’s school bus has been retrofitted with a filter or your child is riding on a brand new 2007 school bus, chances are, your child is breathing in unhealthy pollution levels.
Solutions are at hand

Science indicates that even short-term exposure to elevated particulate levels can have detrimental health effects. The good news is that children do not have to be exposed to diesel school bus pollution. Cost-effective solutions are available. Four Steps to Cleaner Buses.
To cut harmful soot pollution by 90 percent, a bus can be replaced with a new 2007 engine model year bus or retrofitted with a filtering device on the tailpipe, called a diesel particulate filter (DPF).

Engine emissions can easily be eliminated with a crankcase ventilation system (CCVS). A CCVS reroutes the engine emissions to the engine air intake preventing harmful emissions from escaping into the air and the bus cabin.

While working on the long term solution, the immediate action you may take is to install a personal filter (face mask) for your children. However, a surgical mask is useless since the airborne particulates can easily bypass the mask and enter the breathing zone through the gaps. N95 respirator is not available for children because NIOSH never certify any for use on children. Luckily TOTOBOBO mask is now available and it is the first fitting mask designed with the need of children in mind. Even though it is not certified, it is easy to see how it seal the small faces of children. There is even a choice of two different filters; 96% or 94%. The 96% provide higher protection level than N95 mask, and the 94% is only 1% less than N95 mask and has very low breathing resistance.

Reference reading: CLEAN SCHOOL BUS
Idle School bus may be harming your child’s lung

Read more about TOTOBOBO mask for children :

The best fitting mask for children

Say no to pollution in school buses

time for a better mask for children

protect children from incense smoke

How to’s

How to customize TOTOBOBO mask for your children?

How to wash TOTOBOBO mask for reuse?

How to check the mask-to-face-seal without fit-test equipment?

Buy TOTOBOBO mask for children


Mohit recommends Totobobo mask

Mohit from India recommends Totobobo mask. His has been using his trusty Totobobo mask for the last 10 years!
Thank you Mohit!


How to wash TOTOBOBO mask?

After some time of use, any face mask will get dirty. TOTOBOBO mask is praised by many users as light-weight, easy to clean.
Here is a simple step-by-step instruction about how you can do the cleaning under a tap. Make sure you clean your hands before you start cleaning the mask.

1. release the filter cap and remove the filters.

2. apply soap – Apply soap thoroughly inside and outside of the mask.

3. rinse – Rinse the mask, inside and out thoroughly.

5. drying the mask with a clean tissue paper
If you are in a hurry, dry the mask with a clean tissue paper.

6. leave it in clean and dry air for a while
If you have time, simply leave the mask to dry in a clean environment.

7. insert new filters
Now hinge on the filter cap, insert a new filter pair, and you are ready to go again.

More advanced features of TOTOBOBO mask

TOTOBOBO mask can be cut to size

TOTOBOBO mask can be cut to size

The TOTOBOBO mask is the world’s first customizable respirator. Other products are only available in a particular size that only fits a particular age range and facial structure. For everyone else, there is little else that can be done.
TOTOBOBO, on the other hand, is capable of being trimmed to fit a wide range of facial sizes for optimal comfort and filtering. The mask fits most adults and can be modified to fit children as young as 5 years old. TOTOBOBO is the most versatile protective mask on the market. Adjusting the mask’s size is simple, just follow these steps:

Note: Use a pair of clean and sharp scissors. Wash your hands before starting.

You first need to determine how small you want to trim the mask. You can make a quick estimate by covering the mask on the user’s face, or better yet, get a TOTOBOBO dummy mask set. If you are not sure about the accurate size, I suggest you to trim the mask one ring at a time. The mask should form a snug fit to the face, but not so tight as to be uncomfortable. Take this into account when trimming the mask. Remember: measure twice, cut once.
You then carefully cut the material of the mask starting from the bottom. Inserting the scissors, follow the curvature of the mask along one of the ridges as you cut and make a complete loop. Trim any excess for comfort and test size as necessary. The excess material can be disposed of, and the mask is ready for use.

Once the mask is cut to fit the desired size, it is ready for repeated, long term protection.

Step 1 - start the cut from the bottom of the mask

1 - start the cut from the bottom of the mask

Step 2 - insert the scissors into one size of the opening

2 - insert the scissors into one side of the opening

Step 4 - turning around to the other side
6 - almost done

4 - make a loop to the starting point

7 - see! you've got your small mask now

5 - see! you've got your small mask now


Test the cut with a Totobobo mask simulator

Buy Totobobo mask


Document title
Predictive value of the user seal check in determining half-face respirator fit


DERRICK J. L. (1) ; CHAN Y. F. (1) ; GOMERSALL C. D. (1) ; LUI S. F. (2) ;

Author(s) Affiliation(s)
(1) Department of Anaesthesia and Intensive Care, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, HONG-KONG
(2) Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, HONG-KONG
Résumé / Abstract

Guidelines issued by the Centers for Disease Control and Prevention and the World Health Organization state that healthcare workers should wear N95 masks or higher-level protection during all contact with suspected cases of severe acute respiratory syndrome. Before use, the manufacturer recommends performing a user seal check to ensure that the mask is fitted correctly. This study aimed to test the ability of the user seal check to detect poorly fitting masks. This study is a retrospective review of a mask-fitting programme carried out in the intensive care unit of the Prince of Wales Hospital in Hong Kong. In this programme, all staff were tested with two types of N95 mask and one type of N100 mask. The results of the documented user seal check were then compared with the formal fit-test results from a PortaCount. Using a PortaCount reading of 100 as the criterion for a correctly fitted mask, the user seal check wrongly indicated that the mask fitted on 18-31% of occasions, and wrongly indicated that it did not fit on 21-40% of occasions. These data indicate that the user seal check should not be used as a surrogate fit test. Its usefulness as a pre-use test must also be questioned.

Revue / Journal Title
The Journal of hospital infection ISSN 0195-6701



Defeative mask recall

If you purchase a TOTOBOBO mask between September 1st~17th from this site, please check if you have received a defective mask. The problem is the whole filter tend to fall off very easily. It is easy to check: refer to the photo here: try to open up the mask by graping both filters, the mask should be opened without the filter dropping off. If the filter detached from the mask without much force, then the mask is defective. Please contact totobobomask (at) gmail . com to arrange for replacement mask.

We’ve taken immediate steps to correct this problem. Masks purchased after September 17 are free from such defect.

We apologize for the inconvenience caused.

checking if TOTOBOBO mask is defective

Checking if TOTOBOBO mask is defective (view from bottom of the mask)


TOTOBOBO mask in NIOSH site

Totobobo mask was spotted in NIOSH NO-FIT-TEST workshop page    Totobobo mask was spotted in NIOSH NO-FIT-TEST workshop page

I was surpriced when my friend show me this page in CDC site. NIOSH, the National Institute of Occupational Safety and Health under CDC, is the US organization who certify the well known N95 mask. What made TOTOBOBO, a little known Singapore invention of respirator mask, appears in this heavy weight website?

No, TOTOBOBO is not certified by NIOSH, at least not yet. The picture of an early version of TOTOBOBO mask found in the NIOSH website is to serve as an inspirational example for a “No Fit Test” filtering facepiece respirator workshop. The workshop will be conducted in Nov. 6 later this year and the objective is:

“To better understand the interdisciplinary research needs and challenges in developing and certifying a universal “no-fit-test” filtering-facepiece respirator”

I think this is totally appropriate and it shows NIOSH recgonize the need to improve the current procedure in order to motivate manufacturers to innovate toward the direction of “No fit test” respirator. 

Why is this big fuss about “No fit Test”?

If you read carefully the fine text of your respirator instruction, you will notice a statement similar to this:

“Before use of this respirator, a written respiratory protection program must be implemented meeting all the requirements of OSHA 29 CFR 1910,134 such as training, fit testing, medical evaluation, and applicable OSHA substance specific standards.” 

The simple fact is, the rated protection value will be drastically reduced if the mask does not fit your face, and there is no other ways to tell except by doing a fit-test. Buying a mask is easy, but getting a mask fit-tested on each individual is a challenge. In emergency situation like flu pandemic or haze outbreak, it is simply not possible to get everyone a fit tested at once. 

One can start to sense the “pain of fit test” and how touchy this issue is from the following comment in one of the NIOSH science blog :


NIOSH debate how often to fit test

NIOSH debate how often to fit tes

Hopeful to see Fit-Test to be lifted– Edward Hernandez, City of Hialeah, Fire Rescue says:- Thank you for proposing a study as this. For a while now this OSHA (Fit-test) requirement  has been a burden to our Fire/EMS service.

Hopeful to see Fit Test to be simplified-Peggie Reinhardt, RN BSN, says:

I would be interested in this study, we currently fit test our employees annually. If this process could be shortened or redesigned so that it was easier to do would help tremendously.

Fighting to keep Fit-Test in organization– Sgt. Julie Love says:

I would be interested in being part of this study on the law enforcement side. We fit test our officers annually but many departments do not. Law Enforcment traditionally has fallen down in this area as many agencies just give their officers their masks without any fit testing. We also fight the battle with our management with what is mandated.

Worry that No-Fit-Test= Not Safe-Kevin MacDonald says:

 I am concerned that changing the fit test frequency while cost effective may defeat its overall purpose. when fit testing went from every 6 months to one year as a requirement of OSHA it was a step back.

Confused and concern-Kelly Russell says:

I am glad this study is being done. Respiratory fit testing is expensive for employers and it will be good to have a current answer when asked why we have to do the testing so often….or maybe not so often as the case may be.


No matter what, the setting up of this workshop itself is already a breakthrough, and we are definitively happy to be associate with the solution side of the problem. We hope the result of the workshop will bring more practical innovation into the design and certification of respirator, especially taking people like housewife and children who don’t have access to fit-test equipment but also deserved to have good protection when situation come.

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If you burn incense at home regularly you may be putting your children at a risk of developing cancer or lung problems. TOTOBOBO mask may be the only practical solution for children who cannot avoid exposed to the harmful incense smoke in many Asian cities.

Incense burning smoke

Smoke particles from burning incense were found to cause cancer of the upper respiratory track. A 12 years long “Singapore Chinese Health Study” of more than 61,000 ethnic Chinese adults living in Singapore discovered ‘Among non-smokers who used incense during the day or at all times, the increased cancer risk was three times that of smokers.’ said Prof Koh Woon Puay of National University of Singapore.

Children surgical mask

The best way to avoid such risk is not to burn any joss-stick. However, incense has a significant meaning in the minds of many Asian cultures such as Hindu, Buddhist or Taoist. Mr Chung Kwang Tong, secretary-general of the Taoist Federation Youth Group in Singapore, explained that for Taoists, the smoke from incense is a way of communicating with the deities. Even for those who don’t practice any of these religions, may have inhaled incense smoke involuntary. Children are particularly at risk, there is mounting evidence that exposure to air pollution has long-term effects on lung development in children.

Children wearing N95 mask

If stop burning incense is not an option, then protecting the vulnerable children with a face mask should be the second best option, right? To filter out the harmful smoke effectively, a face mask must produce two conditions simultaneously. First it needs to seal the user’s nose and mouth snugly. Second the filter material must be able to filter out those fine smoke particles. The use of simple surgical mask doesn’t help, as air-leaks are all around the face and smoke can easily by-pass the mask to enter the lung. Upgrade to an N95 respirator can help, only if you have access to a fit-test setup to ensure the mask is making a proper fit. Otherwise, if air-gaps exist in an N95 mask, it makes very little difference from using a cheap surgical mask. Buying an N95 mask is easy, but getting it fit-tested is not. Much to disappointment, there is no N95 mask available for children.

Children wearing Totobobo mask

TOTOBOBO mask can be cut to fit children (and adults), and parents can now fit-check the mask without the need of expensive fit-test equipments. The name TOTOBOBO (totobobo.com) suggests the solutions in Chinese: TOTO (transparent) BOBO (protection for baby). Parents can see through the transparent mask to examine the seal on the children face. We compared the visual fit-check method with a high-end fit-test setup call Porta-Count in hospital. The result shows strong correlation between the visual-check method and the official fit-test. “User seal-check has never been able to reach such accuracy. It is possible to ensure protection by simply looking through the mask.

It looks like TOTOBOBO mask is going to provide the much needed alternative to surgical masks or disposable N95 mask, especially for children suffering from incense smoke or other air pollution.


Common sense would suggest smaller particle always penetrate filter easier. But this is not always, as state in the FAQ of CDC site:

1. How effective are the Part 84 filter respirators against particles smaller than 0.3 micrometer in diameter?

The 0.3-micrometer diameter used in the certification testing is approximately the most penetrating particle size for particulate filters. Although it seems contrary to expectation, smaller particles do not penetrate as readily as 0.3-micrometer particles. Therefore, these respirators will filter all other particle sizes at least as well as the certified efficiency level.

2. How effective are the Part 84 filter respirators against asbestos fibers or other rod-shaped particles?

Although fibers or rod-shaped particles may have very small cross-sectional diameters relative to their lengths, the Part 84 particulate filter respirators will be at least as efficient against this particle shape as the certified efficiency level.

CDC is right, this is contrary to expectation. The reasons is explained in another document in more details. Here is a diagram from pg. 9 of the document showing there are actually four different collection mechanisms govern particulate air filter performance: inertial impaction, interception, diffusion, and electrostatic attraction:

4 different collection mechanisms of particulate filters

The first three of these mechanisms apply mainly to mechanical filters and are influenced by particle size.

  • Impaction occurs when a particle traveling in the air stream and passing around a fiber, deviates from the air stream (due to particle inertia) and collides with a fiber.
  • Interception occurs when a large particle, because of its size, collides with a fiber in the filter that the air stream is passing through.
  • Diffusion occurs when the random (Brownian) motion of a particle causes that particle to contact a fiber.
  • Electrostatic attraction, the fourth mechanism, plays a very minor role in mechanical filtration. After fiber contact is made, smaller particles are retained on the fibers by a weak electrostatic force.

Impaction and interception are the dominant collection mechanisms for particles greater than 0.2 ?m, and diffusion is dominant for particles less than 0.2 ?m. The combined effect of these three collection mechanisms results in the classic collection efficiency curve, shown in the following Figure:

Fractional collection efficiency versus particle

The TOTOBOBO filters is a type of electrostatic filters which contain electrostatically enhanced fibers. Such fibers actually attract the particles to the fibers, in addition to retaining them. Electrostatic filters rely on charged fibers to dramatically increase collection efficiency for a given pressure drop across the filter.

Following table gives a rough idea of how small a micron is:

 Substance  Micro-meters (microns)  Inch
 90% of Wood smoke particles are smaller than   1 micron  0.00004
 Bacteria (average)   2  0.00008
 Red Blood Cell   8  0.0003
 Talcum Powder   10  0.0004
 White Blood Cell  25  0.001
 Human Hair   70  0.003
 Grain of Table Salt  100  0.004

Read more:

Used filters from India