Wellness Health & Well-being Are Disposable Hand Warmers Toxic? By Matt Hickman Writer Emerson College The New School Matt Hickman is an associate editor at The Architect’s Newspaper. His writing has been featured in Curbed, Apartment Therapy, URBAN-X, and more. our editorial process Matt Hickman Updated January 22, 2021 Fact checked by Cara Lustik Fact checker and copywriter University of Michigan Cara Lustik is a fact checker and copywriter. Our Fact-Checking Process Article fact-checked on Jan 22, 2021 Cara Lustik Share Twitter Pinterest Email Wellness Health & Well-being Clean Beauty Q: When it comes to winter weather, my recent relocation from Cape Coral, Fla., to Burlington, Vt., is as about as drastic as it gets. However, I’m not going to let this get in the way of my outdoor-centric exercise regime whether I’m in full-on jog mode or enjoying a zesty constitutional around my new surroundings. I’ve switched up my exercise attire so that it’s more frigid-weather appropriate and purchased a large box of those disposable hand warmer things to help things along. I’ve used them several times already and they’re great, but it dawned on me that they might be filled with icky toxic chemicals that are harmful to the environment and possibly to my health. I should have looked into this pre-purchase so I’m hoping you can fill me in. Should I be wary of disposable hand warmers or are they benign? Vivian, Burlington, Vt. A: Hey Vivian, Great question. In a past life as a professional dog walker in not-very-balmy-in-the-winter Boston, I used those delightful little “hot pockets” frequently and they’re truly something. Back then, I never understood exactly how they worked and whether the mysterious contents in them were toxic. I just knew that I loved them dearly and that they made my job a lot easier. So here’s what I’ve got for you: Most major brands of disposable hand warmers, such as HotHands Hand Warmers and Grabber Hand Warmers, contain nontoxic, environmentally safe, odorless and most importantly, non-combustible ingredients. You needn’t worry about accidentally puncturing one and having it leak acid inside of your jacket pocket or having one spontaneously erupt into flames as you go on your morning stroll. As you probably already know, disposable hand warmers kick in when they’re exposed to air. With a majority of disposable hand warmers, that comforting heat is generated by an exothermic chemical reaction called oxidation — or rusting — that occurs when the primary ingredient in those little pouches, powdered iron, is exposed to oxygen. In addition to iron, hand warmers also contain salt, water, activated carbon, cellulose and an absorbent material like vermiculite. All and all, the mysterious ingredients in these things are far from sinister. But, of course, you wouldn’t want to use one as a tea bag or let your cat munch on one. Although the chemicals in hand warmers are about as “natural” as chemicals get, there’s a not-so-slight eco-caveat that needs to be addressed: the dreaded “D word” that I’ve already typed out about a dozen times preceding the phrase “hand warmers.” You guessed it, Vivian: “disposable.” Sure, throwaway hand warmers are super convenient, but for active folks like yourself who live in cold places, they, along with all that packaging (remember, they’re “individually wrapped”) can amount to a whole lot of landfill-bound waste. I certainly don’t think you should chuck your existing supply of disposable hand warmers — that would be a waste of money and just prematurely put them into the waste stream — but I would suggest alternatives when they do run out. The first hand-warming option that comes to mind is a nice big thermos of coffee or what have you, but since you’re moving around when outdoors, gripping a container of hot liquids may not be the most practical choice. Your best bet is to look into reusable hand warmers that function a bit differently from hand warmers of the disposable variety. Perhaps least expensive are reusable hand warmers that generate heat through the exothermic crystallization of a supersaturated solution. These types of hand warmers are triggered by a metal device within the packet and can be “recharged” when boiled in water. If chemical reactions and boiling pouches of sodium acetate doesn’t sound appealing, there are also lighter fluid-based reusable hand warmers and battery-operated hand warmers (make sure you use rechargeable batteries for them). So there you are, Vivian, an answer and a suggestion. I’d do a bit of reconnaissance work before you settle on a pair of reusable hand warmers to make sure they suit you and your needs (e.g. they fit into your gloves or pockets). Let me know how it goes. And stay warm! View Article Sources Sands, William A., et al. “Comparison of Commercially Available Disposable Chemical Hand and Foot Warmers.” Wilderness & Environmental Medicine, vol. 20, no. 1, 2009, pp. 33–38., doi:10.1580/08-WEME-OR-243.1 Weiland, Jessica L., et al. “Chemical Hand Warmer Packet Ingestion: A Case of Elemental Iron Exposure.” Wilderness & Environmental Medicine, vol. 28, no. 3, Sept. 2017, pp. 246–48. doi:10.1016/j.wem.2017.04.006 Speights, Cori J., et al. “Why and How to Create Nighttime Warming Treatments for Ecological Field Experiments.” The Yale Journal of Biology and Medicine, vol. 91, no. 4, 2018, pp. 471–80. "Heat Pack – Supersaturation." California State University, Northridge.