Electronic vaporization of cannabis was supposed to be the safer alternative to smoking. After all, users still get all the benefits of the cannabinoids and terpenes without inhaling combusted products like carbon monoxide, plant matter particulates, or the over 100 toxins that are released when flower is burned.
In 2019, an outbreak lung illness tied to tainted vapes challenged this illusion of safety. Leafly discovered the culprit—Vitamin E acetate, a cheap cosmetics thickener used for diluting weed oil. Sellers quickly removed it from the vapor stream, yet its prevalence may persist in illicit oils and vape pens.
Even though the rates of these electronic vaporization-associated lung illnesses (EVALIs) have been falling drastically since their peak in September 2019, safety concerns around cannabis vaporization are still present in peer-reviewed scientific reports and in popular media sources.
In January of 2024, the California Department of Public Health reported 2% of their recent 250 EVALI patients died. One study also found structural abnormalities in the lungs of vape and e-cig users who didn’t have any respiratory symptoms yet.
Street vape cartridges may contain fillers like vitamin E acetate and added flavoring agents. By contrast, vaping whole flower or licensed extracts that have not been put into a cartridge may not carry the same risks.
Smoking or vaping anything can come with risks. But in the end, the biggest risk factors for vaping seems to come not from the cannabis, but from the substances added to it.
Vaping flower vs vaping cannabis oil
People use the term “vaping” to describe the act of inhaling cannabis that’s been heated with temperatures so low it turns into vapor rather than smoke. But not all vaping is the same – and different types of vaping may require different devices.
There can be some differences in the feel of each method, but they will all effectively deliver a cloud of vaporized cannabis to your lungs.
Vaping flower
Ground cannabis flower can be vaporized directly in a flower vape for a lighter, smoke-free way to access its cannabinoids. That’s the Volcano vaporizer, Mighty, or Venty, the Pax, or dozens more devices.
Vaping oil
Vape cartridges are pre-filled tanks of cannabis oil and usually some kind of diluent or flavorings (which are rarely identified on an ingredients list). This mixture is vaporized using small vape pens.
People also “dab” pure cannabis oils and extracts using a dab-rig or oil vaporizer. This form of vaping allows for hits with a large amount of cannabinoids, which can be great for medical patients. But proceed with caution. Dabbing can be easy to overdo.
Why vape cannabis?
The increased popularity of vaping cannabis is believed to be tied to legal access. Yet vaping is rarely the sole mode of cannabis consumption: 13% who vape cannabis only vape.
People often choose to vape cannabis over smoking flower because of its convenience, discretion, and efficiency; there are times when one just doesn’t want their space to smell like weed.
Vape carts can also be more consistent. Cannabis flower, even of the same strain, can vary widely in terms of end product, whereas carts can use exact formulations of cannabinoids and terpenes to create a consistent experience.
These oils can even be optimized for a particular therapeutic need or recreational desire through the addition of cannabinoids and terpenes at levels that are impossible to achieve with traditional grow methods and the limitations of a strain’s genetics. Notably, the science behind what represents a therapeutically-optimized composition remains mostly theoretical.
Health concerns are another reason consumers might choose vaping over smoking. Vaping is often deemed to be the safer option since the lower temperature reduces the amount of harmful gasses and toxins that are inhaled.
Is vaping safer than smoking?
The evidence on whether vaping is safer than smoking is mixed. On one hand, the lower temperatures used in vaping avoids producing some harmful by-products from combustion like benzene, toluene, and carcinogenic hydrocarbons. This lessens the amount of potentially harmful compounds inhaled when compared to smoking.
One small study (12 participants) found that respiratory function and lung capacity improved for cannabis smokers who spent 30 days vaping instead of smoking. Another study found vaporizer users were 40% less likely to report respiratory effects like cough, phlegm, and chest tightness than those who smoked cannabis. While this evidence is limited, it suggests that vaporization could be used as a harm reduction method.
On the other hand, the 2019 EVALI epidemic showed us that vaping can actually be much more harmful than smoking when we are talking about using vape carts. The crisis caused 2807 hospitalizations with 68 deaths for those vaping e-cigarettes or cannabis cartridges.
This was likely caused by vitamin E acetate, which was discovered in the lung fluid of 48 of the 51 case studies with confirmed or suspected EVALI. Researchers found no vitamin E acetate in the lungs of the healthy control group.
In a 2024 study, researchers added to this theory by showing that vaping vitamin E acetate actually produced ketene. This poisonous gas is already known to cause serious lung damage and even be fatal in high doses.
This toxic substance was added to cartridges to thin the cannabis extract so that it could be used in carts. And it’s important to note that many of these tainted cartridges were obtained from illicit dealers rather than a regulated cannabis dispensary. While vitamin E acetate is rarely used as a thinner these days, other thinning agents and flavorings are used (even in the legal market) which we haven’t studied enough to know if they are safe when inhaled.
The same damaging gas that’s released from heating vitamin E acetate and led to the EVALI epidemic in 2019 can be produced by other compounds found in unregulated delta-8, CBN, and CBG vape products. Inflammation in the airway can also be triggered by vape liquid itself, even in the absence of nicotine or cannabis.
All of this gives vape cartridges a special risk factor above and beyond just the comparison between smoking and vaping cannabis. When you use cartridges, you may also be inhaling a variety of additional substances that might not even be listed as an ingredient. Knowing what’s in your vape cart is essential for safe use.
While vaping cannabis flower or raw cannabis concentrate doesn’t carry the risk from fillers and flavoring agents, it’s hard to say exactly how safe these alternative forms of vaping are. A 2020 study of 2,553 young adults found that cannabis vaping was associated with increased risk for bronchitic symptoms, such as shortness of breath. This outcome persisted even after adjusting for nicotine vaping and smoking cannabis or tobacco. Vaping at least 3 times in the last month doubled the risk for experiencing wheezing, which is a short whistle or rattle when one breathes due to a partially blocked airway.
However, it’s notable that this study came out just after the peak of EVALI and does not separate vaping carts from other forms of vaping. This means the data here might be skewed by the increased levels of vitamin E acetate being used at the time. It’s worth pointing out that the previous studies showing less negative impacts from vaping were conducted years before the EVALI crisis so their results aren’t impacted by it.
Do vaping and smoking have different effects?
Anecdotally, some report differences in the subjective experiences between vaping and smoking cannabis, but there’s a fair amount of variability in the outcomes of studies that compare smoking and vaping cannabis. This highlights the challenges in studying these routes of consumption in people. For instance, history and frequency of use, as well as natural puffing patterns, vary a lot across individuals and can impact how much of the cannabinoids make their way into the body and how long they remain.
In one study, when inhalation amount was tightly regulated, there were no clear differences in THC or other cannabinoids collected in blood between the two methods.
However, in one study of infrequent cannabis users (i.e., no use in the last 30 days), vaporization led to higher amounts of THC in the blood and more impairment across several cognitive, visual, subjective measures, when compared to smoking.
Similarly, a separate study investigated how smoking versus vaping impacted appetite- and metabolism-related hormones after eating a standard breakfast. While both smoking and vaping cannabis blunted insulin levels, smoking cannabis led to a stronger reduction in insulin 15 minutes after use.This reduction in insulin may partially explain the low rates of type II diabetes among regular cannabis users, a disease that stems from excessive insulin release that eventually leads to insulin resistance.
Which is better? Smoking or vaping?
The EVALI scare in 2019 tainted the safety reputation of vaping in the minds of the public, the media, and the research community. And there are definitely big risks to consuming vitamin E acetate and potential risks with other additives to vape cartridges. Still, it’s important to distinguish between vaping cartridges and vaping flower or pure cannabis extract.
Cartridges from the illicit market carry the highest risk of contamination. While most cartridges no longer contain the vitamin E acetate that contributed to hospitalizations and deaths during the EVALI outbreak, illicit vape carts continue to circulate without testing or regulation for their ingredients.
Cartridges from the regulated market are less likely to have these known toxic contaminants but may have other flavorings and fillers that aren’t well studied. No research confirms that these are safe to inhale.
To add to the complications, studies comparing the long-term safety and health effects between smoking versus vaping often capture a use period when unregulated products were more readily available. This makes it difficult to draw conclusions regarding the long-term safety of vaping in general.
Still, most of the known risk factors for vaping are related to vaping cartridges.
When we consider vaping flower or pure concentrates, we have much less evidence for harm – and some evidence for harm reduction over smoking.
Those looking to vape without the risk from fillers found in cartridges can get a vaporizer that works with flower, or undiluted concentrates. Vaping devices like the Storz & Bickel Venty or the Pax Plus offer easy options for flower vaporization. See also: Arizer, or GPen. For those who prefer concentrates, the Puffco New Peak and Dr. Dabber Boost Evo are excellent options for electronic dabbing.
There are even small devices like Puffco’s Plus and Dr. Dabber’s Light portable dab pens, that mimic the size, feel and discretion of a cartridge pen. Of course, you don’t have to choose between flower and extract. Options like the Dr. Dabber Switch or the Puffco Proxy allow you to switch between vaping cannabis flower and concentrate on the same device.
Smoking or vaping anything can come with risks. But in the end, the biggest risk factors for vaping seems to come not from the cannabis, but from the substances added to it. Sticking to a regulated market, reputable brands and products that are 100% cannabis is a great way to lower your risks and avoid outcomes like EVALI.
