MREs can do wonders in a wilderness or survival situation. All you have to do is heat a meal with a heater provided with the meal. This heater may only work for one meal.
MRE (Meal Ready to Eat) heaters are not reusable. The heating process involves a chemical reaction between powdered iron, magnesium, salt, and water. This reaction lasts for 10-12 minutes one time. This is just long enough for the meal to be heated.
MRE heaters only last for one meal, but how and why do they work? Also, what are the dangers of keeping one long term?
Are MRE Heaters Reusable?
MRE heaters are not reusable. These heaters which are packaged along with the MRE are intended for one-time use in all circumstances.
Later on, we will discuss the exact process in which a heating packet works. Simply put, in that section we talk about the chemical reaction that needs to take place for the packet to heat up.
“The flameless heater uses a simple chemical reaction to provide sufficient heat to warm the food.” Source
This chemical reaction is not easily replicated and makes it so that the heaters are only for one-time use.
To take it even further, this reaction only happens for a short period of time. So, not only is it a one-time use, but it is a brief one-time use.
This chemical reaction makes it so that “the heater releases enough heat to warm-up the pre-cooked meal to 100+ degrees Fahrenheit in approximately 12 minutes.” Source
This short period of time is the only time the heater will work. It is just enough to heat the packet to the point where the food is edible. After this point, it is time to open up another heating packet if you want to heat something else.
On the plus side, the packets are fairly cheap. This Amazon link shows 12 heating packets with a cost just short of $20. Source
While heating packets in MREs are intended for only one use, it is fairly easy to purchase more.
What Heats A MRE?
All MRE heaters have to do is use a simple chemical reaction to heat the MRE. This chemical reaction involves iron, magnesium, salt, and water.
The basic idea behind the flameless heater is that metal oxidizes. To put it a little more simply, metals like iron and magnesium start to rust, and when that happens they start to heat up.
The way the heater works is that some magnesium and iron are ground up into a powder so they can rust extremely fast. Along with the powders of these two metals, they add a little salt to the mixture.
All that needs to happen now is that the soldier (or whoever is eating the MRE) needs to add water.
This will start the reaction process, heating the package to the point where it can cook the MRE.
“To make a flameless heater, magnesium dust is mixed with salt and a little iron dust in a thin, flexible pad about the size of a playing card. To activate the heater, a soldier adds a little water.” Source
Again as you can see, this is not a process that is not easily reusable. To be able to reuse one of these heater packets, someone would need to mix more powdered magnesium, iron, salt, and water.
The much simpler option would be to purchase another heating packet.
How To Heat A MRE
Heating up and eating a MRE for the first time may not be an easy process if you are not sure what you are doing. In this section, we aim to help you in that process so you don’t have to embarrass yourself.
Below is a step-by-step list of directions that can help you understand what to do. Along with this is a link to a similar step-by-step list with pictures.
- Open up the MRE bag
- Look for the bag labeled heater
- Fill the heater with water
- Let the heater rest for a minute
- Insert food still in it’s package
- Stand the heater up
- Let the food heat for a few minutes
- Take food out of the heater
- Open the food package from the top Source
Along with this list of directions, below you can find a video that shows you exactly how to heat your MRE.
Dangers Of MRE Heaters
While MRE heaters in themselves are not particularly dangerous, there are federal laws and regulations against storing large amounts of these heaters.
Think about it real quick, one heater can be heated to 100+ degrees in 12 minutes with just a little water.
There is a real possibility of a very dangerous situation happening if a whole bunch of heating packets are together.
“Unused MRE heaters…are considered…a hazardous waste. Organizations which utilize MRE’s must establish procedures to ensure that unused heaters…are not disposed of in the regular trash [but] are collected by supervisory personnel. Collecting and storing unused MRE heaters [with] the…intent…not to…reuse…is a violation of Federal law.” US Dept. of Agriculture Forest Service
Source
Just like all things that use a chemical reaction, these heating packets must be treated and handled the right way. It may not seem like a huge deal, but the fact that it is a federal law makes my ears perk up. I personally don’t want to be looking at a fine or jail time because I didn’t use, store, or keep my heating packets the right way. To me, that has got to be the worst way ever to commit a crime.
In the end, heating packets are not reusable. The chemical reaction that makes it possible can not happen twice with the materials provided in a heating packet. If you only have a certain amount of these heating packets, keep the fact that you can only use them once in mind.
These heating packets make traveling with MREs very lightweight and simple. Instead of having to haul separate cooking equipment, it is replaced by these small packets that work their magic.