Food safety expert’s urgent warning over where you store your condiments as MAYO kills one and infects 75

Dr Darin Detwiler, a food safety expert at Northeastern University in Boston and former FDA and USDA food safety advisor, shared tips for storing condiments like mayonnaise

Food safety experts are warning Americans against storing condiments like mayo, pesto, and barbecue sauce in the pantry following an international outbreak of deadly bacteria.

Earlier this month, health officials in Saudi Arabia sounded the alarm after 75 people were sickened with botulism, a rare food-borne pathogen that attacks the body’s nerves.

Of these cases, 11 were left hospitalized and 20 needed to be monitored in intensive care. One individual died.

The Saudi Food and Drug Authority (SFDA) found that the toxin that causes botulism Clostridium Botulinum, was found in mayonnaise sold at the chain Hamburgini in the capital city Riyadh. 

Dr Darin Detwiler, former FDA and USDA advisor and food safety expert at Northeastern University in Boston, told that while botulism is rare in the US, ‘the severity is high,’ making proper condiment storage essential. 

‘Condiments, including mayonnaise, can be at risk if not handled or stored properly,’ he said.  

Mayonnaise is an egg-based condiment, which leaves it vulnerable to bacteria like C botulinum and salmonella if not stored properly (stock image)

Mayonnaise is an egg-based condiment, which leaves it vulnerable to bacteria like C botulinum and salmonella if not stored properly (stock image)

Claudia Albuquerque Celada was sickened with botulism after eating contaminated soup, which experts believe was from improperly heating it

Doralice Goes was paralyzed after eating pesto contaminated with botulism

Claudia Albuquerque Celada (left) and Doralice Goes (right) were both infected with botulism and paralyzed after eating contaminated food

Botulism is caused by a toxin released by the bacteria Clostridium botulinum, which is normally found in mostly harmless spores in soil, marine areas, and on the surface of foods like fruits, vegetables, and seafood. 

These bacteria make spores, which act like protective coatings, which are usually harmless. 

However, warm and wet tight spaces lacking oxygen – such as plastic jars and cans – can lead to the bacteria to release toxins that attack the central nervous system.

Condiments at risk of foodborne illness 

  • Mayonnaise
  • Aioli
  • Pesto
  • Barbecue sauce
  • Ketchup
  • Mustard
  • Salsa
  • Horseradish
  • Nut butters
  • Tahini
  • Jam
  • Jelly

After opening these ingredients, store in a refrigerator. The exact times vary, but many last for several weeks or months when properly refrigerated 

The CDC estimates that there are just 200 cases of botulism in the US every year, and just 25 are from food, making it vanishingly rare. 

It’s unclear what other ingredients were in the contaminated mayonnaise and if the eggs were pasteurized, meaning they were heated to high temperatures to kill bacteria like C botulinum. 

Dr Detwiler notes that when it comes to botulism, ‘it’s usually the eggs’ that are responsible.

‘Botulism thrives in anaerobic (oxygen-free) environments,’ he said. 

‘Improperly sealed containers or poorly stored mayonnaise can create conditions favorable for the growth of Clostridium botulinum.’ 

Cooking eggs kills off this bacteria, but condiments like mayonnaise, aioli, and hollandaise contain raw eggs. This means they could still harbor harmful pathogens.

Dr Detwiler noted that the risk is highest for homemade mayonnaise, as it’s more likely to have unpasteurized eggs. 

‘However, commercial mayonnaise usually contains pasteurized eggs, reducing this risk,’ he said. 

To counter this risk, Dr Detwiler urges that you should ‘always refrigerate mayonnaise after opening,’ though unopened condiments can be stored in the pantry in a cool, dry place away from sunlight. 

Keeping condiments like these at room temperature for long periods of time allows bacteria to grow more, so storing them in the refrigerator stops that growth. 

And if you’re making mayonnaise from scratch, he suggests consuming it within a few days, and the FDA recommends throwing out perishable foods that have been left out at room temperature for more than two hours. 

In addition to mayonnaise, Dr Detwiler suggested refrigerating pesto due to it containing basil and cheese, as well as mustard.

Even barbecue sauce can be at risk because it ‘contains sugar and other perishable ingredients that benefit from refrigeration.’  

Dr Detwiler also urged consumers to watch out for bulging or leaking containers on the shelves, as these ‘are signs of bacterial activity, possibly including Clostridium botulinum.’

‘Do not consume these products.’ 

And avoid returning unused portions of mayonnaise and other perishable condiments to their original containers. ‘This prevents contamination of the entire container,’ he said.  

Dr Detwiler warned that signs of botulism include difficulty swallowing, muscle weakness, double vision, drooping eyelids, blurry vision, slurred speech, difficulty breathing, and trouble moving the eyes.

Foodborne infection can also cause vomiting, nausea, stomach pain, and diarrhea. 

‘Botulism is potentially fatal if not treated promptly,’ Dr Detwiler said. ‘Early diagnosis and treatment are crucial.’