I got this question from a coop builder a few months ago:
“A friend saw that I had bought OSB [oriented strand board] and mentioned that this was a potential hazard due to formaldehyde emissions. What are your thoughts on this? Am I better off returning it and going with plywood?”
Some background first. Formaldehyde is used in the resins (glues) of some manufactured wood products like plywood and particle board. The emissions the builder was concerned about are often referred to as “offgassing” or “outgassing,” which is the gradual release or evaporation of chemicals from a building material. If these vapors build up in an enclosed space, like a car or home, it could lead to a problem. But what about in a chicken coop?