This is common misconception #2. The fact is, wood hot tubs are no less sanitary than plastic or acrylic spas. When improperly sanitized, wood hot tubs and acrylic spas can both represent a health hazard, but there is absolutely no evidence whatsoever that natural wood is more likely to harbor more bacteria or micro-organisms than plastic or acrylic spas.
In fact, a university study of kitchen cutting boards found that while bacteria multiplied and prospered on plastic cutting boards, it quickly died on cutting boards made from natural wood.
It’s important to remember, that regardless of the material that your hot tub or spa is made of, proper sanitation is the key.