Roughly nine months after an incident at a Wisconsin pizza parlor where marijuana-infused oil was used to prepare dough, the Centers for Disease Control and Prevention (CDC) released a report detailing how dozens of customers experienced symptoms consistent with THC intoxication.
The report, released on July 24, describes how at least 85 people, from ages 1–91, ate food from the restaurant in Stoughton, Wisconsin, between Oct. 22 and 24, 2024, and experienced THC sickness. The restaurant was in a building with a cooperative, or shared kitchen, that was also used by a “state-licensed vendor who produced edible THC products.”
The pizza parlor mistakenly used the THC-infused oil from the shared kitchen to prepare its dough, the CDC said.
Local emergency medical services had reported to Public Health Madison and Dane County (PHMDC) that seven individuals had been taken to hospitals for symptoms including anxiety, dizziness, and sleepiness, with each person reporting eating at the same pizza parlor.
Results for carbon monoxide testing in two homes of customers reporting symptoms and at the restaurant came back negative.
Stoughton Hospital treated the seven individuals with THC intoxication symptoms. One customer who reported eating pizza at the same restaurant mentioned testing positive for THC without knowingly consuming the drug, which led Public Health Madison and Dane County to initiate an outbreak investigation.
On Oct. 24, 2024, the restaurant closed and told PHMDC about the THC vendor in its shared kitchen. The restaurant said they had run out of cooking oil two days prior and used some from the shared kitchen to make the dough, according to the CDC report.
Upon further investigation, the oil used to prepare the dough tested positive for THC. Since law enforcement saw the contamination as unintentional, no criminal charges were filed.
After the restaurant was deep-cleaned according to Wisconsin Food Code sanitation procedures, it reopened on Oct. 26, 2024.
“Eighty-five persons who responded to a health department questionnaire reported symptoms consistent with THC intoxication that occurred within 5 hours after eating food from a pizza restaurant, including 15 who received a positive THC test result,” the CDC report said.
“Respondents were asked to provide the names of others who ate food from the restaurant and became ill, which identified eight additional ill persons. No leftover foods were tested for THC, no quantitative testing was performed on the oil, and no analytical study [case-controlled study] was conducted.”
Tetrahydrocannabinol, or THC, is found in the marijuana plant, including hemp varieties. While the Food and Drug Administration (FDA) has not approved the use of THC in any food products, it is found in many adult cannabis and hemp marketplaces, including in states with medical marijuana industries.