Rumor has it there's a nasty side effect to vaping cannabis called 'Popcorn Lung'. We're here to help set the record straight. We thought it would be useful to unpack the question after reading a similar discussion over on Reddit.

First, we have to consider people talking about 'vaping' may be talking about vaping e-cigarettes, not vaping cannabis. Right there is a proverbial fork in the road. Popcorn Lung is associated more with e-cigs than with cannabis. As far as we can tell, there is little to no concern about getting this gnarly condition with cannabis. Weed vapers can go on with their day without worrying.

For the sake of conversation, let's look at it anyway. This concern comes originally/primarily from the following research paper from the National Institute of Environmental Health Sciences.

"Flavoring Chemicals in E-Cigarettes: Diacetyl, 2,3-Pentanedione, and Acetoin in a Sample of 51 Products, Including Fruit-, Candy-,and Cocktail-Flavored E-Cigarettes" and serves as an excellent example of antismoking bias and deception now turned against vapers.

The main culprit behind popcorn lung is Diacetyl, a yellow/green liquid with buttery flavor. You know those buttery chardonnays? They get their flavor from diacetyl. Heck, even microwave popcorn gets its buttery flavor from diacetyl. In the world of e-cigs, those fruity flavored vape oils are made with diacetyl.

Workers working in the production facilities have the highest exposure to breathing in diacetyl, and thus are the most likely to developing popcorn lung.

    <p class="shortcode-media shortcode-media-rebelmouse-proxy-image"><img src="https://media.rbl.ms/image?u=%2Fblog%2Fwp-content%2Fuploads%2F2015%2F12%2F621x470_566966eeb93795931a8b4663-144974888396.jpg&ho=http%3A%2F%2Fwww.saludtoday.com&s=158&h=99d7635e6dbdb53237446f709969d914f2dca2b9f5c92823f7f6c3073ed4972b&size=980x&c=2511379024" id="cc57b" class="rm-shortcode" data-rm-shortcode-id="EHIZUV1490723760" ><small placeholder="add photo credit..." class="image-media media-photo-credit">photo: saludtoday.com</small></p>
    <p>The study notes that the lowest level of exposure at which popcorn lung was detected in workers working for 8 hours per day was 0.2ppm. We believe that works out to 200 mcg/Liter. that's 200,000 micrograms per cubic meter. At about one meter average working air intake per hour, it was found that workers inhaling 1,600,000 micrograms of diacetyl every day for years began developing popcorn lung.<br></p><p>Conversely, e-cig vapers inhaling flavored e-cigarette oil made with diacetyl are exposed to about 10 micrograms, a fraction of the factory workers. It would feasibly take years of puffing to have a chance at developing popcorn lung.</p><p>So in summary, people who vape cannabis needn't worry about developing popcorn lung, however, they will want to be educated in the event cannabis oil makers start adding flavoring to their oils. The nascent cannabis industry is just starting to figure out the best ways to make beautiful pure plant extracted oils with fractional distillation and winterization. It's possible someone along the way will try to cut corners on an oil that could end up on dispensary shelves.</p>