In article , Badger.badger
wrote:
Multi cylinder packs, used as fuel in o2/h2 burners to work silica.

H2 would be two nines or so pure ; chromatographic grade
hydrogen (should be / is) five nines. 99.999% Every bottle needs it's
certificate of conformity, and they aren't issued for more than a few
months after production and testing.

--
Aidan
Aberdeen, Scotland
Written at Fri, 08 Dec 2006 00:12 GMT, but posted later.