Vape Liquids and Cartridges: Composition and Risks

Urgent first

If someone has trouble breathing, chest pain, or severe shortness of breath after vaping any product, seek emergency care (911 in the US). Tell the clinician what was vaped. The FDA encourages people with vaping-associated respiratory illness to report it to their state or local health department. [1]

Quick answer

Vape liquids and cartridges are the form of cannabis concentrate most closely tied to a serious public-health event: the 2019 outbreak of lung injury called EVALI (e-cigarette or vaping product use-associated lung injury). The FDA and CDC recommend that people not use THC-containing vaping products, particularly from informal sources. [1] This page reports what public-health and laboratory sources found. It gives no instructions for use or preparation. The owner of this site does not sell cannabis products.

Evidence labels: evidence of harm (reported injury), insufficient evidence (not enough studies), mixed.

What EVALI was

The FDA said national emergency department data and state case reports showed a sharp rise in cases in June 2019, a peak in September 2019 and a gradual decline since. [1] Patients reported breathing difficulty, shortness of breath or chest pain, and some had vomiting, diarrhea, fever or fatigue. [1] The FDA said THC-containing vaping products, particularly from informal sources such as friends, family or in-person or online dealers, were linked to most cases. [1]

Vitamin E acetate

The FDA said vitamin E acetate is strongly linked to the outbreak: it was found in product samples and in patient lung fluid, and was not found in lung fluid of people without EVALI. [1] In FDA analysis as of February 12, 2020, about half of the THC products tested (511 samples contained THC) contained vitamin E acetate as a diluent, at concentrations ranging from 23% to 88% in a subset. [1] The FDA also stressed that evidence is not sufficient to rule out other chemicals. [1]

In a New York laboratory analysis of 38 samples from the first 10 EVALI cases with cartridges, vitamin E acetate was in 64% of the cannabinoid-containing fluids. The fluids had relatively low cannabinoid content, sometimes unusual ratios of delta-9 to delta-8 THC, and sometimes pesticides. [2] The label is evidence of harm for vitamin E acetate when inhaled; the full cause of every case is still described as uncertain by those authors. [2]

Other additives and degradation products

A mass-spectrometry study of about 300 cannabis vaping liquids identified a variety of additives beyond vitamin E acetate, including medium chain triglycerides, polyethylene glycols, squalane and pine rosin acids. [3] Pine rosin was also reported as an adulterant with inhalation toxicity concerns. [4] A 2025 review said concentrate vaping can emit toxicants such as isoprene, and noted research on health risks has lagged behind market growth. [5] A 2019 laboratory study found that heating THC, with or without added terpenes, produced degradants such as methacrolein, benzene and methyl vinyl ketone, and that added terpenes increased gas-phase products; the authors also found these were lower than in smoking. [6] These are laboratory findings, not measurements of harm in people.

Counterfeit and mislabeled cartridges

The New York study examined illicit cartridges recovered from patients and found relatively low cannabinoid content and many diluents, so the contents differed from what a consumer might expect. [2] No source read for this page measures how common counterfeit cartridges are now, so that is insufficient evidence. The same reasoning applies to packaging: a label, logo or QR code is not a laboratory result. See adulterated and mislabeled cannabinoid products and how to read a COA.

Special groups

People with asthma or other lung disease, teens, pregnancy and those with heart conditions have extra reasons for caution; see smoking and vaping cannabis risks and cannabis and adolescents.

Laws differ by country and state and change; this is not legal advice. See cannabis laws by country.