It’s 1930 — the height of Prohibition. Thousands of people contract a terrifying illness. Paralysis takes hold of their hands and feet. The muscles in their fingers and legs atrophy. Disabled, many resort to begging in the streets.
Authorities connect the epidemic to Jamaican Ginger, a popular alcohol extract. Manufacturers have cut Jamaican Ginger with a neurotoxic compound, triorthocresyl phosphate (TOCP). This masks alcohol content and reduces production costs. It also leaves thousands of people with “Jake Leg.”
It’s 2019. People across the country sicken and die from vaporized extracts. Scientists and government bodies desperately test samples to understand the cause. Those lucky enough to live suffer severe lung damage.
Vaporizer companies — whether cannabis or nicotine — have used cutting agents since inception. In 2015, The New England Journal of Medicine (NEJM) demonstrated that propylene glycol — a near-ubiquitous thinning agent — degrades to formaldehyde, releasing biocides when vaporized.  Biocides are great for industrial disinfection… less so for human lungs.
One group of scientists connected the chemical acrolein, found in weed killer, to e-cigarette vaporizing. Acrolein has the potential to damage DNA.
Earlier this year, investigations revealed the heavy metal lead (Pb) turning up in vape oil. Lead is powerful neurotoxin with no known safety. Chinese manufacturers add lead to vape parts to soften and shape the metal. But volatile components in the oil may erode the lead.
These concerns are a mere foreword to the current health crisis. Thus far, the Centers for Disease Control & Prevention (CDC) have documented 530 cases of lung injury and 7 deaths across the nation. Most victims used vape products with delta-9-tetrahydrocannabinol (THC), but some only used nicotine products.
At first, officials pointed to high levels of vitamin E acetate. Vitamin E sounds healthy — how bad could it be? Legitimate companies used this cheap thinning agent for vape carts in good (or bad) faith.
But vitamin E acetate is lipid/oil-based. Inhaling lipids is inherently dangerous. It can easily lead to a condition known as exogenous lipoid pneumonia (ELP), where fat accumulates in the lungs, causing a variety of pneumonia-like symptoms.  In the year 2000, a case study was published revealing ELP in a patient who had smoked “weed oil.”  The condition is also associated with accidental inhalation during the alternative health practice of oil-pulling. 
Nonetheless, this epidemic is not your typical ELP. It is far more severe and dangerous. Plus, not all cases have been linked to vitamin E acetate.
Immune cells in certain patients have shown up saturated in fats. But most pulmonary scans of the victims lack the characteristic ELP fat build-up; according to the NEJM, “We have not observed the computed tomographic finding of fat attenuation in the lung, which is a hallmark of lipoid pneumonia…”  Patients have also demonstrated stomach and liver problems. 
So what is it? We don’t know yet. Terms like “acute lung injury” and “vaping-associated lung injury (VALI)” have gained favor. Speaking to Scientific American, pulmonologist Sean J. Callahan posited that if an unknown contaminant inflamed the lungs to a high degree, “the lipids in the surfactant might break down and overwhelm the immune cells, filling them with fat.” Pulmonary surfactant is a lipid/protein mixture that helps the lungs exchange oxygen and carbon dioxide.  In other words, something in the vape oil caused such significant damage that natural surfactant degraded, dissolved, and appeared as fat/oil during the imaging. This led investigators to compare the condition to ELP.
One patient found their THC pen contained a cocktail of formaldehyde, pesticide, and vitamin E acetate.
It seems that one or more contaminants and/or one or more industry-standard cutting agents are acting in concert to produce a novel and catastrophic illness.
Legalization, Regulation, & Labeling
Calls for legalization — and scientific research — have ebbed into a chorus. Prohibition is dangerous. Cannabis legalization and research are fundamental. Product testing/analysis and comprehensive labels come next.
Consider the advent of nutrition labels. According to the Institute of Medicine, “The proliferation of ambiguous claims on labels and in advertising led to charges that the government was tolerating claims that were ‘at best confusing and at worst deceptive economically and potentially harmful.’”  Imagine a box of pasta that just says “Healthy!” on the front. No nutrition facts. No ingredient list. For all we know, this “pasta” is plasticized rat poison.
Welcome to cannabis.
Even if cannabis is legalized, public health and safety cannot endure a wild-west market. Stamping “healthy” on the box and calling it good does not work.
Cannabis flower may undergo pesticide treatment. Depending on soil, it may absorb heavy metals. Fungus is common to the plant. Extraction products rely on solvents, several of which are toxic. Incomplete extraction leaves lipids, which as we’ve noted, can cause ELP. Manufacturing and product design introduce various wild-card ingredients, such as vitamin E acetate or propylene glycol. Of course, the black market hosts a range of unforeseeable chemicals and contaminants.
It would be a mistake to destroy countless small businesses that depend on vaporizer products. A blanket ban is akin to prohibition. Prohibition breeds the conditions for “Jake Leg.” Instead, we must legalize, test, and label. In the meantime, it is imperative to avoid any black market vaporizer products.
If products are fully tested and labeled with every component, it is much easier to ensure an appropriate — and safe — experience. Beyond complete contaminant testing, cannabis labels should report additives, lipids, cannabinoids, and terpenes; indeed, labels should reveal every potential chemical constituent.
Legalization allows more comprehensive scientific research. Cannabis product producers must also test and publish ingredients. The lungs are too sensitive for guess work. Testing and labeling represent the application of science to bridge safety and efficacy. This is not politics, the economy, or wayward opinion. This is human lives.
Written by Lance Griffin, Staff Writer for Terpenes & Testing and Extraction Magazine
1. Jensen, R.P., et al. “Hidden Formaldehyde in E-cigarette Aerosols.” NEJM, vol.372, no.4, 2015, pp. 392-394. Journal Impact Factor = 70.67, Times Cited = 263 (ResearchGate)
2. Simmons, Ashley, et al. “Not Your Typical Pneumonia: A Case of Exogenous Lipoid Pneumonia.” Journal of General Internal Medicine, vol. 22, no. 11, Nov. 2007, pp. 1613–1616, doi:10.1007/s11606-007-0280-7. Journal Impact Factor = 3.701, Times Cited = 33 (ResearchGate)
3. Vethanayagam, D., et al. “Exogenous Lipid Pneumonia Related to Smoking Weed Oil Following Cadaveric Renal Transplantation.” Canadian Respiratory Journal, vol.7, no.4, 2000, pp. 338-342, doi:10.1155/2000/248915. Journal Impact Factor = 1.016, Times Cited = 27 (ResearchGate)
4. Kuroyama, M., et al. “Exogenous Lipoid Pneumonia Caused by Repeated Sesame Oil Pulling: A Report of Two Cases.” BMC Pulmonary Medicine, vol.15, no.1, 2015, doi:10.1186/s12890-015-0134-8. Journal Impact Factor = 2.721, Times Cited = 18 (ResearchGate)
5. Henry, Travis S., et al. “Imaging of Vaping-Associated Lung Disease.” New England Journal of Medicine, June 2019, doi:10.1056/nejmc1911995. Journal Impact Factor = 70.67
6. Layden, J.E., et al. “Pulmonary Illness Related to E-Cigarette Use in Illinois and Wisconsin – Preliminary Report.” NEJM, 2019, doi: 10.1056/NEJMoa1911614. Impact Factor = 70.67, Times Cited = 7 (NEJM)
7. Veldhuizen, Edwin J.A., and Henk P Haagsman. “Role of Pulmonary Surfactant Components in Surface Film Formation and Dynamics.” Biochimica Et Biophysica Acta (BBA) – Biomembranes, vol. 1467, no. 2, 2000, pp. 255–270, doi:10.1016/s0005-2736(00)00256-x. Journal Impact Factor = 3.7, Times Cited = 117 (ResearchGate)
8. Institute of Medicine. “History of Nutrition Labeling.” Front-of-Package Nutrition Rating Systems and Symbols: Phase I Report, edited by Wartella EA, Lichtenstein AH, Boon CS, National Academies Press, 2010, Washington, DC, https://www.ncbi.nlm.nih.gov/books/NBK209859/.
The State Museum of Pennsylvania
Leafly — Credit Andrew Hansen, Jordan Valley Medical Center