Working on large chemical plants We sometimes are issues escape hoods. Dreiger seems to be popular.

I always wonder about these units. It sounds like a good idea but the cost is quite high. Often the single-use-only escape hood that is only rated for 15 minutes is most of the price of a full-face respirator and hood that could, given a change of filter/s, could be used many times and would give you far more time than just 15 minutes.

Anyone else noticed this? Opinions?