What's Inside Spray-On Snow? Fat, Fat and More Fat

• Palmitic acid
  A white fatty acid found in animal fat as well as palm and coconut oils. Artificial snow has to be white, soft, and nontoxic and have good “flocking” qualities (it must readily form flakes). Fat fits the bill. Some formulations use calcium carbonate or even wood pulp instead.

• Stearic acid
  A saturated fatty acid with a waxlike texture. Its color and tendency to clump make it look like wet snow. It’s sometimes made of various forms of vegetable and animal fats (beef fat can be as much as 20 percent stearic acid by weight). Don’t tell the baby Jesus in your Nativity scene, but that faux snow may not be kosher.

• Methyl palmitate
  A fatty acid ester that “fluidizes,” or dissolves, and emulsifies the two fats so they can be sprayed out of an aerosol can, even at cool temperatures.

• Polyvinyl acetate
  A fat-based product can be too slippery to stick to a Christmas tree without help. Enter polyvinyl acetate, which is the fancy name for carpenter’s or bookbinding glue. An adhesive mix of acetic acid and ethylene, this resin keeps the fat on the branches and dries clear.

• Acrylates
  A family of chemicals that can be found in stuff like plastic bone cement and Plexiglas. This resin is used as a binder with (or in lieu of) the polyvinyl acetate.

• Methylene chloride
  If you experience mental confusion, lightheadedness, nausea, and a headache at this time of year, it may not be from your visiting in-laws. It might be from accidentally inhaling too much of this solvent, which is sometimes added to fake snow.

• Powdered sodium chloride
  Salt and snow are usually bitter enemies, but salt and fake snow get along just fine. One artificial-snow recipe that’s built on flour and wood pulp instead of fat uses this ingredient to create a cool visual effect: As the “snow” dries, the salt crystallizes and catches the light, twinkling like real icy dendrites.

• Propellant
  Hydrocarbons such as dimethyl ether and isobutane are used to propel the contents from the can. They’re fairly Earth-friendly and contribute less to global warming than chlorofluorocarbons, the standard propellant back in the Mad Men days. (CFCs are one reason we need fake snow in the first place.)