Ninety Percent of Preschoolers’ Sack Lunches Reach Unsafe Temperatures

Aug. 9, 2011

AUSTIN, Texas — More than 90 percent of sack lunches prepared at home and sent with kids to preschool were kept at unsafe temperatures, a new study by nutritional scientists at The University of Texas at Austin found.

The study will be published in the September 2011 issue of Pediatrics and was published online Aug. 8.

"Parents need to be aware of how important the storage temperature is for foods they pack for their young children," said Fawaz Almansour, a graduate student in the Department of Nutritional Sciences and lead author of the research.

The best storage temperature is below 40 degrees Fahrenheit for cold foods and above 140 degrees for hot foods. Between 40 and 140 degrees is the "danger zone."

Study authors suggest that parents and the public need to be educated on safe food packing practices in order to prevent bacteria from growing and potentially causing illness.

Almansour and his colleagues, including Professor Margaret Briley and postdoctoral researcher Sara Sweitzer, collected data on sack lunches from more than 700 preschoolers at nine Texas child care centers. The lunches were measured with noncontact temperature guns one and one-half hours before the food was served.

They found that while 45 percent of the lunches studied had at least one ice pack, 39 percent had no supplemental ice packs. Even including lunches with ice packs, 88 percent were at room temperature. Less than 2 percent of lunches with perishable items were found to be in a safe temperature zone, while more than 90 percent (even with multiple ice packs) were kept at unsafe temperatures.

Perishable items studied included meats, cheeses and vegetables. Prepackaged foods produced by manufacturers were not included in the study.

“The simple addition of one extra icepack could have prevented many of the perishable items in lunches from reaching the danger zone,” wrote the researchers in their study.

They go on to say that the addition of two or more icepacks in lunches could help prevent food-borne illness in children.

For more information, contact: Lee Clippard, Lady Bird Johnson Wildflower Center, 512-232-0104; Fawaz Almansour, graduate student in the Department of Nutritional Sciences.

28 Comments to "Ninety Percent of Preschoolers’ Sack Lunches Reach Unsafe Temperatures"

1.  karen sullivan said on Aug. 9, 2011

As a mother, I already know that bag lunches rise to room temp. before lunch time. I need to know if children who bring bag lunches get sick with food borne illness more that those who eat school provided lunches. We all grew up "brown bagging it" and seemed to be fine. My child is overweight and eats healthier choices if I pack his lunch from home. What bacteria actually grow and do they reach dangerous levels? Preschoolers and those in primary grades are already at increased risk of rotovirus and fecal borne illnesses because of their peers' hygiene habits, so this issue is important to me. Thanks for doing this types of research.

2.  Peter Tsan said on Aug. 9, 2011

Could this be verging into the realm of sensationalism? I survived years of eating sack lunches when I was in school without ever paying attention to the temperature at which I stored my food. I think it would have been more relevant if the study authors had measured how many kids actually got sick as a result of eating their improperly stored lunches, along with the impact of illness.

3.  Amanda said on Aug. 10, 2011

I agree with the sensationalism comment. And really, most food borne illnesses occur as a result of human contamination (i.e. servers with unwashed hands).

4.  Lauren said on Aug. 18, 2011

I, like the above commenters, grew up bringing my lunch from home. However, since these lunches consisted mostly of sandwiches made of processed luncheon meats and mustard, whole fruits or bagged chips and a packaged juice drink, the likeliness of food poisoning was probably low. I agree that the impact of the lunches on kids seems more important than the temps of the food. The authors also might want to reiterate what types of food are most dangerous (mayo, chicken or egg salad, deli meats, etc) and which are probably ok.

5. said on Aug. 18, 2011

Thank you for performing the study. I will add more ice packs to my daughter's lunches. It is always appreciated when research helps me to be a better parent.

6.  Chris said on Aug. 18, 2011

Is this a joke? I still take a lunch with me to law school and so far, over 25 years of eatIng brown bag lunch, I am fine. This study was inadequate at best and offers no source of information, no details on the study, and as a poster above said, no information about the likelihood of injury.

7.  R Noel Rodriguez said on Aug. 18, 2011

An article begging to ask "what are they doing with public money in universities? " Grow up. There are thousands, no millions, of us out here in the real world who survived sack lunch diets throughout primary and secondary school. I cannot remember anyone going home from food poisoning. The better thing would be educating parents about what is real food and what is filler. Most people today have no idea what is really food anymore. Mister researcher, get a life.

8.  John Kent said on Aug. 18, 2011

Good information worth heeding, but as a survivor of un-air conditioned schools in Fort Worth from kindergarten to 12th grade in the '60s and '70s, I must have eaten a thousand 85-to-95-degree tuna or ham sandwiches that my mother packed in my lunch box. They progbably were teeming with who knows what kind of microbes, but I can't recall ever getting sick.

9.  steve said on Aug. 18, 2011

My friend who cannot afford private school volunteers as a lunch room monitor/helper at an elementary school so the teachers can have a respite and to keep school bullies at bay was constantly amazed at the lack of nutrition in the sack lunches brought from home. Seems to me some of the PhD brilliance and “religious” “charity” that is not phony PC religion individual dignity debilitation could be just as easily spent on "discovering" low and no cost, not requiring more taxes, ways and strategies to affect higher reading writing and arithmetic scores and to solve and ameliorate rush hour traffic. I had an aunt, albeit before computers and computer donations to schools, than was a school teacher. At the start of a typical school year she would have 18-22 students that spoke seven different languages in grade levels 1-6 in a one room school. There were few books and no library. Within three weeks they were all on task in English. Within three months everyone was speaking rudimentary English. This type of individual character is not what made our state an imperialist or communist high tax dependent agent of oppression and suppression that just goes through the motions and that is in reality and result insensitive to “the least of these”. Don't say it is lack of money either. The former superintendent of schools in my area is being paid over eight thousand dollars a month in retirement and two schools were closed under his reign. The new boss is same as the old boss. The above is my opinion based on real facts not contrived often maudlin data and statistics gathered or provided by a paid consultant dependent on a grant or a future grant or sales contract or over paid bureaucrat job. We need more doers and less carpers and naysayers and fewer lawyers and more regular people running for elected offices. The bureaucrat tail end is wagging the dog and debilitating the common sense and the common good-again, my opinion.

10.  Amy said on Aug. 18, 2011

Do y'all ever talk about brown bagging in your ed. w/parents?

11.  Mui-Hiang Goh said on Aug. 18, 2011

When can you tell how many ice-packs are sufficient in keeping food at the right temperature?

Based on the research that even with multiple ice-packs, more than 90% of lunches are kept at unsafe temperature levels.

12.  Charles Soto said on Aug. 18, 2011

Amanda, please cite your sources. Peter, that's anecdotal. Karen, thanks for bringing up a very good question about sack lunches versus school meals. I'd like to know that, too. Finally, is it really that hard for people to remember to throw in a "cool pack" with your kid's sandwich? We got a pair at Target with Star Wars stuff on it. It's trivial to wash it and pop it back in the freezer every afternoon. Geez.

13.  Stacy said on Aug. 18, 2011

Common sense tells us to pack school lunch bags with sufficient ice packs. This sounds more like a junior high science fair project, not a graduate level project.

14.  Greg Gordon said on Aug. 18, 2011

Ice packs in bag lunches, give me a break. Kids have been carrying their lunch to school since the pilgrims landed on Plymouth Rock. Get sick from a lunch your mom packed, forget about it! It never happens. Cheese is dangerous, since when? Rub the mold off and eat it anyway. I hope the federal government didn't pay for this study.

15.  Peter said on Aug. 18, 2011

By the time I have finished perparing my sandwich for lunch it is at ambient temperature. No measurement needed. The relevant questions which are not addressed here are: How long does it take for harmful bacteria to grow to harmful levels at ambient temperature if the food was prepared using household "clean" practices? How about if the food preparer (aka Mom or Dad) did not wash their hands (non-clean practices)? How much is the growth of these bacteria slowed down if an ice pack is used? What is the effect of proper wrapping (e.g. ziplock bag) alone?

16.  CW said on Aug. 18, 2011

While the study is on an important topic it really seems to miss the most important information. I need to know the real effect of a lunch going to room temperature. The fact that it does is no surprise. How much bacteria growth actually occurs and how does it affect the likelihood of sickness. I suspect that the lunch leaves home at a cool temperature, then its temp moves toward room at some rate during the morning hours. If the child eats it a noon (my kids actually eat before noon) then there will have been a certain amount of time that the lunch is in the "danger zone." Is there enough time in that temp zone for there to be an appreciable increase in bacteria to the extent that more sickness results? My experience (assuming the lunch gets eaten at lunch and doesn't sit until the late afternoon or next day) tells me there is not any change in sickness rates. But if I'm wrong, then that's what I want to know.

17.  Cyndy Pare' said on Aug. 18, 2011

With the vast majority of schools being air conditioned, I don't see the temperature reaching 140 degrees. As a teacher, those few who did bring lunch kits, usually had at least one ice pack and were in insulated lunch kits.
My grandchild's lunch kit is insulated. I put in 2 ice packs into an insulated lunch kit and usually put the small water bottle into the freezer first thing in the morning. It usually is in there about 1 hour, and is just beginning to freeze, so there is a 3rd cold item in the lunch kit. Upon returning home in the late afternoon, the ice packs are still partially frozen.

18.  Linda Jowett said on Aug. 18, 2011

The study said the lunches were tested 1 - 1 1/2 hours before they were served. I would like to know how many hours passed from the time they were prepared to the time they were served.

Also, there seem to be somewhat contradictory statements about the effectiveness of the use of multiple ice packs.

What is the amount of time that lunchmeats, cheese and raw vegetables can be left at room temperature and still be eaten safely? I know that mayonnaise is not to be left out, but a lot of these lunch items are taken on picnics and set out on casual lunch buffets all the time and there are not many problems we hear about.

Thank you!

19.  Geraldine Conrad said on Aug. 18, 2011

This might be a bit off-topic but all this puts me in mind of the "we were tougher when we walked to school in the snow," outlook, something to which I heartily subscribe. When I was in 8th grade, almost 100 died in our Lady of Angels school fire, when one class of almost 48 suffered the worst. No law suits, no counseling, just grit. One nun did have a breakdown and left the classroom a month later. Puts room temp lunches in perspective.

20.  Whalen said on Aug. 18, 2011

Maybe schools and preschools should have refrigerators that the students can use? Of course an adult would have to oversee the fridge to ensure stealing didn't occur. At least in elementary school. They do make them with locks. But I would think it would be safe to eat cheese, fruits and vegetables at room temperature.

21.  Mike B said on Aug. 19, 2011

If the food stayed at room temperature for two days, I would see this as an issue. But the food is packed in the morning and eaten within a few hours. If you food is catching harmful bacteria that fast, a filthy environment is the problem, not the food temperature. Trying to prevent this would require fridges and heaters for millions of lunches every day. The space and logistics alone are not easy to overcome. These fridges and heaters would only be used for 4 hours a day, and then left on the rest of the time. There would probably be more detrimental consequences of using all the extra energy and polluting the air and using tax money for this instead of books, and the cost of everyone's energy prices going up, preventing families from affording healthy food and medicines than from potential bacteria growth on food.

In schools, if children have a medicine they need to take and it need to stay cold, teachers will let them store the medicine in the faculty lounge.

Parents already know about safe food temperatures. These food items are taken out of a fridge and put into lunch sacks. A parent that didn't know about safe food temperatures would not own a refrigerator and would store their diary and meat products on a regular shelf.

22.  Dick said on Aug. 23, 2011

Thought this was an article from the onion at first. Worst graduate research project ever. Who funded this?

23.  Shawn Miller said on Aug. 23, 2011

So glad that my taxdollars and students' tuition dollars are being spent on important information like "Ice packs keep food cold."

And people wonder why tuition keeps rising, to pay for studies like this.

24.  Mom of 2 said on Aug. 24, 2011

Honestly as a single mom of two in elementary, I would rather delegate out and have my kiddos eat at school more. However, given what they serve at the school, I would rather risk my kids eating a home made lunch with 1 ice pack (unlikely they will get food poisoning) than eat the unhealthy junk they serve. My school actually serves something called pancake and sausage on a stick for Lunch! I actually ate tuna sandwiches back in the 70's with no ice pack and questionable air-conditioning...nothing ever happened! I am curious, what were your controls? At the school you tested, did any of the kids actually get sick from their home-made lunches? Or are you just assuming they would? Plus, did you take your research further to eliminate the possibility that if they did get sick that it could be from uncleaned table surfaces??? Has anyone ever looked at the cleaning equipment the facilities staff uses - disgusting! Sure, no bacteria there! I think concept screaming this study in the face is that parents are doing the very best for their children by making lunches because we cannot get the state/govt/school systems to see that they serve gross food! Ever eat a burrito from an elementary school? My kids refuse to eat at school. I am a bit of a health nut, so my kids grew up eating fresh and healthy food cooked the right way; not the over processed-over cooked food they serve in the schools - how is THAT healthy. They find the school food disgusting - from the mouths of they take "brown bag" lunches, eat it all and are happy and healthy! Sorry, I hope this isn't the main theme of your research-I don't think it will cut it. :o (

25.  Jim Santiago said on Aug. 25, 2011

This is good information for school age children.

26.  Thomas Palaima said on Aug. 26, 2011

As a faculty member who is tired of seeing mindless research promulgated on the UT Web site--the all-time classic was a study of whether having young children watch television 5-6 hours per day would affect negatively their development of interpersonal social skills--I am glad to see so many respondents wondering whether this was the equivalent of a spoof from *The Onion*. Sadly it is proof of what the satirist Juvenal wrote during the late first and early second centuries AD. Just observe and write what you see. Your indignation at what is happening will in and of itself turn your factual account into satire.

And just wait until the Longhorns Network kicks in with its entertainmentification (my neologism) of what professors research, write and think.

27.  Jenne said on Aug. 28, 2011

If the FDA sets the maximum time food can be within 39-140 degrees to FOUR hours, why did the researchers say it was unsafe after TWO hours?

28.  Tiffany said on Aug. 29, 2011

Thank you for this information - I have been curious about this for my own 2 young elementary children and will add more ice packs and pack things that are not prone to food borne illness. Ignore the haters - there is a reason some people have advanced degrees and some don't. Perhaps once this information is published in Pediatrics, schools will think about offering refrigeration for sack lunches. Right now, where I live (in Austin) the choices are a) unhealthy cafeteria food or b) send something that can reach a high temperature and be safe - often PB&J (which is dangerous for kids with allergies).