Don Schaffner, a food microbiologist from Rutgers University, leads the discussion challenging the validity of the '5-second rule,' revealing that even the most innocent-looking food can harbor hidden dangers. Sally Bloomfield, a home hygiene expert, highlights the risks we take daily, including improper fridge temperatures, while Ellen Evans discusses our behavior around food safety. They explore how wet foods like watermelon attract more bacteria, and offer practical tips to navigate cleanliness in our kitchens without sacrificing our snacks.
The five second rule is debunked as bacteria transfer occurs almost instantly, influenced more by food moisture than time on the floor.
Hygiene should focus on minimizing harmful microbes from food preparation areas rather than solely fearing contamination from dropped food.
Deep dives
The Mystery of the Five Second Rule
The five second rule is a widely known guideline suggesting it's safe to eat food that has fallen on the floor if picked up within five seconds. However, research indicates that there is no safe time threshold; bacteria transfer can occur almost instantaneously across various surfaces. This understanding challenges the perception that simply picking food up quickly can prevent contamination. Instead, factors such as the moisture of the food and the nature of the surface play a crucial role in the degree of bacteria transfer.
Moisture and Bacteria Transfer
Moisture in food significantly affects bacteria transfer; wet foods like watermelon attract bacteria much more than dry foods. Research demonstrates that when moist food comes into contact with a contaminated surface, a significant bacterial transfer occurs immediately. In contrast, dry foods like bread and gummy candy reveal much less bacteria transfer. This insight highlights that the type of food dropped is critical in assessing potential safety concerns.
Surface Matters in Hygiene
The type of surface where food lands also influences bacterial transfer. Studies show that food dropped on surfaces such as carpet may have less bacteria transfer due to the way bacteria sink into the fibers, making them less accessible for transfer. However, this is not an endorsement for using carpeted areas in kitchens, as hidden bacteria can still pose risks. This finding emphasizes that surfaces not immediately visible can contain contaminants that could affect food safety.
The Role of Risk and Hygiene Practices
Hygiene practices should focus on avoiding the transfer of harmful microbes, particularly from raw food preparation areas rather than fearing contamination from floors. Experts suggest that while people should be cautious of where food falls, they must also understand that the risks are often minimal in many household environments. Building awareness about proper handwashing and food handling practices can significantly reduce the risk of illness. Ultimately, risk management and mindful hygiene practices create a better balance between living with everyday risks and maintaining health.
Would you eat food that fell on the floor? That’s the question Hannah and Dara are getting their teeth into this week as they put the so-called ‘5 second rule’ through its paces.
For some people it’s 3 seconds, and for others its 10 – especially if it involves a dropped ice cream and a screaming child. But microbiologist Don Schaffner says there’s no safe amount of time to leave food on the floor if you’re planning to eat it. And while you might think buttered toast would pick up the biggest number of bugs, it may surprise you to hear that wet foods like watermelon are actually the worst when it comes to attracting harmful bacteria.
If all this is putting you off your dinner, the bad news is that the rest of your kitchen is also a microbiological minefield. Research shows nearly 70% of us keep our fridges are the wrong temperature, which sparks a lively discussion about whether it’s ever safe to reheat rice.
For home hygiene guru Sally Bloomfield it’s all a question of being a bit more clever about the kind of germs we expose ourselves to and weighing up risks.
Contributors:
Dr Don Schaffner: Rutgers University
Dr Ellen Evans: Cardiff Metropolitan University
Professor Sally Bloomfield: International Scientific Forum on Home Hygiene
Producer: Marijke Peters
Executive Producer: Alexandra Feachem
A BBC Studios Audio Production
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