As far as "Dangerous Toxic Fumes" Anything new smells. Every New Trailer, Motorhome I've stepped into for the last 28 years has smelled/burnt your eyes/set off co2 detectors. You leave the doors open for a while and it goes away. Same with "New Car Smell".
You have to ask how these tests are done. If there taken while some of the adhesives are still wet, Its going to fail. A lot of the time the manufacturers can't vent them after there done. In most cases, I know we do an RV is always left open for a while to vent.
When the government buys thousands from the manufacturer, Keep in mind the government doesn't know a thing about trailers and there's no dealer to prep them, The first time there vented is when the tenant opens the door. Those odors could have been cooped up in there for months.
As far as these trailers being trashed after seeing what happened to the Super Dome it doesn't surprise me.
Happy Trails
Len