Our Blog

Rules for Refrigerating Leftovers, Avoiding the Danger Zone

If you are a regular reader of our Make Food Safe Blog, you have certainly come across the danger zone phrase at least a time or two. Understanding this risky temperature range and what makes it so dangerous is a big part of food safety.

When talking about leftovers, there are a few rules to keep in mind. Follow along to keep your leftovers safe and understand when it is time to bid them goodbye.

These are the danger zone rules.

Let’s get started!

Danger Zone Rule Number 1: Know the Zone

You can’t avoid the danger zone if you don’t know what it is. Hint, it has nothing to do with a fighter pilot movie or the iconic song that goes along with it.

The danger zone is the well-established temperature that unfriendly microbes thrive in.

That comfy range of 40° F to 140° F.

Danger Zone

40° F to 140° F

It is the temperature between refrigeration and cooking.

While in this zone, harmful germs can rapidly reproduce. Even doubling in number within 20 minutes. Consider that a double of a double, then a double after that can quickly become an infectious quantity fairly quickly.

This is why it is important to keep hot foods hot and cold foods cold.

It is nearly impossible to keep food out of that temperature unless your salad is served on a plate of ice, or you are eating out of a heated crock.  The former would likely make a mess of the table, and the latter could pose potential burn risk.

So, under reasonable dining conditions, how long do you have in the danger zone?

Danger Zone Rule Number 2: Watch the Clock

This real, albeit mental clock does have a ticking timer. A theoretical time bomb.

So, when do things get dangerous.

How long until the proverbial BOOM?

That actually depends on the ambient temperature.

The warmer the temperature around the food, the narrower the window.

The commonly accepted danger zone time period is two hours. Under normal circumstances and ideal conditions. Assuming, of course, that the food has not been grossly contaminated prior to serving that is.

You lose an hour, though, if the temperature around the food is hotter?

The maximum amount of time food should be left in the danger zone drops to one hour if ambient temperature is 90°F or warmer.

Discard food left in danger zone for 2 hours

If ambient temperature is over 90° F, discard after 1 hour

For us in Texas, that could even be Spring picnic weather. It is important to keep an eye on the weather temperature as much as the food temperature if serving food outdoors or in a warm kitchen.

Danger Zone Rule Number 3: Serve Food Quickly

The clock doesn’t start when you take the first bite. The clock starts as soon as the temperature drops below the 140° F threshold for warm foods or rises above 40° F for cold ones.

Dinner conversation is an important part of the human experience. Especially when the gathering involves people you don’t see every day.

Don’t waste those precious minutes leaving food out before serving.

Keep the cold food chilled on ice or safely in the fridge before serving.

Use equipment like slow cookers, chafing dishes, warming trays to keep hot foods hot.

Take advantage of slow cookers set to “keep warm.” Or when applicable, use chafing dishes, preheated steam tables, or warming trays to keep food out of the danger zone for as long as possible. This is especially important if food is served buffet style and left out for those wishing for seconds (or let’s face it, some dishes need thirds).

If there is still time on the clock, you can save those leftovers safely with our next rule.

Danger Zone Rule Number 4: Refrigerate Leftovers Promptly and Properly

It may be tempting to just put that deep pot of soup in the fridge. Or save dishes and stuff the leftover rice into a single bowl. Those could be mistakes.

The more dense the food is packed, the longer it takes for it to chill to refrigerated temperatures.

Avoid placing hot dishes in the refrigerator. It will increase the temperature of the space and take longer to cool your leftovers and leave food already in the fridge more vulnerable.

Transfer leftovers to shallow containers as quickly as possible. A shallow container will cool faster than a deep one.

Place leftovers in shallow containers for faster cooling.

The clock doesn’t hit pause just because you placed the food in the refrigerator. There are situations where you can earn an “E” for effort. But this isn’t one of them. The clock is only paused when the food reaches the lower end of the danger zone. 40° F. Don’t’ waste valuable cooling time with unnecessarily deep leftover containers.

Future you will appreciate the effort.

What Kind of Germs Thrive in the Danger Zone?

Most germs love the cozy temperatures in the danger zone. Some, more so than others.

  • Staphylococcus aureus
  • Salmonella Enteritidis
  • Escherichia coli O157:H7
  • Campylobacter

These bad bugs can cause serious illness, including:

  • Vomiting
  • Diarrhea (bloody diarrhea)
  • Headaches
  • Muscle aches
  • Fever
  • And more!

Certain complications may arise from these bad bugs.

Complications like:

  • Reactive arthritis
  • Guillain Barré Syndrome
  • Hemolytic uremic syndrome
  • Brain damage
  • Death

How Long Are Leftovers Safe?

Now that you know how to store leftovers properly, how long are they good for? The danger zone is not a suspended period. It does have its limits after all.

If leftovers are stored in the refrigerator, you can keep them around for three to four days.

If frozen, technically they can be kept indefinitely. However, long periods in the freezer may leach moisture out of the food and change the texture. The rule of thumb is to discard frozen leftovers after three to four months in the freezer.

Want to Learn More? Stay in Touch with Make Food Safe!

If you’d like to know more about food safety topics in the news, like “Rules for Refrigerating Leftovers, Avoiding the Danger Zone,” check out the Make Food Safe Blog. We regularly update trending topics, foodborne infections in the news, recalls, and more! Stay tuned for quality information to help keep your family safe, while The Lange Law Firm, PLLC strives to Make Food Safe!

By: Heather Van Tassell (contributing writer, non-lawyer)

Heather Van Tassell

Recent Posts

How Many of These Risky Food Behaviors Are You Guilty Of?

Risky food behaviors can lead to foodborne illness. Small choices can have a big impact…

13 hours ago

Outbreak Data Through 2023 Now Available to the Public

Have you ever wanted to comb through outbreak data like the pros do? The comprehensive…

15 hours ago

New Use for Existing Technology to Detect Salmonella May Make Eggs Safer

Whole genome sequencing can detect Salmonella faster than traditional culture methods. Especially at lower concentrations.…

2 days ago

USDA Withdraws Proposed Updates to Prevent Salmonella in Raw Poultry After Working on the Project for Years! Why?

A recent announcement from the United States Department of Agriculture (USDA) to nix a regulatory…

2 days ago

The Biggest Raw Milk Recalls in History

Raw milk has been a controversial topic especially lately when it seems that every time,…

3 days ago

CDC Releases Updated Foodborne Illness Statistics Report. Why Does Historical Data Matter?

The Centers for Disease Control and Prevention (CDC) issued their updated foodborne illness statistics report.…

3 days ago