The 'stockpile' problem is another misnomer. Chemical and Bio agents are not the sorts of things that you'd ever want to have a very large amount pre-made at any one time. There are shelf-life issues, but more to the point they have some genuinely non-trivial management and logistics issues. It is most definitely not like storing ordinary high explosives.
Most of the time, you'd prefer to have only a relatively small amount ready to use, and make more as you need it. A little bit goes an extraordinarily long way, and replenishing is quick and easy.
An excellent point. And, I like the way you casually refer to "ordinary" high explosives. I tend to treat 'em that way, too. /smile