Oct 20, 2025
When it comes to building materials, not all products are created equal — especially in the face of fire. OSB, one of the most common materials used in residential construction, is increasingly being scrutinized for its dangerous behavior during fires. Not only does OSB ignite faster and burn hotter than Class A materials, but research shows it poses serious health risks to firefighters responding to house fires.
In a 2019
In a 2019 study published in the International Journal of Hygiene and Environmental Health, researchers found that just one day of fire training involving OSB exposed firefighters and their instructors to over 30 times more toxic byproducts than typical training exercises, which is more than what firefighters encountered in actual house fires.
Another study noted that formaldehyde levels during OSB fire scenarios were more than 280 times higher than the recommended NIOSH ceiling limit. This toxic chemical is known to cause cancer and respiratory issues, and it becomes highly concentrated when OSB burns.
Perhaps most alarming: researchers also recorded a 30-fold increase in 1-hydroxypyrene, a chemical linked to carcinogenic polycyclic aromatic hydrocarbons, in instructors’ systems after just one day of OSB training burns, reaching levels 3.5 times higher than firefighters who responded to real structure fires (Fent, 2019).
Because of these risks, fire safety experts are calling for a reduction in the use of OSB during training and construction. As the researchers concluded, “Efforts should be taken to minimize the use of OSB during training fires… particularly when possible to meet training objectives without the use of this material.” (Fent, 2019)
At HydroBlok, we believe in building with materials that prioritize both safety and performance. Our building systems are Class A rated, meaning they offer the highest level of fire resistance. HydroBlok has a flame spread that’s 13 times less than OSB, making it a smarter and safer choice for homes and the first responders who protect them.
Because your home—and your health—deserve better.
Fent, K. (2019, July 2). Firefighters’ and instructors’ absorption of pahs and benzene during training exercises. International Journal of Hygiene and Environmental Health. https://www.sciencedirect.com/science/article/pii/S143846391930313X?via%3Dihub
Fent, K. (2019, June 6). Understanding Airborne contaminants produced by different fuel packages during training fires. Journal of Occupational and Environmental Hygiene. https://www.tandfonline.com/doi/full/10.1080/15459624.2019.1617870
