I came across Totobobo while searching for a filter to combat the haze in Penang. I wanted to continue cycling when the haze came, and didn’t want to stop because of lung cancer worries. Googling for Cycling Mask returns the popular Respo Mask as the top search, but further down is where I found Totobobo. I was initially attracted by the entry price. It is much cheaper than Respo and much more breathable.
To no surprise, the filter darks up as reported by the London Cyclist. When I put the filter under a microscope, I could see all the tiny carbon particles sticking to the fiber of the filter. The filters have electrostatic charges and this helps it to attracts the carbon particles. I have also taken a photo of the filter after 4.2hrs of usage. This is where I stop and change the filter as I believe, the filter looses the filtering efficiency as more and more particles are getting through.
I tried to improve the filter efficiency by using two 92% filter back to back. My theory is, I can get a filter efficiency up to 99.35% (92% + [8%x0.92]). Though I could not prove 99.35% efficiency, but I did notice that the second layer of filter do darkens quite significantly, and I am definitely getting a filtering efficiency of more than 92%. The caveat in doing this is that I broke the filter holding clips because the thickness of the two layers of filter.
I am horrid by the carbon particles that goes into my lung. Without this filter, I would have been inhaling the particles and these tiny particles may get traps in the inner catacombs of my lung. Not sure what long term damage this could do to my lungs, but it is better not to have them there. Totobobo is now my cycling companion, together with my gloves, shoe and helmet.