Aug. 8, 2011 -- School sack lunches packed by parents can save money and help satisfy picky eaters, but the perishable foods in these lunches are often potentially hazardous because the foods are not always kept at safe temperatures. That’s according to a new study conducted at preschools and published in Pediatrics.
"Our study found that most parents do not keep their preschoolers' lunches cooled enough to be safely consumed," says Fawaz D. Almansour, a PhD candidate at the University of Texas at Austin.
Almansour and colleagues tested 705 sack lunches given to 235 preschool children, aged 3 to 5, on three different days.
Only 1.6% of the 1,361 perishable foods tested were at safe temperatures, they found.
School Sack Lunches: Study Detail
Almansour focused on meats, dairy, and vegetables. Those foods are linked to a higher risk of causing food-borne illness if eaten at unsafe temperatures, he says.
The researchers tested school lunches at six different central Texas child care centers in the fall of 2008 and at three other centers in fall 2009. The classrooms were air-conditioned, with temperatures about 71 to 75 degrees. Outside temperatures were about 81 degrees.
Using a temperature gun, the researchers tested lunches on three random and nonconsecutive days. Testing was done between 9:30 a.m. and 11 a.m., about an hour and a half before the children ate.
Although about 12% of the lunches were stored in refrigerators, more than 88% were stored without refrigeration.
Even with ice packs in the sack lunches, most of the lunch contents that were perishable were at unsafe temperatures. "More than 95% of them were in the danger zone," Almansour says. "The average temperature was 62 degrees Fahrenheit.”
To be safe, the perishable foods should have been at 40 degrees or below, he tells WebMD.
Keeping perishable foods at more than 140 degrees or less than 40 is advised to prevent food-borne illness, Almansour says. Perishable foods left out between 40 degrees to 140 degrees for more than two hours are considered unsafe to eat.
When researchers looked at the types of foods, they found 97.4% of the meats were at unsafe temperatures, as were 99% of the dairy and 98.5% of the vegetables.
Even school sack lunches placed in the refrigerator were at unsafe temperatures. Almansour says many of the refrigerators were old, some were not working properly, others were opened and closed often.
Nearly half of day care centers, he says, require parents to pack lunches. Older children, too, often skip the hot lunch program at school and presumably take their own brown bag lunches.
School Lunches: Perspective
Aaron Glatt, MD, a spokesman for the Infectious Diseases Society of America, tells WebMD the risk identified in the study is theoretical, as the researchers did not track food-borne illness.
"It's unknown if this makes a difference [the study findings] from a health point of view," says Glatt, president and CEO of St. Joseph Hospital in Bethpage, N.Y.
Even so, safe food storage is important, he says. He urges parents to ask schools about refrigeration if they pack perishables in their kids' lunches.
Lunch-Packing Tips for Parents
Almansour, a parent, knows mornings can be hectic when trying to get to work and get your child to school or day care.
He advises parents:
- Keep the packed lunch in the refrigerator until right before the child is ready to go.
- At school, put the lunch of a younger child in the refrigerator yourself, if possible, instead of relying on staff to do so. Ask your child's preschool staff to monitor opening and closing of the refrigerator so food will remain cold.