There's a particulate filter and an organic vapor cartridge, and you're primarily worried about the organic vapor cartridge which has a peel-off seal when you a

There's a particulate filter and an organic vapor cartridge, and you're primarily worried about the organic vapor cartridge which has a peel-off seal when you assemble it. https://multimedia.3m.com/mws/media/1948355O/combination-cartridge-filter-p100-6000-series-user-instructions.pdf?&fn=34872639413.pdf https://multimedia.3m.com/mws/media/1948355O/combination-car... 40 hours of use or 30 days, whatever comes first, it says. It's probably not what I would bet my life on, but I've used a bunch of these up doing wood finishing and cleaning. You swap them when you start to smell anything through the cartridges, because it's not actively handling organic vapors anymore. I think 30-40 hours of real exposure use is realistic. I typically wipe down & pack masks with organic vapor cartridges into a ziplock bag filled with paper towels when I'm done for the day. This ziplock thing is just what I started doing after leaving it out on the counter and found the cartridges weren't effective the next day. This is entirely unscientific, but I think they last longer stored like this.