Better Than Carbon Neutral Panels for Furniture+Interiors

No other material has a lower carbon footprint, or is compatible with more surface finishes.

10.03.2016
By Kenn Busch

Medium density fiberboard (MDF) just might be the perfect material for building furniture, casegoods, fixtures, and interior millwork.

It is easily machinable with common woodworking tools, accepts many types of finishes and surface treatments, makes use of wood fiber that would otherwise be considered waste, and can be engineered to meet the demands of a wide range of applications and performance requirements.

Like raw wood, MDF can be carved and sculpted into almost anything a designer can imagine. Unlike raw wood, it is much more dimensionally stable and therefore less susceptible to changes in climate or environment.

MDF is the most refined member of the composite wood family, which includes particleboard, OSB, and hardboard. By “refined” we don’t mean the most sophisticated, although that case could be made based on the types of products it makes possible.

In this case, “refined” refers to the size of the basic elements within the finished panel. MDF is literally made from the most basic building block of wood, the lignocellulosic fibers that give structure to trees and all woody plants.

“Medium density fiberboard” is actually a generic term for a panel created by combining these fibers with a bonding resin system and subjecting the mix to heat and pressure, creating panels with a density between 31 and 50 pounds per cubic foot. Other additives may be added to the mix to give the finished panels specific properties.

MDF and other composite panels offer improved mechanical performance over natural wood in one very important way—dimensional stability. Wood fibers, when all aligned as they are in solid lumber, shrink and swell dramatically with changes in temperature and humidity. Composite panels reorient these fibers to offset those environmental responses.

Learning Objectives

interiors+sources’ Continuing Education Series articles allow design practitioners to earn continuing education unit credits through the pages of the magazine. Use the following learning objectives to focus your study while reading this issue’s article. To receive one hour of continuing education credit (0.1 CEU) as approved by IDCEC, read the article, then log in to take the corresponding exam.

After reading this article, you should be able to:

  • Explain how MDF differs from other composite wood panels
  • List the special properties of different MDF products as they apply to project applications
  • Discuss the different surfacing options for which MDF is the most appropriate substrate
  • Explain the factors that make MDF “better than carbon neutral”
 

Composite panels also drastically reduce consumption of forestlands by offering alternatives to solid lumber. Much of the wood we harvest for lumber is not be suitable for building. MDF and its complementary composite panels make use of the parts of trees that can’t be turned into furniture or pallets. These panels also give a second life to the pre- and post-consumer wood fiber wood from furniture, pallets, and other wood products.

HISTORY

Developed in the early 1960s in the U.S., MDF is actually based on a hardboard product first created accidentally by William H. Mason (of Masonite fame) in 1925. He was trying to turn wood chips discarded by lumber mills into an affordable insulation product. One evening he forgot to shut down his equipment, and instead of a lightweight sheet of insulation he created a thin, very durable composite wood panel.

RAW MATERIALS

The wood fiber, or “furnish,” for MDF comes from many sources. Most commonly it is pre-consumer wood waste that would otherwise be landfilled or incinerated—forest thinnings and wood residuals from lumber, plywood, and furniture plants. Additional sources include post-consumer items like wood pallets and retired wood furniture (after impurities are removed). It should be noted that different fiber sources may require different bonding systems.

A few vertically integrated forest products companies have streamlined their sourcing of furnish for MDF and other composite panels by optimizing transfer from their other lumber, engineered wood, and panel operations.

MANUFACTURING PROCESS

The remaining material is pre-steamed, where low-pressure steam is injected to heat and soften the lignin. After pre-steaming, fibers are fed into a plug screw feeder where they are compressed to remove the water from the steaming process. Fibers are then transferred into the pressurized vessel, or digester, and finally to a refiner where the material is separated into usable fibers by two grinding discs.

Resins and a wax emulsion are applied to the fiber at the inlet pipe to the drying tube. This is also the stage were additives to enhance flame retardancy, moisture resistance, or other properties are introduced. Ratios of resin, fiber, additives, and catalysts are carefully controlled by weighing each ingredient. Single- or multiple-stage tube dryers dry and blend the fibers.  

To create a panel, the dried fiber is pushed through scalping rolls to produce a thick, fluffy mat of uniform thickness.

The mechanical stability of MDF is attributable to three primary variables: physical and mechanical properties of individual wood fibers, fiber-to-fiber stress transfer, and fiber orientation. These origins of fiber properties and stress transfer can be traced to the fiber generation method wherein fiber orientation is associated with mat formation.

A continuous or “feed-through” press equipped with a steel band running over large heated drums compresses the mat at a uniform rate, or a multi-opening vertical “daylight” press that creates several panels in a single pressing operation.

Modern MDF presses are equipped with electronic controls to prevent resin pre-curing, creating MDF with the desired density and uniform strength as efficiently as possible.

As the finished board emerges from the press it is cut to panel lengths using automated saws before the MDF cools.

After cooling, the panels are sanded on both sides by large belt sanding machines using either silicon carbide abrasives, or for finer surfaces, ceramic abrasives like zirconia alumina and aluminum oxide.

QUALITY CONTROL

Most MDF plants use computerized process control to monitor each manufacturing step and to maintain product quality. Product consistency is maintained by a combination of continuous weight belts, basis weight gauges, density profile monitors, and thickness gauges. In addition, the American National Standards Institute has established product specifications for each application, as well as formaldehyde emission limits. As environmental regulations and market conditions continue to change, these standards are revised.

The standard for MDF, (ANSI A208.2-2016 Medium Density Fiberboard for Interior Applications), is the most recent version of this industry standard. This standard classifies MDF by density and use (interior or exterior) and identifies four interior product grades. Specifications identified include physical and mechanical properties, dimensional tolerances, and formaldehyde emission limits. Specifications are presented in both metric and inch-pound limits.

Physical and mechanical properties of the finished product that are measured include density and specific gravity, hardness, modulus of rupture, abrasion resistance, impact strength, modulus of elasticity, and tensile strength. In addition, water absorption, thickness swelling, and internal bond strength are also measured. The American Society for Testing of Materials has developed a standard (D-1037) for testing these properties.

MDF AND SUSTAINABILITY

Few materials on earth are as perfect for their purpose as wood. Trees grow essentially by building themselves, efficiently creating their own construction materials along the way. The lignocellulose fibers that form the essence of wood create a unique combination of strength, resilience, workability, and renewability that no other material can even come close to.

The inherent properties of wood are what make MDF and other composite wood panels an environmentally positive choice for furniture, fixtures, and interiors.

A brief overview:

  • Wood is one of the planet’s most easily renewed resources.
    • During the past 60 years, net growing-stock growth has consistently exceeded growing-stock removals in the United States.
    • In terms of percent of standing volume, removals are at the lowest level in the past 60 years and growth has also slowed.
    • The volume of annual net growth is currently two-times higher than the volume of annual removals.
      • Source: “U.S. Forest Service Resource Facts and Historical Trends,” FS-1035, August 2014
    • North American panel producers have proven themselves to be exceptional stewards of their resources.
  • Composite wood panels make use of wood fiber left over from other manufacturing processes.
    • This material would otherwise be destined for landfills and incinerators.
  • These panels are more stable than solid wood, and may be engineered for specific applications and performance characteristics.
    • Moisture resistance, fire resistance, strength, weight, machinability, etc.
    • These properties ensure a longer useful life, requiring less frequent replacement.
  • Composite wood panels have been shown to be “better than carbon neutral” in a recent lifecycle inventory analysis.
    • The wood in composite panels acts as a carbon sink, sequestering more carbon than is expended in their production, transportation and installation.
      • Source: “Cradle to Gate Life Cycle Assessment of U.S. Medium Density Fiberboard Production”; see sources section
  • Rare and endangered wood species are spared by the use of decorative composite wood panels.
    • High-definition printed and textured decorative surfaces offer the beauty of any wood, with better design consistency and durability.
    • Carefully cut veneers maximize the decorative square footage of responsibly harvested trees.

BETTER THAN CARBON NEUTRAL

Although they’ve been around for a while, composite panels like particleboard and MDF are constantly evolving. Thanks to the California Air Resources Board (CARB) standards, panel producers have stepped up and modified their products and processes accordingly. Composite panels produced in North America now meet, and usually exceed, these newly established indoor air quality goals.

Producers have also invested in further research on the true impact of their materials and their operations. Through a recent lifecycle impact assessment (LCIA), they discovered something extraordinary—that their materials are actually “better than carbon neutral.”

One major factor in this finding has more to do with traditional makeup of the panels than any recent modifications. MDF and particleboard represent the highest level of evolution in maximizing the use of wood fiber left behind by other manufacturing processes, as a recent study shows.

North American composite panel producers commissioned an LCIA of particleboard and MDF, taking into account all inputs and outputs required to manufacture these products, from the College of Forestry’s Wood Science and Engineering Department at Oregon State University.

The analysis began with the generation of the forest, through harvesting, examining delivery, product manufacture, use and disposal—whether to landfill, fuel use, or recycling. All inputs are measured, including electricity, fuels, chemicals and materials use, from their in-ground resource through extraction, delivery, and manufacture. Outputs measured include product, co-product, and emissions to air, water, and soil.

A SUMMARY OF THE LCIA FINDINGS:

Composite wood panels make incredibly efficient use of resources:

 

Particleboard

MDF

Use of wood resource

%

%

Wood residue into panel

95.7

84.8

Wood fuel use in mill

3.5

14.9

Wood residue sold

0.74

0.01

Wood particulate emissions

0.03

0.05

Wood waste to landfill

0.06

0.28

     

Total

100

100

As stated earlier, wood is one of the planet’s most easily renewable resources; it’s also carefully regulated for sustainable management.

  • To ensure wood is from specific sustainable sources, producers can request certification by such third-party groups as FSC (Forestry Stewardship Council), SFI (Sustainable Forestry Initiative), ATFS (American Tree Farm System), and CSA (Canadian Standards Association).
  • Wood stores carbon as it grows.
  • 50% of wood's chemical structure is absorbed carbon, which is not released back into the atmosphere until it burns or decomposes.
  • The carbon sink properties of the wood in composite panels more than offset its carbon footprint, including manufacture and transportation.
  • Net carbon footprint is negative, actually offsetting some of the CO2 in the atmosphere.
  • The longer a composite wood panel lasts in an application, the longer that carbon is sequestered.
    • Composite panels with durable decorative surfaces tend to last years longer in a given application than other “natural” materials.

 

MDF uses significantly smaller amounts of fossil fuels and feedstock, water and other resources when compared to steel, cement, plastic and glass:

* Not available in database
** “Tool for the Reduction and Assessment of Chemical and other Environmental Impacts”
Source: “Cradle to Gate Life Cycle Assessment of U.S. Medium Density Fiberboard Production”; see sources section

COMPOSITE PANELS AND LEED v4

The new LEED v4 certification accepts existing standards and pushes them further, by focusing more on end results rather than the ingredients used to create composite wood panels. This is a big leap forward in the usefulness of the program.

At issue is the amount of formaldehyde emissions that can be measured in the finished product. Wood itself naturally emits a small amount of formaldehyde, but glues and binders have historically been a larger source of emissions from composite panels.

In previous versions of LEED, composite wood products were required to be absent of urea formaldehyde in order to support the Indoor Environmental Quality Credit 4.4 for low-emitting materials. So, the panels might be NAUF (no added urea formaldehyde) or NAF (no added formaldehyde) to meet this criteria, but there was no requirement for these panels to reach targeted emissions levels.

When CARB ATCM (California Air Resources Board Airborne Toxic Control Measure) 93120 became law and mandated a reduction in emissions for composite wood products, manufacturers modified their recipes to comply.

                                  
CARB formaldehyde emission limits for MDF and thin MDF

 

For reference, the ambient level of formaldehyde in indoor and outdoor air is 0.03 ppm. 

The World Health Organization and Health Canada have estimated that the average adult ingests nine-times more formaldehyde each day from food than they inhale from all airborne sources combined. The human body is able to easily and rapidly metabolize formaldehyde, so the low levels at which most people are exposed throughout their everyday lives present little risk to health.

See sidebar article for more details on formaldehyde.

CARB’S INFLUENCE ON LEED v4

In effect, CARB changed the conversation about composite panels. Instead of asking, “Does the product contain urea formaldehyde?” the question will be, “Is the product low-emitting?” thus contributing to healthier indoor environments.

After all, better indoor air quality is the ultimate goal, particularly for those who may be extra sensitive to formaldehyde. Rigorous third-party testing and certification of the finished product for low- or ultra-low-emissions targets is a far more effective method than just restricting certain ingredients—ingredients that, despite their names, serve to enhance the desired outcomes for health, safety, and comfort.

The broader goal with LEED v4 is to help users understand the intent behind the credits. LEED 2009 used a numbering system that tended to obscure the real meaning of the credit, to the point that people filling out the paperwork weren’t even cognizant of how their project actually performed.

Here’s a snapshot of how the composite panel-related LEED language has changed, not just regarding indoor air quality, but resource management and materials sourcing as well:

MDF – ENGINEERED OPTIONS FOR SPECIFIC APPLICATIONS

Perhaps more than any other construction material, MDF can be engineered and produced with specific properties for specialty applications:

  • Fire retardant
  • Moisture resistance – 3 grades (MR10, MR30, MR50)
  • Lighter weight/lower density
  • Exceptional machinability/higher density
  • Powder coating grade
  • Coated Decorative MDF

FIRE RETARDANCY

For use anywhere Class A/Class 1 rated fire-retardancy is a requirement and anywhere people congregate. These non-structural panels can be machined, cut, grooved, and sanded without compromising the flame-retardant properties. Typical applications:

  • Hotels
  • Schools
  • Hospitals
  • Theaters
  • Restaurants
  • Doctors’ Offices

MOISTURE RESISTENCE

Especially suitable for interior applications where moisture or humidity is a concern. The higher the grade number (MR50 for example), the greater the moisture resistance:

  • Window and skirting boards
  • Architectural interior moldings
  • Laminate flooring
  • General interior joinery in humid conditions
  • Locker rooms
  • Food service
  • Doors and door components
  • Kitchen door and drawers in commercial and residential applications
  • Bathroom cabinetry, shelving, or moldings

EXCEPTIONAL MACHINABILITY

Engineered for demanding multi-level machining applications, these panels are available in thicknesses ranging from ½-inch to 1¼ inches. Typical applications:

  • Molding
  • Raised panel doors
  • Door and drawer fronts
  • Display panels
  • Furniture
  • Laser cut and water-jet cutting
  • 3-D laminated components

LIGHT WEIGHT

Best for vertical applications where weight might be an issue, and where efficient shipping and ease of handling is paramount:

  • Wall panels
  • Dividers and partitions
  • Light-duty cabinetry
  • Ready-to assemble furniture
  • Store fixtures

POWDER COATING GRADE

Powder coating wood materials is a tricky process, but when done right it offers a stunning effect. Properties required for a flawless powder coated surface:

  • Consistent surface
  • Smooth machinability
  • Enhanced resistance to edge cracking
  • Dimensional stability

Coated Decorative MDF

These panels have a UV-finished decorative layer already applied, most commonly a subtle woodgrain pattern. Common uses:

  • Drawer bottoms
  • Cabinet interiors

DECORATIVE SURFACING OPTIONS FOR MDF

MDF, as a core material for decorative surfaces, is easily carved by CNC machines and is exceptional for its smoothness on its face and throughout its depth when it is machined. These characteristics make it an ideal substrate for many surfaces and finishes. Indeed, for some surfaces, MDF can be the only choice.

For instance, materials like 3D laminates and lightweight paper foils have a tendency to “telegraph” any imperfections and surface details of the substrate they’re laminated to. The surface of particleboard is too rough for these materials unless a surface filler is applied before laminating, adding cost and time to the process.

Unlike HPL, these materials are too thin to have any impact resistance of their own. MDF’s density brings that important property to these surfaces.

TFL DECORATIVE PANELS

TFL (thermally fused laminate) panels use a melamine-impregnated printed or solid-color décor sheet similar to that used in HPL, but instead of being laminated to layers of kraft paper, it is pressed directly onto a composite wood substrate.

Under heat and pressure the melamine resin from the décor layer flows into the substrate to create a crosslinked thermoset bond, effectively creating a homogenous decorative panel without the use of adhesives. Some TFL products also carry the same type of wear layer as HPL, and can be embossed to mimic stone, wood, and other materials.

Because the finished TFL surface is much like HPL, using a finer substrate like MDF isn’t always necessary; particleboard is the most common choice.
There are several exceptions to this, however. 3DL components, as mentioned above, usually have a TFL surface on the back. This means the panels start out as a one-sided sheet of TFL on MDF, which are then carved on a CNC router and 3D laminated.

And if you’re looking for a decorative contoured paper-foil edge combined with the surface performance of TFL, MDF would be your substrate choice.
Another reason to specify TFL on MDF is if your project requires the special properties offered by moisture-resistant, fire-retardant, or other specialty MDF panels.

TFL panels are very popular in residential cabinetry, furniture, and closet systems, and are used in similar applications in retail, healthcare. and hospitality. Mid-market office furniture producers commonly use a lot of TFL. It has even been used for removable decorative wall systems in commercial and retail settings. TFL carries woodgrain designs so well that it has become an economical and durable substitute for veneered panels in many architectural projects.

Most residential-grade laminate flooring uses TFL on MDF. Place-and-click flooring installation systems require intricate machining that can only be done with MDF. Many of these floors also use moisture-resistant MDF for better performance in kitchens and bathrooms.

3D LAMINATES

3D laminates, also known as rigid thermoformable foils (RTF), are formable overlays created from calendered PVC or polyethylene polymers. They are available in solid color, metallic, and printed designs, and can be specified in a variety of surface textures, including realistic woodgrain ticking and high gloss. 3DL with enhanced wear-, stain-, and chemical-resistant properties are available from several suppliers. 

3D laminates are applied in membrane or vacuum presses. A substrate with an applied heat-activated adhesive enters the press, the 3DL is heated to make it more pliable, and then is either pressed onto the panel by an inflatable silicone membrane, or pulled onto the panel by a vacuum system.

What makes 3DL unique is that they can be laminated to panels with intricate 3-D details machined into their faces, as well as unconventionally shaped panels and panel edges. Once again, MDF is really the only choice for 3DL decorative panels because of its smoothness and core material consistency.

3DL’s ability to “self edge” —wrap seamlessly around the edges and interior cut-outs of a panel—reduces processing steps and helps seal the panel core from moisture and bacteria. This ability also helps create “soft” edge shapes that mimic mechanically shaped solid wood, stone, and solid surface materials.

3DL are often used on panels with a TFL back in matching designs. Many components suppliers specialize in fabricating 3DL parts to order.
The use of 3DL has grown in recent years as the office furniture industry has embraced nonstandard and organic shapes for worktops, and are increasingly being specified for store fixtures and point of purchase (POP) displays. They are also commonly found in RTA furniture, particularly where the design calls for soft edges and unusual shaped components, and on cabinet doors and drawers in place of lacquer finishes.

3DL decorative panels are finding wider acceptance in healthcare, education, and hospitality applications, where improved surface resistance to cleaning chemicals and the ability to seal the panel core against moisture and bacteria without seams provides a competitive advantage over other material options.

HPL

One of the most familiar and widely used decorative surfaces is high-pressure laminate (HPL), first made famous by Formica. HPL is typically constructed in several layers:

  • Several sheets of kraft paper (similar to shopping bag paper) impregnated with phenolic resins. This creates the “brown layer” you see on HPL-surfaced panels
  • A sheet of melamine resin-impregnated décor paper carrying a solid color or printed design
  • On the top, there is a protective wear layer for added scratch resistance, that can also carry printed design accents and other decorative material inclusions

HPL is a very durable, rigid surface that can be laminated to a wide variety of substrates. Because it doesn’t telegraph surface details, particleboard is the most common choice as a substrate for HPL. However, MDF may be chosen for its moisture resistance, fire resistance, or other special properties, or if the designer is looking for a more intricate edge profile. 

HPL is commonly specified for high-use commercial applications like counters, desktops, and commercial laminate flooring, and it is a mainstay in healthcare, hospitality, office furniture, retail, and other demanding commercial applications. And of course, it's still the most popular option for residential counters and tabletops. Unlike most other surfacing options, HPL can be laminated to a substrate in the field.

PRINTED PAPAER FOILS

Printed paper foils, also known as light basis weight papers, are printed or solid-color décor papers saturated with a blend of resins engineered for the final application of the paper, including scratch, moisture, and chemical resistance. They may also receive a thin top or a “finish” resin coat for additional performance characteristics. Printed paper foils are capable of providing very high print fidelity and realism for woodgrains, in particular.

Because they are fragile until laminated, paper foils are glued to substrates in high-tech production lines. They are very thin, which means they can telegraph any imperfections in the substrate surface. MDF is the natural substrate choice for these foils because of its smooth surface.

Some printed paper foils can be pressed onto MDF panels machined with 3-D surface details to give the effect, for example, of a raised-panel kitchen cabinet door.

Foils are a perfect surface for edge profile details machined into MDF, creating a perfectly matched edge for desktops, drawers, and door fronts, as well as pretty much the entire picture frame industry.

Printed paper foils are widely used in wall paneling, ceiling panels, drawer and cabinet interiors, closet systems, RTA, and home office furniture, often in combination with other materials like TFL and HPL, which are capable of higher wear and impact resistance. Because of their high-design fidelity, they are also often used with veneers to help value engineer a finished piece or project, allowing designers to make the best use of rare, fragile, and expensive veneers.

VENEERS

As an alternative to solid wood, hardwood veneers can be laminated to a wide variety of substrates, including MDF. This option offers the best of both worlds: a real wood surface with authentic wood grain in a variety of species, while using just a fraction of the tree.

Hardwood veneers bond very well to MDF. Although there are veneers available with phenolic backing similar to HPL, raw veneers will look and perform best when bonded to the smooth faces and edges of MDF.

Many manufacturers combine real veneer faces with matching decorative foils on contoured edges for durability on doors, drawers and tops—a combination that can only be realized with an MDF substrate.

POWDER COATING

Powder coating is a rather involved coating method, but results in a finish that is thicker and more durable than painting or lacquering.
If you want the exceptional durability and uniformity of a powder coated finish on wood, MDF is your only choice. Powder coating applies a finish similar to paint, but because it is not a liquid process it doesn’t require solvents to suspend the binder and fillers.

Instead, a dry-pigmented powder is applied to parts by charging the powder with a positive electrostatic charge in a spray gun, and the part to be coated with a negative charge. The difference in charges attracts and hold the powder to the piece. Coated pieces are then heated to over 200 degrees F to melt the powder into a uniform film, and cooled to harden the newly applied coating.

Powder coating is most commonly applied to metal parts. Powder coating wood presents a special challenge on two fronts: the level of electrical conductivity required to attract the power to the part (wood is a natural electrical insulator), and the high temperatures required to create a smooth, finished coating.

MDF is the only wood product that’s compatible with the smoothness required for a powder coat finish. But it’s still a wood product, so special material grades and application methods had to be developed to create quality finished parts.

Parts are preheated before application, which accomplishes three things:

  • Allows the board to outgas, if necessary, before the coating is applied
  • Helps the moisture in the wood, usually between 4 percent and 7 percent, to create enough surface conductivity to attract the charged powder particles
    • Ideally, the moisture content of the panels is controlled by the manufacturer through staging in environmentally controlled rooms
  • Allows powder to better stick to the panel surface; powder particles will partially melt on contact with a heated surface—“impact fusion”—creating a better bond than if particles are clinging on by static alone

In preheating and curing, uniform distribution of heat in the panel is key to a good finish. MDF’s uniform density lends itself to even heating, as well as a smooth surface to bring out the most in the powder coat finish. Special powder-coating grades of MDF have a flatter “density curve,” meaning they are exceptionally uniform in core density. Higher variations in density lead to greater variations in temperature throughout the panel, and a higher likelihood the panel will split.

LACQUERING AND PAINTING

Unlike powder coating, paints and lacquers are wet finishes, for which there are also special “paint-grade” versions of MDF.

Once again, surface smoothness is key for the best finish, and most fabricators recommend painting on the panel surface as it comes from the mill, without additional sanding.

The coarser edges of MDF are more absorbent than the face, and therefore do require treating with a filler material (drywall compound or similar) or a paintable edgeband material for the best painted finish. If assembled casework is being painted, creating mitered corners addresses the edge finish issue.
It should be noted here that lacquers are technically a “paint” product, but thinner than paint in application, and available in clear versions with different gloss levels. Clear lacquers may be applied to MDF panels for an “industrial” or unfinished look, as well as over paint to add durability or gloss effects.

REFINED DESIGN WITH MDF           

While all composite panels offer the same general environmental and mechanical advantages when compared to solid wood and other materials, MDF truly sets itself apart.

No other material is available in such a wide range of application-specific variations, able to accept as many finish options, or is as responsive to three-dimensional designs.

While it may not be the most economical choice for every application, the things you can do with it can’t be done by anything else.


THE F-WORD: WHAT IS FORMALDEHYDE, AND WHY IS IT IN OUR FURNITURE?

Formaldehyde is a simple chemical made of hydrogen, oxygen, and carbon, from a family of gasses called aldehydes. As a byproduct of essential cellular metabolic processes, it is produced by nearly every living organism, including plants, animals, and people, and exists naturally in the air at concentrations of 0.03 ppm (parts per million), commonly referred to as “background levels.”

The formaldehyde content of an apple, for instance, is up to 22 ppm. It is exhaled in human breath at low levels (1 to 3 parts per billion). All wood naturally contains small amounts of formaldehyde; formaldehyde concentrations in dry solid wood measured across a number of species is 3.7 ppm on average. (This is not the offgassing level.)

Studies show that formaldehyde does not accumulate in people or animals because it is quickly broken down by the body’s natural metabolic processes. In the environment, formaldehyde is quickly broken down in the air by moisture and sunlight, or by bacteria in soil or water.

It is an important industrial chemical used in the manufacture of numerous consumer products, including permanent-press fabrics, wallpaper, carpet products, nail hardeners, shampoos, and even toothpaste. Formaldehyde also has a long history of safe use in the manufacture of vaccines, anti-infective drugs, time-release pill coatings, and hard-gel capsules.

Formaldehyde is also used to inactivate viruses so they don’t cause disease.

HOW MUCH FORMALDEHYDE IS IN NATURAL WOOD?

All wood species, and therefore all wood products, contain and emit small amounts of formaldehyde.  Because formaldehyde occurs naturally in wood, there is no such thing as “formaldehyde-free” wood. An oak tree, for example, emits 0.009 ppm of formaldehyde. By itself, this is a very low quantity, but densely wooded areas can have much higher concentration levels. It follows that any wood cut from that oak tree also contains small amounts of formaldehyde, like all wood. 

WHY IS IT IN COMPOSITE WOOD PANELS?

Formaldehyde-based resins and glues are elemental in the creation of composite wood panels and the value-added products manufactured with them: cabinetry, fixtures, flooring, furniture, wall systems, etc. Formaldehyde helps to create exceptional bonds at a lower cost than any other alternatives. Because of this, it plays a huge role in helping the wood industry utilize fiber that would otherwise be waste, destined for the landfill or incinerator.

HEALTH ISSUES RELATED TO BUILDING MATERIALS PRODUCED WITH FORMALDEHYDE

Formaldehyde levels in typical indoor environments are below 0.1 ppm—well below the threshold that triggers sensory irritation in most people. The World Health Organization and Health Canada have estimated that the average adult ingests nine-times more formaldehyde each day from food than they inhale from all airborne sources combined. The human body is able to easily and rapidly metabolize formaldehyde, so the low levels at which most people are exposed to formaldehyde throughout their everyday lives present little risk to their health.

Here are some documented levels of formaldehyde content and expected exposure levels:

TAKE THE TEST

Sources:

“Relationship between Fiber Furnish and the Structural Performance of MDF”
Author: Groom, Leslie H.; Mott, Laurence; Shaler, Stephen
33rd International Particleboard/Composite Materials Symposioum Proceedings (1999)

“Medium Density Fiberboard Manufacturing”
US EPA, 2002
https://www3.epa.gov/ttnchie1/ap42/ch10/final/c10s0603.pdf

White Paper:  “Cradle to Gate Life Cycle Assessment of U.S. Medium Density Fiberboard Production”
Maureen Puettmann, WoodLife Environmental Consultants, LLC; Elaine Oneil, CORRIM; Jim Wilson, Oregon State University
http://www.corrim.org/pubs/reports/2013/phase1_updates/MDF%20LCA%20final%20Sept%202013.pdf

“Tool for the Reduction and Assessment of Chemical and other Environmental Impacts”
US EPA, ORD/NRMRL/Sustainable Technology Division, Systems Analysis Branch
https://www.pre-sustainability.com/download/TRACI_2_1_User_Manual.pdf

Relationship between Fiber Furnish and the Structural Performance of MDF”
Groom, Leslie H.; Mott, Laurence; Shaler, Stephen
33rd International Particleboard/Composite Materials Symposioum Proceedings (1999)
https://www3.epa.gov/ttnchie1/ap42/ch10/final/c10s0603.pdf

“Final Regulation Order: Airborne Toxic Control Measure to Reduce Formaldehyde Emissions from Composite Wood Products”
California Environmental Protection Agency Air Resources Board
https://www.arb.ca.gov/regact/2007/compwood07/fro-final.pdf

 “How to Powder Coat MDF,” Paint & Coatings Industry Magazine, 1 May 2006
http://www.pcimag.com/articles/94360-how-to-powder-coat-mdf

Interview: BTD Wood Powdercoating Inc., March 2016

Interview: Hoffman Manufacturing, Madison Wis., Sept. 2016.

= = = = =

“Formaldehyde Emissions and Exemptions,” Structural Insulated Panel Association
http://www.sips.org/green-building/formaldehyde-emissions-and-exemptions

“Indoor Air Pollution: An Evaluation of Three Agents”
University of Minnesota School or Public Health, Environmental Health Services, 2003
http://enhs.umn.edu/current/5103/air/formaldehyde.html

“Manufacturing Environmental Regulation”
American Wood Council, 2016
http://www.awc.org/pdf/formaldehydefactsheet.pdf

“Formaldehyde”
Chemical Safety Facts .Org Website
http://chemicalsafetyfacts.org/formaldehyde/?tab=2

Formaldehyde Facts .Org: Health & Safety
American Chemistry Council
http://www.formaldehydefacts.org/health_safety

 


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