There has been some discussion on this matter. If you read the tigerfoam MSDS, the only really nasty stuff is the isocyanates. Which when cured harden the foam. Once the foam cures there is a bit of off-gassing which might be dangerous if you sleep in the van with zero ventilation for the first few weeks.
After about 3 weeks, there was almost no noticeable odor in the van, even after baking in the sun with all the windows closed.
Honestly the exhaust from the diesel engine is more of a health concern IMHO. These foams do not contain formaldehyde, which was the primary concern with foams used a few decades ago.