MDF is Safe, Right? The Truths and Myths About MDF

PRLog (Press Release) - Jun 11, 2009 -
MDF has a reputation of being a questionably safe building material, and so we hear from concerned mums and dads all the time asking us to clarify its merits. In short, yes, it is 100% safe once it is used to construct a finished piece of furniture, but it does require care if you decide to do a DIY project with MDF where there will be sawdust flying about. (Wear a mask!)

For those who may not be familiar with it, MDF (or medium density fibreboard) is a building material composed of wood fibres which are held together with resin, heat, and pressure to create a solid piece which can then can be used in all the same ways that natural wood can be.

The main issue perceived with MDF is that its production involves a resin containing formaldehyde which is a known toxin and carcinogen in high concentrations. In the process of cutting and working with MDF in building, sawdust and formaldehyde are released. Both of these are bad to inhale (particularly the formaldehyde), there are very strict health and safety regulations in place in the UK and around the world governing MDF dust and its extraction and disposal to ensure a safe working environment in the workshops. Because much of The Children’s Furniture Company’s furniture is made in the UK (including in our own workshop where my husband Charlie works) we take every precaution to make sure that everyone in contact with MDF dust is adhering to the rules! (It really is horrible stuff)

During the ‘machining’ process, however, is the only time that MDF poses any kind of health risk. The reality is that once the MDF is cut and finished with sealant or paint, it is no more harmful than a tomato. In fact, weight for weight, MDF and tomatoes have the same percentage of formaldehyde content. I am quite sure no one would be tempted to eat a lethal dose of 56 pounds of the fruit in one sitting, just as no one would sit in a room of MDF saw dust all day every day for years and years!

The benefits of MDF make it a great choice for children’s furniture as it is strong, stable, and provides many fun options for design.

Versatility: Anything that can be done to wood, MDF can handle! It can be glued, nailed, screwed, moulded, painted and so on. When compared to timber, MDF actually takes better to veneers because it is made to be dense, flat, stiff, and flaw-free which results in a superiorly uniform finished surface. Unlike other particle boards, MDF can be cut easily and leaves a smooth edge which makes it easier to use in final products.
Stability: Timber is hydroscopic (acts as a sponge) and adapts to different humidity levels. For instance, in the colder months when the central heating is running, the air in the house will be drier, which will draw the moisture out of the wood, causing it to shrink. Conversely, in the summer months when the windows are open and the air in your home is more humid, the wood will swell again.

Seasoned timber can be expected to change in size by anything up to 5%, depending on the direction of the grain, even Antiques are prone to timber movement, and that wood was seasoned hundreds of years ago.

These dimensional changes manifest themselves as cracks, splits, cupped and bowed panels. Wood is somewhat elastic, so it will maintain a generally uniform size and shape, though eventually, the expansion and contraction can cause warping and may wreak havoc on the fittings used in the furniture which will impact the longevity and overall resilience of the piece. MDF does not have this problem to the same extent as the fibres are packed so tightly, there is little room for the material to react to the atmosphere.

The particles in MDF also provide stability without a predominant grain which means that MDF is less likely to split or fracture. This is a particularly important consideration for painted furniture which shows very obvious splitting and cracking in the finish when the wood changes.

Environmentally Friendly: Because MDF uses “leftovers” and waste from wood processing, it is economical and environmentally friendly. A piece of MDF uses a much higher percentage of the tree it is sourced from. Wood requires the disposal of imperfections in the tree, (it is not uncommon for only a 1/3 of the wood in a tree to be good enough to make furniture with) while MDF uses more of what would be considered rubbish in traditional planking.

Because MDF is a manmade board with no faults, or grain a much greater percentage of raw material ends up in the furniture and not the furnace, thus saving all the associated emissions transporting quantities of heavy timber from the mills to the workshops.

Another thing to consider is that if perfect, natural timber is used in furniture then painted over (as opposed to varnished or stained), the beauty of the wood is covered up completely, which is a real shame!