Hookah and vaping are two popular methods for inhaling flavored substances, often containing nicotine, but they are fundamentally distinct processes that result in very different chemical exposures. While both devices involve heating a material to produce an inhalable cloud, the heat source and materials consumed determine the specific toxic compounds that enter the body. Comparing these systems requires examining the mechanics of delivery, the raw ingredients used, and the resulting toxic profiles.
The Delivery Systems
A traditional hookah relies on the combustion of charcoal to generate the heat needed to operate the device. The charcoal is placed above the shisha, a mixture of tobacco and flavoring. Heat from the burning charcoal warms the shisha, producing smoke that is drawn through a water-filled base before being inhaled. Although the water cools the smoke, this process does not remove the majority of toxicants produced, contrary to common belief.
Vaping devices, in contrast, utilize an electronic heating element, such as a coil or atomizer, powered by a battery. This element heats a liquid to a specific temperature, converting it into an aerosol, or “vapor,” without involving combustion. This electronic process eliminates the need for an external burning material like charcoal. The resulting output is an aerosolized mist, which is chemically different from the smoke generated by the high-temperature burning process of a hookah.
Material Differences
The raw material consumed by a hookah is called shisha, typically a blend of tobacco, molasses or honey, vegetable glycerin (VG), and various flavorings. The VG and molasses keep the tobacco moist, allowing it to be heated rather than combusted directly by the charcoal. Even non-tobacco or “herbal” shisha requires charcoal, meaning the user still inhales combustion products regardless of the tobacco content.
E-liquids, the material used in vaping devices, have a simpler base composition, consisting primarily of propylene glycol (PG) and vegetable glycerin (VG). These two compounds are solvents that create the visible aerosol when heated, and they are mixed with flavorings and, optionally, nicotine. E-liquid flavorings are highly diverse, often involving complex chemical compounds. The concentration of nicotine in e-liquids can vary widely, ranging from nicotine-free options to high-concentration nicotine salt formulations.
Toxic Exposure Profiles
The fundamental difference in the heat source leads to distinct toxic exposure profiles for each method. The use of charcoal in hookah smoking is a major source of carbon monoxide (CO), a colorless and odorless gas that can be acutely toxic. A single hour-long hookah session can expose a user to CO levels hundreds of times greater than a single cigarette, leading to documented cases of carbon monoxide poisoning. Hookah smoke also contains high levels of tar, heavy metals, and combustion-related carcinogens, none of which are effectively removed by the water filtration system.
Vaping, by avoiding combustion, does not produce carbon monoxide, but the electronic heating of the e-liquid creates its own set of chemical concerns. When the solvents, like PG and VG, are heated, they can thermally decompose to produce toxic carbonyl compounds, including formaldehyde and acetaldehyde. Formaldehyde is a known human carcinogen, and its presence in the aerosol is a byproduct of the heating process itself. Furthermore, the heating coils in vaping devices can degrade, leading to the aerosol containing heavy metals such as nickel, lead, chromium, and tin, which are leached from the metallic components of the device.