Dripping is awesome.

A little more hands-on and hard work than vaping with a tank, I’ll admit, but the flavour and clouds of vapour are hard to beat even with a sub ohm tank.

But if you’ve been reading the news over the last few weeks, you’ve probably heard another side to the story.

According to various articles, dripping is a new “fad” among teens, with about a quarter of teens who’ve vaped saying that they’ve tried it.

Turn that over in your mind for a moment. One in four teens who’ve tried vaping have supposedly dripped.

This is a practice that requires you to own a purpose-built atomizer, a spool of resistance wire, wicking material and several tools, not to mention having the ability to actually wrap and connect the coil.

If you think it’s a little fishy that a quarter of teens who’ve ever vaped – including those just experimenting – have actually gone to all this effort, you’re right to be suspicious.

The finding may come from a peer-reviewed study, but as most vapers have learned by now, that doesn’t necessarily mean it’s reliable.

In fact, as a comment from Professor Riccardo Polosa and PhD candidate Amelia Ruby Howard points out, the headline claim that a quarter of teens who’ve vaped have tried dripping is very unlikely to be true.

Why?

Because researchers have such a poor grasp of what dripping is they can’t put together an easily-understandable question about it.

What the Study Says

The study this all comes from is really quite straightforward.

In 2015, researchers gave surveys to over 7,000 students from high schools in Connecticut about their tobacco use, as well as their vaping habits.

They asked about past vaping, whether the students had tried dripping and if so, why they tried it.

In total, just less than 1,900 had tried vaping, but a lot of the students’ answers to the questions about dripping didn’t make sense. After removing close to 800 students for either being inconsistent or just not answering the dripping questions, there were about 1,100 students left.

Out of these students, 26.1 % said they’d tried dripping. They said they did it because it produces thicker clouds (63.5 % of the drippers), that the flavour is better (38.7 %), that the throat hit is stronger (27.7 %) and out of curiosity (21.6 %).

In the introduction to the paper and its discussion section, the authors also claim that dripping makes your e-cig put out more formaldehyde and similar chemicals. This claim is based on another study looking at dripping.

What is Dripping? A Guide for Vaping Researchers and Journalists

The media storm that resulted from this study was quite surreal to read as a vaper.

Not only did they do everything they could to make “dripping” sound like a form of drug abuse, almost every piece of coverage did a monumentally awful job of explaining what dripping actually is.

Most journalists’ explanations relied on how the researchers described it. Unfortunately, the researchers made it seem like dripping is applying e-liquid directly onto the hot coils of your e-cig and then huffing whatever fumes it gives off.

So as a public service to any journalists or researchers reading, here is what dripping really is.

E-cigarette tanks have two main parts: the tank section (which holds the e-liquid) and an “atomizer head.”

This atomizer head holds a coil and some “wick” material (usually cotton). The wick soaks up the e-liquid before it is vaporized by the coil. When you vaporize the e-liquid in the wick, the tank resupplies the wick with more liquid so you can continue vaping without getting a “dry hit.”

Dry hits are just what they sounds like: vaping without enough liquid in the wick. It makes your coil run hot and gives the vapour an unpleasant burnt taste.

Dripping is essentially the same as any other vaping, except that there is no tank to resupply liquid to the wick.

Instead, users directly apply e-liquid to the coil and wick while it is at room temperature (or at least not in use).

This soaks the wick, and means that when the coil is activated again, there is enough liquid in the wick to avoid dry hits.

Since there is no need for a tank, there are atomizers specifically designed for dripping (Rebuildable Dripping Atomizers – or RDAs, for short). These feature two posts for you to connect your coil to and a small “deck” for the tips of the wicks to sit in and soak up any extra e-liquid pooling there. You have to actually wrap your own coil and attach it yourself to use one of them.

There’s more detail on what dripping is and the different types of rebuildable atomizer here.

How Many Teens Have Tried Dripping? Not as Many as the Researchers Think

Professor Polosa and Amelia Howard’s comment opens by schooling the researchers on what dripping really is and how it works.

But the key part of the comment explains how this misunderstanding completely undermines the conclusion of the study.

The comment offers an excellent explanation of what’s wrong with this study, and you should read it in full to get all of the details.

We spoke to Riccardo and Amelia about their comment, and opened by asking them to summarise the problems with the study’s conclusion:

The main issue with this conclusion is that the question used to assess dripping was poor.

All we know from this study is that 1/4 of the students in their sample answered yes to doing something, but this something probably wasn’t “dripping” as vapers would understand it (e.g. using an RDA) because the question “have you ever used the dripping method to add e-liquid to your e-cigarette?” wouldn’t pick that up.

We aren’t really sure what it picked up, but we believe most students interpreted it as refilling, since refilling does involve a method of dripping e-liquid into an e-cigarette.

As the comment explains in more detail, the definition of e-cigarettes given by the study emphasises refilling.

When combined with the confusing phrasing of the dripping question, the chance of students misunderstanding the question is substantial.

They continue:

The other problem with the claim “One in four teens who had ever vaped had tried dripping,” is that they did not base this stat on all teens who had vaped in their study.

1874 (26.6%) of surveyed teens answered yes to the question “Have you tried an e-cigarette?”

That’s an easy question to understand, and the rate of ever-use it returned is very close to the rate of ever-use in representative surveys of American youth like the National Youth Tobacco Survey, so it’s safe to say that students probably answered that one correctly.

But one out of ten students who vaped left the dripping question blank. And another 31.8% gave inconsistent answers (indicating that they didn’t know what the question meant). The authors excluded these students from their analysis - which greatly inflated the proportion of “yes” answers.

The results are essentially meaningless.

So all in all, the study seems pretty hard to defend. It’s yet another example of the peer review process letting serious issues slip through the cracks.

That’s a big problem in general, but comments like Riccardo and Amelia’s is an example of the self-correcting mechanisms that are supposed to weed out bad science. Pre-publication reviewers might miss some important points, but the scientific community (hopefully) spots them and calls them out.

I asked Riccardo and Amelia what they think should happen as a result of the comment. Are they hoping the authors will revise the study, retract it or something else?

We hope it gets them to think about what they are doing when they design future studies.

To be honest, we think that the misunderstanding of the phenomenon was so deep that revising the manuscript wouldn’t fix anything - simply because you cannot really conclude anything from a question it doesn’t seem that anyone understood.

We’re curious though, if they will understand the kind of argument we’ve made, and find it convincing. That would require seeing their study from a different perspective, and they may not let go of theirs.

As for retraction, we’re not sure what they will do or if the journal would retract. Personally, if either of us became convinced we made an error like this, we would retract the paper.

Is Dripping More Dangerous Than Other Ways to Vape?

The coverage of the study also made a big deal about the supposed risks of dripping compared to other methods of vaping.

So you might be wondering: is dripping really more dangerous than ordinary vaping?

As Riccardo and Amelia point out in the comment, directly soaking your wick before vaping will probably reduce the risk of dry hits.

Normally, dry hits happen when you vape too quickly (or at too high a power) for your tank to keep up with. Because only a small amount of wick is touching the liquid in your tank, it takes a while for more to soak in after you’ve vaporised what’s already there.

When you drip, you soak the whole wick directly, so as long as you drip regularly, dry hits are much easier to avoid.

Without dry hits, the temperature of your coil stays so low that only very small quantities of chemicals like formaldehyde make it into the vapour. We’ve spoken about this before in relation to the infamous New England Journal of Medicine formaldehyde study.

The study the authors reference to support their claim has its own issues.

The researchers added one or two drops of e-liquid to the coil and wick, on a very old dripping atomizer. They then puffed it between two and four times for a massive 8 seconds per puff. To make this worse, they only gave the coil 10 seconds to cool down between puffs. So, for example, the two puff tests would have lasted 26 seconds, but the coil was activated for 16 of those.

This method would undoubtedly lead to dry puffs. Real vapers can detect these easily, and in real life they’d just add more liquid at the first hint of the wick drying up.

Vapers also learn how long they can puff for without problems. A study observing vapers habits found that most took four-second puffs, and left between 20 and 30 seconds between puffs. In other words, this study could have hardly got it more wrong.

You’d expect that dripping is no more dangerous than vaping with a tank, because it’s basically the same: e-liquid is soaked into a wick and then vaporised. There is a possible increase in risk from consuming more e-juice over the course of a day, but you’d do the same with sub ohm tanks anyway.

In a nutshell: dripping 5 ml of e-liquid per day is probably no more dangerous than consuming that same 5 ml using any other approach.

The Big Problem: Vaping Researchers Don’t Understand Vaping

The recent study is also yet another example of something that’s been bothering me for a while: many vaping researchers don’t understand vaping.

Professor Polosa and Amelia Howard concur:

This is a huge problem.

A lot of research on e-cigarettes is conducted by people who are inexperienced in using the technologies, and even lack basic practical understanding that would be necessary to talk about the technologies competently. You can’t design valid research on something that you don’t understand.

Despite referencing a Spinfuel article on the topic, the authors of the dripping study appear completely clueless on the topic.

The poor explanation of what e-cigarettes are is bad enough, but the bizarre “dripping onto hot coils” description and their poorly-worded question make the authors look very much out of their depth.

As well as this example, another group of researchers attempted to test “dripping” by exposing the coil on a Kanger Protank and dripping tiny amounts of e-juice onto it.

This is kind of laughable. I’m sure they tried to understand what they were doing, but I can’t help but think that asking a vaper a simple question would have helped them avoid this disaster of an approach.

Other studies make simpler mistakes, from using the wrong settings for the atomizer (the NEJM formaldehyde study and many others) to testing concentrated flavouring as if it’s ready-to-vape e-liquid. Again, these mistakes seem entirely avoidable.

The real question is how we could solve this issue.

Do we just need to force researchers onto some sort of “Vaping 101” course, or is the problem something deeper?

I asked Riccardo and Amelia what they thought we could do about it:

This depends on how we see the problem. If the problem is a simple deficit in some researchers’ understanding of the technologies, the solution is for those with the relevant technological expertise (e.g. vapers) to teach non-experts about the technologies.

But in the case of vaping research, we think it’s an epistemological problem: It’s about getting expertise specific to the vaping community to generally inform scientific research design on these products. Experts (vapers) know how to use the technologies, and they also know how to know about the technologies. Meaning, they have criteria for what counts and does not count as valid knowledge, and this needs to translate into formal research. So I think the challenge is to change norms in the research community conducting studies.

Emissions studies are a good example: in “real-world use” dry puffs are an error. That understanding (from vapers) is now translating into the laboratory. But before it did, high levels of formaldehyde were seen as a function of e-cigarettes, and not a result of an error. Vapers’ technical knowledge needs to be brought into the design and evaluation of research, and this needs to be a community standard for the scientists studying vape.

But if researchers insist on pressing ahead with their studies without knowing what they’re doing, what can we do about it? Can we stop the misleading headlines these results create? What should we do when we see such poor understanding of vaping from researchers?

Riccardo and Amelia encourage vapers to speak out:

Vapers should absolutely speak out about this.

Submitting letters to the editors and comments to journals is one way of calling attention to researcher misunderstanding.

In a case like this one, where the study was picked up by the media, submitting letters to the editors of newspapers can help inform the public. Blogs are also a great way to respond to problematic studies in depth.

Ideally, journals should be consulting experts in the technologies when the validity of research hinges on that sort of expertise, and vapers should be vocal about this. We are wasting enormous resources on studies that don't produce meaningful results.

Conclusion: A Case Study in How Vaping Research Can Fail Smokers and Vapers

Despite the crippling issues with this study, the unavoidable truth is that the damage has probably already been done. The headlines have been written and the average person on the street now probably thinks that dripping is just another way vaping can be dangerous. Whatever comes of the comment from Riccardo and Amelia, the damage probably can’t be undone.

But it’s not all bad news.

The more we correct these misunderstandings of vaping by researchers in official channels, the more researchers will be encouraged to get a good grasp of what they’re talking about before forming hypotheses and conducting badly-designed studies.

We’d like to thank Riccardo and Amelia for their comments to us and for their critique of the study. And finally, if you agree with their analysis, please read and share their comment on the research! The more people see it, the more chance there is that it will be published as a full-fledged letter to the editor and reach the wider research community.