Cross-contamination at high levels due to poor hygiene, study finds

Caitlin McCormack
Shine On

A recent study released by the Global Hygiene Council has found that preparing one meal can contaminate up to 90 per cent of kitchen surfaces touched — putting many Canadians at risk for foodborne illness.

"The kitchen is a bacteria hotspot and proper food storage and hygiene during food preparation and cooking are very important for preventing foodborne illness," says Dr. Donald Low, microbiologist-in-chief at Mount Sinai Hospital in Toronto and Canadian member of the Hygiene Council. "There are an estimated 11 million cases of foodborne illness in Canada every year. Although most people fully recover, foodborne illness can cause serious health complications, and sometimes death, in children, the elderly and those with weakened immune systems."

In the 2012 Lysol Cross-Contamination Study, volunteers were asked to prepare various meals, including a chicken-stir fry, a salad and a packed lunch. What researchers found was that germs were spread among surfaces, including kitchen towels, sponges and dish cloths.

As previous studies on hygiene have found, washing your hands well is paramount to preventing the spread of germs and preventing foodborne illness. This study found that participants were more likely to simply rinse their hands after touching raw chicken or vegetables than wash them with soap, even when it was provided.

While most people know that raw meats carry harmful bacteria, few realize that raw veggies can also be a source of foodborne illness, as evidenced by a deadly E. coli outbreak in Europe last summer from raw, unwashed vegetables.

Not only did the study participants not wash their hands after touching the raw vegetables, they also didn't wash all of the salad items before consuming.

Chopping boards and knives were found to be contaminated in 92 per cent of cases. The faucet was contaminated in 86 per cent of cases. Other heavily contaminated items included kitchen towels, cloths and sponges, which participants used to wipe their hands during the meal prep.

[See also: The secrets of people who never get sick]

A second study was conducted in which an environmental health practitioner carried out meal preparation tasks with deliberately contaminated foods. The researchers found that when good hygiene practices were followed; cross-contamination was reduced from 90 per cent of sites to 16 per cent of sites touched, underscoring the importance of proper food preparation.

"Bacteria such as E.coli have been a major cause of recent food associated outbreaks," says Professor John Oxford, chairman of the Hygiene Council and professor of virology Queen Mary College, University of London. "However, simple hygiene measures can protect you and your family from infection. Washing your hands with soap after touching raw meat and vegetables is vital, as is disinfecting food and hand-contact surfaces, such as cutting boards and fridge door handles."

For information on proper food safety, check out Health Canada's Safe Food Handling page or see the tips below from the Hygiene Council to protect against harmful bacteria and cross contamination:

Hand hygiene

  • Wash hands thoroughly using soap, hot water, and clean towels after each stage of food preparation and before eating. Simply rinsing hands under the faucet is not effective.
  • Automatic soap and liquid cleaner dispensers (no touch) reduce the spread of contamination from hands to the soap dispenser bottle.

Surface hygiene

  • Clean and disinfect food preparation areas prior to contact with food and immediately after contact with any raw food (e.g., poultry, meat, fish, eggs, vegetables).
  • Hand-contact sites, including faucet handles, condiment jars and garbage can lids should be sanitized. Consider using antibacterial wipes or antibacterial sanitizer with paper towels for cleaning high risk surfaces.
  • Kitchen towels, cleaning cloths and sponges used for cleaning up after handling raw meat, poultry, and vegetables, should be disinfected, washed in a hot wash (greater than 60 degrees Celsius) or disposed of after use.
  • Refrigerators and sinks are at a high risk of contamination and should be cleaned and disinfected regularly.

Food preparation

  • Cut meat and vegetables with separate knives and cutting boards.
  • Soak, scrape, brush, scald, or wash all fruit, salad and vegetables.
  • Do not wash raw meat in the sink prior to cooking as this spreads germs around the sink area. Washing raw meat is unnecessary as proper cooking will destroy harmful bacteria.


  • Always cook all poultry, pork, and ground beef thoroughly above 75 degrees Celsius.
  • Don't leave cooked food sitting at room temperature for longer than two hours.
  • Reheat and re-serve leftovers only once.

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