Part 3: Visual walkthrough of deconstructed vape pen hardware
This took much longer than expected. I...don't always know how clear my communication is, and from some of the feedback on the initial set, there were gaps.   

From the initial feedback, I built in diagrams (example above), akin to "You Are Here" maps, to illustrate what the images are trying to convey and "where" in the vape pen the image is located, and highlighted key points and annotations in red.   

Key point
Prior to this experience, I did not know what the insides of a vape pen looked like and I suspect the same for those reading this.  

Q: Would you voluntarily inhale vapor that had been sitting on 40-80 milligrams of metal solder, (regardless of whether it contained cadmium)?
A: You would not.  

It is readily apparent that certain models of inhalation-activated vape devices expose the user to the toxic contents of the battery compartment (leachable metal solder). This is true, regardless of whether cadmium is ultimately determined to be the cause of EVALI.

Not all vape pens pose this hazard, but there are no unified international standards regarding the quality of their construction and no standards at all on the products imported to the United States.

Audience: Regulators
The source of the problem associated with EVALI/VAPI illness has yet to be ascertained. Regardless of the cause (most likely a chemical contaminant, not vaping itself), bans do not work and would almost certainly promote more harm by fueling the illicit market for vape devices. A rationale approach to harm reduction would be to model e-cig and vape device safety requirements after those currently being implemented by the European Union Tobacco Products Directive (TPD). These include sharp limits on heavy metal content (like cadmium) in batteries and device power circuit safety testing. The EU is still not experiencing an outbreak of vape-related illness.   

Audience: Vape product manufacturers in the United States 
Having complete  freedom to operate ended with the start of the vaping illness epidemic. I suggest a discussion with your Shenzen suppliers to request they provide you with the same TPD-compliant hardware used in vape devices imported by countries in the European Union. 

Pro-actively moving toward regulation is problematic (for one thing, the industry needs more qualified and trustworthy labs), but it is more profitable than the cost of irrational blanket bans on whole products and markets.  

https://www.flickr.com/photos/184689826@N07/albums/72157711682991023

 Foreword (key findings revisited)

tl;dr

• Inhalation-activated vape pens expose users to the contents of the battery compartment
• Cheap cartridges leak into the battery compartment, and may leach metal from exposed solder
• Liquid and vapor contaminated with heavy metal can be inhaled by vape pen users  

​
The CDC and the FDA have not found a common causal agent in the cartridges/products used by all people who have developed the illness.

The presence of cadmium has not been confirmed yet in the products used by patients who developed EVALI. The hypothesis remains plausible: 

1. Progression of cadmium pneumonitis (Greenberg & Vearrier, 2015) closely resembles the clinical findings of patients with EVALI (Layden et al., 2019; Schier et al., 2019)
2. Cadmium is frequently present in solder used in the construction of cheap electronic devices like vape pens
3. When they are present in vape pens or e-liquid, cadmium and other toxic metals have been shown to transfer into the lungs on vapor (Aherrera et al., 2017; Goniewicz et al., 2018)

Key findings from our vape pen study
Findings relate only to airflow-activated ("auto") vape pens, as only these designs have an open channel into the battery compartment. Our results indicate plausible scenarios for contamination of vape liquid and transfer of contaminated vapor to the lungs.

Quite unexpectedly, we also discovered the lithium ion cells contained within unbranded/counterfeit vape pens can be traced back to their manufacturer. This may be useful in determining the original source of the tainted hardware and cartridges.

• Significant Potential for Contamination. Vape liquid readily seeps into the battery compartment of airflow-activated ("auto") vape pens
• Heavy Metal Leaching. In the majority of auto vape pens examined, significant amounts (40mg-80mg) of exposed metal solder is in direct contact with vape liquid entering the battery compartment  
• Significant Potential for Transfer to Lungs. Vape liquid that has entered the battery compartment can re-enter the atomizer compartment and be inhaled
• Traceability. The exterior of counterfeit vape pen hardware and cartridges contain no information on the identity of the manufacturer. Once disassembled, however, the lithium ion cells from the interior of the vape pens were are imprinted with 1) date of production, 2) barcode and battery model/product number, and, 3) the manufacturer's ID code.

Using the information printed on the lithium cells, we were able to identify the OEM of the batteries used in the unbranded vape pens. It may be possible to use this information to track assembled devices back to the manufacturer, following the information contained on the batteries alone.

Recommendations

1. Examine the internal battery casing for signs of corrosion (ex. verdigris), as well as exposed metal solder. 
2. If corrosion and/or exposed solder are evident in the battery compartment, this may indicate vape liquid was exposed to heavy metal contamination. Exposed circuitry and solder joints in the battery compartment should be tested for a panel of toxic metals, including cadmium. 
3. If cadmium or other toxic metals are found in the battery compartment, whole blood samples should be evaluated to establish the level of acute exposure. Long term monitoring may be necessary, as cadmium has a urinary excretion half-life of 10-30 years. Long after the respiratory illness resolves, patients with significant exposure would be at increased risk of kidney damage (. 

Vape Pen Vivisection

To assess the exposure model, I used motive, means, and opportunity as a framework again. I will expand on some of the previously introduced concepts and include visual evidence to support. 
 
Cheap Manufacturing and/or Cadmium Solder ("motive"). The causal agent or contaminant must be present in the vape pen hardware for a valid reason, and that reason is money.
  
Cadmium-containing silver solder is less expensive than cadmium-free alternatives, and has improved flow properties which facilitate the joining of dissimilar metals found in vape pen electrical components. 

Expanding on this concept: Regardless of cadmium content, not all vape pens are created equal. Clean and safe manufacturing processes are always more expensive than quick and dirty assembly using crude, exposed solder joints.

Both of the examples below come from auto vape pens and are in direct contact with vape liquid. In assembled vape pens, these components are located directly below the atomizer and would be exposed to any liquid that drips from the heating coil into the battery area.

Contamination would be minimal in the example on the left. The leads are completely insulated, preventing short-circuit and electrical shock, and there are no exposed globules of metal solder to leach into liquid that falls into the compartment.

The example on the right is functional, but....less correct. Dropping 40 mg blobs of solder onto 2mm wires requires very little expertise or training, allows rapid turnover of assembled and working units, uses cheap solder and skips the extra step of insulating the exposed metal.

Bathing this amount of solder in vape liquid would unquestionably expose the user to significant amounts of aerosolized metal, and that would present a clear health risk. The type of solder used would determine the severity of illness. If I'm correct about the cadmium, it will most likely appear in hardware depicted below and to the right.

Not All Cartridges Are Equal ("means")
Cheap cartridges with low design complexity typically have just two vent ports and a disk-shaped flange incorporated into the cartridge base. As noted in a recent patent (Levitz, 2018), these features contribute to poorly controlled air intake and exhaust pressure in auto vape pens and leakage of vape liquid into the battery compartment inevitably occurs. Liquid in the battery compartment does not cause the device to immediately fail, however, and contaminated liquid can pass back into the atomizer of the vape device, convert to vapor, and be inhaled. 

From United States patent (US 9,675,107 B2), ​"Battery Connector for Electronic Cigarette With Side Air Intake", https://patentimages.storage.googleapis.com/3c/e8/cb/38d052d5aebbfd/US9675107.pdf.

"there has often been a specific problem with [auto vape pens]. When the smoker exhales into a [auto vape pen] (as smokers often do), the vapors from the mouth follow the reverse of the path described above - they flow inside the Battery towards the sensor and often condense causing the sensor to become clogged and fail. The exhalation likewise causes excess liquid in the Cartomizer to follow the same path into the Battery part towards the sensor.". 


Figure 2: Cartridge Features 
Dank Carts and counterfeit "Cookies" brand cartridges have only two (2) air intake/exhaust vents and flattened disk flanges in cartridge thread. Cartridges with cross-cut flanges similar to those described in Levitz patent have better air flow and decreased risk of leakage into battery area.

Figure 3: Exposure to the Battery Compartment in Airflow-Activated Vape Devices ("means and opportunity" for inhalation exposure)

Inhalation (left). Air is drawn through sensor in battery compartment, activating the heating coil in the atomizer. Vapor produced from heating coil is inhaled. 

Exhalation (middle). On exhale or release of suction, vapor and liquid may be push/pulled into the battery compartment and exposed to metal solder and other contaminants.

Re-Inhalation (right) Contaminated vape liquid can be drawn back into cartridge atomizer, vaporized, and inhaled 

Considerable Risk of Exposure to Heavy Metal in Some Inhalation-Activated Vape Pens ("means")
40mg to 60mg of exposed metal solder was present in some of the models of vape pens evaluated in our study.

High Variability of Exposed Solder Levels
Identical units (left, three (3) unit of Model A, and right, three (3) units of Model B) same model) exhibited high degree of variability in the amount of exposed solder inside the battery compartment.

These are not visible unless the vape pen is completely disassembled. The variability in solder quantity may provide insight to explain two contrasting traits of the EVALI epidemic: wide geographical dispersion and low number of affected people. Wide dispersion suggests a large production batch, whereas the limited number of EVALI patients indicates this illness is constrained somehow. Variable levels of contaminated solder would correlate with varying degrees of exposure to toxic contaminants, and sufficient exposure to cause EVALI may only occur in certain circumstances (leaking cartridges, heavy/daily vape use, etc.).      

Vaping Type vs Vaping Frequency: Utah
A recent report on the EVALI outbreak in Utah tracked the type of vaping (nicotine or THC) and also the frequency of vaping per day (Lewis N, 2019). The tables below are adapted from that report.

The largest group of patients (60%) used both nicotine- and THC-containing products, which is consistent with the national findings.

The relationship between frequency of vaping and type was interesting.

• The largest group of patients (55%) reported high frequency (> 25 times per day) of vaping nicotine products 
  
• A similar percentage of patients (54%) reported only modest use (1-5 times per day) of THC products 

​

Visual Evidence of Liquid Entering Battery Compartment in Auto Vape Pens ("opportunity")
The presence of visible oxidized copper scale (verdigris) inside the battery compartment is a positive indicator that vape liquid readily enters the battery compartment. Worth mentioning again that this only occurs in auto vape pens.

Oxidation was variable in units examined. Minimal in some cases (left), very evident in others (middle), and not evident in some cases (right).   ​

Traceability
None of the hardware (cartridges or auto pens) examined in this study contained branding information or serial numbers. The lithium polymer batteries contained within the vape pens, however, are imprinted with a model number, a two- to three-digit manufacturer's code, the production date, and often a barcode with additional information. Using Google or Alibaba, we were able to use this information to determine the manufacturer of the battery. Further work would be required to use that information to source the assembled vape pens, but it should be possible.  

Conclusions

Auto vape devices, which include the 2-piece auto vape pens examined here and 1-piece disposable e-cigarettes, expose users to the contents of the battery compartment.

Motive. In well-manufactured devices, this may not be cause for serious concern, but there is financial motive for manufacturers to mass produce cheap vape devices. In the low quality devices examined here, varying, but significant, amounts of metal solder are present in the flowpath leading to the lungs.

Means and Opportunity. Bidirectional transfer of vape liquid between the cartridge and battery compartment is possible, and likely. Contamination of vape liquid with components of the solder is also probable. Depending on the type of solder used, heavy metals of varying toxicity would be inhaled by the user.  

These types of devices are ubiquitous in the vape pen market. If similar hardware is linked to patients who have developed the illness, solder exposure represent a plausible explanation for EVALI and should be investigated. 

Foreword to Vape Pen Vivisection: Not All Vapes

To answer some FAQ:

No, I do not believe all vape devices contain cadmium, nor do I believe that about most auto-vape pens (which are the focus of this study).

Yes, I recognize the cadmium hypothesis is unusual and acute cadmium exposure is rare. So is VAPI/EVALI. If the cause of the epidemic was common or easily recognized, we'd already know what it is.  

Yes, I vape. Some of the dissected vape pen battery compartments show signs of use and corrosion because *I* was vaping from them over the past year.
*I was literally shocked when I opened the battery compartment.  

If you don't learn from history...
It does not diminish the seriousness of the current epidemic, nor the lives lost, to point out that millions of people in the United States enjoy vaping (nicotine and cannabis) in the United States every year and most experience no adverse effects. It merely places the epidemic in the correct context. 

Among the millions who vape, there have been 1,604 cases of VAPI/EVALI, with 34 confirmed deaths. The predictable (and somewhat understandable) political response has been to call for bans on vaping. 

Let me speak to that, briefly. 

If we recognize that illicit or poorly regulated vape products are to blame for the recent spate of deaths, then we must also recognize that banning vape products will worsen the problem. Multiple lessons from our nation's history have demonstrated that prohibition does not work, and has never worked.

Regulation and harm reduction approaches, on the other hand, save lives and money; Prohibition does the opposite. I'll talk about the European Union's Tobacco Product Directive (still no VAPI in the EU, btw) and how it impacts vape product safety in a later post.  

Meanwhile, to counter the rising tide of "illegalize it!", the source of the problem must first be identified, then nullified.

So, here we go, down the hole!

Audience:

• Members of health and public safety organizations working to determine the cause of VAPI/EVALI
• Members of the cannabis community  

  
Purpose:
We respect and support the efforts of the CDC and the FDA to determine the cause of VAPI/EVALI. Colorado Green Lab is contributing our study on airflow-activated vape pens with the intent of adding a useful piece toward solving the puzzle.

Problem and Scope:
As of 22-October-2019, 1,604 cases of "Vape-Associated Pulmonary Injury" (VAPI) or "e-cigarette, or vaping, product use associated lung injury" (EVALI) have been reported to CDC, with thirty-four (34) confirmed deaths.

At this time, FDA and CDC have not identified the cause of the lung injuries in these cases, and the only commonality among all cases is that patients report the use of e-cigarette or vaping, products. No single compound or ingredient has emerged as the cause of these illnesses to date.

Proposed Common Source of Exposure

Patients have reported using:

• 31% of patients reported exclusive use of only THC-containing products
• 48% reported using both THC- and nicotine-containing products
• 10% of patients reported exclusive use of only nicotine-containing products

*The remaining 11% was not reported on the CDC site

(Source: https://www.cdc.gov/tobacco/basic_information/e-cigarettes/severe-lung-disease.html)
Information downloaded 28-October-2019
 
We propose that the common source of illness in VAPI/EVALI patients is the vape pen battery.

Cartridges designed specifically for nicotine or THC vape formulas are unlikely to come from the same manufacturing batch, nor would the vape formulas contain identical additives. 

Both cartridge types incorporate universal (#510) threading, and nicotine and THC #510 cartridges can be vaped using the same vape pen battery.
 
The study will present key findings here, with related recommendations, and followed by additional posts with the study design, comprehensive results to support the proposed hypotheses, and extended conclusions on the findings. 
 
Key Findings
Findings relate only to airflow-activated ("auto") vape pens, as only these designs have an open channel into the battery compartment.

1. Vape liquid readily seeps into the battery compartment of airflow-activated ("auto") vape pens.
2. In the majority of auto vape pens examined, significant amounts (40mg-80mg) of exposed metal solder is in direct contact with vape liquid entering the battery compartment.Test exposed circuitry and solder joints for toxic metals, including cadmium
3. Vape liquid that has entered the battery compartment can be inhaled.
4. The lithium ion pouches in the battery casing have sufficient information printed on their exterior to track the hardware back to the manufacturer. 

Recommendations

1. Evaluate the vape pen battery hardware used by patients who developed VAPI/EVALI for signs of corrosion (ex. verdigris) and exposed metal solder
2. Test exposed circuitry and solder joints for toxic metals, including cadmium
3. If cadmium or other toxic metals are found in the hardware, patients should be monitored (near- and long-term) for blood and urine cadmium levels. Cadmium has a urinary excretion half-life of 10-30 years and patients with acute exposure would have an increased the risk of kidney damage long after the respiratory illness resolves. 

Update: Full set is now uploaded:

​https://flickr.com/photos/184689826@N07/albums/72157711682991023

"Those cannabidiol-laced gummy bears may be entirely legal, but they could still get you arrested on marijuana possession charges."
​
Click here to jump to the New York Times Article.

We were interviewed for this article months ago. It has no connection to VAPI. It talks about false THC positives in users who are CBD consumers only.

False positives occur both by derivatization and the Duquenois–Levine test. The DL test is commonly used to quickly detect THC at the roadside. It is an extremely unreliable test.

​Both are blog posts for another day. 

​


​

Photo Credit: Matthew Staver for The New York Times

Y'all have been very patient with my painstaking approach (particularly my partner, Cindy); I am being appropriately careful about some of the conclusions drawn.

Here's a preview of Vape Pen Vivisection: Power Supply Connectors

A picture is worth a thousand words. These will be posted in higher resolution in the final version.

The top photo compares an auto vape pen to a non-auto vape pen (("external on/off switch"). 

The second photo is the external view of a #510 female thread connector (battery case removed) that connects to the male thread vape cartridge.

The third photo shows what is not typical visible: the internal view of six (6) vape pen power modules, and specifically the solder points connecting the battery and control circuit to the underside of the #510 femaled-thread connector (which connects to #510 male-thread cartridges to power heating coil).

The Liquid
A visible air channel in the center flange is how e-liquid enters the battery compartment. The underside of one of the #510s even has obvious verdigris (green scale from oxidized copper), probably from exposure of internal coper wiring to liquid condensing in the compartment. 

The Metal
The most significant take-home message is that there is a risk of short circuit between the large proximal globules of solder connecting the circuitry to the #510. In some cases (the far left example), the risk is minimal, but not in those with red circles. The solder points there are quite large and separated by no more than a millimeter or two. These solder points can be bridged by liquid entering the compartment and short circuit. Short circuits generate considerable heat and lead to solder fume production directly in the inhalation path of the vape pen user.

As an aside, I got to experience the phenomenon first hand when disassembling one of the pens. A short circuit caused a nasty little fire and plume of greyish-white smoke. I made a very undignified shriek and smothered the fire in a bucket of sand. I was working in the fume hood (no danger of exposure), but it was quite startling. 

​Cautionary note: Curiosity killed the cat, and more than a few scientists. Please don't play this way without safety precautions and appropriate PPE.

©2019 Colorado Green Lab | coloradogreenlab.com

VAPI update
As of October 8th, 2019, 1,299 vape product users have developed a condition now known as "Vaping-Associated Pulmonary Injury" or VAPI, and 18 deaths have occurred as a result of the illness. As the name implies, VAPI occurs in individuals who have used vaping products. Although THC products have been strongly correlated with development of the illness, 17% of patients with VAPI reported exclusive use of nicotine-containing products 
source: https://www.cdc.gov/media/releases/2019/s1003-lung-disease.html

Please consider refraining from the lettuce for a while
While it is true that millions of people in the United States enjoy vaping and experience no adverse effects, the current epidemic *is* linked to vaping.  

For the duration of any epidemic with an identified source, the safest course is to refrain from the associated activity.

If romaine lettuce is identified as the source of a deadly E. coli outbreak, you would probably stop eating romaine lettuce until the CDC gives an all-clear. In the same mindset, the CDC/FDA currently recommend that you refrain from vaping until the cause of VAPI is determined.

Some of you are going to eat the lettuce anyway
No judgment if you choose to continue vaping, but please monitor yourself for symptoms (e.g., cough, shortness of breath, chest pain). If you have concerns about your health, seek medical attention. I recognize that can be a hard ask; many people (including me) endure illness and avoid accessing healthcare due to the financial cost, taking time off work, childcare issues, lack of access, etc. I can't address any of those things in a blog post, but I can ask that you please see a healthcare provider if you are experiencing symptoms that aren't getting better or symptoms that keep coming back.  

More information on VAPI from the Centers for Disease Control (CDC)
For the Public: What You Need to Know
https://www.cdc.gov/tobacco/basic_information/e-cigarettes/severe-lung-disease/need-to-know/index.html

Más información de los Centros para el Control y la Prevención de Enfermedades
Para el público: Lo que debe saber
https://www.cdc.gov/tobacco/basic_information/e-cigarettes/spanish/enfermedad-pulmonar-grave/lo-que-necesita-saber/index.html


©2019 COLORADO GREEN LAB | COLORADOGREENLAB.COM

​

July/August 2019. Hundreds of patients with an unusual respiratory illness began popping up in clusters across the United States. In the days and weeks prior to their hospitalization, these patients exhibited typical signs and symptoms of pneumonia and most were prescribed antibiotics as the first course of treatment. None of the patients (who were eventually diagnosed with vaping-associated pulmonary injury; VAPI) improved on antibiotics and lab workups revealed no evidence of pulmonary infection. 

The full range of findings is conflicting and no clear pattern has emerged regarding the source or cause of the illness.

Symptomatology
Patients have highly similar clinical characteristics and all developed the illness within a similar timeframe.

• All reported use of THC or nicotine e-cigarette devices ("vaping") prior to illness
• All displayed signs of damaged lung tissue
• Most progressed to hypoxemia and required hospitalization
• Some progressed to respiratory failure
• The majority of patients exhibited clinical improvement after treatment with systemic corticosteroids
• Most reported constitutional/gastrointestinal symptoms that preceded the onset of respiratory symptoms

Vaping Products
Most patients reported using vaping devices with THC and nicotine cartridges, but some reported exclusive use of only THC or only nicotine. A wide variety of cartridge brands and products were reported.

US-wide, US-specific
Cases are not specific to any one region of the United States, but the syndrome appears to occur only in vape users in the United States.  Other parts of the world with a high prevalence of vaping (ex. the European Union) are not reporting similar illnesses. More on that in second and third part of series.
 
Correlation ≠ Causation
The underlying cause is now believed to be chemical exposure, and not an infectious disease. The VAPI syndrome is strongly correlated with the use of black market THC vape cartridges, but the CDC has yet to conclusively identify a vaping product, substance, or additive common to all cases.

Metal Fume Fever
Unless you're a metalworker, work for OSHA, or, in my case, previously employed at a respiratory hospital, you've probably never heard of Metal Fume Fever (MFF).
 
There are only 1500-2500 cases of MFF reported in the United States each year, and the illness is typically restricted to individuals with very specific occupations (e.g. welders).

MFF is caused by inhalation of metal-containing fumes (ex. zinc oxide) produced by welding, soldering, and brazing. Typical symptoms of metal fume fever are non-specific ("flu-like"), and can include cough, raised temperature ("fever"), headache, chills, aches, dizziness, and a sweet or metallic taste in the mouth. More severe exposure can result in gastrointestinal symptoms, including nausea, vomiting, and diarrhea.  Metal fume fever caused by zinc oxide inhalation is the most frequently reported type of exposure and bears superficial resemblance to VAPI. Acute symptoms develop 4-12 hours following zinc fume exposure, but do not usually progress to lung damage. The zinc oxide-associated form of the illness typically self-resolves within 12- to 48-hours.

Cadmium Pneumonitis
A far more serious form of metal fume fever occurs after inhalation of cadmium oxide fumes. The immediate effects are similar to those described above ("flu-like"), but unlike zinc oxide exposure, cadmium fume inhalation causes significant lung damage post-exposure (pneumonitis), and can progress to hypoxia, respiratory failure, and death.

The table below compares the clinical presentation of zinc oxide metal fume fever (MFF), cadmium pneumonitis (CP), and vaping-associated pulmonary injury (VAPI).