20+ Flammable Items You Should Never Leave in Your Car

I shared this article back in 2024, but after what happened last night, I felt like I needed to share it again.

Sometimes life gives you those unexpected moments that make you stop and think. Last night, after I settled in from the gym, I was trying to write down some of the emotions I was feeling. My partner was in the kitchen preparing a meal, and I was simply talking to myself while getting comfortable.

Then he walked into the living room and said, “There is a car burning.”

At first, I honestly thought it was one of his jokes or one of his little tricks. But the look on his face told me he was serious. I followed him, and there it was.

A car was completely engulfed in flames, being consumed by fire right in front of us.

Thankfully, a firefighter was already approaching. I watched as the fire fighters arrived, pulled the hose from their van, brought out their equipment, and immediately started working to control the flames.

What stood out to me the most was how careful and professional they were. They did not rush blindly. They took their time, controlled the situation, put out the fire properly, then opened the car and continued checking for any remaining smoke, heat, or hidden flames. They stayed for almost an hour making sure everything was fully safe.

I have to commend them; from the window, we were just “window warriors,” observing everything unfold. My first thought was about the owner of the car. Imagine having your evening interrupted by something like this. Imagine watching something you own as it gets destroyed in front of you.

The car belonged to a young man. He seemed surprisingly calm. He walked around, stood at a distance, and watched as everything happened. I could only imagine the thoughts running through his mind.

Thankfully, from what I could see, no other cars were physically affected, even though there were other vehicles parked very close by. The flames were intense and honestly uncomfortable to watch, but the firefighters handled it incredibly well.

The police also arrived and were checking the situation, speaking with the owner. Eventually, I decided to call it a night. I truly hope that young man is doing okay and that he was able to get some support after such a stressful experience.

By today, the area already seems calmer, and even the smell of smoke is starting to fade.

But this incident got me thinking.

How often do car fires happen, and what are some common things that can cause them?

According to fire safety research, vehicle fires can happen for several reasons, and some causes are more common than people realise.

1. Electrical Wiring Problems

One of the common causes of car fires is electrical issues. Modern cars rely heavily on electrical systems, and when something goes wrong, it can create serious problems. Damaged wires, exposed wiring, poor repairs, loose connections, or electrical faults can cause overheating and potentially start a fire. Occasionally the issue is not obvious. A car may appear completely normal until a hidden electrical problem becomes dangerous.

2. Unsafe Car Modifications and Customisations

Many people love personalising their cars, whether it is adding sound systems, lighting, cameras, extra electronics, or other upgrades. However, problems can occur when a modification requires more electrical power than the car’s original system can handle. If a customisation is installed incorrectly or the wiring cannot safely support the extra electrical load, it can cause overheating, short circuits, and, in some cases, fires. This is why it is important to ensure modifications are done properly by someone who understands the vehicle's electrical system and can tell you if it is not a good idea.

3. Fuel and Fluid Leaks

Cars contain several flammable fluids, including fuel and oil. A leak near a hot engine part can become dangerous very quickly. Even a small leak can create a serious fire risk if it comes into contact with heat.

4. Battery Problems

Car batteries can also cause fires, especially when damage, poor maintenance, or incorrect installation occurs. With the rise of electric and hybrid vehicles, battery safety has also become an important topic because damaged batteries can create unique fire risks.

5. Poor Maintenance

Sometimes small warning signs are ignored. Strange smells, unusual noises, dashboard warnings, overheating, or electrical problems should not be dismissed. A little attention early can prevent bigger problems later.

Last night was a reminder that we often think, “It won’t happen to me,” until we see something happen right in front of us. A car is something many of us use every day, but behind the comfort and convenience are systems that need care and attention.

6. Human factors

Sometimes fires happen because of everyday mistakes, such as:

• Leaving flammable items in hot vehicles

• Smoking materials

• Improper storage of chemicals or fuels

• Incorrect repairs

Flammable items you should never leave in your car

Did you know that you should never leave certain items in your car? Some items have the potential to cause explosions! If you're a car owner or driver, you really need to check this out!

Listen up! It's truly enlightening. So, buckle up and brace yourself for some surprising stuff.

The Hazardous Items Breakdown

Pressurized & Aerosol Cans

When heated, the gas inside these containers expands rapidly. Once the pressure exceeds the structural integrity of the metal, they can explode violently, shattering windows and spraying flammable contents.

• 1. Aerosols (Deodorants, Hairsprays, & Sunscreen): These pressurized canisters pose a massive risk of explosion when exposed to high temperatures. They are filled with highly volatile liquefied petroleum gases (like butane or propane) that expand until the canister ruptures. Sunscreen is a beach bag staple often forgotten in the backseat, but its pressurized, alcohol-based formula becomes highly unstable in a hot cabin.

• 2. Automotive & DIY Aerosols (Spray Paint, WD-40, Carburetor Cleaner): Left in the trunk or side pockets by DIY mechanics, these cans combine heavy-duty pressurized propellants with highly flammable solvents that have incredibly low flashpoints.

• 3. Canned Air / Electronics Dusters: Packed with compressed fluorocarbons, these expand rapidly under direct sunlight and can easily burst their containers with projectile force.

Personal Care & Flammable Liquids

Many liquids we use daily rely on high concentrations of alcohol or solvents to dry quickly, making them volatile fuel sources when cooked inside a closed vehicle.

• 4. Hand Sanitizer: Alcohol-based hand sanitizers can pose a distinct fire risk. Alcohol evaporates quickly, and in a confined, hot vehicle, vapor concentrations can leak out and reach flammable levels. If exposed to an ignition source, like a spark or a lighter, this vapor cloud can ignite instantly.

• 5. Perfume and Cologne: Unlike plain mineral water, perfumes contain high concentrations of flammable ethyl alcohol. When left in a hot car, the liquid evaporates into a pressurized gas. Furthermore, the glass bottle itself can act as a lens, focusing intense sunlight onto fabric seats while venting flammable vapor.

• 6. Nail Polish & Remover: Acetone (the primary ingredient in remover) and nitrocellulose (found in nail polish) are deeply volatile chemicals that easily vaporize into highly ignitable gases inside a hot glovebox.

• 7. Rubbing Alcohol: Often kept in first-aid kits, it evaporates rapidly into a heavy, ignitable gas if the cap's seal degrades under extreme heat.

• 8. Sun Cream (Bottles & Tubes): While non-aerosol lotions won't explode, the active ingredients degrade rapidly when exposed to high temperatures, reducing their effectiveness and leaving you unprotected against UV radiation. (Note: While standard lotion isn't a fire starter, the FDA warns that continuous exposure to high heat compromises the product packaging and stability).

Electronics & Batteries

Lithium-ion batteries do not handle extreme heat well. When pushed past their thermal limits, they can undergo thermal runaway—an internal short-circuit loop that causes the battery to heat up exponentially until it bursts into an intense, self-sustaining chemical fire.

• 9. Power Banks: Portable chargers left baking on a console are a leading cause of modern vehicle fires. They house large lithium-ion batteries that become highly unstable, warp, and catch fire or explode in extreme heat.

• 10. Electronics (Smartphones, Laptops, Tablets, & Consoles): Heat damages internal circuits, swells batteries, and causes components to expand or contract, leading to permanent malfunctions. Leaving a device in direct sunlight significantly increases the risk of a battery breach.

• 11. Vapes / E-Cigarettes: Frequently left in cup holders, these devices pack high-output lithium batteries into small casings that warp easily under heat.

• 12. Loose Batteries (Disposable & Rechargeable): Batteries rolling around in a glove compartment can leak corrosive electrolytes when exposed to high temperatures. Worse, if AA, AAA, or 9V batteries touch loose coins, paperclips, or keys, they can complete a circuit, short out, and spark an electrical fire.

Smoker's Supplies & Tools

• 13. Lighters: Disposable plastic lighters contain highly flammable liquid butane under pressure. When exposed to temperatures above 50°C (122°F), the plastic casing softens and cracks, causing an immediate explosion and releasing an easily ignitable fuel source right on your dashboard.

• 14. Matchbooks: Kept in a hot sun visor, the friction-sensitive chemical tips can degrade or ignite if the dashboard reaches extreme temperatures.

Light-Refracting Objects (The Magnifying Glass Effect)

Some of the most surprising car fires are caused by completely non-flammable items that happen to be transparent or reflective, focusing intense rays of sunlight onto a single spot until it smolders.

• 15. Glasses & Sunglasses: Heat can warp plastic frames and cause metal frames to become hot enough to burn your skin. More dangerously, prescription lenses left face-up on the dashboard can act as perfect magnifying glasses, focusing intense sunlight onto nearby plastic or fabric surfaces and starting a fire.

• 16. Plastic Water Bottles: A round, smooth, clear plastic bottle filled with clear liquid acts as a physical lens. Fire departments have documented instances where water bottles left on car seats focused sunlight cleanly enough to burn holes straight through vinyl and fabric upholstery.

• 17. Glass Suction-Cup Mounts: GPS or dashcam mounts with clear, curved plastic or glass surfaces can accidentally redirect and focus beam paths onto flammable interior surfaces.

Perishables, Meltables, & Vulnerable Assets

While these items may not always spark an explosion, extreme vehicle heat causes severe damage, structural issues, or tragic safety hazards.

• 18. Food & Snacks: Perishable foods (meat, dairy, produce) spoil rapidly in a hot car as bacteria multiply exponentially, leading to severe food poisoning risks. Even dry snacks containing oils or fats will oxidize and turn rancid, completely ruining their quality.

• 19. Pet Food: Just like human food, pet kibble and canned food degrade quickly in high heat. It accelerates mold growth, destroys essential nutrients, and causes bacterial contamination that can make your pets incredibly sick.

• 20. Drinks & Sodas: High temperatures alter the flavor of beverages and cause alcohol to evaporate. For carbonated sodas, the heat creates immense pressure from expanding CO₂ gas, causing cans and plastic bottles to violently burst and ruin your car's interior.

• 21. Plastic Bottles (Chemical Leaching): When commercial plastic bottles are exposed to high heat, the plastic degrades, releasing harmful chemicals like BPA and phthalates directly into the liquid inside, making it unsafe to drink.

• 22. Medication: Many medications are highly sensitive to heat. Exposing them to extreme car temperatures accelerates chemical breakdown, rapidly reducing their potency and making them ineffective or unsafe.

• 23. Makeup & Candles: Lipsticks, lotions, and wax candles melt into a destructive mess on upholstery. In extreme cases, glass candle jars can fracture or shatter due to severe thermal stress and cause fire.

• 24. Art Supplies: Crayons and oil pastels will liquefy completely in a hot car, creating a permanent, staining mess inside door pockets and cloth seats.

• 25. Handbags & Wallets: Beyond the obvious, massive risk of theft, leaving these items in a hot, confined space creates a breeding ground for bacteria on leather and fabric surfaces that are frequently touched by hands.

• 26. Children & Pets (NEVER LEFT UNATTENDED): Leaving children or pets in a car is a life-threatening hazard. Because a child’s body heats up three to five times faster than an adult's, and pets (especially dogs) cannot sweat to cool down, temperatures inside a parked car can reach lethal levels in mere minutes—even with the windows cracked.

A car fire can happen rapidly, which is why regular checks, proper repairs, and safe modifications matter. Last night’s incident is a clear example of how quickly a normal parked car can turn into a dangerous situation.

Don't just think about convenience—think about safety and preserving your belongings. So, there you have it, folks. Keep your car clear of these items, and you'll avoid a world of trouble. Stay safe out there!

Have you ever witnessed a car fire before? If you have, what did you do in that situation, and how did the incident occur?

Photo by Uriel Mont