Essentially, a lot of chemicals that were once chemical weapons, now basically just hazmat. I wouldn't crack open those bunkers without professional top of the line hazmat gear.
The difference is the same as the difference between a nuclear weapon and a radiological weapon. They could strap explosives to bulk containers and cause contamination issues. But not exactly ideal for actual weapons production. Saddam scrapped most of the equipment, and we blew up what was left.
It's a toxic junkyard.