The EN 779:2012 standard expired at the end of 2016. The method of classification was no longer optimal. A minimum efficiency had to be achieved after which the filter was classified into one of nine classes.
In this, the G1 to G4 classes were aimed at coarse dust particles, the M5 and M6 aimed at somewhat smaller dust particles and the F7 to F9 classes were aimed at fine dust particles.
In 2016, the ISO 16890 standard was therefore introduced. This standard tests filters very specifically for particle size and indicates by means of a percentage how well the specific filter scores. Via the button you can find the detailed explanation of the current air filter standard.