MDF: Medium Density Fiberboard (not to be confused with My Dear Friend!)

As I stated in my twin cradle series, I used MDF to build my templates.  I have tried not to use a lot of MDF in my shop, mostly because my wife hates the stuff and gives me lectures every time I mention the three letters.

My wife, who we’ll call “Ellen” (since that’s her name), is a production designer for film and television.  That means she designs the scenery and deals with the carpentry shops that build it.  Most of the scenic shops will not use MDF and the unions strongly discourage it’s use due to the health concerns.  I was shocked to read a recent article in Fine Woodworking, that while it recommended using dust protection, it did not mention anything regarding any potential health risks.  Pretty irresponsible.  Present the information and let the reader decide, but please don’t ignore the obvious potential risks.

I found it frustrating, however, that this commonly used, extremely flat and useful material was getting such a bad wrap (even if not in FN).  So I decided I needed to do my homework and find out what the story really is.  So here is what I found:

MDF or Medium-Density Fiberboard is made from wood fibers glued together under heat and pressure.  It is commonly used in mass produced furniture, for a veneering substrate, as well as moulding for kitchens and baths, plus you and I like to use it for templates and shop jigs.

It has many qualities that make it an ideal replacement for plywood or particle board.  It is dense, flat, stiff, has no knots and is easily machined.  Unlike most plywoods, MDF also contains no voids and will deliver sharp edges without tearout.  However, MDF is not entirely isotropic, since the fibers are pressed tight together throughout the sheet. Like natural wood, MDF may split when woodscrews are installed without pilot holes, it can however be glued, doweled or laminated, but smooth shank nails do not hold well.

In spite of its many positives, medium density fiberboard does have some drawbacks. Its comparatively high density makes it heavy and difficult to move. It dulls more quickly than other wood options, and it is somewhat susceptible to chipping and denting. More seriously, the glue used to bind the wood fibers in MDF contains urea formaldehyde, which the US Environmental Protection Agency classifies as a probable carcinogen. The cancer-causer is released in sawdust particles when MDF is machined, and these can quite dangerous to inhale in large quantities. This gives rise to health concerns for workers who produce it and cut it, but these risks can be minimized by wearing goggles and masks and by using saws that cut the board more cleanly. For the average person working with MDF, sawdust can be avoided by gluing pieces together with wood glue instead of nailing them. Alternatively, boards of MDF can be connected with wood-joints or pins. Yet, even when it is not being cut, MDF is constantly releasing urea formaldehyde at a slow rate, so it is important that its entire surface be coated in a finish to trap in the poisonous chemical. Wax and oil finishes are acceptable, but the most effective seal is an even layer of paint. Properly coated, well-maintained MDF poses no health threat, but consumers should be aware of the risk of cancer from unfinished products. 1


MDF Was developed in the US in the Early 1960’s based on the design of Hardboard, a similar product invented by William Mason in 1925.  Mason Attempted to turn woodchips discarded by Lumber mills into affordable insulation, but when he forgot to turn down his machine one evening, his machine continued working, turning the wood chips into a thin durable sheet. 2.


Perhaps MDF should be considered one of the greenest products in woodworking as it is all recycled materials (or perhaps not due to the use of Rainforest wood!).  The most common raw materials are wood chips and saw dust, but some manufacturers add other materials such as corn silk and wasted paper such as telephone directories, old newspapers, and cardboard.  The raw material that goes into MDF must do through a process before it is able to be used. A large magnet is used to remove any impurities and separate the material by size.  The materials are then compressed to remove water and then fed into a refiner, which shreds them into small pieces.  Resin is then added to help the fibers bond. The mixture is put into a very large dryer and heated by gas or oil.  This dry combination is run through a drum compressor equipped with computerized controls to guarantee proper density and strength.  The resulting pieces are then cut to the correct sizes with an industrial saw while they are still warm. 2.

Here is a cool video on how MDF is made.

Now for the Health Concerns:

MDF has a reputation for it’s health risks.  The International Agency for Research on Cancer (IARC) classified all wood dust as a human carcinogen and the substantial dust produced by MDF has been connected to other health problems such as asthma.  One of the affordable resins used as a binding agent in MDF is urea-formaldehyde.  Formaldehyde is also classified as a likely carcinogen on the Agency for Toxic Substances and Disease Registry. Prolonged exposure to formaldehyde can result in cancer, including nasal and sinus cancer and leukemia. These cancers take several years or decades to develop (usually 10-15 years). Working eight hours daily for 40 years at the level of the government standard would give you a risk of about 2 in a thousand for getting cancer (based on the OSHA standard of 0.75 ppm and 1991 USEPA estimates).   When formaldehyde is present in the air, some individuals may experience adverse effects such as watery eyes; burning sensations in the eyes, nose, and throat; coughing; wheezing; nausea; and skin irritation.  Repeated exposure to formaldehyde may cause bronchitis or skin and asthma-like allergy. Some people are very sensitive to formaldehyde, whereas others have no reaction to the same level of exposure. There is limited evidence that formaldehyde may damage the developing fetus and affect female fertility.

The OSHA Formaldehyde Standard requires employers to conduct air monitoring or have other documentation that shows exposure limits will not be exceeded. Workers’ average daily and peak exposure must be below 0.75 parts per million (ppm) and the peak exposure must be below 2 ppm. If greater than 0.1 ppm in the air is expected, then the employer must enforce labeling, education and Material Safety Data Sheet (MSDS) requirements of the OSHA Hazard Communications standard.   OSHA does not have a wood dust or urea formaldehyde standard. OSHA may rely on The American Conference of Governmental and Industrial Hygienists (ACGIH) guidelines for wood dust when evaluating a wood dust hazard. ACGIH recommends average exposure to inhalable wood dust be kept below 1 milligram per cubic meter (mg/m3); and half that amount for western red cedar. 3.

Precautions and Options:

What are the recommended special precautions should you take while handling MDF?     1) always wear a protective face mask such as a respirator 2) always wear eye protection, 3) Only saw in a well ventilated room with adequate dust collection, 4) wear gloves to avoid formaldehyde coming in contact with the skin.  Does any of this stuff sound familiar?  Don’t we do that already in our shops?  Well maybe not the glove/formaldehyde thing…but you get the point.  It’s all common sense.  Remember: Sawdust is a known carcinogen!   If your not comfortable using the stuff, then don’t, or at least find a product that you are comfortable with.  Some companies, especially due to California law, are replacing the resins with phenolic resins, such as Medex  or Ultra Stock-Free. Check em out and see where you can source them locally.

So, if you haven’t figured it out by now:  I’m no doctor, no OSHA consultant, and no chemical engineer.  I don’t pretend to have all the answers, I’m just searching for them and sharing what I’ve found.This is one of those topics, like SawStop, that could be debated for days in the forums.  The truth is, even as a hobbyist, you need to educate yourself and take what steps you feel are necessary for a healthy work environment.  Like anything we use in the shop, it is important to know the risks and potential hazards.  People work in extremely dangerous work environments every day, but they are safe when they take the appropriate precautions.





Read more: The History of Medium Density Fibreboard |

Some other options for MDF with no added urea formaldehyde:




12 Lighthearted Questions for Tom Iovino of Tom’s Workbench

For this installment we reached out to Tom Iovino of Tom’s Workbench!

1- You are an Emergency Prep Manager, a weather nerd , a mac nerd, a tool nerd, a sports fan, a shop monkey, an educator,  a cook, a husband and a father of two boys,  never mind all the great blog articles you put out each week: where do you have time to fit in any shop time?

It ain’t easy! Fortunately, I have a very understanding wife – and I don’t really watch a lot of TV at night. Getting out into the shop at the end of the day – even for an hour – is a tonic for me. Gives me a chance to clear my mind of the stuff that goes on during the day and get into the groove. I also like to take a chunk of part of the weekend – a few hours really energizes me.

2-Is it about the tools or the wood?

The wood wins hands down. Tools are nice, but when there’s no wood (or no projects to work on), they sit out there in the shop by themselves. The wood – on the other hand – calls to me. And, when a board goes through the thickness planer, and I see the figure, color and grain pattern, there are moments when I still have to catch my breath.

3-What is the most surprising poll result you have seen?

Just how many people hand-cut their dovetails.  It’s an awesome skill to have, and I am jealous as heck of those who can cut them that way. Given the fact that a high-end saw and set of chisels will set you back more than the cost of a premium router jig, I thought more folks would go that way for sure.

 4-How many pieces of furniture in your home have you built?

Wow… I sure have built a lot of it. There are entertainment centers, blanket chests, desks… let’s just say that a big part of planning for projects involves deciding where they will go.

5-What sports will get you out of the shop?

During football season, I end up going into my shop. The local radio broadcast of the Tampa Bay Buccaneers games is better than what’s on TV. But, I will get out of the shop for college basketball. And, coaching my sons in their basketball leagues will get me away from the bench and make me put down the Wood Magazine. 3-2 zone anyone?

6- I see you use a Tormek system.  How many different sharpening techniques have you tried?

How many fingers do I have to count on?  I’ve done scary sharp (sandpaper), oil stones, diamond stones, a Work Sharp and then the Tormek. Each of these methods has its pluses and minuses… But, that Tormek really does make it easy.

7-You are a great story teller. I enjoy how you set up each story with an analogy.  Is there a book in your future?

Funny you should ask that. Tom’s Workbench actually started as a book called Knothead: Adventures of a budding woodworker. Once I got started with the blog, it sort of became the beast that ate the book. I would LOVE to write a book one day about woodworking… One of these days…

8-Being a self proclaimed weather nerd do you obsess about the current weather conditions and the effects they might have on your wood projects?

Not really. Since I woodwork in Tampa, I know I’m building with the impacts of high humidity in mind all the time. I try to make allowances for expansion and contraction at all times, or I build with plywood. So far – knock on wood – no troubles…

9-Red or White?

Red. Big red. Zinfindel. Shiraz.  Boooyah…

10-What tool do you own that is so bad, you would never think of giving it away to a friend or in good conscience sell on eBay.

It’s a router bit. A lock miter router bit. I think I’ve spent more than 20 hours (over a few days) on that sucker and never got it to work. Ever. It sits in my shop – I can’t bring myself to throw it out, but I’d never give it away.

11-When creating a dado: table saw or router?

Depends. I dig the table saw a lot. Plowing dadoes with a dado stack while using the rip fence is very convenient. But, the larger the piece gets, the more I rely on the router.

12-What project has been sitting in your shop uncompleted for more than a year?

It’s not in the shop – it’s in my oldest son’s room. I built a ‘home office’ system for him – lower cabinets and upper bookshelves with a desk spanning the two units right under his window. Nice place to sit and do homework. I still have to trim out the unit, build the upper doors and do some other finishing tasks on it… I think I put the cases and desk in place back in 2009… One of these days, I’ll get to it… 🙂

Many Many Thanks To Tom!

I’d love to hear your feedback and suggestions.  Who would you like to hear from?

Northeastern Woodworkers Association’s Fine Woodworking Show

I was fortunate enough to attend the Northeastern Woodworkers Association annual Fine Woodworking show again this year in beautiful Saratoga Springs NY.  This is the 21st year for the all volunteer show, and it is really worth the trip.  There is a showcase room with some very impressive work by local members on display.  The show floor is a nice mix of smaller dealers, local sawyers and hands on demos.  While there is certainly attention given to the young ones, with a toy section devoted to kids- giving them the opportunity to use tools and build toys, the participants in the show were, well,…..let’s just say I was the only one there sporting a Modern Woodworkers Association t-shirt (know what I mean?).  Although I did speak with some fellow Wood Whisperer members! Paul Sellars was in attendance and had a similar observation you can read about on his blog.

Peter Sellars giving demos and promoting his new school

I sat in on Paul Sellers demo.  I am very excited to attend a three day class with him in May at his New Legacy School of Woodworking which is opening this month right here in Eastern NY.  My hand tool skills need sharpening!  I picked up Paul’s book as well- Working Wood 1 and 2: The Artisan Course with Paul Sellers, which looks great, and I am still getting through it.

Tico Vogt and the LCM (large carcase miter) Shooting Board.

Tico Vogt, a show favorite, was on hand to debut his prototype of the LCM (large carcass miter) Shooting Board.  I had a great chat with Tico and was able to give the LCM a spin. I don’t see a need for me to own it in the near future, but I was impressed and I liked the biscuit feature.  You can read more about it on his blog.

Chuck Brock and me.

One of the highlights of the show for me was the chance to talk with Chuck Brock.  Everything you’ve read and heard is true.  He is the ultimate gentleman.  We had the nicest chat about woodworking, work, and even mutual acquaintances.  Lot’s of vendors at these shows should take a note from Chuck.  Stop selling your wares and just introduce yourself and have a chat with a woodworker.  That’s the best thing about any of these shows.  The chance to talk with others who love what you do.  The sales, etc will happen regardless.   I own the plans and DVD to The Low Back Dining Chair, it’s certainly on the list.  Chuck prodded me in his southern accent “Now what are we gonna do to get you building?”  Sometimes that’s all the incentive one needs…

Here are some pieces from the show that caught my eye:

Wegner Chair, Charles Trabold. Syracuse, NY
Maple, Walnut, Oak and Bubinga

Maloof Rocking Chair
Thomas Wetzel
Middle Grove, NY
Tigre Maple

Lounge Chair Kitty Scharl of Voorheesville, NY Mahogony Oil, Poly

Lounge Chair
Kitty Scharl of Voorheesville, NY
Oil, Poly

Pedestal Table
Howard Jackson of Altamont, NY
Cherry, Maple Veneer
Oil Varnish

Mission Style Mantle Clock
Paul Ryan of Coeymans, NY
Walnut Stain, Laquer

I’ve decided to join the association, although I am not sure how much I’ll be able to participate given the location, but dues are only $25 annually and I think it’s important to support groups like this.