A flameless
MRE heaters, or FRH, or flameless ration heaters, are made from iron, magnesium, and salt. They react with water as a catalyst to heat it to a boiling point. A by-product is the offgasssing of hydrogen.
Background: Subject units are water activated devices for warming military Meals, Ready-to Eat (MRE). FRHs contain magnesium-iron alloy (Mg-Fe) and other powdered ingredients in flat High Density Polyethylene (HDPE) pouch. The exothermic chemical reaction which warms the meals, produces hydrogen gas as a by-product.
The reaction that occurs in the MRE's flameless heater involves the oxidation of magnesium by iron oxide.
While these products aren't dangerous when used outside or when camping due to adequate ventilation, using them inside can expose you to dangerous Carbon Monoxide gas that's released during the reaction.
The short answer is yes, you can live on MREs. MREs are designed to provide all the necessary nutrients and calories for a full day's worth of meals. However, it is important to note that MREs are not intended for long-term use. MREs are high in sodium and low in fiber and fatty-acids.
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. Within seconds the flameless heater reaches the boiling point and is bubbling and steaming.
Meals Ready to Eat (MRE's) are shelf stable because they have been commercially sterilized by heat in a sealed container to destroy bacteria that can make it unsafe or spoil the food.
Temperatures in excess of 215°F and violent ignition events were observed. It is evident from the tests performed that the release of hydrogen gas from these flameless ration heaters is of a sufficient quantity to pose a potential hazard on board a passenger aircraft.
The gum found in an MRE, for example, isn't classified as a laxative — but there is truth to that myth. It's a widespread belief that the gum packaged in MREs is a laxative and will clear a plugged-up gut. But Task & Purpose previously reported it's not a laxative.
An MRE (Meal, Ready-to-Eat) heater bag typically contains a small amount of water and a chemical heating agent, such as iron powder, sodium chloride (salt), and activated charcoal. The heater bag works by mixing the water with the chemical heating agent, which causes an exothermic (heat-producing) chemical reaction.
Chemical reaction
Ration heaters generate heat in an electron-transfer process called an oxidation-reduction reaction. Water oxidizes magnesium metal, according to the following chemical reaction: Mg + 2H2O → Mg(OH)2 + H2 [+ heat (q)]
While the entree may be eaten cold when operationally necessary, it can also be heated in a variety of ways, including submersion in hot water while still sealed in its individual entree package. Since mid-1992, a flameless ration-heating device has also been packed into each meal bag to heat the entree.
What is it? The Meal, Ready-To-Eat (MRE) is designed to sustain an individual engaged in heavy activity such as military training or during actual military operations when normal food service facilities are not available.
A: A long time, I've eaten MREs that were over 20 years old. But I would say around 5 years and they are safe. Just make sure the packet you open is not already open, keep in a safe area not below O degrees and not over 120 degrees.
As a result of earlier unauthorized sales to civilians, the Department of Defense requires that "U.S. Government Property, Commercial Resale is Unlawful" be printed on each case of MREs. The warning is only intended for service members as there are no laws that forbid the resale of MREs by civilians.
MRE heaters that have not been properly activated must be disposed of as hazardous waste. Disposing of an un-activated MRE heater in a solid waste container is against the law.
It is extremely dangerous and WILL damage your microwave and could cause serious bodily harm.
“I can say without hesitation that it is only a myth,” wrote David Accetta, an Army veteran and chief of public affairs at Natick. “Any ideas about that being the purpose of the gum are completely incorrect.”
MRE's are ready to eat and no preparation is required, while freeze-dried and dehydrated foods require clean drinking water to rehydrate for consumption. Each has a different recommended storage condition and shelf life, although the shelf life of storable foods can be extended if stored at lower temperatures.
However, the question of whether subsisting solely on MREs could cause gut leakiness or other gastrointestinal symptoms and change the gut microbiome had not been considered. It turns out that the MRE does not appear to have negative effects on gut health and has only a small impact on the gut microbiome community.