Considering a Cedar Sauna? Think Again.

As an outdoor building material for fences and decks, cedar may be the wood of  choice for some people, but as a major component in a personal far infrared sauna cedar should never be used. The primary irritant in cedar is plicatic acid, and western red cedar contains the highest concentrations. Eastern white cedar and Japanese cedar also contain this toxic material. Plicatic acid has been shown to cause an array of pathological changes consistent with inflammatory and allergic reactions. Exposure to plicatic acid can cause or worsen asthma, inflame the mucous membrane in the nose and inner surface of the eyelids in humans and in animals, and the damage can be progressive. Asthmatics who are continuously exposed to cedar can experience a deterioration in their asthma over time. The plicatic acid present in cedar can also cause destruction and scaling or separating of tracheal and bronchial epithelial cells.

As a toxic material, cedar also contains a poisonous protein complex called Cedrus that acts on the nervous system. Although cedar is used in clothing chests, drawers and closet linings to repel insects and kill moths, this neurotoxin which gives off gas in a small area can be very hazardous if used in a sauna. Cedar is now considered a workplace hazard by provincial workers compensation boards and is recognized as a potential carcinogen among workers because occupational exposure to cedar can cause asthma and chronic lung disease. Long‑term exposure to red cedar or pine in humans can lead to a decrease in forced expiratory volume, or FEV, which is a measure of lung capacity and the ability to breathe freely.

Many saunas that have incorporated cedar into the construction have shown severe signs of premature warping and wear. The oils in the wood can volatilize from the heaters and fill the room with cedar oils that are not healthy if absorbed over long periods of time. A far infrared sauna should be a long term investment in your enjoyment of life. You should not expose your good health to the risks that cedar poses.

Cedar Saunas—Are they safe?
The toxicity of constituents of cedar to pulmonary epithelium.
Ayars GH, Altman LC, Frazier CE, Chi EY.

Department of Internal Medicine, University of Washington, Seattle 98195.
Occupational exposure to cedar can cause asthma and chronic lung disease. Prior studies suggest that plicatic are responsible for the asthmatic reactions that occur in cedar-wood and colophony workers; however, the etiologic mechanism(s) of the chronic lung disease is unknown. To determine if plicatic acid from cedar wood could directly damage lung cells, we exposed monolayers of rat type II and human A549 alveolar epithelial cells, intact rat lungs, and rat tracheal explants to solutions of plicatic. As indices of injury, we measured lysis of alveolar epithelial cells with a 51Cr technique, quantitative desquamation of epithelial cells from tracheal explants, and histologic alterations in tracheal explants and intact lungs. Plicatic acids caused dose- and time-dependent lysis of alveolar epithelial cells. Instillation of plicatic acids into rat lungs produced bronchial epithelial sloughing. The addition of acid to rat tracheal explants caused epithelial desquamation that was dose- and time-dependent.

Our results suggest that plicatic acid, a unique constituent of cedar wood, can produce lytic damage to alveolar, tracheal, and bronchial epithelial cells. We hypothesize that repeated occupational exposure to these substances might promote the chronic lung damage observed in some cedar-wood workers.