How long can the mask be used for?
Cambridge Masks‚ are non-disposable, meaning that you can use them for potentially 340 hours of active use, or 6 months of daily use during a commute or other activity. The length of time they are suitable for depends on how polluted the environment is when you use it.
A general guideline is that you can use the masks on a regular basis for 3-6 months before it needs replacing. Once the mask is past its useful life a new mask is needed. A table is provided below.
|Pollution Level||Air Quality Condition (AQI)||Description||Replace after|
|Good||Below 50||Clear visibility to horizon||Mask not needed|
|Moderate/Unhealthy for Sensitive Groups||51 - 150||Cannot see pollution with the naked eye, slight haz on horizon||340 hours|
|Unhealthy/Very Unhealthy||151 - 300||Haze at 2-3km visibility||220 hours|
|Hazardous||301 - 500||Clouds of pollution, visibility around 1km||180 hours|
|Beyond Index||Above 500||Visibility below 600 meters. Fog-like clouds of Pollution clearly visible even in bright sunlight||90 hours|