Dangerous if the ambient air contains under 20.9% oxygen.
If possible always use a filter that protects against the expected hazardous substance because this specific filter has a much longer lifetime.
If there is uncertainty about the hazardous substance, use an ABEK2-P3 filter, but this has a substantially shorter lifetime - up to 70% less!

NB!
Once a filter has been used for one type of gas or vapour, even if the filter is not yet saturated, afterwards the filter concerned may only be used for the same type of gas or vapour.
Take no risks, fit a new breathing filter!

Standard: EN 148-1 (threaded connection)
: EN 14387:2004+A1:2008 (filter)