Starting with the No Added Urea Formaldehyde (UF emits the most formaldehyde) the first alternative is Phenol Formaldehyde (PF). This is a red and black colored substance, used as a substitute for UF in outdoor products because it has better moisture resistance. PF emits considerably less formaldehyde than UF.
The most commonly used No Added Formaldehyde options are MDI (methylene diphenyl isocyanate) and PVA (Poly Vinyl Acetate--this is NOT a PVC). Offhand PVA sounds more interesting to me, as far as less toxic breakdown products (this is just an offhand reaction, I've done no actual research), but in a list of NAUF products only one used MDI, and none used PVA. Offhand I would not be happy about having 60 pounds of MDI or whatever in my door.
There are also soy based glue alternatives, but possibly only used in plywood, not MDF, so far. MDF is a challenging product to make, it uses more glue than other products which only need to layer wood together, etc., and therefore has the biggest problem with formaldehyde emissions.
My friend suggested I just get another of these all wood doors (Isodoor Basic) for my room as well. I might just do that, looking at these limited (and unavailable) alternatives. But actually, I was thinking about going in the opposite direction for both door, getting both with NAUF Isodoor HD's. Well scratch that, I'm afraid. I might try NAUF in my door, which is much farther from the bed. But PF or something like that was actually the kind of thing I might be smelling in Lyndhurst!
Now what about those Overly doors? Actually a 300 pound metal door might not be the ticket for a lady with pets, or either. But I don't see a problem with it for me, and I do really like to sleep all morning, and I'm footing the bill for both doors.
So that's what I'm thinking now, Overly (unapologetically heavy metal) door for me, Solid Fir Isodoor Basic for her. Will have to check that Overly doesn't use MDF. It's said that UF is used in fiberglass...but I have to think that is trivial compared with MDF--compare the weight!--and that it all gets released quickly and isn't a problem for decades like UF--well that might not be true, perhaps even the reverse.
Which leads to a question actually. Just why do these things release formaldehyde? Is it that there was present from free formaldehyde that just slowly leaks out? Or are chemically glued together things coming apart slightly--and then releasing the formaldehyde as the bond is broken. I don't know and it may well be something I wouldn't even think about. But the latter would suggest the release of formaldehyde forever, as the product slowly breaks down into dust. That can't be it though...that isn't at all consistent with a half life, in at least that way. MDF isn't 89% dust in 20 years, even though its emission level may fallen that much. But it could fit the description if there are a minority of say sloppy bonds, just waiting to give away. And over time, perhaps even 20 years, those have mostly gone broken apart, leaving the more strongly bound stuff, which might have half life of 10,000 years in a cool dry climate, or about 100 in a San Antonio garage. That long half life stuff doesn't have to be worried about, that's another way of saying it's incredibly stable, and isn't emitting much, and we're talking about something that is naturally in the air, in our breath, etc. Formaldehyde is not plutonium, but all the same we don't want it elevated much, so we worry about those things that release lots of it, as ordinary unfaced MDF does. When the kitchen was new (or if I moved into any new house!) it had hundreds of pounds of MDF cabinetry, and you would also get formaldehyde from the furniture, the carpeting, etc.
(As I'm writing this, I'm rubbing my foot against a small microtable under the kitchen table which I made a couple of years ago. It is never painted
formaldehyde MDF and weights about 25 pounds. It was ultra clear at Home Depot that this was the one wood product which would be easy for me to work with. I could barely touch the plywood without getting splinters, and it was warped and whatever. I cleaned the surface off meticulously before moving it into the kitchen, making sure there were no particulates. I did notice some smell for a matter of weeks. I never thought about formaldehyde until now.)
But if only Some of the UF bonds break apart, then it is only them we need be worried about (except in case of catastrophe, but that's another story). So don't think you are sitting next to 100 pounds (or whatever) of UF (actually, it would not be surprising if you were in a modern house) but only 1 pound, say, of sloppy bonded UF that is going to go in the next 20 or so years. So how many sloppy bonds are there in the fiberglass batts surrounding a room? Well this depends not only on the quantity of UF which has to be much smaller, but what the proportion of sloppy bonds is. So just knowing the weight of a formaldehyde product doesn't tell us much. We might even have to know which supplier and what process they used, etc.
