U.S. intelligence officials say they don't believe IS has the technological capability to produce nerve gas or biological agents, and that the militants were more likely to harm themselves trying to make them. A European official privy to intelligence on the extemist group's programs agreed, saying so far even IS production of mustard gas was in small quantities and of low quality.
These are the same people who had to be reminded to use a VPN and not to click suspicious links on Twitter, I highly doubt their minds are of the complexity to create or even use biochemical weapons.