Marijuana Edibles

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Key Facts

  • Edibles are food products infused with cannabis extract
  • Extraction of THC and CBD from cannabis plant mixed with heating creates “high” for consumers
  • Food safety concerns around edibles include the extraction process, possible bacteria growth, chemical exposure, pest contamination, and employee handling of product
  • Unintentional ingestion of a marijuana-infused food is a reportable foodborne illness
  • Types of edibles include solids, drinks, powders, tinctures, sprays, oils, and butter


Marijuana edibles are food products infused with cannabis extract. Cannabis is a genus of flowering plants in the Cannabaceae family. The number of species within the genus is not defined, but the most commonly recognized are Cannabis sativa, Cannabis indica, and Cannabis ruderalis. In the United States, marijuana is one of the most commonly used drugs, with approximately 22.2 million users each month. A number of foodborne outbreaks have been associated with marijuana consumption, which makes understanding the edible production phase important in reducing food safety risks.

Foodborne Outbreaks and Recalls

There have been a number of marijuana-associated outbreaks dating as far back as the late 1970s. In 1981, 85 cases of Salmonella Muenchen were reported across multiple states with significant marijuana exposure among cases compared to controls. The level of Salmonella contamination and accompanying microflora in marijuana samples collected from case households suggested direct mixing of the marijuana with animal feces. The source of contamination was hypothesized to be a result of fertilizing marijuana plants with untreated manure, accidental contamination during storage or drying processes, or intentional mixing to artificially increase the product’s weight. 

Another notable outbreak occurred in 2014, when retail marijuana became legal in Colorado. The Denver County Fair hosted a “Pot Pavilion” with vendors who were available to inform people about their businesses and products. Each vendor signed an agreement that they would not exhibit or sell any marijuana or marijuana-infused products at the fair. However, the Marijuana Enforcement Division (MED) was contacted by Denver Public Health (DPH) about four cases who reported unusual symptoms after attending the Pot Pavilion and ingesting chocolates that were not supposed to contain marijuana. A criminal investigation was launched, as well as an outbreak investigation, because unintentional ingestion of a marijuana-infused food is a reportable foodborne illness. The likely source of illness was determined, and the marijuana facility was shut down and inspected. 


Marijuana edibles can be produced in a home environment or prepared commercially for dispensaries. The extraction of cannabinoids (tetrahydrocannabinol (THC) and cannabidiol (CBD)) from the cannabis plant involves heating the flowers from the female plant in an oil-based liquid. THC is the major psychoactive ingredient that causes the marijuana “high”. However, this chemical in the plant in its nonpsychoactive acid form is tetrahydrocannabinolic acid (THCA). THCA is then heated, in order to convert it into THC. The THC can be diffused out of the plant and dissolved into an oily liquid with other cannabinoids, such as CBD. The plant material is then discarded.

Food Safety

Extraction Concerns

The extraction process can be dangerous if not performed correctly. All extractions must be done using a closed loop system with an approved solvent. Contamination of Clostridium botulinum, a bacteria with spores found on plant material and in soil, is a concern during chemical extraction of THC. These bacteria can survive past cooking and pasteurization temperatures during the extraction process. The bacteria has the ability to produce severe illness or death. The products of concern are those of cannabis extractions and concentrations for oral consumption, infusions made from these extractions (oils, butters, honey), and foods that have such infusions/extractions as an ingredient.

Aflatoxins on Cannabis Bud

Improper growing conditions cause mold growth which, in turn, creates aflatoxins that can cause serious health problems. High humidity is a particular concern and should be monitored closely during both storing and transportation of product.

Recalls for Suspected Mold Contamination

Over 330,000 edible marijuana products were recalled in January 2021 due to a suspected mold contamination. Ten complaints were filed to the TerrAscend Canada leading to Health Canada recalling 33 lots of two products, both THC infused gummies.  All recalled products were sold between September 2020 and January 2021 in Canada at provincially authorized retailers in Ontario, British Columbia, Alberta, Prince Edward Island, New Brunswick, Saskatchewan, Manitoba and Newfoundland.

Earlier that month, Health Canada also recalled over 700 cannabis products sold at authorized retailers in Saskatchewan. Four complaints were filed to Agro-Greens Natural Products regarding possible mold contamination one of their dried cannabis products; one complaint reported an adverse reaction to the recalled product. In total, the recall affected one lot of cannabis product sold between December 4 and December 23, 2020.

Chemical Residues on Plants

The risk of chemical residues contaminating cannabis plants is high because a variety of chemicals can be introduced at many different points of production. Facilities should follow proper instructions in applying fertilizers and pesticides to crops. Chemicals should be clearly labeled throughout facilities. There is also risk of contamination by chemicals in the washing tank. Chemicals in the washing tank are there to reduce the risk of pathogenic bacteria, such as staphylococcus aureus and salmonella, in the water.

Contamination from Pest Infections

Pests spread disease and pest control measures must be taken to ensure that the facility is clean and closed off to any opportunity of contamination. All product should remain covered and contained in order to prevent fecal contamination by pests. Storage units must be checked for holes or openings.

Contamination from Improper Employee Handling

The high risk of cross-contamination from employees to product is also a concern, and personal hygiene standards need to be adhered to. Employees should be encouraged to stay home when feeling sick and not return to the facility until cleared by a doctor. When harvesting, employees must also adhere to proper cleaning techniques of the tools used because they may carry unsafe microorganisms.

Known Controls

Exposing marijuana plant material to radiation destroys the spores and bacteria, which in turn prevents toxin formation. It is also important to refrigerate the extractions and concentrates at 41° F to prevent growth of existing C. botulinum spores.  Another control measure is immediate infusion of extracted cannabis concentrates into a 190/200 proof alcohol to prevent the growth of spores.

Types of Edibles

Edibles Infusions

Drinks – can be taken in through the digestive tract; slower acting process; half hour to hours before taking effect; stays in body longer

Solids – dosing varies widely from one to another; gummies and mints are among the most popular edibles

Tinctures – alcohol-infused cannabis extracts; easy application and accurate dosing; apply a few drops into mouth

Sprays – directly sprayed under the tongue; for consumers on-the-go; provides an immediate effect; easily transported

Inhalers – popular among users who would like to be discreet; limited in availability

Dissolvables/Powders – have no taste or flavor; can be dissolved into any liquid; added to protein or workout supplements as cannabis use in exercise programs becomes more popular

Infusion Methods/Binding Agents

Oil – coconut oil has emerged as the more popular choice among health-conscious consumers, as it has cited health benefits; other options are olive, avocado, and walnut oils

Butter – the binding agent that turned edibles into the product they are today; allows consumer to control dosage; delays psychotropic effects

Distillates – more versatile infusion option; dabbing to direct oral application; distilling precise compounds from plants can produce purities of up to 99%; isolate and target exact effect desired


One of the preferred methods of marijuana consumption is the ingestion of edibles. Edibles, as opposed to smoking products, offer a more discreet and convenient way to ingest marijuana. They also provide a calmer and more relaxing “high” than smoking. Additionally, edible consumption allows users to avoid the harmful toxins and negative health impacts that are associated with smoking. The smoking rate among adults is down from 20.6% in 2009 to 16.8% in 2014. Since edibles can be sold for higher prices, they also account for between 25-60% of a dispensary’s profits.

Since legalization of recreational marijuana usage in Colorado, the state has seen an increase of sales from $17 million in early 2014, to $53 million in the middle of 2016. Edible sales in the state of Washington also increased 121% in 2016. It is estimated that the growth of edible sales will continue to increase up to 25% annually.

Legalization and Regulation

Brief History/Legalization


The industry of cannabis-infused goods is emerging; therefore, regulation within this industry is new. There is little to no known published research about how pathogens grow into cannabis extractions. It has become the responsibility of public health departments to protect consumers with existing research on foodborne disease risk that already exists.

A total of 33 states and territories allow the use medical marijuana. Of those, Washington, Alaska, Oregon, California, Nevada, Colorado, Illinois, Michigan, Maine, Vermont, Massachusetts, and the District of Columbia all regulate and allow adult and medical use of marijuana. The state of Colorado has since enforced new packaging and labeling rules as of October 1, 2017 in order to promote public health and safety, educate the public, and raise awareness in better identifying marijuana products.

On the federal level, marijuana remains classified as a Schedule I substance under the Controlled Substances Act, which means that it is considered to have a high potential for dependency and no accepted medical use. However, the Obama Administration encouraged prosecutors not to prosecute people for distributing marijuana for medical use in accordance with state law in 2009.

Medical Benefits/Adverse Side Effects

The use of cannabis is known to have some health benefits. Edibles have been studied in a number of clinical trials attempting to understand how they help cancer patients reduce nausea and vomiting, stimulate appetite, aid in pain relief, and help people with anxiety and sleep. CBD has been used in cancer patients in an attempt to treat tumors. There are also FDA approved drugs that have been used in the treatment of chemotherapy-related nausea and vomiting in patients who did not respond to standard drug therapies. Another trial also showed that patients with HIV/AIDS and weight loss had an increased appetite and stopped losing weight compared to those patients who took a placebo. However, use of edibles was not effective in cancer patients who experienced loss of appetite. Edibles have also benefited patients with severe pain. Studies have shown that the use of cannabis improves pain relief when taken in combination with oxycodone or other strong opioids. Lastly, those with issues of anxiety and sleep, have shown to have improved mood, better sense of well-being, and less anxiety after taking edibles.

There are, however, some concerns of adverse health effects in the consumption of edibles. Some adverse effects include addiction and interference with cognitive and motor function. It has also been studied that repeated use in adolescents can result in long-lasting changes to brain function that may impact their educational, professional, and social achievements. As usage increases with more widespread legalization, we can anticipate a rise in health studies to determine what the true negative health consequences will be.


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Brianna Raymes

Brianna Raymes

MPH Student at the Colorado School of Public Health

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