Correction on Binders in Interior Plywood

I’d like to offer a minor correction to your otherwise excellent article “Structural Engineered Wood: Is it Green?” (EBN

Vol. 8, No. 11). You stated that interior-grade softwood plywood uses a urea-formaldehyde (UF) binder. While that was once the case, all construction-grade plywood (both interior- and exterior-grade) now uses a phenol-formaldehyde (PF) binder. In fact, if you look on an American Plywood Association (APA) grade stamp on one of their interior-grade products, it will say “exterior glue.”

On the other hand, furniture-grade or cabinet-grade plywood (which is for interior use) does typically use a UF binder. This type of plywood does not come under APA jurisdiction. So, the distinction is this: construction-grade plywood uses a PF binder, furniture-grade plywood uses a UF binder. Thus, the unhealthiest binder (the one that usually outgasses more formaldehyde) is used in plywood that is directly exposed to the occupants, and the healthier binder is used in plywood that is typically separated from the occupants to some degree.

John Bower

The Healthy House Institute

Bloomington, Indiana