The 3M Cool Flow™ Filter Fan, 1040 is attachment for reusable half masks. This fan features a single button control function offering improved wearer comfort during long work shifts. It is rechargeable and is supplied with a UK plug. It is an innovative attachment for the mask to provides a noticeable cooling sensation on your face as you work and provides additional comfort without compromising on breathing protection
As particle filters load up with the contaminant they actually become a better filter. However, they become a harder filter to breathe through. The user will notice breathing becoming too hard and will then need to change the filter.