Question to the Department for Transport:

To ask Her Majesty’s Government what are the requirements on airlines using UK airports for frequently changing air filters in all cabins and what is the maximum permitted interval between changing air filters.

The filters are changed in accordance with the manufacturer's routine maintenance schedules. It is in the operator's interest to change the filters in accordance with the schedule; with time the pores in the filters become congested with material.

This congestion can increase the efficiency of the filter in removing particles from the air, but also increases the resistance to air flow. Therefore greater pressure and power is required to maintain the cabin air flow, which in turn increases fuel-burn and therefore costs.