As contractors incorporate environmentally conscious practices such as ventilation and moisture control systems into their projects, they may be overlooking an important aspect of sustainable construction: the impact of engineered wood building materials. Many construction-grade plywood, medium-density fiber board (MDF), oriented strand board (OSB) and particleboard products are made with wood-bonding adhesives that emit formaldehyde, which has been designated a human carcinogen by the U.S. government and many other regulatory groups around the world.

Additionally, many private sector influencers, such as Perkins + Will and the International Living Building Challenge, have prominently listed formaldehyde among chemicals used in the building industry that are detrimental to human health and the environment.

Not surprisingly, the growing concerns about formaldehyde and increasingly tighter global standards have impacted manufacturers of engineered wood building materials and their adhesive suppliers. Some manufacturers are committed to using adhesives that do not emit formaldehyde, while others have asked adhesive suppliers to reduce the level of formaldehyde emissions from their products.    

Formaldehyde-emitting construction materials must become part of the sustainable construction conversation. Understanding the range of adhesives currently used to make engineered wood construction materials is critical to construction firm owners and their management teams given the high probability these materials are used in their projects. 

Viable Alternatives to Formaldehyde-Emitting Adhesives
Among the latest developments are efficient and effective adhesives that do not add any formaldehyde into the environment. These are classified as no-added-formaldehyde (NAF) adhesive systems, and engineered wood construction materials made with them have the lowest level of formaldehyde content.

Soy-based adhesives, which neither contain nor emit formaldehyde, are the latest breakthrough in NAF adhesives. These systems, which contain low VOCs and meet or exceed all critical performance targets for adhesives, are made from soybeans—a renewable resource. In the past several years, soy-based adhesives have gained share in the particleboard, MDF and OSB markets.

Another NAF option available to manufacturers is adhesives made with isocyanates, which provide strength and high resistance to water and are widely used to produce OSB. 

Confusing Terminology
Adhesives in the middle of the formaldehyde-emitting spectrum are categorized as no-added-urea-formaldehyde (NAUF) adhesives. This can be a confusing term for construction executives and other industry members, who may interpret it to mean there is no formaldehyde of any kind in the adhesive. In fact, NAUF adhesives do contain phenol formaldehyde (PF) or melamine formaldehyde (MF).

PF resins typically are found in products such as construction-grade plywood and OSB, which require high durability, as well as moisture and weather resistance. Engineered wood products made with PF adhesives are considered “low emitting.” MF resins are primarily used in interior-grade products that require greater strength and improved moisture resistance and generally emit more formaldehyde into the environment than PF adhesives.

High Formaldehyde-Emitting Adhesives
Adhesives made with urea-formaldehyde (UF) emit the highest rates of formaldehyde into the environment. As a result, they are scrutinized by regulators around the world. Products made with UF adhesives are most often found in building interiors because they have a lower tolerance to moisture and humidity, especially when the ambient temperature rises.

Producers of UF adhesives have been able to modify their formulations to reduce emissions and create products that comply with most global standards. Unfortunately, this often has been at the expense of product performance and manufacturing efficiency. 

UF adhesives containing melamine are called melamine urea-formaldehyde adhesives. The melamine adds strength and durability to the adhesive and can help lower formaldehyde emissions from the adhesive relative to emissions from UF adhesives.

LEED-Compliant Engineered Wood Products

LEED v4 changed how manufacturers can produce LEED-compliant engineered wood products, as well as the information they must convey about the adhesive used to make them. The Building Design and Construction section requires that engineered wood products meet the California Air Resources Board (CARB) emission testing requirements for ultra-low-emitting formaldehyde products, or they must be made with an NAF adhesive. 

Construction executives searching for information on formaldehyde content in an adhesive must rely on the Material & Resource section for Building Product Disclosure and Optimization of LEED v4. This section requires that there be no Benchmark-1 hazards using the Greenscreen v1.2 Benchmark system. Formaldehyde would be identified as a Group 1 Human hazard by GreenScreen, and any adhesive using formaldehyde would not qualify for this point.

Factual information about formaldehyde emissions from a specific engineered wood building material brand can be gleaned by asking the manufacturer three basic questions.
  • Are its engineered wood construction materials made with NAF adhesives?
  • Are its finished products independently certified to be LEED compliant by an organization like the GREENGUARD Environmental Institute or Floorscore?
  • Do its finished products meet CARB standards for ultra-low-emitting formaldehyde?
Manufacturers committed to producing sustainable products will answer “yes” to each question.


Melinda Burn is global business manager of sustainable building and construction for Ashland Inc. For more information, email mjburn@ashland.com.