The following comes from a story story about 50 gal. drums of CW:

"A chemical team checked the drums, one of which tested positive for
cyclosarin, a nerve agent, and a blister agent which could have been
mustard gas, Martin said."

There was an earlier story (later retracted) not unlike this one
about mustard gas (a blistering agent) and sarin being mixed together in
50 gal. drums.

Sarin is far more deadly than mustard gas. Finding the two mixed together is
like mixing C-4 plastic explosive with black powder. Maybe what we
are finding here are sites where CW artillery and missile rounds had been
unloaded. The emptied shells were hauled off (buried) somewhere else
(nearby?) while the chemical agents were poured together in 50 gal. drums
for later disposal. Our finding this stuff might be examples of
Iraqi bureaucratic stupidity where a responsible official was ordered to
destroy WMDs but did so incompeletly. Semi-destroyed WMDs would not really
represent the sort of "smoking gun" that the Pentagon is looking for.

Gary