thoughtful responses, I hope I can cover them here, but it's the other end of my post I wish to continue with...that's the notion of rather than being inside a unforgiving box, build-up around it and use it for structure which would create healthier and more comfortable living spaces.

Robert--didn't quite find the specific talk on hazards in that link, but yes formaldehyde is a big problem in plywood. It is the basis of the glue. Some industrial plywood has been regulated out of both EU and US markets for housing construction. There is a particular kind of plywood that I know of to stay away from it's made with a reddish tint glue and I was told that it is massed produces in China and India on large scale. I saw that reddish tinted plywood in a group of containers that I was looking at, they all came together from the port of Singapore.
I thought I was extremely lucky in finding a group of eight containers that were up for auction, but then decided against it.
The containers that I was looking at weren't made in the states, they were Asian. Nowadays everybody has glues that are mostly soy based I believe and are safer. Remember many of the containers you get aren't new, they might be from older not regulated production methods.
I remember five years ago or so that there were a lot of warnings on high formaldehyde plywood. The key reason that this is a problem to me is that you really can't ventilate a shipping container easily especially since the ceiling is low and at the same height all the way back.
I'm betting that most container housing doesn't do much with venting and for the most part suffers with the poor space configuration.

arka... whole new floor? yeah but....

Robert... you're worrying me cover a toxic with toxic? what respirator you been wearing? I've used those epoxies on a small scale and wouldn't even think of putting them in an enclosed space. Two part epoxies worry me cause they keep interacting chemically long after they are applied, some eventually turn to dust as the chemical process finally either hardens it to the point it shatters or it hardens to the point it is no longer flexible. Yeah this is ten, twenty years down the road and we'll be gone. But I don't want to use them cause I'm constantly running into things needing to be tossed cause the materials used have met their match or are improper. Inert is inert and is my primary consideration nowadays.

OK so what about building around the containers. I see containers as a solid structure that could be used for mechanicals and good storage. Using the containers to create nice open space which would then be modified into a living space. Obviously one container doesn't work unless your making a lean to. But three or four could help with enclosing quite abit of space. Five could make a nice multi level space and an easy roof. Easily more than 1500 sq ft. Then you'd have actual adjoined closed space created by the inside of the containers. The buildout materials used could be moved with the container itself. So you get the containers in a port city, fill them with less expensive building materials and then transport them directly and effectively to remote sites.

One crucial thing is making a winch to get one of the containers high enough to move it atop the others.