This might seem fairly negative. The EPA has all sorts of precautions it urges for spray poly foams. Most are in regards to its application, but others warn of long term exposure to improperly applied foam and to messing with it later.

Much of the hullabaloo concerns pollution in living areas, but the EPA doesn't quite agree with out-gassing warnings (some of then horrible and nasty) and states: "The potential for off-gassing of volatile chemicals from spray polyurethane foam is not fully understood and is an area where more research is needed".

Although it's functionally wonderful stuff it might be best to be circumspect in isolating it from the living areas of tight homes, but by no means is it automatically going to kill you. Kind of like the Formaldehyde scare forty years ago: real but manageable. There are precautions to take that can ameliorate most if not all the possible hazards, but proper installation is such a big factor you'd do well to check for certification(s) held by the contractor.

But of all the horror stories of spray poly foam, most point to the contractor having the worst exposure risk.

Sorry if this rambled a bit!

Oh, further rambling: foam beats batts in sound dampening hands down, but insulation is never the primary way to go to cut down the noise filtering into and out of rooms. That best dealt with as a design consideration and you get better results by looking at non-parallel opposing wall/ceiling/floor surfaces, room proportions, and material resonances.

Here is a link that might be useful: EPA Homeowner information (not scary)

thanks, so much! yes, i forgot that the contractor also mentioned that he personally doesn't like using the foam b/c he doesn't like the idea of spraying formaldehyde inside a house

hmm... urgh. i can/will ask him about certifications for installing it. i like the idea of superior performance, but obviously don't like the idea of any possible health risk.

thank you again.

he doesn't like the idea of spraying formaldehyde inside a house

Except that it's polyurethane that's being sprayed.

The complaints that get all the publicity all come back to poorly trained applicators. Plus the inability of the spray foam insulation companies to prove the impossbile, i.e., that foam causes no harm now or in the future.

Spray foam is inert when fully cured. It may take up to 72 hours to fully cure. Some variates can cure in 24 hours or less.

There are also two types of spray foam, open and closed cell. The two types have different properties.

If there is or ever are moisture problems in the basement, batt insulation can be degraded or have mold/mildew problems from the moisture---even with a vapor barrier between the basement wall and the insulation.

However, batt insulation is much easier to replace should problems occur.