>Mixing phosphoric acid and hypo clear (specifically the sodium
>sulfite in it) will produce sulphurous acid which will cause you to
>leave your darkroom in a hurry.
Actually,as I turns out, I did have to leave the darkroom in a hurry as my
asthma suddenly flared up upon the addition of KHC and Phosphoric Acid and
without warning and I couldn't breathe. I counldn't figure it out as my
asthma is usually not a problem. But thanks to your posting, that is now
understandable and I confirm your finding of the production of sulphurous
Acid and the secondary symptoms of asthma and suffocation. Thanks for the
valuable info.
Stephen Harrison