The advantages of MDF for manufactured furniture is that the material is perfectly dimensioned, has no knots, and machines fairly well. It can accept dowels easily, but doesn’t hold screws or other mechanical fasteners as well as grained lumber. 

On the down side, MDF tends to dull blades rather quickly, cannot be routed well (particularly since it is typically veneered at the factory) and requires pilot holes to avoid splitting. It also is very susceptible to water damage.

Then there is the formaldehyde. The fine < style="font-size:16px;color:#000000;">sawdust produced by cutting MDF is quite unhealthy to breathe, so one should always wear a dust mask and work in a well-ventilated area when cutting MDF. Additionally, the veneers on MDF don’t prevent the urea formaldehyde from seeping through and evaporating into the air. Painting or fully sealing MDF will help stop the off-gassing urea formaldehyde, but in the case of mass-produced furniture, this step has been skipped. This likely means that every piece of cheap, mass-produced furniture in your home or office is off-gassing formaldehyde.