Thanks for pointing that out, I was not aware of those markers.

AFAIK, nobody rates their cartridges for use with isocyanates so I feel like they wouldn't put detection strips on it for that. However, from what I read after this thread started, they stop working for VOC before they stop working for isocyanates, so maybe it's okay. Take that as internet wisdom though, wasn't from an authoritative source My asthma annoys me enough that I'm not taking risks with something like that, as enticing as the thought of saving $400 might be