Red Light – Green Light: Shopping Cart Bacteria

Posted in Food Safety,Pathogens on October 5, 2018

The official start of fall is just around the corner, but for many parts of the country this doesn’t mean much when it comes to the temperature dial.  At least not right away.  While temperatures scorch and it’s hot enough, albeit messy, to cook an egg on the hood of your car.  Hot enough for the bacteria lurking in your food to play a dangerous game of Red Light – Green Light. The Shopping Cart Bacteria Game begins.

Red Light – Green Light?  You know.  The childhood game where one kid acts as the traffic cop.  Kids line up waiting for the traffic cop to give the signal.  Green Light!  Kids take off running toward the finish line.  Red Light!  Traffic cop turns around and kids freeze in place.  Anyone still moving gets a “ticket” and has to leave the game.

So what does this have to do with food safety?  Unless a package is hermetically sealed and non-perishable, some bacteria can be present in the food.  This is generally not a really bad thing, unless the bacteria grow in abundant numbers.  Perishable foods kept outside of the danger zone – between 40 ⁰F and 140 ⁰F.  Hot foods must stay hot (above 140 ⁰F) and cold foods must stay cold (below 40 ⁰F).  Anything in between is the happy, frisky temperature where bacteria happily and quickly reproduce.

The Food Safety Investigative Services (FSIS) warns that foods should never be left outside of refrigerator temperatures for more than 2 hours and that clock gets reduced to 1 hour if temperatures raise above 90 ⁰F.  The moment you remove that meat from the refrigerated bin at the grocery store, that clock starts ticking.

Green Light!  That light stays green while you are walking around the grocery store – Taking your time deciding between saltine or club crackers.  Deciding which brand of juice to get.  Wait…  I forgot to get bread, let me go back for that. Tick tick tick.  Green light is still on, the temperature is rising to the danger zone.  Bacteria reproduce.

You get to the checkout line.  Wait.  Still Green Light.  Step outside in the Texas sun.  Now we are well within the danger zone.  Sitting in your car at a red light.  There is still a Green Light going on in your grocery bags.  Stopping for an errand on the way home?  That is dangerous.

The moment the air conditioning stops in your car, the temperatures begin to rise.  Within minutes the temperature on the inside of the car can go from 80 ⁰F to a toasty 99 ⁰F.  After just 20 minutes this can get to 109 ⁰F or hotter.  The greenhouse effect inside the glass windows of the cab are responsible for this effect.  Though the real damage will be discovered much later.

That game of Red Light – Green Light continues on until the food is prepared and consumed.  Unfortunately for that package of meat, in the game of Red Light – Green Light, the light doesn’t turn Red until the package makes its way below 40 ⁰F again in your refrigerator at home.  Red Light!  Every time you remove the item from the refrigerator – Green Light!  Cook foods to above 140 ⁰F – Red Light!  Cooked foods begin to cool – Green Light!  Leftovers are refrigerated – Red Light!  You get the picture.

Bacteria will grow and reproduce.  We are certain of that.  But what can we do to minimize this growth?  How can we keep that light Red even longer?  I have compiled a list of tips that will help keep that light Red for as long as possible, keeping your food out of the danger zone to minimize the growth of harmful bacteria.

Shop Cold Items Last –  Shop smart in the grocery store.  Plan your path to pick up cold items last.  Shop the dry and canned goods first, produce next, then refrigerated and frozen items.  I also like to keep cold foods together in the shopping cart to help keep things cooler longer and to help the cashier or bagger put my cold things together.  I say this with the warning to keep meats together and away from other items.  Let the meats keep each other cold.  The ambient coolness is not worth the potential cross-contamination from sitting refrigerated lettuce on a package of pork chops.

Bag Smart at Check Out – If you are not bagging the items yourself, ask your bagger to put the cold items together.  This will help reduce the ambient temperature and keep the collective group colder a little longer.  The same goes for segregating meats.  Do not put meats in the same bag as anything but meat.  Avoiding cross-contamination begins in the grocery store.

 Pack an Insulated Bag or Cooler – Invest in a good insulated bag or cooler.  An insulated bag and an ice pack can do a lot of good for keeping the temperature down on the ride home.  If home isn’t your only stop, opt for a cooler with ice to ensure you keep your cold things cold in transit.  It takes a little planning, but a little planning goes a long way to keep your family safe.  The light is Green while walking through the store and to your car.  Flip that light to Red by cooling the food again in the vehicle.

Put Groceries in the Cab – While it may be easier to use the trunk of your car to load and unload groceries, it might not be your safest option.  If the weather is close to or below 40 ⁰F then you may be able to consider that option.  Otherwise, your groceries should enjoy the cool air of the air-conditioned cab alongside you.  Allow them to ride “shot-gun” (in the front seat) if you can or put them in the seats as opposed to the floor to elevate them to where the air vents can reach them.  The name of the game is lowering the temperature and trying to keep that game on Red Light as long as possible.

Go Straight Home – If at all possible, go straight home.  Leaving groceries in a hot car will rob you of precious time before the food begins to spoil.  Remember food should only be left out of refrigeration only one hour if the temperature reaches 90 ⁰F (easily achieved when the car is left in a hot parking lot).  If you aren’t going straight home, bring a cooler with ice, but keep an eye on the time.  You will want to get home as soon as possible

Shopping can be tedious or fun, but it can also prove dangerous.  Remember this little game of Red Light – Green Light next time you are transporting perishable items home from the grocery store.

By: Heather Van Tassell, Contributing Writer (Non-Lawyer)