Sassafras (Sassafras albidum) is a tree native to eastern North America, historically recognized for its aromatic qualities and diverse uses. Its roots and bark have been utilized for centuries to create teas, flavorings, and medicinal remedies, particularly in colonial America. The unique scent and taste of the plant stem from its concentrated essential oil. Understanding the core composition of sassafras and the physiological effects of smoke inhalation is necessary to address the safety of inhaling smoke from dried sassafras plant material.
Sassafras Composition and Safrole
The distinctive, sweet, and spicy aroma of the sassafras tree is primarily due to a single organic compound in its volatile essential oil: safrole. Safrole (1-allyl-3,4-methylenedioxybenzene) is a phenylpropanoid that gives sassafras its characteristic flavor and scent, historically associated with root beer before regulatory changes.
The concentration of this compound is notably high in the essential oil extracted from the root bark of the plant. Sassafras essential oil typically contains a substantial percentage of safrole, sometimes reaching up to 90% by weight in the steam-distilled product. Other compounds, such as camphor and methyleugenol, are also present but in much smaller quantities, making the high concentration of safrole a unique feature of the plant.
Historically, the concentrated oil was widely used as a flavoring in chewing gum, candies, soaps, and pharmaceuticals. The chemical structure of safrole is a precursor to certain illicit substances, which explains why some people might seek psychoactive effects from the plant. However, its use in food was restricted due to health concerns, shifting the focus to safrole-free extracts. This chemical makeup is central to understanding the health risks associated with intentionally inhaling the smoke from the plant material.
Immediate Health Effects of Inhalation
Inhaling the smoke from any burning plant material, including sassafras, immediately introduces a mixture of gases and fine particulate matter into the respiratory system. The act of combustion itself creates a number of toxic and irritating substances, irrespective of the plant being burned. The smoke contains microscopic particles (PM2.5) that penetrate deep into the lungs and potentially remain there for years.
These particles and irritants, such as sulfur dioxide, hydrogen chloride, and various aldehydes, cause immediate respiratory distress. Symptoms include a scratchy throat, coughing, wheezing, irritated sinuses, and stinging eyes. For individuals with existing conditions like asthma or chronic obstructive pulmonary disease (COPD), smoke inhalation can significantly worsen symptoms and trigger acute attacks.
A systemic danger comes from carbon monoxide, a colorless and odorless gas produced by incomplete combustion. When inhaled, carbon monoxide binds to hemoglobin, displacing oxygen and reducing the body’s ability to transport it to tissues. This can lead to symptoms like headache, dizziness, nausea, and in severe cases, unconsciousness or death.
Regarding psychoactive potential, the high heat required for smoking is likely to degrade much of the safrole before it can be effectively absorbed through the lungs. While the boiling point of pure safrole is high (around 232-234 °C), the extreme temperatures of a burning substance cause thermal decomposition. The resulting smoke may contain breakdown products that are more toxic than the parent compound, or the compound may simply fail to vaporize efficiently for any recreational effect. Consequently, the primary and most immediate health impact of smoking sassafras is the general, acute damage caused by smoke inhalation and carbon monoxide exposure.
Safrole Toxicity and Regulatory Controls
Beyond the immediate effects of smoke inhalation, safrole introduces severe long-term, systemic health risks. Safrole is classified as a substance reasonably anticipated to be a human carcinogen, primarily based on extensive studies in experimental animals. These studies have consistently shown that safrole exposure leads to the development of liver tumors, specifically hepatocellular carcinoma, in both rats and mice.
The compound is hepatotoxic, meaning it is toxic to the liver. It is metabolized in the body into more potent carcinogenic substances, such as 1′-hydroxysafrole. This metabolite is considered a proximate carcinogen that can cause a high incidence of liver tumors in animal models. Ingestion or repeated inhalation of safrole-containing smoke exposes the body to this substance, putting the liver at risk as it attempts to process the compound.
Due to these significant health concerns, particularly the liver cancer risk demonstrated in animal models, safrole and sassafras oil are subject to strict regulatory controls. The U.S. Food and Drug Administration (FDA) prohibits the direct addition of safrole or sassafras oil to food for human consumption. This measure was put in place to protect the public from chronic exposure to the carcinogenic compound.
Sassafras oil is also heavily regulated by the U.S. Drug Enforcement Administration (DEA) because of its chemical properties. Safrole is designated as a List I chemical, a classification for substances used in the illicit manufacture of controlled substances. This is because safrole is a primary precursor chemical for the synthesis of 3,4-methylenedioxymethamphetamine (MDMA), also known as ecstasy. The regulatory status reflects not only the inherent toxicity of the compound but also its potential for diversion into illegal drug production.