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Are there heavy metals in delta-8?

Delta-8 tetrahydrocannabinol (delta-8 THC) is a psychoactive cannabinoid found in the cannabis plant. It has become increasingly popular over the past couple of years as a legal alternative to delta-9 THC, the main psychoactive compound in cannabis. Delta-8 THC produces similar effects to delta-9 THC, but it is less potent. While delta-8 THC from reputable brands and suppliers is considered safe, there have been some concerns about potential contaminants like heavy metals.

What is delta-8 THC?

Delta-8 THC is one of over 100 cannabinoids produced naturally by the cannabis plant. It has a similar molecular structure to delta-9 THC, with the difference being the location of a double bond on the compound. Delta-8 THC binds to the same cannabinoid receptors in the body that delta-9 THC does, which results in psychoactive effects when consumed. However, delta-8 THC typically produces a milder high compared to delta-9 THC.

While delta-8 THC is found naturally in cannabis, only small traces of it are present. Most commercial delta-8 products are synthesized from CBD that was extracted from hemp. The 2018 Farm Bill federally legalized hemp and its derivatives, as long as they contain 0.3% delta-9 THC or less. This opened the door for delta-8 THC products to enter the marketplace.

How is delta-8 THC made?

There are a few common methods used to synthesize delta-8 THC from legal hemp-derived CBD:

  • CBD isomerization – CBD is chemically converted into delta-8 THC through the use of solvents and acids/bases.
  • Oxidation – Oxidizing agents are used to convert CBD into delta-8 THC.
  • Extraction – Delta-8 THC can be selectively extracted and concentrated from hemp.

The conversion process requires the use of chemicals like solvents, acids, and oxidizing agents. If not properly purged, residual contaminants from these chemicals may remain in the final delta-8 product. Proper purging, cleaning, and testing is necessary to ensure contaminant-free delta-8 THC.

Could heavy metals be present in delta-8 products?

Heavy metals refer to metals that have relatively high densities and are toxic or poisonous even at low concentrations. Examples include lead, mercury, cadmium, and arsenic. Heavy metals can accumulate in the body over time and cause health problems.

There are a few ways that heavy metals could make their way into delta-8 THC products:

  • Contaminated hemp material – Hemp is known as a “bioaccumulator” meaning it absorbs contaminants from the soil it is grown in. If the hemp used to produce CBD extract was grown in contaminated soil or with contaminated fertilizers, the CBD (and resulting delta-8) could contain heavy metals.
  • Chemicals used in processing – Solvents, acids, oxidizing agents, etc. used to synthesize delta-8 may introduce impurities like heavy metals if low purity reagents are used.
  • Extraction equipment – Using unclean or contaminated equipment to perform extractions and conversions could lead to cross-contamination.
  • Added thickeners/diluents – Some delta-8 companies have been found adding undisclosed thickeners and diluents to their products that contain heavy metals.

Without proper quality control and testing, the risk of heavy metal contamination in delta-8 THC is not insignificant. Reputable brands analyze their products for heavy metals to ensure safety and purity.

Have any delta-8 products tested positive for heavy metals?

There have been a handful of cases where independent lab testing has detected dangerous levels of heavy metals in commercially available delta-8 products:

  • In 2021, a biotech company tested 16 delta-8 vape cartridges from 10 different brands purchased online. Nearly half (7 out of 16) contained unsafe levels of lead and other heavy metals according to California standards.
  • Earlier in 2022, Virginia regulators issued a warning about delta-8 THC containing unsafe levels of heavy metals based on department testing.
  • A 2022 study published in the Journal of Environmental Science and Health tested 39 delta-8 products from 20 brands and found 18 products (46%) exceeded California thresholds for allowable lead concentrations.

While not all delta-8 products contain heavy metals, these results demonstrate that contaminants are a real concern for some brands and manufacturers in the largely unregulated delta-8 industry.

How are delta-8 products tested for heavy metals?

There are a few analytical chemistry techniques commonly used to test cannabis products like delta-8 THC for the presence of heavy metals:

  • Inductively coupled plasma mass spectrometry (ICP-MS) – Samples are ionized and heavy metals are identified based on their mass-to-charge ratios.
  • Inductively coupled plasma optical emission spectrometry (ICP-OES) – Plasma is used to excite atoms which emit wavelengths of light specific to different metals.
  • Atomic absorption spectroscopy (AAS) – Uses absorption of light to determine concentrations of specific metallic elements.

These sensitive scientific techniques can detect even tiny traces of contaminating heavy metals within a sample. Reputable delta-8 brands submit their products to third-party labs for heavy metal analysis by these methods.

How much heavy metal contamination is allowed in delta-8 products?

Since delta-8 THC is federally legal through the 2018 Farm Bill, there are no federal regulations or standards in place specifically for allowable heavy metal limits in delta-8 products. However, many states like California, Colorado, Michigan, and others have set maximum contaminant levels for regulated cannabis products including:

Heavy Metal Maximum Allowable ppm in Cannabis Products
Lead 0.5 ppm
Arsenic 0.2 ppm
Cadmium 0.2 ppm
Mercury 0.1 ppm

While these state cannabis regulations do not apply directly to delta-8 products, many reputable delta-8 brands aim to meet the more stringent state standards for allowable heavy metal levels.

How can you avoid delta-8 products with heavy metals?

Here are some tips for consumers to avoid purchasing delta-8 THC products that may contain potentially dangerous heavy metal contaminants:

  • Look for brands that provide updated, current third-party lab test results showing their delta-8 is free of heavy metals and other contaminants.
  • Stick to reputable, trustworthy brands with transparent business practices and many positive customer reviews.
  • Avoid cheap delta-8 products that seem too good to be true – highly discounted or low-priced products often cut corners on quality and safety testing.
  • Purchase from states or jurisdictions with legal, regulated cannabis markets and testing requirements for products.
  • Look for signs of ISO certified or GMP compliant manufacturing facilities.

Checking for proper certifications and up-to-date lab tests provides assurance that a brand analyzes for and does not have issues with heavy metal contaminants in their delta-8 THC products.


While delta-8 THC offers consumers a legal alternative to experience cannabis’ effects, there are potential risks like heavy metal contamination to be aware of. Heavy metals could be introduced during hemp cultivation, delta-8 processing, or via diluents and thickeners. Analytical testing has found elevated heavy metal levels above safety limits in some delta-8 products on the market. To avoid unsafe exposure, purchase delta-8 from reputable brands that provide thorough contaminant testing by independent laboratories. Look for products meeting state cannabis safety standards, and be an informed consumer by vetting companies, certifications, and lab results closely.