...and as far as I know chemical/biological agents used in weapons have 'shelf-life' 10 years or less unless stored in specialized environment. Meaning a vast controlled storage site. You just don't put anthrax in a bottle and put it in a desk drawer and expect it to stay vibrant.
Also, before the war started I read from somewhere that Iraq never had such equipment (one thing you never sold to them
) and never aquired any.