A new report from the Centers for Disease Control (CDC) has identified the cause of the recent E-cigarette or Vaping product use–Associated Lung Injury (EVALI) outbreak. This CDC report doesn’t delve into the history or causes of EVALI, but it does identify a likely potential cause as Vitamin E acetate, an additive used to dilute THC oil vape cartridges. No nicotine-related cause has been found, and the additive appears restricted entirely to THC oil vapes, and not any kind of nicotine e-liquid.
To understand the reasons why, we must first take a look at what Vitamin E acetate is used for. Also known as tocopheryl-acetate, vitamin E oil has been sold for years as an additive for hand creams and even for some food products. This fluid is thick, and almost precisely matches the thickness of THC oil. Historically, manufacturers of THC oil cartridges used PG or VG, common vape ingredients, to dilute their THC oil. This “cutting” is sometimes used as a cost-saving measure, and other times is used to bring the potency down to acceptable levels. However, PG and VG have a lower viscosity than THC oil, and so customers learned to turn their cartridge over and watch a bubble move through the liquid: a fast-moving bubble meant the product was cut, a slow-moving bubble showed it was not.
In 2015, a California medical cannabis company applied for a patent on the use of alpha tocopherol to dilute THC oil. The alpha tocopherol possessed the critical difference from PG or VG: it matched the viscosity of THC oil, and thus could be used to defeat the “bubble test”. Within a few years, a copycat had entered the market: vitamin E acetate, which has the same viscosity as alpha tocopherol, and thus seemed perfect for manufacturers looking for a non-patented THC cutting fluid.
Unfortunately, vitamin E acetate (tocopheryl-acetate) is not chemically the same as alpha tocopherol! The manufacturer datasheets for vitamin E acetate warn specifically against inhalation, and studies have shown inhalation of vitamin E acetate can and does damage lung function. But in the spring of 2019, a formulation containing 90% - 95% tocopheryl-acetate was released to the market, and almost immediately it took the THC vape world by storm. Any manufacturer who wanted to undetectably dilute the THC oil in their product could - and many of them, particularly black market or otherwise illicit producers, did just that.
The first reported cases of EVALI came in mid-July, just months after vitamin E acetate formulations entered the market. The common element quickly found amongst the growing number of those affected was that most admitted to vaping. Unfortunately, questioners often didn’t ask the follow-up question of what those afflicted were vaping.
To the average person, vaping is vaping, but there’s a critical reason that EVALI hasn’t been tracked to nicotine-containing vape juice, and that’s because the entire reason for tocopheryl-acetate as an additive simply doesn’t apply to nicotine vape juice. A manufacturer wouldn’t “cut” the active ingredient with vitamin E acetate (tocopheryl-acetate), because the active ingredient comes in extremely specific, customer-facing amounts, like 3 mg per ml. The “dilution” in this case simply involved using less PV or VG, and more nicotine!
Reputable nicotine-containing e-liquid manufacturers were required more than two years ago to list any and all products (and their specific constituent components) with the FDA. These manufacturers are disallowed, by law, from changing those formulations in any way. That happened more than 2 years prior to the introduction of vitamin E acetate, so no reputable nicotine e-liquid manufacturer could use tocopheryl-acetate, and even not-reputable manufacturers would simply never have any reason to.
Unfortunately, by the time the culprit of EVALI was identified by the CDC, the Food and Drug Administration (FDA), state and local health departments, and multiple public health and clinical partners, in their groundbreaking report, much of the damage to public perception had been done: many people simply conflated THC vaping with nicotine vaping, not realizing that the two use almost entirely different chemical compositions and delivery systems.
Fortunately, while the CDC has not yet offered any guidance for THC vapers to be able to determine if their product contains vitamin E acetate, with the release of this report, nicotine vapers may now breathe more easily knowing that the cause of this terrible illness has potentially been identified, and that the only action necessary to avoid EVALI is to not vape THC cartridges.