Electronic cigarettes, commonly known as vapes, have become a popular method for nicotine delivery, but establishing a universal definition for “heavy use” remains challenging for researchers and clinicians. Unlike traditional cigarettes, which offer a relatively standardized product, vaping involves a vast ecosystem of customizable devices and user habits. These variables make a simple count of puffs or sessions an unreliable metric on its own for determining a user’s true level of exposure. This article defines the metrics and factors used to quantify vaping frequency and determine what is considered heavy use.
Defining Usage Metrics
The most straightforward way to quantify vaping frequency is by measuring the number of puffs per day (PPD) or the total number of sessions a user engages in. Puffs per day is a widely collected metric in surveys and clinical studies as it represents an observable measure of consumption behavior. Researchers also track the total number of distinct vaping sessions throughout the day, which provides insight into the user’s dependency on continuous nicotine availability.
Another important behavioral metric is the duration of inhalation during each puff, often referred to as puff topography. A user may take fewer puffs but inhale for a longer duration, delivering a substantially larger volume of aerosol per puff. While PPD is a common starting point for measurement, its inherent variability means it is an incomplete measure when considered in isolation.
Factors Influencing Nicotine Delivery
Simple metrics like puff count are insufficient because the actual dose of nicotine absorbed is influenced by several device and liquid factors. The most significant variable is the e-liquid’s nicotine concentration, which can range from 0 milligrams per milliliter (mg/mL) up to 69 mg/mL in some products. For example, a user taking fifty puffs from a 50 mg/mL device will have a far greater nicotine intake than one taking one hundred puffs from a 3 mg/mL device.
Device power, or wattage, is another determinant. Higher wattage settings vaporize e-liquid more efficiently and at a higher temperature, increasing the nicotine yield in the aerosol. This means a lower-strength e-liquid used in a high-wattage device can deliver comparable or higher levels of nicotine than a high-strength liquid in a low-power device.
The chemical form of the nicotine also matters, with nicotine salts providing a smoother inhalation experience that allows users to tolerate much higher concentrations without the harshness associated with free-base nicotine. The ratio of propylene glycol (PG) to vegetable glycerin (VG) in the liquid can also affect delivery, as a higher proportion of PG tends to increase the nicotine yield in the vapor.
Identifying Heavy Vaping Thresholds
Heavy vaping is defined by a combination of high consumption volume and indicators of nicotine dependence. Research focusing on daily exclusive users has cited a median e-liquid consumption of approximately 4.6 milliliters (mL) per day, though some high-volume users report consuming over 34 mL per day. Exceeding this median volume is a strong quantitative sign of heavy use and elevated nicotine exposure.
Clinically, a heavy user is often identified by the behavioral markers of addiction, which correlate with high-frequency consumption. A common threshold is daily use, but a more telling sign of dependence is the need to use the device immediately upon waking, such as within five minutes of getting out of bed. Daily users who report unsuccessful attempts to quit or reduce their use also fit the heavy user profile, indicating a loss of control over the substance.