No ventilation or air circulation can prevent this.
Cedar wood sauna toxic.
Never use synthetic wood in a sauna.
Composite woods are made of a mixture of wood fibers plastics glues and other binding agents.
But in the case of cedar and hemlock and other softwoods the chemicals that produce the scent they give off can be to some people annoying or intolerable even dangerous.
However some may be sensitive to the cedar odors.
All wildwood grilling cedar planks are made from western red cedar.
To most people naturally occurring wood phenols are harmless but people with particular sensitivities or people who are prone to allergies should avoid saunas made from cedar and other fragrant woods.
If what was being outgassed from wood into the air was harmless say like the smell of vanilla from a baking cake this wouldn t be a problem.
This is the safest and most recommended for cedar plank cooking.
Western red cedar is delicious and non toxic.