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Toxic Lead Discovered in California Vape Cartridges

By Alexander Beadle

Published: Feb 04, 2019   

Credit: Pixabay

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California’s notoriously strict cannabis testing requirements tightened another notch on January 1, with some products already running afoul of the new restrictions. Specifically, dangerous levels of lead contamination are now showing up during the testing of a number of disposable e-cigarette devices, known as “vaporizer cartridges” or “vape carts”.

The e-cigarette craze

Easily the most popular method of consuming cannabis product is by smoking, whether that be from burning cannabis cigarettes or blunts, or through inhaling cannabis vapors using a bong or water-pipe device. But an alternative method — vaping — has been gaining popularity with both medicinal and recreational cannabis users over recent years.

Vape cartridges contain a cannabis concentrate and are available in various cannabinoid concentrations. This cannabis concentrate is flash vaporized by an electrical ignition circuit inside the cartridge apparatus to create a cannabinoid aerosol cloud that can be easily inhaled. The main advantages to these vape carts are their portability and their ease-of-use compared to rolling cannabis cigarettes. Additionally, vaping is also a more discreet method, as it gives off far less of the distinctive smell that comes with smoking cannabis flower.

In California, vape cart sales have been booming. Eaze, a California-based cannabis delivery company, each year publishes an annual report called “The State of Cannabis” which, among other variables, tracks the type of cannabis products that consumers in California are buying. Their 2016 report noted an increase in vape cart from 6% of total sales in 2015, to 24% in 2016 — an increase of 400% in just one year. And their 2018 report is no different; vape carts consistently ranked as the most popular non-flower purchase, in some months accounting for up to 40% of the product sold through Eaze.

The dangers of lead contamination

But California’s vape product industry has been shaken. Under the new testing regulations, which require all cannabis products to undergo extensive heavy metal testing, testing laboratories are reporting that some vape carts are testing positive for concerning levels of lead metal contamination.

In the words of the World Health Organization, “There is no known level of lead exposure that is considered safe.” And while lead exposure is much more dangerous to children, adults can still suffer from significant adverse health effects following exposure to lead — symptoms can include high blood pressure, joint and muscle pain, headaches or abdominal pain, mood disorders, and difficulties in memory or concentration. For pregnant women, lead exposure can directly cause miscarriage or premature birth and may adversely affect the health of the child even if the child is carried to term and otherwise born without complications.

For these reasons, care has been taken to minimize lead exposure in society wherever possible — this is why we now have unleaded petrol alternatives, and most developed countries have taken steps to ban products such as lead-containing paint or other previously common sources of lead poisoning.

The source of the lead

Usually, heavy metal contamination of cannabis products comes about as a result of some sort of cross-contamination during processing, or through the cannabis plants themselves absorbing soil-borne heavy metals during the growing stage. But in the case of the vape carts, the contamination source is much more unusual.

A significant proportion of the electronics used in vape carts are produced at metal foundries in China, where it is common to add small amounts of lead into the brass and copper feedstocks in order to make the metals more moldable when shaping all types of electronics. More moldable metal usually means a lower production cost for the electrical parts being made. By shaving off pennies in the ‘per unit’ production price, manufacturing companies can save millions of dollars per year like this.

This isn’t to say that the Chinese factories are willingly putting people at risk of lead contamination; Chinese metal foundries follow some of the toughest lead laws in the world, which cap the levels of lead allowed in electronics to 4%, or 40,000 parts per million. However, this standard does not gel with the new controls put in place in California, where detectable lead levels must be under 0.5 parts per million.

And this is where an important distinction must be made — just because the metal used in vape carts contains 40,000 parts per million of lead, that doesn’t necessarily mean that the cannabis oil inside the cart will be contaminated.

Josh Wurzer, the president and co-founder of SC Labs, says that approximately 0.5% of the vape carts being tested at his lab have failed lead contamination tests. He believes that the failed heavy metal tests are likely the result of the acidic cannabis oil leeching lead out of the metal components, but equally, different testing methods being used in different laboratories might be contaminating previously uncontaminated cannabis oil during testing.

“Maybe some oil is picking up some of the lead and failing there,” explains Wurzer to Leafly. “We have tested actual empty cartridges and confirmed a number of ‘over the limit’ hits for lead.”

He continues, “The lab has to be very careful to make sure they’re not actually contaminating the concentrate with lead.”

What this means for consumers

According to Peter Hackett, a hardware expert with AiR Vapor, the most common type of vape cart, CCELL carts, are one of the better performers when it comes to heavy metal testing. These particular carts were failing the test with lead levels of around 0.6 or 0.7 parts per million — which would be acceptable in most other US states, but not under California’s new regulations. But, Hackett still believes that any amount of lead is too much.

“Seventy percent-plus of the visible brands are using CCELL. This is something that’s widely affecting the industry,” says Hackett, also to Leafly. “But it’s only getting popped in California.” “I don’t want any lead in anything. I don’t want 4%, not 0.5 ppm. I don’t want any in there. If it’s two or three parts per million lead, I don’t want people smoking that. I’m glad we’re catching it.”

Completely removing the risk of lead contamination from the metal components will require a change in production process in the metal foundries in China, which unfortunately cannot happen immediately as many foundries are currently closed for the Chinese New Year celebrations. Hackett says that he has ordered lead-free carts for his business, but they likely won’t be able to hit the Californian marketplace until the end of February at the earliest.

In the meantime, consumers who are concerned about the lead detection should check the dates of manufacture on the carts in their possession. Anything produced after Jan 1, 2019 will have passed the heavy metal detection tests and have lead levels no higher than 0.5 parts per million, but any produced during 2018 will be completely untested. Any carts bought through the illicit black market will also not have been subjected to testing and may contain high levels of lead.

For those who wish to ensure their products are lead-free, you will have to wait until the new lead-free vape carts enter the California market in late-February.

Alexander Beadle

Science Writer

Alexander Beadle has been working as a freelance science writer since 2017 and has covered the cannabis industry for Analytical Cannabis since 2018. He has also written for our sister publication, Technology Networks, and the cannabis industry consultant firm Prohibition Partners, among others. Alexander holds a Master's in Materials Chemistry from the University of St. Andrews, where he won a Chemistry Purdie scholarship, and conducted research into zeolite crystal growth mechanisms and the action of single-molecule transistors.


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