Due to the strict controls carried out, the FOX 5.5 Z21 was designed, built and certified in compliance with ATEX Directive 2014/34/EU by the certification body DNV-GL. It is equipped as standard with AISI 304 stainless steel chamber and dust bin, IP65 EXPLOSION PROOF certified circuit breaker in enclosure, SIEMENS certified side channel blower, silencer with safety filter at the outlet; vacuum gauge with clogging indicator, Class M certified primary anti-static filter, vacuum breaker safety valve and absolute filter certified by the German certification body IFA as class H14 (99.995%), for vacuuming fine or toxic dust. The version with compressed air cleaning system with FA/BGIA M-PES/EX EXAM certified cartridges is available as an option. The compressed air enables cleaning to backwash and subjects the filter media to a high-frequency oscillatory motion. The PLC installed inside the electrical panel determines the cartridge cleaning time and ensures filtration efficiency at the highest level at all times.