How to Make White Fire


Magnesium burns with a white fire.
Magnesium burns with a white fire. (photo: Cullan Smith)

You can make fire burn with a pure white flame. White is an elusive fire color because the fuel that supports a flame burns with its own characteristic spectrum. But, with a little chemistry know-how, you can get white fire. Here’s how to do it, along with tips to make the fire last.

White Fire Materials

The easiest way to make white fire uses principles of the flame test in analytical chemistry. How it works is the heat of the flame excites electrons in atoms, raising them to an excited state. When the electrons return to a more stable, lower energy state they release a photon of a color characteristic of that element or ion. Different oxidation states of an element release different colors, so the test is one way to help identify an ion.

Epsom salt (magnesium sulfate) is an inexpensive, readily available chemical that makes white fire. Epsom salt is sold as a bath salt, foot soak, and soil additive. However, you can’t just toss Epsom salt on a campfire and get a white flame because other elements in the fuel release colors that will overwhelm white fire! You need a fuel that burns nearly invisible or blue to see the white color. Alcohol is the best fuel choice. Of these, methanol gives the best results. Methanol is sold as Heet fuel treatment. Rubbing alcohol, grain alcohol, and alcohol-based hand sanitizer also work as a fuel.

  • Epsom salt (magnesium sulfate)
  • Alcohol (either methanol, isopropyl alcohol, or ethanol)
  • Heat-safe dish
  • Magic Eraser or melamine foam (optional)

Basically, all you do is stir a small amount of Epsom salt into the fuel and ignite it. For a bright flame that lasts about 45 seconds, break off a small piece of Magic Eraser, saturate it with the alcohol and salt mixture, and ignite it. Turn out the lights to observe the white fire.

Other Ways to Make White Fire

Epsom salt contains the metal magnesium, which burns with a white flame. If you have pure magnesium metal, you can ignite it using a blow torch and get a brilliant white flame. The light is so bright you’ll want protective eyewear. The white magnesium flame burns brighter and longer if the metal is ignited within a bed of dry ice or solid carbon dioxide.

Other elements that burn with a white flame include titanium, nickel, chromium, hafnium, beryllium, aluminum, and cobalt. Of these, the easiest to obtain are flakes or filings of aluminum or titanium.

Chemicals that burn with a white flame and no additional required fuel include isopropyl nitrite, nitromethane, and hexamine. Hexamine is a solid that burns for quite a while after ignition with a match or lighter. You’ll likely need access to a chemistry lab to find these chemicals, although it may be possible to order them online.

This video shows what the white flames from magnesium metal and various chemicals looks like. It’s got a shaky-cam effect, but clearly displays the brilliance of magnesium:

How Hot is White Fire?

While the spectra of the fuel and any added chemicals influences flame color, so does incandescence. Incandescence is the emission of light as a function of temperature (black-body radiation). From coolest to hottest, incandescent flame colors are red, orange, yellow, and white. Incandenscence begins to become visible as a dark red glow between 500 and 600 °C and reaches a white flame around 1400 to 1600 °C. Blue also occurs sometimes, when there is a low amount of soot. While blue is relatively uncommon in campfires, it often occurs in welding metals.

This chart shows the relationship between flame color and temperature. Keep in mind, the table is only a rough approximation, and varies from one fuel to another.

Flame ColorTemperature
Dark red500 to 600 °C (900 to 1,100 °F)
Dull red600 to 800 °C (1,100 to 1,650 °F)
Bright cherry red800 to 1,000 °C (1,650 to 1,800 °F)
Orange1,000 to 1,200 °C (1,800 to 2,100 °F)
Yellow1,200 to 1,400 °C (2,100 to 2,500 °F)
White1,400 to 1,600 °C (2,500 to 2,900 °F)

In case you’re curious, it’s also possible to make black fire!

Safety Information

As this is a fire science project, adult supervision is required. Always keep children and pets away from flames and chemicals and have a fire extinguisher handy. While Epsom salt in alcohol yields a flame that is easy to extinguish, pure magnesium metal basically burns to completion. Also, wear gloves and avoid skin contact with methanol, if you use it. Read and follow safety information printed on any product labels.

References

  • Hannavy, John (2013). Encyclopedia of Nineteenth-Century Photography. Routledge. ISBN 978-1135873271.
  • Landis, Arthur M.; Davies, Malonne I.; Landis, Linda; Nicholas c. Thomas (2009). “”Magic Eraser” Flame Tests”. Journal of Chemical Education. 86 (5): 577. doi:10.1021/ed086p577
  • Natural Resources Canada (2003). Pyrotechnics Special Effects Manual (2nd ed.). Minister of Public Works and Government Services Canada.
  • Patnaik, Pradyot (2002). Handbook of Inorganic Chemicals. McGraw-Hill. ISBN 0-07-049439-8.
  • Sanger, Michael J.; Phelps, Amy J.; Catherine Banks (2004). “Simple Flame Test Techniques Using Cotton Swabs”. Journal of Chemical Education. 81 (7): 969. doi:10.1021/ed081p969

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