ISO 16890-1: 2016 is an international standard that relates to the testing and classification of air filters. It replaced the EN779: 2012 standard, which was based on measurements of 0.4μm particle filtration efficiency. - Klimasystem
49 instead of 9 Filter Classes – The Air Filter Standard ISO 16890 in an Overview.
Compressed Air Filter Replacement - Class 1 | Compressed Air USA
Amazon.com : Celestron – EclipSmart Safe Solar Eclipse Telescope Filter – ISO 12312-2 Compliant – Works with 8” Schmidt-Cassegrain/EdgeHD Telescopes – Observe Eclipses & Sunspots – Secure Fit – Natural Orange Tint : Electronics
ISO 16890 is LIVE and replaces EN779:2012 - AFPRO
What Is a HEPA Filter & How Does It Work? | ISO-Aire