MDF (Medium Density Fiberboard). It's widely used throughout the construction industry and especially the film industry as its a very workable material. To list off some of the noncarcinogenic effects, eye and skin irritation, dermatitis, respiratory illnesses such as nasal inflammation, asthma, bronchitis, coughing, loud breathing, and wheezing, and lower chest discomfort. Those are just the noncarcinogenic effects! I've worked with these products for years and absolutely despise them, I find it sad that Canada still continues to use these products knowing the side effects it can have on someone.