Toxic Lead Discovered in California Vape Cartridges

California’s cannabis testing requirements tightened further on January 1, 2019 with the introduction of the BCC's Phase III compliance regulations -- mandating, amongst other things, heavy metal testing of all cannabis products. While all product categories have been impacted by the change, vaporizer cartridges (disposable delivery devices similar to e-cigarettes) in particular have struggled to meet the new permitted limits for lead.

   By Nari Nayini, Ph.D – Food and Cannabis Consultant

Line-of-cannabis-vapes

California’s cannabis testing requirements tightened further on January 1, 2019 with the introduction of the BCC’s Phase III compliance regulations — mandating, amongst other things, heavy metal testing of all cannabis products. While all product categories have been impacted by the change, vaporizer cartridges (disposable delivery devices similar to e-cigarettes) in particular have struggled to meet the new permitted limits for lead.

The vape craze

Vaping has gained popularity with both medicinal and recreational cannabis users in recent years. The main advantages of vape cartridges are their portability and ease-of-use compared to smoking cannabis flower. Additionally, vaping is a more discreet method of consumption, as it gives off far less of the distinctive smell that comes with smoking. Vape cartridges contain a cannabis concentrate and are available in various cannabinoid and terpenoid concentrations. The concentrate is flash vaporized by an electrical ignition circuit inside the cartridge apparatus to create a cannabinoid aerosol cloud that can be easily inhaled.

In California, vape cartridge sales have been booming. The 2018 “The State of Cannabis,” an annual report tracking consumer trends published by Eaze, a California based cannabis delivery company, shows vape cartridges consistently ranked as the most popular non-flower purchase, accounting for up to 40% of the product sold through their service.

The dangers of lead contamination

The new testing regulations require all cannabis products to undergo heavy metal testing prior to sale to the general public. Testing laboratories are reporting that some vape cartridges are testing positive for lead contamination (in particular) at unacceptable levels.

There is no known level of lead exposure that is considered safe.  Lead exposure is especially dangerous to children; however, adults can still suffer from significant adverse health effects following exposure. Some known symptoms include difficulties with memory or concentration, mood disorders, high blood pressure, joint and muscle pain, headaches and abdominal pain.  In pregnant women, lead exposure can directly cause miscarriage or premature birth and may adversely affect the health of the child even if carried to term.

Sources of heavy metal contamination

Flowers can contain failing levels of heavy metals because cannabis is known to bioaccumulate soil borne heavy metals to the degree that the plant is used for phytoremediation.  This source of contamination can be controlled by testing growth medium and fertilizers to be sure they are free of heavy metals and limiting environmental exposure to contamination from other sources.

Even provided “clean” flower material, it is possible for contamination to occur during the extraction process. Low levels of heavy metals in the flower (possibly below detection limits) can concentrate with cannabinoids during extraction, and leaching from processing equipment (even stainless steel and glass) can likewise introduce contaminants.

Even clean extract is not safe from contamination.  A significant portion 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 to make the metals more moldable when shaping into electronics. Even though the Chinese metal foundries purport to follow strict regulations which cap lead at 4% or 40,000 parts per million, these laws were designed for electronics and not consumption devices, like vape cartridges. As a result, the Chinese standard is much higher and does not match with the new controls in California, where detectable lead levels must be under 0.5 parts per million.

[It must be noted that just because the metal used in vape carts contains up to 40,000 parts per million of lead, that doesn’t necessarily mean that the cannabis oil inside the cart will be contaminated.  Various factors such as the length of time of the oil in the cart, the environment in which the cart is stored, and the temperature at which the oil is heated, may all factor into how much lead migrates into the oil.]

The Chinese foundries are aware of the lead contamination issue and are implementing procedures to reduce the amount of lead used during manufacturing. Cartridges in the future may be free of lead but it is unclear how long it will take until the changes are implemented or when stocks of contaminated cartridges already in the US will be exhausted.

Last, it is possible that analytical laboratories may be the cause of some of the variability in heavy metal findings.  Standard methodologies for cannabis heavy metal testing do not yet exist and most cannabis-only labs have little experience performing the analysis.  If a laboratory’s internal methods and protocols are not properly validated, additional leaching or contamination could occur during sample preparation or testing, resulting in the reporting of false positives.

Anresco Laboratories recommends that you know your source of vape cartridges and conduct R&D testing with a qualified laboratory prior to purchasing cartridges in bulk or filling large batches of oil.

Anresco Laboratories is a family owned and operated analytical testing provider to food, cannabis and related industries.  It has performed heavy metal testing for over 30 years and worked directly within Perkin Elmer to develop testing methodologies for various cannabis matrices.

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