Wisconsin pizza THC incident: what it teaches us about accidental THC exposure

A few months ago, a Wisconsin pizzeria made national headlines after more than 85 people became unintentionally intoxicated.

The cause? THC – the main psychoactive ingredient in cannabis (commonly known as marijuana) – had been added to the cooking oil used to prepare pizza dough.

According to a CDC report, customers experienced symptoms like confusion, dizziness, and even unconsciousness, and many didn’t realize what was happening until they ended up in the emergency room.

This incident highlights the growing risks of accidental THC exposure, especially as THC-infused products become more common.

In this blog, we’ll break down what happened, explain how THC affects the body, and explore how laboratory drug testing can help detect exposure and support public safety.

What caused the Wisconsin THC pizza incident?

In October 2024, at least 85 people ranging in age from 1 to 91 experienced THC intoxication after eating food from Famous Yeti’s Pizza in Stoughton, Wisconsin.

The contaminated items included pizza, garlic bread, cheese bread, and sandwiches, all made from dough that had been unknowingly prepared using THC‑infused oil mistakenly believed to be ordinary cooking oil.

Here’s how the situation unfolded:

• Emergency responders first became aware of the situation when seven people were transported to local hospitals with symptoms including dizziness, sleepiness, and anxiety – none of whom knowingly consumed marijuana/cannabis.
• One patient later tested positive for THC, prompting a public health investigation
• Public Health Madison & Dane County issued a survey to restaurant patrons and received 107 valid responses, of which 85 met the case definition: they had eaten food from the restaurant and experienced at least one symptom within five hours, such as nausea, increased heart rate, paranoia, vomiting, short-term memory impact, or hallucinations.
• Investigators determined the cause: the restaurant shared a kitchen in the same building as a state-licensed THC edibles vendor. When cooking oil ran out, staff unknowingly used a jug of THC-infused oil from the shared kitchen to make dough.

The incident is one of the largest cases of unintentional and mass THC exposure via food in the US, underscoring the importance of proper labeling, secure storage, and strict safety protocols, especially in shared commercial kitchen environments.

Related: THC-infused drinks – understanding the risks

How does THC exposure happen through food?

THC (tetrahydrocannabinol) is the main psychoactive compound in marijuana; the part that causes a “high.”

While it’s commonly smoked or vaped, THC is also used in edible products like gummies, baked goods, and oils. These products are legally sold in many states but must follow strict labeling and packaging laws.

Here’s how accidental exposure can happen:

• Infused ingredients look like regular ones. THC-infused oils, butters, and baked goods can look identical to regular food, especially if not clearly labeled.
• Shared kitchens increase risk. In restaurants or food businesses that share kitchen space, poor labeling or storage practices can lead to accidental mix-ups – as seen in the Wisconsin pizzeria case.
• Homemade or unlabeled products. Without proper packaging or warnings, homemade marijuana edibles can easily be mistaken for regular food, especially by children or visitors.

Unlike smoking marijuana, which takes effect quickly, THC edibles can take 30 minutes to 2 hours to kick in. This delay can lead people to consume more than intended, increasing the risk of severe symptoms, particularly if they don’t know what they’ve ingested.

Learn more: CBD vs THC – what’s the difference?

Symptoms and health impacts of accidental THC consumption

When someone unknowingly consumes THC – especially in high doses – the effects can be frightening and unpredictable.

Unlike intentional use, accidental exposure often leads to panic, confusion, and medical visits, because the person doesn’t know what’s happening to their body.

Common symptoms of THC intoxication include:

• Drowsiness or dizziness
• Confusion or disorientation
• Paranoia or anxiety
• Rapid heart rate
• Nausea or vomiting
• Slurred speech or difficulty walking
• Hallucinations (in severe cases)

Who’s most at risk?

Accidental exposure is particularly dangerous for:

• Children, who are smaller and more sensitive to THC
• Older adults, especially those with heart conditions or cognitive issues
• People with no history of marijuana use, who may react more strongly

In serious cases, high doses of THC can lead to loss of consciousness, dehydration, or hospitalization. While fatalities are extremely rare, the psychological and physical effects can be distressing, especially when the exposure is unexpected.

How THC can be detected in the body

When someone is exposed to THC – whether intentionally or accidentally – drug testing can help confirm the presence of the substance and provide important answers.

When a person consumes drugs, these substances and broken down by the body and a proportion of the parent drug and its metabolites are circulated in the bloodstream, before being expelled from the body in different ways.

At AlphaBiolabs, we provide three different test types for the detection of THC/marijuana:

✅ Home Urine Drug Test (pack of 3)

• Discreet and easy way to test for 10 drugs at home, including THC/marijuana
• Simply collect a urine sample and read the results on the side of the device in just 5 minutes
• Up to 99% accuracy and FDA approved
• Only $24.95 for a pack of 3 kits

✅ Home Hair Drug Test

• Detects drugs and their metabolites in hair
• Easy-to-use kit – following the instructions included in your kit to collect your hair sample and return it to our accredited lab
• Up to 12-month overview of drug use
• Just $99 for results in 7-10 business days from lab receipt of samples

✅ Home Drug & Alcohol Nail Test

• Test for drugs (including THC/marijuana) and/or alcohol using fingernail clippings or toenail clippings
• Up to 12-month overview of drug and/or alcohol use
• Non-invasive and easy to collect
• From $99 for results in 7-10 days from lab receipt of samples

Analysis for our hair and nail tests is conducted at our ISO 17025 and BBB-accredited laboratory.

Whether you’re concerned about a loved one’s drug use, seeking answers after a possible exposure, or simply need a test for other personal reasons, AlphaBiolabs offers fast, discreet testing you can trust.

Related: How long does marijuana stay in your system?

Home drug testing you can rely on

The Wisconsin pizzeria case serves as a reminder of how easily THC can end up where it shouldn’t – especially in shared kitchens or food businesses without strong safety protocols.

As THC products become more common across the US, accidental exposure remains a real concern. And when questions arise, drug testing can provide answers.

Learn more and explore our range of at-home drug tests here.

Alternatively, visit our Learning Center, or contact our friendly, knowledgeable team on 727-325-2902 / info@alphabiolabsusa.com.