The good news is that there are some useful resources and a number of "greener" options. The bad news is that at least some of that information seems tainted by bias and that makes it really hard to get a real sense of what the true pros and cons of each insulation type are. The GreenHomeGuide is the most useful site about insulation I've found. It has a handy insulation comparison chart, an article that delves into the health and environmental issues with insulation and how each type fares, and a product directory.
And yet, even with all this information, I'm still not sure which will be the best for us and the house. Here's a distilled version of what I've learned so far:
- Fiberglass: Most fiberglass has formaldehyde in it, which is bad; but there are formaldehyde-free versions as well. I don't know what else is in fiberglass that might be bad though. Is produced through an energy-intensive and somewhat polluting process. May, and this is where the confusion starts because there's a lot of back-and-forth on this one, stand up to moisture and pests better than other options. And it won't burn.
- Cotton: This is by far the most novel option, since one brand (and maybe more than one?) uses recycled blue jeans. Treated with chemicals to make it fire-resistant and to discourage pests and moisture, but it sounds like moisture may still be a problem.
- Cellulose: Recycled newspaper is treated with chemicals to make it fire-resistant and to discourage pests and moisture. But there seem to be at least a loud minority that say it's not as fire resistant as it should be.