Vape pen lung disease has insiders eyeing misuse of new additives

Published on August 30, 2019 · Last updated July 28, 2020
illegal vape carts, dangers in vaping, health concern
(Alpgiray Kelem/iStock)

UPDATED Mon. Sept. 9 at 8 a.m. PST

SAN FRANCISCO—During alcohol prohibition, drinkers had to worry about getting sick and dying from “bathtub gin.” This week, vapers are learning of similar quality control issues with cannabis oil vape cartridges purchased on the illegal market.

People were vaping illicit cannabis carts last year without ending up in the hospital. So it makes sense to ask: What has changed?

A rash of tainted THC vape cartridge poisonings is thought to have claimed one life in Illinois and caused lung inhalation injuries to as many as 215 people in 25 states, according to a Centers for Disease Control (CDC) conference call last Friday, and updates Aug. 30.

California now has 24 suspected cases of the hyper-inflammatory lung response, first identified by doctors in the Central Valley town of Hanford on Aug. 14 after recognizing that seven young adults had all suffered from sudden acute respiratory distress in the past month. The common thread: Each patient had purchased disposable, THC-filled vaporizer cartridges from illegal street markets.

Nearly all cases in illegal states

Most importantly, no cases are associated with adult-use or medical cannabis products from legal state-licensed stores. Almost all affected states do not have adult-use legalization in effect. They include Connecticut, Illinois, Indiana, Iowa, Minnesota, Michigan, North Carolina, New Jersey, New Mexico, New York, Pennsylvania, Texas, Utah, and Wisconsin. Additional states are pending verification. The California incidents occurred in Kings County, which has banned licensed cannabis stores.

Reports indicate that severe acute respiratory distress resembling lipoid pneumonia followed the repeated use of tainted carts. The patients’ heavily inflamed, fluid-filled lungs lost function and sometimes failed. Two patients in California required mechanical ventilation. Steroids knocked down the lung inflammation, but recovery has taken weeks of hospital care. Some patients may have permanent lung damage.

West Coast Carts, Dank Vapes named

Public health officials have interviewed patients and obtained samples of tainted products in California, Wisconsin, Illinois, and other states. Officials in each state plan to analyze the seized carts. The California Department of Public Health had no test results to share as of Friday morning.

In Hanford, a small county seat south of Fresno, officials released a photo of one patient’s brand, called West Coast Carts.

Tainted vapor: One victim in central California inhaled THC oil vapor from the illegal West Coast Carts brand. (Courtesy Kings County Public Health)

In Wisconsin, a family member of a victim there said another suspected tainted cartridge came from an illicit-market brand called “Dank Vapes.” Medical and adult-use cannabis products are not legal in Wisconsin.

Neither brand is traceable to a single company. Outside of a state-regulated system, anyone can order vape packaging and fill it with their choice of ingredients.

The CDC is not sure whether the national reports are all linked to a common contaminant or a combination of toxins. Officials are not sure if every patient has the same illness or when the series of respiratory injuries really began. They’re just starting to coordinate information collection among the states, agency officials said last Friday.

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“The bottom line is there’s a variety of things in e-cigarette aerosol that could have implications for lung health,” said CDC Deputy Director Dr. Brian King.

What could taint the carts?

Consumers have used disposable vaporizer cartridges with standard additives—propylene glycol, vegetable glycerin, or medium-chain triglyceride (MCT) oil—for many years. That alone gives regulators pause. Earlier this month, officials at the US Food and Drug Administration proposed adding propylene glycol as a respiratory toxicant to its list of “Harmful and Potentially Harmful Constituents in Tobacco Products.” FDA officials have also proposed regulating all e-cigarette ingredients by 2022.

A new type of additive started showing up in vape carts in late 2018.

Past lab tests have also caught pesticides, residual solvents, heavy metals, and synthetic cannabinoids in illicit-market cannabis vape carts. Yet we’ve never had clusters of life-threatening lung injuries like we’re seeing this summer.

We don’t know what precipitated the current health crisis. But we do know people used illicit cannabis vape carts last year without ending up in the hospital. So it makes sense to ask: What’s changed recently in the street vape cart market?

New ‘Thick’ cutting agents under scrutiny

Industry insiders who track the legal and illegal vape cart markets closely tell Leafly that a new type of additive started showing up in late 2018, and has since become widely used in underground markets. It’s a novel class of odorless, tasteless thickening agents. These liquids come in different proprietary formulations manufactured by both legal, above-board companies and by shadowy underground operations.

This new additive may or may not play a role in the current health crisis. But it is one of the major new ingredients in illegal vape cart oil in widespread use this summer.

Big profit incentive

Cannabis is a $52 billion US industry, according to a 2019 estimate by the RAND Corporation. Legal state-regulated sales represent $11 billion of the total—only 21%. That leaves a massive $41 billion illegal market open to anybody willing to take the legal risks necessary to supply it. Demand for vape carts has also surged nationwide.

“It’s fraught with problems—this sort of thickening agent. ... what the heck do you think it’s going to do to your lungs?”

The cannabis oil extracted from plant material doesn’t go straight into a THC vape cartridge. Cutting agents, also known as diluents, are liquids that chemists mix with the cannabis extract to create a consistent viscosity within the cart. Diluents also allow unlicensed manufacturers to stretch their supplies of THC oil.

In legal state-regulated markets, vape carts undergo mandatory lab testing to insure potency and purity. But in the illegal markets, anything goes. As a result, some consumers of illicit carts have learned how to spot watery oil cut with traditional propylene glycol, vegetable glycerin, or MCT oil. Without the assurance of lab testing, vapers often judge the THC potency of a cart by looking at the thickness of the oil in the chamber. Thick oil has become a proxy for purity. Thin oil is a red flag.

Cart makers in the illegal markets know this. Some have responded by adding new cutting agents designed to mask the dilution. Instead of thinning oil, these new substances thicken it.

Proprietary formulas, untested on lungs

“No one knows what this stuff is made of, and [the manufacturer’s] own safety sheets say, ‘Don’t use this with high temperatures,’” said Peter Hackett, the owner of Air Vapor Systems of Concord, CA. Hackett’s company supplies diluents to cannabis cart manufacturers nationwide. “It’s fraught with problems—this sort of thickening agent. If you’re going to take some solution that thickens up solutions, what the heck do you think it’s going to do to your lungs?”

“We don’t sell a thickening agent because of this issue,” Hackett told Leafly.

A trend that started in Los Angeles

If the past dynamics of the cannabis industry hold true, trends in vape additives likely began in Los Angeles and emanated nationwide.

Hackett points to downtown LA, the epicenter of the US street cart market. Warehouses in LA will sell you empty carts and preprinted packaging to stick them in, fresh from China. A pack of 100 empty glass tank carts and counterfeit packaging—ripping off Cookies, a highly regarded legal cannabis brand—runs $18 on

As Hackett puts it, “The illicit market in California is the source market” for every other place in the country. “So whatever happens in downtown Los Angeles starts becoming replicated by industrial and commercial supply houses throughout the country.”

Los Angeles ‘pen factories’

In “pen factories,” illicit market manufacturers fill thousands of these illegal carts per day with mixtures of street-grade THC oil, cutting agents, and flavorings. Distributors then wrap them in professional-looking packaging and ship them to illicit pop-up markets in California and beyond. The suspected tainted carts seized in the Hanford, CA, investigation—labeled West Coast Carts—read “80-85% THC,” “lab tested,” and “100% Dank.”

Any illegal cart maker can claim “lab tested” on the label. But only legal state-licensed products are actually lab tested. State law requires manufacturers to post test results on product labels.

In California, a legal label often looks like this:

Legal additive, off-label use

As health officials investigate the source of the lung injuries, another possibility includes legal substances used incorrectly. Think of an extreme version of off-label use, where a physician prescribes a legal medication for a condition beyond the drug’s intended use.

“Nothing is proven to be safe for vaping. We are aware that people are using it for that use. We don’t recommend or direct them to do that.”

That can put the legal makers of these products in a bind. For example, consider the case of True Terpenes, a leading manufacturer of terpenes and diluents based in Portland, OR. Their products are meant for specific purposes. But they have no control over the uses to which their customers put the products once they’re shipped.

Ben Disinger, the company’s marketing manager, told Leafly their leading diluent brand, Viscosity, is “recommend for use in winterized extracts.” (Winterizing means removing the extract’s fats and waxes.)

Disinger said that one recommended use of Viscosity is for diluting THC oil in cannabis balms and lotions meant to rub on the skin, not for ingestion or inhaling. Using such a diluent in vape pens, he said, is not an approved use. Burning or inhaling Viscosity might or might not be harmful, he said, but the company has no data either way.

“Nothing is proven to be safe for vaping,” said True Terpenes Chief Science Officer David Heldreth. “We are aware that people are using it for that use. We don’t recommend or direct them to do that. We don’t inherently believe there will be a danger, but it’s not something we can speak directly to because no one can.

Similarity to mineral oil poisoning

In some media stories and online cannabis forums, discussion has centered around the possible mineral oil content of some thickening diluents. The Washington Post reported that one Utah patient’s lung injury looked a lot like mineral oil poisoning, and symptoms mirrored medical literature on a phenomenon known as lipoid pneumonia, or oil pneumonia, which can be caused by inhaling petroleum oils. (Read up on lipoid pneumonia from mineral oil here, and here.) Mineral oil is a petroleum product; it’s an ingredient in Vaseline and many baby oils.

Ben Disinger made it clear to Leafly that True Terpene’s Viscosity product did not contain the stuff. “It is not mineral oil, no,” he said.

Use it for this, not for that

It can be difficult to discern the use limitations of these products. The True Terpenes web page makes it clear that Viscosity is “NOT to be used with CBD products,” but mentions nothing about THC products. True Terpenes does not state on its website that Viscosity is meant for diluting cannabis topicals, not oil in vape carts.

Similarly, another manufacturer, the Ypsilanti, MI-based Floraplex Terpenes, also offers a proprietary diluent known as Uber Thick. Described as a “naturally derived uber viscous terpene diluent,” the manufacturer suggests using the product to “control the thickness of your products.”

A certificate of authenticity posted on the company’s website states that Uber Thick has a boiling point of 554 degrees Fahrenheit. The optimal range for the vaporization of cannabinoid oils is 280-350F. But varying battery voltage, atomizer quality, wick quality, and oil quality results in a much wider range of operating temperatures. Vaping devices can run from sub-300 degrees to 800 degrees and above. Consequently, any setting above 554°F could potentially transform Uber Thick diluent into an aerosol with unknown implications for respiratory health.

On Floraplex’s posted safety data sheet, the company warns that “excessive thermal decomposition at very high temperatures can lead to the release of irritating gases and vapors.” Does irritation occur only when the diluent is in its pure form, or when mixed with cannabis oils or other substances? No one knows. Additionally, the same data sheet acknowledges the company has no data available on the product’s acute inhalation toxicity.

Floraplex Chief Science Officer Jared McKinney told Leafly that vape pen cartridges are not an approved use for Uber Thick.

“We don’t sell it for vaporization, but that’s what some customers use it for,” he said. “Whether it would be bad or good, we can’t say either way.”

Last year’s trendsetter: Honey Cut

Floraplex, True Terpenes, and competitors like Abstrax, Peak Terpenes, and, operate legally and openly. Terpenes sold by companies in this market segment go into a wide variety of products ranging from beer to cannabis to ice cream. They may be used to adjust a product’s fragrance, flavor, or viscosity. Commercial manufacturers have used terpenes safely and legally for decades.

However, other terpene and diluent makers operate in the shadows. Full health data may not be available from companies producing above-board products, but underground manufacturers post no safety data sheets at all. They don’t even want their location known.

Peter Hackett of Air Vapor Systems and Disinger and Heldreth of True Terpenes both mentioned the recent introduction of a novel diluent thickener called Honey Cut. The product swept through LA’s pen factories late last year. Honey Cut maintains a website, but the identity of the product manufacturer remains unknown, as does the chemical makeup of the substance. Leafly has made many attempts to reach officials at Honey Cut, but they have chosen not to respond.

Honey Cut’s introduction last year proved so popular that competing products by other diluent makers soon began appearing.

Unlicensed LA Dispensary Sold Pesticide-Tainted Cannabis, City Says

“There’s tons of them and those are the ones [we know about] who have a Squarespace web page,” said Heldreth, chief science officer at True Terpenes. Others, he said, are “just selling on a corner into vape shops.”

“Who knows what people are putting into these products,” he added.

Disinger said in-house lab tests done by True Terpenes on Honey Cut led company officials to suspect a substance known as tocopherol-acetate, usually found in skin creams. The National Institutes of Health database states that inhaling tocopherol-acetate can cause wheezing, coughing, shortness of breath, and burning in the mouth, throat or chest, and could potentially lead to hospitalization.

Stronger dilutions

Importantly, Peter Hackett also suspects pen factories may be diluting THC oil now more than ever in response to cannabis flower supply shortages in the California street market this summer. Cannabis flower comprises the raw material from which THC oil is extracted. Experts attribute current shortages to falling prices (which led some illicit farmers to stop growing) and California’s stepped-up campaign to end unlicensed growing and sales through civil enforcement actions.

Honey Cut proudly advertises its use in diluting vape pen oil up to 75%.

However, True Terpenes’ Viscosity should not account for more than 10% of a mixture, Disinger said. But street chemists might ignore the company’s advisory and use multiple times that amount. In an unlicensed, unregulated market it’s nearly impossible to know.

Disinger said cutting THC distillate by 80% with anything—Viscosity, Honey Cut, terpenes like pinene, or even water—“is not going to be a good idea.”

The complex mix of factors that go into the manufacture and use of a vape cartridge make the job of health investigators especially difficult. That’s doubly true in an illegal market. When an E. coli outbreak occurs, investigators usually have a clear trail of legal distributors, growers, and documents to aid in their search for a primary cause. Illegal vape cart makers mask their trail.

In California’s Cannabis War, Civil Is the New Criminal

Also, hotter vapes

Joshua Richard, an official with Anresco Laboratories, a San Francisco-based food and cannabis testing lab, says the culprit “might be a combination of everything.”

“It may be diluents technically safe to use as specifically directed,” he told Leafly. “But if they’re buying the cheapest vape carts that are burning hot or whatnot, with god knows what other contaminants in there—none of this makes your lungs happy.”

Dale Gieringer, co-director of California NORML, has watched the evolution of vaporizer technology since the earliest introduction of the Volcano, the German-made product that remains the gold standard for high-end hardware.

What pains Gieringer about the current scare is the fact that long-term studies on the lung health of cannabis flower smokers show no comparable ill effects. Gieringer himself has published studies on vaping buds at 385°F in a Volcano, which he found to be “safe, safe, safe.”

By contrast, Gieringer notes the paucity of health studies on modern diluents, or analysis of any chemical changes that might occur when they become heated or burn in a vape cart.

“The thing about some vape carts is the temperature can run considerably higher than burning flower, and you could be forming new chemicals that you would have never gotten before,” he told Leafly.

Still the wild west

In conclusion, all of these factors remain in play this week as local and national health authorities hunt down the source of the severe respiratory ailments.

Dr. Mitch Zeller, FDA Director of the Center for Tobacco Products, wondered last week if the vape products in question were “used as intended or was some other compound added? Those kind of facts need to be strung together for every single one of these cases so that we can see if there are any kind of patterns that emerge.”

“We believe we need to regulate these additives,” said True Terpenes’ Heldreth. “Unfortunately it takes someone getting hurt for people to take things like this seriously.” He said company officials have begun reviewing both their marketing and sales channels in light of the current rash of respiratory distress incidents.

“We stand by our products and we encourage everyone to do their own testing. It’s still the Wild West, and there is still a lot of misinformation out there,” said Disinger.

Leafly will continue to update this story as it develops. Read the first chapter here.

Related reading: Vape cart lung distress

UPDATE Tues. Sept. 3 at 12 p.m. PST—On Friday, the CDC specifically warned consumers about bootleg THC vape carts, as more evidence indicated the outbreak stems from adulterants in the illicit market.

New York State data confirmed the presence of at least one type of suspicious adulterant—vitamin E oil, aka tocopherol-acetate—in that state’s street market. The FDA stated Friday that it is testing 80 suspected tainted vape carts.

And more medical information trickled in about sufferers.

Street market source update

California has tallied 44 cases, and state officials there said patients reported purchasing vaping materials from street vendors or pop-up shops (temporary, unregulated, unlicensed sellers) and warned “vaping products are poorly regulated and may contain or generate chemicals that are unsafe and potentially cause illness.”

New Mexico reported 8 suspected cases, all linked to bootleg THC carts.

The AP reported Thursday that 9 out of 10 suspected Wisconsin cases come from illicit market vapes containing THC.

Utah, Wisconsin, and Minnesota doctors have all pointed to adulterated THC oil from the street. Ditto in Long Island, New York. New York has reported 27 suspected cases.

The legalization state of Washington reported no cases as of Friday. Health officials there stated: “Anyone who uses e-cigarette products should not buy these products off the street and should not modify e-cigarette products or add any substances that are not intended by the manufacturer, including THC products and other cannabinoids.”

Colorado reported two in the Denver area. A health official there stated: “vaping products are poorly regulated and may contain or generate chemicals that are unsafe and potentially cause illness.”

Prohibition also appears to be hindering medical responses, because patients often lie to doctors to avoid incriminating themselves in federally and state-illegal cannabis use. “Treatment has been complicated by patients’ lack of knowledge—and sometimes outright denial—about the actual substances they might have used or inhaled.”

Suspect additives update

Washington Post on Friday also confirmed the CDC is looking at adulterants.

“What’s likely causing the harm is something that they are putting in to make it easy or cheap to mix,” said former FDA Commissioner Scott Gottlieb.

Gottlieb went to twitter to emphasize “It’s probably something new that has been introduced into the market by an illegal manufacturer, either a new flavor or a new way to emulsify THC that is causing these injuries,” he said.

The Times Union reported vitamin E oil, aka tocopherol-acetate in “nearly all” the New York cases. Anyone can buy vitamin e acetate online with a google search and a credit card. A 38-pound pail of it runs $21.54.

And another doctor told the Times he suspects the misuse of vegetable glycerin. Mr. Eissenberg, director of the Center for the Study of Tobacco Products at Virginia Commonwealth University said “A common ingredient was vegetable glycerin, which is made from vegetable oil,” he said. “If there is some incomplete process, there can be oil left in the vegetable glycerin when that person is using it, and inhaling oil and getting oil into your lungs is what is causing some of the lung injuries we see.”

Medical updates

One professor of pulmonary and critical care suspects “at least three distinct manifestations of vaping-associated pulmonary injury: lipoid pneumonia, cryptogenic organizing pneumonia, and alveolar hemorrhage syndrome. ‘For me, the main importance of that finding is that it suggests the immune system is being revved up,’ he said.

A Utah woman went public with her suspected case of vape-related acute eosinophilic pneumonia. Doctors suspect fatty deposits in her lungs (from the additive propylene glycol) caused a severe immune system reaction. Utah has adult use cannabis prohibition, and non-functional medical use.

Illicit market size, user advice

Thousands upon countless thousands of potentially adulterated THC vape carts are on the streets of the East Coast, based on reporting of busts there Tuesday.

Speaking to the black market in New York: “I can buy these oils like a bag of potato chips,” one consumer told the Times.

Rolling Stone published how to spot a bootleg vape pen, noting: “big brand-name companies like Kingpen, PAX Era and Stiiizy don’t sell outside licensed shops in states with legal cannabis—if your dealer is offering them, there’s a good chance they’re counterfeit, and filled with possibly contaminated distillate.”

UPDATE Mon. Sept. 9 at 8 a.m. PST—The CDC suspects 450 cases in 33 states with five deaths. California has 57 suspected cases. Los Angeles County health officials have dubbed the illness “VAPI“. The FDA thinks the national outbreaks are related.

Experts deplored the use of forms of vitamin E oil for inhalation.

A new New England Journal of Medicine article detailing a 53-patient cluster in Wisconsin and Illinois this summer noted the average age was 19. The Illinois spike is real. Steroids often work. The patient who died did not get steroids for 50 days. The survivors got steroids in the first week. Dank Vape comprised the majority of tainted carts. The NEJM concludes there’s a variety of nasty stuff we now about that can cause VAPI.

Mr Extractor owner Drew Jones confirmed to Leafly that Clear Cut is tocopheryl-acetate and he’s stopped selling it as a precaution. He said the Oregon Liquor Control Commission knowingly permitted him to use it. The product and its knock-offs are in 60-70% of pens nationwide, he said.

In San Francisco, cannabis brand Constance Therapeutics reports it has a patent for natural vitamin E oil (alpha-tocopherol) for use in a vape pen. They believe it to be safe. However she called acetate, “a synthetic cheap form of vitamin E implicated in lung problems potentially”. The company said others were “[knock-offs] with cheap, inferior, and harmful substitutes.”

Doctors in Utah believe they may have identified a key marker for VAPI—a rare type of fat-laden immune cell. Doctors found lipid-laden macrophages in all six of Utah’s patients. Now doctors are wondering if the rare cells are unique to VAPI sufferers, or if all vapers are making these rare cells.

“When vaping-related lung injury is suspected and infectious causes have been excluded, the presence of lipid-laden macrophages in BAL fluid may suggest vaping-related lung injury as a provisional diagnosis.”

According to the Washington Post, “vitamin E acetate is basically grease, said Michelle Francl, a chemistry professor at Bryn Mawr College. Its molecular structure means that ‘you have to heat it up pretty hot’ for it to vaporize. Its boiling point is 363 degrees Fahrenheit, which is well above the 212 degrees F boiling point for water. Once the oil is heated hot enough to vaporize, it can potentially decompose, and ‘now you’re breathing in who-knows-what,’ Francl said.”

Medical cannabis book author Michael Backes stated: “Using tocopherols as a carrier just seems so intuitively dumb, that I have a tough time hearing “expert” opinions on their safety, especially when those opinions are coming from sources that have historically taken any thread of scientific evidence to justify their lucrative business practices. Letting amateurs or well-intentioned fools design derivative products to be heated for inhalation seems to be a disaster waiting to happen and now one has happened.”

Jones at Mr Extractor estimates 60-70% of the US street cart supply might contain some form of vitamin E oil. Floraplex CEO Alex Riffle estimates 50 million street cartridges contain it.

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David Downs
David Downs
Leafly Senior Editor David Downs is the former Cannabis Editor of the San Francisco Chronicle. He's appeared on The Today Show, and written for Scientific American, The New York Times, WIRED, Rolling Stone, The Onion A/V Club, High Times, and many more outlets. He is a 2023 judge for The Emerald Cup, and has covered weed since 2009.
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