For the media-literate amongst us, you may have noticed some alarming headlines popping up recently about vaping possibly causing a horrid thing called "Popcorn Lung".

Here are three I found published just in the last week.

From http://www.laboratoryequipment.com:

From fox6now.com:

From www.care2.com:

Gah! All so scary! So let's examine this torrent of information to see if there's any truth to it.

What is Diacetyl?

Diacetyl is the artificial flavouring responsible for that "buttery" flavour we all know and love.

More technically, "Diacetyl (IUPAC systematic name: butanedione or butane-2,3-dione) is an organic compound with the chemical formula (CH₃CO)₂. It is a yellow/green liquid with an intensely buttery flavor. It is a vicinal diketone (two C=O groups, side-by-side) with the molecular formula C₄H₆O₂. Diacetyl occurs naturally in alcoholic beverages and is added to some foods to impart its buttery flavor" (thanks Wikipedia!).

Although it has a scary name, Diacetyl is a naturally occurring compound. It is mainly a by-product of some fermentation processes, and along with its good friend Acetoin is naturally present in actual real-life butter.

Unfortunately for a number of factory workers in a Missouri microwave popcorn manufacturing plant, inhaling airborne Diacetyl vapours caused them to develop bronchiolitis obliterans, a disease every bit as nasty as it sounds.

What is Popcorn Lung?

Popcorn Lung is what bronchiolitis obliterans is more commonly known as. It was called "popcorn lung" or "popcorn worker's lung" as it came to public awareness thanks to the poor souls in the aforementioned Missouri microwave popcorn facility back in 2000.

Popcorn Lung is "a rare and life-threatening form of non-reversible obstructive lung disease in which the bronchioles (small airway branches) are compressed and narrowed by fibrosis (scar tissue) and/or inflammation" (thanks again Wikipedia). It is progressive, non-reversible and the only way to treat it is with a lung transplant.

As far as lung diseases go, this one is a doozey and should definitely not be on your bucket list.

What does any of this have to do with e-liquid?

Since Diacetyl is a widely used artificial flavouring, it was initially used in e-liquids that needed a buttery flavour. This posed an obvious problem because - y'know, bronchiolitis obliterans and stuff. And although most reputable and responsible e-liquid manufacturers have not used Diacetyl in their e-liquids for years, the fact remains that it has been found in some e-cigarette products.

Fast-forward until now and the media have suddenly decided they need something new to scare people away from vaping, hence such startling headlines of late. But the fact remains that if you do vape e-liquid that contains Diacetyl for extended periods of time, you are at risk of the dreaded Popcorn Lung.

I want to vape, but I REALLY don't want to get Popcorn Lung. What should I do???

Fear not my young padawans. There are some very simple steps you can take to keep on vaping and ensure you don't end up with an irreversible chronic obstructive pulmonary disease that will leave you requiring a lung transplant.

As mentioned above, most responsible e-liquid manufacturers ceased using Diacetyl as a flavouring as soon as they realised the potential danger. Unfortunately, not all e-liquid manufacturers are responsible; some don't use proper QC methods, some don't mix in a clean room, and some don't pay very much attention to the safety of the ingredients they use.

So my top tips to stay safe when buying your e-liquid are:

1. Avoid buying e-liquid from countries without rigorous QC standards.

Your safest bet is buying either Australian or U.S.-made e-liquid.

2. Only buy from vendors with a high trust factor.

Any fly-by-nighter can throw a few ingredients together in a shed. Pick a brand with a solid reputation either by way of social media or trusted third-party review sites.

3. Check the ingredients list.

If you've picked a good vendor, the ingredients will be listed on the bottle. If they aren't - contact them and ask. If you aren't satisfied with their response - go elsewhere.

4. Avoid "buttery" flavours.

If you want to be extra-careful, you can just avoid buttery flavours altogether. This suits some people who prefer fruity or spicy flavours just fine, but could make life difficult for those of us who just love our pastry and custard flavours.

5. Mix your own e-liquid.

Again, there are great swathes of vaping enthusiasts who do this because they want to. If you are the one adding the ingredients, you can know with 100% certainty what's going into them - although, of course, you would still be well-advised to check off the above points with your flavouring supplier...

Oh no! I've just realised my all-day-vape contains Diacetyl! Am I going to suffer from a horrible and protracted illness?

Don't go asking your rellies to reach for their donor cards just yet.

The CDC, who investigated the Missouri popcorn factory case, noted that Diacetyl inhalation in high concentrations and/or volumes over an extended period were one factor in the development of the disease. They also noted that the mixers - who basically had their head over a big bowl of the stuff all day every day - had the worst of it, with the most severe symptoms developing after 12 months of continuous exposure of this kind (check the source here).

There was one reported case of a man contracting Popcorn Lung from eating microwave popcorn. This particular guy ate two to three bags of extra-buttery popcorn every day for a decade.

Lastly, it is common knowledge in medical circles that the disease is rare, and may even be idiopathic (medical speak for "no idea how it happened"). It's also not a guarantee that inhaling Diacetyl vapour will give you the disease - it simply puts you in the risk category.

In all likelihood, unless you're already experiencing the symptoms of wheezing, shortness of breath and difficulty exhaling, you're probably in the clear, and discontinuing use of your Diacetyl-laden e-liquid will be enough to keep you there.

So there you have it, folks - the skinny on Diacetyl, Popcorn Lung, e-liquids and not needing a lung transplant. Remember that if you hear a scary headline telling you e-cigs will kill you, it always pays to get to the source and get the facts straight. Because in this case, as in so many others, the facts don't seem to have gotten in the way of a good news story.