What are Signal Flares Made of?

by Jennifer Boyden
Police officer about to ignite two flares.

Police officer about to ignite two flares.

Signal flares can mean the difference between life and death for people in distress. On a boat, you can use aerial flares to send a distress signal to other vessels in the area. If your car breaks down on the side of the highway, you can light flares to warn other motorists. Traditional signal flares contain multiple components – some hazardous – that combine to form the popular safety device.

Signal Flare Composition

All signal flares include four important elements – color, fuel, oxidizer and binder. Strontium nitrate creates the red-orange hue that helps signal flares catch your attention. Signal flares also require fuel to burn – for example, sulfur, charcoal or magnesium. In addition, signal flares need a quick combustion to create a bright light. Oxidizers such as potassium perchlorate or potassium nitrate provide this extra energy. Finally, binders help hold the various components together and give signal flares their cylindrical shape. Parlon, epoxy resin, and shellac all serve as binders.

Signal Flare Warnings

According to a 2008 report by the Weapons and Equipment Research Institute, the chemicals used in signal flares are hazardous. Strontium nitrate can irritate your eyes and skin and exposure to potassium perchlorate may lead to kidney and thyroid damage. Signal flares pose a risk to the environment as well – discarded flares can contaminate local soil and water sources. Always stand clear of lit flares, keep them away from combustible materials, such as spilled fuel and dried grass and brush, wash your hands after use and dispose of flares correctly.

About the Author

Jennifer Boyden has been writing professionally since 2007. She holds a Bachelor of Fine Arts in creative writing from Emerson College and graduate degrees in mental health counseling and criminal justice from Suffolk University. Boyden also has experience playing and coaching collegiate softball and is a CrossFit Level 1 trainer.

Photo Credits

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