[dynoman]

Binary sarin shells don't degrade at all. Did he have them? We don't know.

I read somewhere Iraq did have binary shells.

[dynoman]

Here is is; Sarin, Mustard Gas Discovered Separately in Iraq

The round was an old "binary-type" shell in which two chemicals held in separate sections are mixed after firing to produce sarin, Kimmitt said.

If these 500+ shells are indeed binary shells the argument the sarin is old, degraded, and therefore ineffective is destroyed. Binary sarin shells never get old and ineffective because the components don't mix until the shell is fired, that is why they are called binary and made to hold the components separately until use. When the shell is fired the components mix and produce sarin.