Ammonia, or compounds that release it, is included as a chemical additive in the manufacturing process. Tobacco companies have used this substance for decades as part of a category of substances intentionally added to the tobacco blend. Its presence in commercial cigarettes has been a matter of public record and scientific investigation. The inclusion of ammonia plays a specific role in altering the chemical dynamics of the smoke inhaled by the consumer.
The Purpose of Ammonia in Cigarettes
The primary function of adding ammonia or ammonia-releasing compounds to tobacco is to influence the chemistry of the smoke, a process known as alkalization. Nicotine naturally exists in tobacco as a protonated form, often referred to as a nicotine salt, which is less volatile and is not readily absorbed by the body. Ammonia, being a base, raises the pH level of the tobacco and the resulting smoke, making the environment more alkaline.
This increase in alkalinity shifts the acid-base equilibrium of the nicotine molecules. The change converts the less-easily absorbed nicotine salt form into its non-protonated, volatile state, commonly called freebase nicotine. Freebase nicotine is significantly more lipophilic, meaning it dissolves easily in fats and oils, allowing it to cross biological membranes, like those in the lungs, much more efficiently. This enhanced absorption rate leads to a faster and more intense delivery of nicotine to the brain.
Freebase nicotine provides a quicker “impact” on the smoker, which is a desirable characteristic for tobacco companies aiming to increase the product’s appeal and dependence potential. Ammonia sources like diammonium phosphate and urea are used to achieve this effect. Studies quantifying ammonia levels in tobacco filler have shown a typical range of approximately 0.9 to 2.4 milligrams per gram of cigarette filler across different commercially available brands. This variation suggests that the manipulation of smoke chemistry is a purposeful design feature in domestic cigarettes.
Direct Health Impact of Ammonia Exposure
Beyond its function in enhancing nicotine delivery, the ammonia released during the combustion of a cigarette presents its own set of health concerns. Ammonia is classified as an irritant gas, and its presence in tobacco smoke contributes to the overall burden of toxic chemicals inhaled by the smoker. When the vaporized ammonia makes contact with the moist surfaces of the body, it can react to form ammonium hydroxide, a corrosive agent.
This corrosive property causes immediate irritation to the tissues of the upper respiratory tract, eyes, and throat. Smokers frequently experience a burning sensation and irritation in these areas due to the presence of alkaline compounds like ammonia. Exposure to the gas can lead to cellular irritation and damage to the protective lining of the bronchial tubes.
Inhaling ammonia can also contribute to a chronic cough and may exacerbate existing respiratory conditions. The compound’s role as an irritant highlights that it is a harmful constituent of smoke, separate from the addictive effects it facilitates.
Oversight and Disclosure of Tobacco Additives
The presence of ammonia and other chemical additives in cigarettes falls under the regulatory oversight of government bodies, such as the U.S. Food and Drug Administration (FDA). The Family Smoking Prevention and Tobacco Control Act grants the FDA authority to regulate tobacco products and requires manufacturers to report the ingredients and additives they use. This requirement mandates that tobacco companies disclose the specific quantities of harmful and potentially harmful constituents (HPHCs) in their products, with ammonia being one such substance.
The FDA makes this ingredient information publicly accessible, promoting transparency regarding the chemical makeup of commercial tobacco products. The ongoing debate in public health focuses on whether this disclosure alone is sufficient to protect consumers, especially considering the known function of ammonia in increasing nicotine’s bioavailability. Although manufacturers must report the use of ammonia, the agency retains the ability to impose product standards, which could include restrictions on certain additives in the future.