Americans swear off Domino's pizza after learning its sauce once tested positive for a cancer-causing toxin

Americans have vowed to ditch Domino's after learning the pizza chain's marinara sauce tested positive overseas for a carcinogen linked to pesticide use. 

Social media posts circulating this week have revived a 2024 incident in Taiwan, where the country's Food and Drug Administration (FDA) detected ethylene oxide, a chemical classified as a human carcinogen, in Domino's pizza sauce concentrate imported from the US.

Ethylene oxide is an EPA-registered antimicrobial pesticide commonly used to sterilize heat-sensitive medical equipment and, in some countries, certain food ingredients such as spices.

Ingesting this chemical can trigger nausea, vomiting and abdominal pain, while long-term exposure has been linked to an increased risk of cancer. 

Taiwan's FDA reported finding the chemical in 41,888 pounds of Domino's pizza sauce concentrate, at levels roughly equivalent to a tiny grain of salt spread across about 2.2 pounds of sauce.

The FDA Deputy Director-General Lin Chin-fu stated at the time that the agency suspected the substance could be linked to the spices used in the pizza sauce. The tainted sauce was intercepted before it was used on pizza and never reached consumers. 

Although the testing occurred two years ago, viral posts this week reignited backlash against the brand.

On X, one user wrote: 'Well, guess I am never eating Domino's again,' while another added: 'I'm done with Domino's Pizza! Boycott Domino's.'

The US does not regulate or test for ethylene oxide in food using the same standards as Taiwan. Daily Mail has contacted Domino's and Taiwan's FDA for comment.

Domino's released a statement in 2024, saying: 'This is the first time such a substance has been detected in products we use, and we ensure it will be the last time.'

Taiwan enforces a strict zero-tolerance policy for ethylene oxide in food products.

This stems from the chemical's classification as a Group 1 carcinogen by the International Agency for Research on Cancer (IARC), meaning it is considered a known cancer-causing substance with no permitted residues allowed.

In contrast, the US permits the use of ethylene oxide as a postharvest fumigant and antimicrobial agent for certain dried foods, primarily spices, herbs and similar commodities, with established maximum residue limits rather than zero tolerance.

Under US  federal regulations, ethylene oxide residues are permitted at levels of up to 7 parts per million on most foods such as dried herbs and spices, licorice root, sesame seeds and dried vegetables, with a higher limit of 50 parts per million for walnuts.

Parts per million (ppm) means the number of units of a chemical found in one million units of food by weight.

For example, 7 ppm equals about 7 milligrams of a substance in 2.2 pounds of food.

According to Taiwan's FDA, between July 29, 2022 and January 29, 2024, 447 batches of Domino's pizza sauce were submitted for inspection, of which 18 were unqualified, accounting for 4.03 percent.

Pesticide residues such as flunimine and sub-quinone were detected, Taiwan News reported.

Flunimine refers to flunixin meglumine, a potent non-steroidal anti-inflammatory drug (NSAID) used in veterinary medicine for pain, fever and inflammation in horses, cattle, and pigs.

Sub-quinone is a chemical compound that can form as a breakdown product of certain pesticides or from processing ingredients, and is not typically added intentionally.

However, it can appear in food through contamination, ingredient breakdown, or chemical reactions during production.

Because some sub-quinone compounds can be toxic, their detection is treated as a safety concern, which is why the batches were flagged as unqualified.

Yen Tzung-hai, a toxicology researcher at Chang Gung Memorial Hospital, told Taiwan News that ethylene oxide is recognized as a human carcinogen by the World Health Organization's International Agency for Research on Cancer.

He noted that only a small number of countries, including the US and Canada, still permit its use to sterilize products such as spices and sesame.

Taiwan's FDA shifted inspections for similar products from random sampling to enhanced, targeted checks to prevent future issues.

Domino's promptly suspended the use of the affected sauce, though the batch never entered the market, and replaced it with locally produced Taiwanese alternatives across all its stores in Taiwan.

Domino's emphasized its commitment to food safety and ongoing collaboration with suppliers.