"No they do not. The cuffs are sealed by gloves, the legs tied off over boots, and the hood tied off over the respirator.
Military CBW suits seal in the same way."

Well you may wish to test such protection in an environment containing an unidentified agent. I do not think I would. That word seal and suggested method of ensuring it gives me serious misgivings.
My safety training has included using radioactive sources, working in contaminated ground ranging from suspected anthrax sites to chemical contamination, and hazardous atmospheres. So I have some familiarity with the various levels of hazard recognised, although I am far from expert especially on the latest legislation.
Presuming a nerve gas to be lethal through absorption, ingestion and inhalation then only a totally sealed protective suit fits the bill.
If you are rash enough to believe those little white suits, gloves, boots and respirators will do the job all I can say is you'll make a good canary. If you have zero knowledge of the agent being used a thinking person would go for the maximum level of protection. If you have knowledge of the volatility or particulate nature, density of the agent etc. then perhaps lower levels of protection can be employed.
But we are awaiting analysis we are told. If the substance is known, why invite international experts to analyse it? Supposedly we have no idea if it is liquid or solid,or how it reacts to wind, rain, evaporation??? Until this agent is identified and it's complete properties determined, caution would dictate a maximum level of protection. I am afraid for the majority of Joe public, wearing a white paper suit(level5) is regarded as equivalent to a bright yellow fully self contained suit(level1).Existing European directives recognise at least 6 levels of hazard.

The way this story has evolved highlights, for me, some rather glaring inconsistancies even when subjected to the most cursory investigation. My feeling is that the little snack of an unfortunate poisoning is being built up into a multicourse multimediafest. Perhaps the question to be asked is not who? but why?(the hype!) I am convinced it is a distraction or more likely, a means to an end.