[1] When the catalyst, fuel (e.g., natural gas), and oxygen combine together, they react at a low enough temperature that a flame is not produced.
These hand warmers are for people who work or pursue leisure activities outdoors in very low temperatures, especially those that require manual dexterity that is not possible while wearing thick gloves or mittens.
[3] John W. Smith, President of Aladdin Laboratories, Inc. of Minneapolis was awarded a US patent for a product called the Jon-e (pronounced “Johnny”) catalytic hand warmer on December 25, 1951.
[4] In 2010 the Zippo lighter company introduced an all-metal catalytic hand warmer, along with other outdoor products.
Typically used in Thermoelectric Generators (TEG's or thermopiles) off of raw well gas or H2S to create enough electricity to operate the remote well site at great distances from their parent processing plants.
Catalytic heaters can have several potential safety issues if incorrectly installed or placed in poorly ventilated areas, including fuel leakage and carbon monoxide poisoning from insufficient exhaust extraction or improperly tuned reaction.