Do road flares really making life safe on our highways? – Most people think of flashing red lights and an organized roadwork crew whenever a road flare is used. Although this is true, the fact is that most flares are actually used by state police officers. Nevertheless, road flares may pose safety risks all on their own. So, the answer to these questions may surprise you.
Are Road Flares Legal?
Yes, road flares are legal to be used on roadside emergency situations.
In California, road flares fall under the vehicle code VEH, Division 12 – Equipment of Vehicles [24000 – 28160], Chapter 2 – Lighting Equipment [24250 – 26106], Article 8 – Warning Lights and Devices [25300 – 25305].
According to this code:
Three vehicle reflectors shall be carried with all cars, trucks, or tractor operating in darkness.
During a roadside emergency, reflectors shall be placed not more than 10 feet in front or behind the vehicle. One reflector shall be placed 100 feet to the rear of the vehicle in the center of traffic so that oncoming vehicles can spot it in time to switch lanes.
If the accident occured near a bend, blind corner, or hill, a reflector shall be placed between 100 and 500 feet behind the vehicle to warn oncoming drivers.
Vehicle reflectors should always be in good working condition.
A parked vehicle that is disabled should have reflectors placed 100 feet and 200 feet to the rear of the vehicle, and one 10 feet on the traffic side of the vehicle.
When reflectors are not available, lit red burning flares can be used in place at the required locations.
Lit burning road flares shall be used as long as the vehicle is stopped, and extinguished and removed once the vehicle is moved. A lit road flare shall not be placed near a contaner of gasoline or other flammable liquid, except at a safe distance to prevent a fire or explosion.
Drivers of vehicles shall only use flame producting emergency flares during emergencies, and for no other reason.
U.S. Department of Transportation – Road Flares Classification
The U.S. Departments of Transportation (DOT) classifies pyrotechnic road flares as a flammable solid.
United Nations – Road Flares Regulations
Road flares are classified under the UN explosives shipping classification system. Road flares are classified as 1.4 explosives.
Road Flares – Toxicity to Drinking Water
The potassium perchlorate used to make pyrotechnic road flares are regulated by several US states, including California and Massachusettes. Potassium percholorate can cause certain negative health conditions, such as nausea, skin rashes, fever, or other more severe issues.
Is Igniting A Road Flare Always Legal?
Pyrotechnic flares should only be lit and used during a roadside emergency, and not for recreational purposes. Laws for the use of road flares will vary from state to state.
Can Road Flares Explode?
Road flares are not likely to explode. Road flares grouped together are also not going to cause a mass explosion. Even so, it is best to keep them stored away from flame or heat.
Road flares are made of materials that are made to burn for an extended period of time, but are not conducive to causing an explosion.
Are Road Flares A Fire Hazard?
Yes, road flares are a fire hazard when lit and placed near combustible materials or flammable liquids. Road flares are used by law enforcement officers and emergency road services to mark an accident for traffic to avoid. This provides increased visibility, but also creates an additional fire hazard.
Road flares have flammable ingredients which is the reason why they ignite and burn. However, they produce a flame that puts the surrounding area at risk. The flame burns for 15-30 minutes at high temperature, which can ignite flammable material or fluids.
This is the reason why many government agencies are switching to LED road flares, which use electricity as a source of energy.
How Bright Is A Road Flare?
Road flares are bright enough to be seen at night from passing drivers to alert them to an accident or obstacle on the road. They can be visible up to 3 miles away in normal road conditions at night. They also have 360 degree visibility.
The brightness measure of road flares is not less than 70 candela, for a set period of time depending on the manufacturer.
Road flares are made to provide bright light even at long distances and in poor conditions (snow, rain, fog).
How Hot Is A Road Flare?
Stick road flares can burn up to temperatures of 2000 to 5500 degrees fahrenheit (1200 – 3000 degrees Celsius).
How Long Does A Road Flare Last?
Road flares can burn between 10 and 30 minutes, depending on the manufacturer. This should be enough time for an emergency situation to be resolved. If not, additional flares will need to be lit as they burn out.
Do Road Flares Work In Rain?
Yes, road flares are made of combustible compounds that work well enough in nearly all weather conditions, including rain. However, road flares are susceptible to moisture, however rain should not affect them too much while burning.
Road flares are not designed to work underwater, so placing them in a puddle will cause them to malfunction. They may still work, but the light output will be less and not visible enough to other motorists.
A flare is more likely to have trouble burning in rain storms with cold temperatures and high winds. Cold ground and air will pull heat away from the flame, which can possibly extinguish it.
Do Road Flares Work In Wind?
Yes, road flares will burn in wind, unless it is very high winds. Usually its a combination of high winds, rain, and cold temperatures that will conspire to make a flare extinguish. Road flares are designed to provide bright light in many different weather conditions.
The ingredients in road flares are capable of sustaining a flame through different temperatures, moisture, and wind.
Do Road Flares Burn Underwater?
Yes, under certain circumstances. Road flares are testing for underwater burning and are able to stay lit only if they are placed vertically in a bucket of water. If a flare sits horizontally in water, it will not have sufficient gas generation for the combustion process to push away water from the flame.
So, road flares placed in puddles on roadway surfaces or in ditches will likely not stay lit. Even if they do, the flame will be decreased enough to not be visible by other motorists passing by.
What Are Road Flares Made Of?
Pyrotechnic road flares are made of a number of different chemical components designed to keep them lit for an extended period of time. These include:
- Strontium Nitrate
- Potassium Nitrate
- Paraffinic Oil
- Potassium Perchlorate
- Polyvinyl Chloride
- Polymeric resin
- Pyrotechnic colorants
For more information, see the Orion road flare SDS safety data sheet.
Types of Road Flares
There are several types of road flares available. These are:
- Pyrotechnic flares
- LED flares
- Snaplight flares
- Handheld flares
Pyrotechnic road flares are traditional flares that most people recognize when they see them on the road. Pyrotechnic flares have been used for a long time for emergency roadside situations. They are inexpensive and reliable, but do come with some safety risks. They burn using a chemical reaction and last for around 15 minutes each. They are usually bright red in color and come grouped in a box.
LED flares have become more popular because of their versatility and lack of fire risk. LED flares use batteries instead of chemicals as a power source. They have a variety of lighting modes, and are waterproof and crushproof. Many LED flares are IP67 rated – waterproof, dustproof, and shatterproof.
Snaplight flares resemble very bright night club glowsticks and are easy for anyone to use.
Also known as chem lights, these models are often advertised as military-grade and are easy to use; you just have to snap and shake them. They work like glow sticks, so they don’t produce fire and don’t need batteries, making them very versatile and resistant to different weather types. However, sometimes they are literally outshined by their counterparts.
Handheld flares are shorter burning than standard pyrotechnic flares and are meant for getting attention from someone nearby. They can be used in place of regular road flares and also in boating incidents on lakes or the sea. They can even be placed in water because they are bouyant to help other vessels locate an incident. The distance handheld flares can be seen is usually around 3 miles.
Which one of these types of road flares work best depends on the road and weather conditions they are used in. Remember that pyrotechnic flares need to be handles cautiously because they can cause serious burns to anyone nearby who touches them.
How To Store Road Flares?
Road flares are easy to store but must be stored properly in a vehicle.
Pyrotechnic road flares should be stored in their original cardboard box or container and closed securely. The ingition area of the flares should not be exposed to a striker or other object that could cause it to ignite. Flares should be stored away from other objects in a bag or box and they should not be allowed to move around freely.
Road flares should be inspected for any damage regularly. Their plastic cap should be firmly secured over the ignition button.
Road flares should always be stored in a dry place, away from moisture, heat, or sunlight. They should never be stored near flammable liquids, or sources of flame, heat, or sparks. Road flares should not be stored near exposed electrical connections in a vehicle or building.
Are Road Flares Waterproof?
Road flares are very water resistant, but not entirely waterproof. If submerged horizontally (puddles), road flares could exitinguish or not burn bright enough to be seen.
Road flares can burn in rain, but windy conditions could make them less effective. Pyrotechnic road flares can be water damaged over time and not ignite. This is why there are other flare options to choose from, such as LED flares. Pyrotechnic road flares are most likely not IP65 rated (waterproof) but are water resistant.
Some boating flares are rated waterproof and can be used in the rain, rough seas, and even underwater. Some flares are made for divers and other marine purposes.
How To Dispose Of Road Flares?
Spent road flares can pose an environmental hazard due to toxic chemicals they leave behind. So, disposing of them properly is very important.
The best way to dipose of expired or spent road flares is to find a place that accepts them. This can be a local fire or coast guard station, sanitation department, or household hazardous waster transfer facility.
Road flares should never be put in the regular trash.
Always keep road flares out of reach of pets or children, and stored in a dry cool place. Do not store used flares with new ones. Even flares past their expiration date can ignite, causing injury to anyone nearby. In fact, the chemicals inside old road flares are more unstable than new ones.
Used flares should be placed in two plastic bags (one inside the other) and sealed.
Do Road Flares Expire?
Road flares generally do not expire. This is the case even if they have an expiration date, or “use by” stamped on the side of them. An expired road flare can still work and even ignite accidentally, so be careful. If they are past the use by date, do not use them.
However, road flares are more often damaged, or go bad for some reason. The casing of the flare could become cracked or deriorate in time, making the flare useless. Water damage can cause a flare to not work as well.
The U.S. Coast Guard has the expiration date set on marine flares at no more than 42 months from manufacture because boaters are not expected to inspect them regularly.
Road flares are more likely to never expire because of storage in dry vehicles, as opposed to marine flares which can be damaged from water.
Are Expired Road Flares Dangerous?
Yes, expired road flares are dangerous for several reasons:
- They can still ignite accidentally.
- They will fail to ignite when you need them to.
- They will not burn long enough.
Chemical compounds inside of old flares become more unstable in time and can cause them to ignite spontaneously. Flares also have toxic chemicals inside that are hazardous to a person’s health and they must be stored in closed bags, boxes, and containers.
How To Light A Road Flare?
Lighting a road flare is easy and fast.
First, know exactly where you want to place the road flare before you light it.
One end of the flare has a cap, which you can locate. Remove this cap, exposing the end of the flare.
The exposed end of the flare will have an ignition surface or button shaped area. This is the part of the flare that you ignite. Before lighting the flare, hold it away from your face and body as far as possible.
A flare is lit just like a large wooden match. It is struck by the cap in a quick scratching motion with your finger. While the flare is lit, hold it downward and pointed away from you because burning residue can drip on your hands otherwise.
Place the cap on the other end of the flare that is not burning. Place the lit flare on the ground at the correct distance from vehicles and away from any flammable liquids or materials.
How To Place Flares
Once the flare is lit, carry it with it pointed downwards and outwards from you to your intended location.
Road flares should be placed on the ground and not thrown or dropped. They should be placed away from any roadside flammable debris or fluids. If gasoline is leaking onto the roadway, the flare should be placed at a safe distance away.
DIY Road Flares – Are They Safe?
It is possible to make your own road flares using chemicals you can buy. Mixing the ingredients, such as potassium nitrate and aluminum powder and cook it. Add a bonding agent to and let it cool off. Placing the mixture into a cylinder tube once it becomes semi-solid. It should be ready to light and use on the ground.
However, DIY road flares are not recommended to use because they are not necessarily safer than road flares you can buy. They may also not work very well, putting your safety at risk on the roadside.
When To Use Road Flares?
Road flares are universally understood as signs of an oncoming emergency roadside situation. These should only be used to signal other motorists or emergency crews of an accident. Alternately, they can be used to signal to helicopters or airplanes when stranded.
Road flares should never be used near flammable materials or fluids, such as gasoline containers.
Where Should Flares Be Located?
Road flares should be located on the paved roadway on a level surface. One lit flare should be placed 15 feet behind the vehicle, with another placed 30 feet behind it. You can use more than 3 flares behind the vehicle placed 15 feet apart. Flares can be placed to span a distance of 100 feet or more if needed.
Also place 1 or 2 flares in front of the vehicle to warn head on traffic.
Using multiple flares is best on bending roadways or around blind corners to warn oncoming traffic of an accident scene. Flares are also best placed slightly away from the vehicle into the roadway or close to the next lane.
Can You Hold A Road Flare?
Yes, you can hold a road flare for a short time. They should be held outward and downwards away from the body. If they are held straight up, burning chemicals could drip onto the hand of the person.
Do not carry a lit flare over flammable materials and find a place to put it down as soon as possible.
Where Should Flares Be Stored?
Storing flares is easy to do and will keep them working properly for a long time.
Storing Road Flares In Buildings
Road flares are best stored in a wood or plastic box or container that keeps them firmly in place and sealed. The storage box should be water tight and have a silica gel desiccant packet placed inside to keep it dry.
Good places to store flares are garage shelves out of reach, and under work tables where animals and children cannot reach them.
Flares should be stored with the plastic caps in place, with the ignition tips or striking ends not touching other flares. Do not store them with other items.
If the storage container has extra space where the flare could move around, then place a cardboard box or wood to fill it and prevent the flares from shifting.
Storing Road Flares in Vehicles
Road flares should not be stored in hot and humid areas, such as exposed in an open vehicle or pickup truck bed. They should be stored in a way that prevents them moving around or being bumped.
Road flares should never be stored in a car or truck glove box due to heat. Always store the flares with the plastic cap and removeable lid firmly in place. Use the original cardboard container or box with a secure lid. Make sure the flares are not stored next to the ignition button or striker ends of other flares.
If you find old road flares that are past their “use by” date, then discard them and purchase new ones.
Can A Road Flare Start A Fire?
Yes, they can.
Road flares burn with temperatures between 2000 to 5500 degrees fahrenheit (1200 – 3000 degrees Celsius) and produce a hot flame that burns for 15 minutes or more.
If the road flare is too close to flammable materials or fluids, such as sticks, branches, leaves, or gasoline, it can start a fire, or even cause an explosion.
In fact, survival practitioners in wet climates, such as in tropical jungles bring road flares to start fires in storms or damp areas. Road flares can also help ward off wild animals or signal for help.
Is It Safe To Keep Road Flares In Your Car?
Yes, road flares are safe to keep in a car if they are stored in their original cardboard or plastic box separate from other items. Do not store them in the glove box because it can get too hot. Avoid storing them in a plastic bag because they can shift around and accidentally ignite eachother.
If you live in hot weather locations, such as Phoenix, Las Vegas, or other areas, be very careful how you store road flares in your car to make sure they stay cool and out of the sunlight.
Are Road Flares Toxic?
Yes, road flares are toxic. They are made of many different chemicals that have proven to be hazardous to a person’s health and the environment. Road flares are made of strong oxidants, flammables, and dies, along with other additives (see the flare ingredients list above).
Spend flares left on the roadway can leach chemicals into the nearby environment, which can contaminate the water supply.
The Verdict – Are Road Flares Safe?
Yes, road flares are generally considered safe when used properly.
Road flares are vital to keeping passing motorists alerted to emergency roadside situations, but need to be handled and stored carefully as they do come with some safety risks.
Nick Klamecki is a certified Fire and Workplace Safety expert with 15 years experience in product research and testing. He has a degree in Economics from U.C. Davis, is an active outdoorsman and spent years ensuring the safety of special needs children. Nick researches and tests workplace, industrial and safety products and provides advice on their safe use.