Hi,
P.S. - I ordered a dust collector last week. The dust plumes that form while routing MDF are nasty. I'm working in by basement near my furnace. I'm going to have this dust all over my house in no time without a collector.
Any standard bag for a dust collector won't deal with all aspects of mdf dust. MDF dust has two separate problems, one is the urea formaldehyde released when machining it, the other problem is that the dust generated (I read somewhere once that mdf generated 27 times as much dust compared to pine) some of it might not stay in the dust collector but just get recirculated. If you can get the 1 micron hepa bags for it, thats what I would use for working with mdf.
I strongly recommend using a charcol respirator (not a cheap dust mask) when working with mdf. Personally I prefer plywood over mdf but thats me and my experiences as a woodworker, a standard dust collector and a good quality dust mask is fine for wood I believe. Also keep in mind the dust particle size is proportional to the grit you use when sanding. You need to circulate some fresh air to the area as well for the fumes.
Be careful no matter what though, when working with any of this stuff, even worse for your health than mdf are some of the exotic woods ... so if you work with them be extra careful (like fine sanding some exotic veneer for instance). Also the actual formula of mdf (and plywood for that matter) varies by type and manufacturer, some are better, some are worse for health. Google is your friend, read up on the hazards and safety precautions for whatever you are working with, I would advise as I expect all here would. Fumes from glues and cement are no joke either.
Finally, MDF does not have the general strength of either wood or plywood, so you can't use it interchangeably with wood. My experience is that mdf doesn't tolerate assembly and disassembly very well, plywood is better, soft wood (pine etc) is better yet, and hard woods (oak etc) are best for screws. As long as your expectations are in line with whatever material you choose's characteristics, you won't be disappointed. Tips ... they make screws especially for use with mdf, always predrill mdf with a bit same size as shank of the screw you will be using, drill a hole deeper than the screw, coun tersink ... and screwing into the end of mdf is to be avoided bigtime.
Thats what I can offer from my 40 odd years of messing with wood hope it gives you some food for thought anyway.
Any day now I should get the parts to make my AV3's, Danny just sent me an email saying they are on the way!! I have chosen to use 13 ply actual Baltic Birch (all 13 plys are slow growing birch from northern europe)
Brian