We are also very worried about nitrogen dioxide - and we support many efforts to reduce this gas at the source. It's a nasty pollutant and difficult to treat!
In short: yes. We filter nitrogen dioxide with a high-surface-area activated carbon layer in our filter.
Scientifically, the best way to filter from the air is to boil or freeze the air; this is because different gases have different boiling and freezing points. Obviously not a great solution for real world use.
The next best way is to use carbon treated with chemicals, but most of the chemicals are not approved for medical use. This is common in industrial settings.
For medical use, the best way is to use treated carbon cloth with salts. This is what we opted for. We use an activated carbon cloth with a large surface area, that is treated with metallic salts approved for medical use.
With treated carbon, more surface area equals more filtration, and the cloth we chose has the largest possible surface area of any carbon cloth available, which is achieved with a microporous structure. Just 1g of this carbon can have the surface area of half a football pitch.
The amount and percentage of nitrogen dioxide Brizi Baby can filter depends on the concentration in the ambient air, as well as temperature and humidity, so I’m afraid we can’t tell you exactly how much it will filter.
In our tests with Professor Kumar, Brizi Baby filtered around 50-80% of the total pollutants in the air - we walked around a heavily polluted area in London and tested specifically for nitrogen dioxide and carbon monoxide, in addition to other gases and also particulates.
Brizi Baby also dilutes the air in the breathing area by pushing filtered air into the equation, which will reduce the overall concentration of pollutants. But the % efficiency still depends on what concentration of NO2 is in the air to begin with.
We're talking about gas of course, and according to the WHO the medical impact depends on the concentration of gas and length of exposure.
When it comes to particulates, the WHO recommends exposure of zero - or as low as possible - which is why we paired the activated carbon filter with a nanometric woven fabric.