The question of whether burning resin is toxic has a complex answer because the term “resin” applies to two very different material classes. In the context of fragrance, resin refers to natural, hardened saps from trees, such as frankincense or myrrh. When any organic material is burned, it undergoes incomplete combustion, which produces smoke containing numerous airborne pollutants. This process means a degree of toxicity is always present, regardless of whether the source material is natural or synthetic.
Components Released During Combustion
The smoke produced by burning resin is a mixture of gases and solid particles, which are the source of its toxicity. A major concern is Particulate Matter (PM), including fine particles (PM2.5) and ultrafine particles. These microscopic particles can penetrate deeply into the lungs; studies show that burning incense can generate up to four times the particulate matter of a single cigarette.
The gaseous phase contains a range of Volatile Organic Compounds (VOCs) and other hazardous gases. Specific VOCs frequently detected include benzene, a known carcinogen, and toluene. Aldehydes like formaldehyde and acetaldehyde, which are strong irritants, are also released. Incomplete burning generates carbon monoxide (CO), a colorless and odorless gas that impairs the blood’s ability to carry oxygen.
Health Impacts of Inhaling Resin Smoke
Exposure to these airborne components can result in both immediate and long-term biological consequences. Acute effects are felt quickly and include irritation of the eyes, nose, and throat due to the presence of aldehydes and irritant VOCs. Individuals with pre-existing conditions like asthma or chronic obstructive pulmonary disease (COPD) may experience a rapid exacerbation of symptoms, such as coughing and difficulty breathing.
Chronic exposure, involving inhaling these compounds over months or years, poses more serious health risks. The deep penetration of ultrafine particulate matter into the lungs can lead to a decline in lung function and increased susceptibility to respiratory infections. Long-term inhalation of smoke containing compounds like benzene and Polycyclic Aromatic Hydrocarbons (PAHs) is associated with DNA damage and an elevated risk of developing cancers of the upper respiratory tract.
Natural Resins Versus Synthetic Compounds
The source material determines the specific chemical profile of the smoke, creating a significant difference in toxicity. Natural resins, such as copal, frankincense, and myrrh, are derived from tree exudates and primarily release complex aromatic terpenes and essential oils upon heating. While some cite potential health benefits of compounds like boswellic acids in frankincense, these benefits are studied in extracts, not smoke inhalation. The combustion of natural materials still produces the general hazards of smoke, including PM and VOCs, but the chemical mix is less complex than synthetics.
Synthetic resins are industrial polymers like epoxy, polyurethane, or materials used in 3D printing. When subjected to high heat, these materials break down into highly toxic and distinct chemical byproducts. For example, burning urethane-based materials can release trace amounts of hydrogen cyanide gas, which is extremely toxic. Methacrylate resins can decompose into benzene and butane.
Minimizing Risk During Use
Individuals who choose to burn resins can take specific actions to reduce their risk of exposure to harmful byproducts. The most effective mitigation strategy is ensuring robust ventilation during and after the burning period. Opening windows and using exhaust fans helps to continually replace the polluted indoor air with fresh air from outside.
Limiting the duration and frequency of burning is a simple way to reduce the overall dose of inhaled pollutants. When purchasing resin, select pure, natural resins and avoid commercial products like incense sticks that may contain synthetic binders or accelerants. Finally, place the burning material away from areas where people are sitting or spending extended time to maintain distance from the densest smoke plume.