Cedar wood encompasses several species, including Western Red Cedar and Eastern Red Cedar. Whether it is toxic depends on the specific species, the level of exposure, and the biology of the person or animal exposed. Cedar’s natural resistance to pests and its distinctive aroma come from potent chemical compounds, which are the source of both its commercial utility and potential health concerns. Understanding the distinction between a sealed wooden product and concentrated sawdust or bedding is necessary to accurately assess the risk presented by this common material.
Chemical Components Causing Irritation
The distinct scent of cedar wood comes from a high concentration of volatile organic compounds (VOCs) within its structure. These compounds are primarily terpenes, which are released as aromatic oils that contribute to the wood’s insecticidal properties. The main mechanism for harm involves the inhalation of these concentrated aromatic oils or fine wood dust particles. Certain species, particularly Western Red Cedar, contain a potent chemical called Plicatic Acid, which is a known respiratory sensitizer. When cedar is cut, sanded, or shredded, these compounds become aerosolized, making them bioavailable for inhalation or direct skin contact.
Respiratory and Dermatological Risks for Humans
Exposure to cedar wood dust is primarily an occupational health concern, affecting woodworkers and mill laborers. Inhaling the fine sawdust can lead to respiratory issues, including irritation of the eyes, nose, and throat. This mechanical irritation combines with the chemical effects of volatile compounds, creating a toxic environment for the respiratory tract.
The most specific risk is Western Red Cedar Asthma, a form of occupational asthma caused by sensitization to Plicatic Acid. Symptoms include shortness of breath, wheezing, and coughing, which characteristically worsen during the work week and improve on weekends. Repeated exposure can cause chronic lung disease and a measurable reduction in lung function over time.
Dermatological risks also arise from direct contact with the wood dust or oils, leading to contact dermatitis or allergic skin reactions. While the risk is significantly lower for casual users handling sealed cedar products, those engaged in sanding or cutting raw lumber must take precautions against both respiratory and skin sensitization.
Specific Dangers for Household Pets and Bedding
The aromatic nature of cedar wood presents a pronounced danger to small household pets, such as guinea pigs, hamsters, mice, and rats, when used as bedding. The confined space of a cage concentrates the volatile phenols and aromatic hydrocarbons released by the shavings, leading to chronic exposure. These inhaled toxins are absorbed into the bloodstream and metabolized by the liver, the body’s primary detoxification organ.
Continuous exposure to cedar bedding induces hepatic microsomal enzymes in laboratory animals. This enzyme induction forces the liver to work harder and more rapidly, which can alter the metabolism of medications, including anesthetics, complicating veterinary treatment. Elevated liver enzymes indicate the organ is under significant stress as it attempts to process the toxic compounds.
Beyond metabolic effects, the acids released from the shavings, in combination with the phenols, are directly damaging to the respiratory system. These chemicals can destroy the delicate cells lining the lungs and trachea, leaving small animals highly susceptible to upper respiratory infections and pneumonia. For species already prone to respiratory illness, cedar bedding can be a significant factor in poor health outcomes. While the risk is lower for larger pets like dogs and cats, excessive dust or ingestion can still cause respiratory irritation and gastrointestinal upset.
Strategies for Minimizing Exposure
For humans working with raw cedar wood, mitigating exposure requires controlling dust and ensuring adequate ventilation. A quality respirator or dust mask is necessary when cutting, sanding, or milling cedar lumber to prevent inhaling fine particles and Plicatic Acid. Work areas should also be equipped with effective dust collection systems to capture airborne debris.
Once cedar wood is finished and sealed with a varnish or paint, the volatile compounds are largely trapped, significantly lowering the risk of chemical release. For finished products like cedar chests, occasional exposure to the aroma is considered low-risk for most people.
For small caged pets, the safest approach is complete avoidance of cedar shavings as bedding material. Pet owners should choose safer alternatives that do not contain irritating aromatic oils:
- Paper-based products
- Aspen shavings
- Hemp bedding
- Kiln-dried pine (as a safer wood option)
Ensuring good air circulation where cedar items are stored or used is also advisable to prevent the buildup of VOCs.