A cigar is a rolled bundle of dried and fermented tobacco that is intended to be smoked. A cigar’s composition is complex, involving hundreds of chemical compounds naturally present in the tobacco leaf and others introduced during processing. This article will detail the materials that make up an unlit cigar and the toxic substances generated when it is smoked.
The Tobacco Leaf: Structure and Natural Composition
A cigar is typically constructed entirely from different sections of the tobacco leaf, unlike many cigarettes which contain processed tobacco, paper, and filters. The three main components are the filler, which is the bulk of the tobacco inside; the binder, a tobacco leaf that holds the filler together; and the wrapper, the highest-quality leaf that forms the exterior. These leaves are air-cured and then undergo a long fermentation process, which is a significant factor in the final chemical profile.
The fermentation process is responsible for the formation of certain naturally occurring compounds, including the primary addictive agent, nicotine. Fermentation also results in the creation of tobacco-specific nitrosamines (TSNAs), which are potent cancer-causing agents that exist in the leaf before it is ever lit.
The high temperature and moisture conditions during fermentation impact the pH of the tobacco leaf. Cigar tobacco typically has a higher, more alkaline pH than cigarette tobacco, meaning the nicotine is present in a free, un-ionized form. This higher pH allows the free nicotine to be readily absorbed through the mucous membranes of the mouth, even without deep inhalation into the lungs.
Manufacturing Additives and Treatments
Although traditional, premium cigars often contain only tobacco, water, and natural binding agents, many mass-market cigars and cigarillos include intentionally added non-tobacco ingredients. These additives serve various purposes, primarily to maintain quality, enhance flavor, or control moisture. The frequency of additives is significantly higher in flavored and machine-made cigar products compared to traditional hand-rolled ones.
Humectants are substances added to maintain a desirable moisture level in the tobacco, preventing it from drying out. Common humectants include propylene glycol and glycerol, which are colorless, odorless liquids that draw moisture from the air. They ensure the product remains fresh and pliable, sometimes present at levels of two to five percent by weight in the filler.
Flavorings represent the largest category of intentionally added ingredients, particularly in cigarillos and smaller cigars. Manufacturers use hundreds of different flavor additives to achieve a specific taste or aroma, such as cocoa, coffee, and various fruit essences. The tobacco may also contain trace residues from agricultural treatments, such as pesticides, or agents used during the curing process, which remain.
Toxic Byproducts of Smoking
When a cigar is lit, the heat causes pyrolysis and combustion, generating thousands of chemical compounds not present in the unlit tobacco. The smoke contains many of the same toxic and carcinogenic substances found in cigarette smoke, often at higher concentrations due to the cigar’s less porous wrapper and incomplete burning. These byproducts are divided into the gas phase and the particulate phase, each containing distinct hazards.
The gas phase includes significant levels of carbon monoxide (CO), which forms from the incomplete combustion of the tobacco. Nitrogen oxides, which are also abundant, are generated from the nitrogen compounds naturally present in the fermented leaf. Other toxic gases are volatile organic compounds (VOCs) such as benzene, 1,3-butadiene, and formaldehyde.
The particulate phase, often referred to as tar, is a complex mixture of non-gaseous compounds. This tar contains heavy metals like cadmium and lead, which the tobacco plant absorbs from the soil. Highly carcinogenic compounds, including polycyclic aromatic hydrocarbons (PAHs) and tobacco-specific nitrosamines (TSNAs), are released and concentrated in this smoke particulate.
The chemical exposure is further complicated by the difference between mainstream smoke, which is drawn through the cigar, and sidestream smoke, which is emitted from the burning tip. Sidestream smoke often has higher concentrations of certain toxic compounds, like ammonia, because it is generated at a lower temperature and under less oxygenated conditions.