Thanks, that is really interesting. I'll have to read up on the Dragon capsules, I have enjoyed reading about their boosters and their landing attempts.
If they're using stuff like hydrazine in their thrusters, that's always going to be a major concern. They are planning on using the thrusters for every landing over land, eventually, or so I thought.
This is actually one of the concerns with SpaceX Dragon capsules - they use significantly more toxic components.