The Meal, Ready-to-Eat – commonly known as the MRE – is a self-contained, individual field ration in lightweight packaging bought by the United States Department of Defense for its service members for use in combat or other field conditions where organized food facilities are not available. While MREs should be kept cool, they do not need to be refrigerated. [source Wikipedia] During natural disasters MRE have been distributed to civilians.

Are meals ready to eat dangerous goods?

No, but the Flameless Ration Heater (FRH) comes with it may be dangerous goods.

There are two types of Flameless Ration Heaters (FRH), water-activated and air-activated. Both works on chemical reaction. In water-activated the reaction with water releases hydrogen which is a highly flammable gas.  Hence water-activated flameless ration heaters cannot be used in closed spaces like aircrafts or submarines. Also requiring water to heat the ration may considerably reduce the stock of water carried by a solder. As every drop of water in a soldier’s canteen is precious in the field.

The Chemistry of a Flameless Ration Heater (FRH) – The reaction of magnesium and water

How air-activated MRE heaters work

One of the brands of air-activated FRH contains zinc powder, carbon black, binder fibers and potassium hydroxide solution. Due the construction of the product potassium hydroxide solution is completely absorbed within the heater and no emission of flammable gas when in use this product is not regulated for transport.

Meals ready to eat packed with water-activated flameless ration heaters releasing flammable gas are classified under Class 4.3 substances which, in contact with water, emit flammable gases. One of the products is classified as UN UN2813 Water Reactive Solid, N.O.S. (Magnesium-Iron Mixture).

Depending on the type of Flameless Ration Heaters (FRH) the product may be dangerous goods. Check your product details carefully before shipping.