Carbon dioxide fire extinguisher (Op-amp) is one of the most effective tools for extinguishing fires in cars, server rooms and electrical installations. Its main advantage is the ability to extinguish fire without leaving a trace (unlike powder analogues) and safety for electronics. However Improper handling of the OU can result in tragedy: from cylinder rupture to carbon monoxide poisoning.
According to statistics from the Ministry of Emergency Situations, 37% of emergencies with fire extinguishers occur due to violation of the rules for operating carbon dioxide models - They are often confused with powder fires, kept in inappropriate conditions, or used on the wrong types of fires. In this article we will analyze 12 critical errors, which turn a means of salvation into a source of danger, and we will also provide a checklist for checking the OU before purchasing for a car.
We will pay special attention car fire extinguishers (for example, OU-2 or OU-3): Their compact size and high efficiency make them popular among drivers, but these are the models most often misused. If you keep a carbon dioxide fire extinguisher in your car, check to see if you are making at least one of the mistakes described below.
1. Extinguish class A fire (wood, paper, fabric)
Carbon dioxide (CO₂) works on the principle of displacing oxygen and cooling the combustion zone. This method is great for electrical equipment (class E) and liquids (class B), but useless against smoldering materials - wood, paper, rubber or textiles.
Why is it dangerous:
- 🔥 After extinguishing with carbon dioxide, a smoldering fire (for example, a car seat) may re-ignite after 5–10 minutes, when the gas has dissipated.
- 💨 CO₂ does not cool the material deeply - it only blocks the access of oxygen to the surface.
- ⚠️ In a confined space (car interior), a high concentration of carbon dioxide can cause suffocation.
| Fire class | Examples | Is it possible to extinguish the OU? | Recommended fire extinguisher |
|---|---|---|---|
| A | Wood, paper, rubber, textiles | ❌ No | Water based, powder (ABC) |
| B | Gasoline, oil, paint, solvents | ✅ Yes | OU, powder (BC) |
| C | Gases (methane, propane) | ❌ No (only block the source) | Powder (ABC), gas |
| D | Metals (magnesium, aluminum) | ❌ No | Special powder (D) |
| E | Live electrical equipment | ✅ Yes (optimal) | OU, freon |
⚠️ Attention: If the wiring in the car catches fire (class E), but the fire spread to plastic panels (class A) - use powder fire extinguisher (OP-2). Carbon dioxide is useless and dangerous here!
2. Keep the fire extinguisher horizontal or upside down
The carbon dioxide fire extinguisher cylinder is filled with liquid CO₂ under pressure ~58 atmospheres. If stored or transported incorrectly liquid may flow into the siphon tube, which will lead to:
- 💥 Water hammer when triggered, the cylinder can be torn out of your hands.
- ❄️ Frostbite on hands - the temperature at the bell drops to -70°C.
- 🔧 Breakdown of the locking and starting device (ZPU).
How to hold it correctly:
- 📏 Vertical — the bell is directed upward, the cylinder stands at the bottom.
- 🚗 In the car - secure in bracket (for example, bracket "Tornado" for OU-2).
- 🏠 In the garage - hang on the wall using certified holders.
Exception: some models (for example, OU-3-I) have special valve, allowing for short-term use of the fire extinguisher at an angle of up to 45°. But even in this case Long-term horizontal storage is prohibited.
3. Fight a fire in a confined space without protection
Carbon dioxide displaces oxygen, which leads to suffocation at concentration CO₂ above 9%. In a small room (car interior, truck cabin) this happens within 10–15 seconds.
What to do:
- 🚗 In the car: open all the doors before extinguishing, then retreat 1–2 meters.
- 🏢 Indoors: use a fire extinguisher at the exitto be able to quickly leave the area.
- 😷 Put it on gas mask or respirator, if you are putting out a fire in the basement/garage.
⚠️ Attention: When extinguishing electrical equipment in a car (for example, a battery fire) do not lean over the fireplace — CO₂ heavier than air and accumulates at the bottom. Keep the fire extinguisher at arm's length!
4. Use an expired fire extinguisher
Shelf life of carbon dioxide fire extinguishers: 10–15 years (indicated on the cylinder), but recharging is required every 5 years. By missing a reload, you risk:
- 🔋 Loss of pressure - fire extinguisher won't work at a critical moment.
- 💥 Cylinder corrosion is a risk gap when heated.
- ❄️ If the valve freezes, it will be impossible to activate the ZPU.
How to check deadlines:
- Check the manufacturing date on cylinder body (embossed on metal).
- Find the date sticker last check (must be no older than 5 years).
- Check pressure gauge (the arrow should be in the green zone).
☑️ Checking the fire extinguisher before purchasing
If the fire extinguisher expired, you can’t just throw it away - CO₂ under pressure may explode when heated. Hand it over to specialized recycling point (addresses can be found on the website of the Ministry of Emergency Situations of your region).
5. Point the bell at people or animals
Gas temperature at the exit from the socket - -50°C to -70°C. Contact of the jet with the skin or mucous membranes causes:
- ❄️ Frostbite 2–3 degrees (blisters, tissue necrosis).
- 👁️ Loss of vision if it gets into the eyes.
- 💨 Choking when inhaling concentrated CO₂.
Safety rules:
- 🎯 Direct the bell only to the source of the fire, and not on surrounding objects.
- 👨👩👧👦 Before stewing evacuate people at a distance of at least 3 meters.
- 🐕 If there is an animal in the car, do not use op amp - use a powder fire extinguisher.
When extinguishing a fire in a car engine, direct the jet from the side, and not from above - this will reduce the risk of frostbite on your hands from reflected cold.
6. Keep the fire extinguisher near heat sources
The carbon dioxide cylinder is designed for pressure up to 60 atmospheres, but when heated higher 50°C pressure grows exponentially. Risks:
- 🔥 Temperature 60°C - pressure reaches 90 atm (risk of rupture).
- 🚗 In the car: do not place a fire extinguisher on the dashboard in the sun or near the engine.
- 🏠 In the garage: keep away from heaters and radiators.
Optimal storage conditions:
- 🌡️ Temperature: -40°C to +50°C.
- 💧 Humidity: no higher than 95% (to avoid corrosion).
- 🚫 It is prohibited to store in trunk next to office supplies or chemicals.
⚠️ Attention: If the fire extinguisher is overheated (the cylinder is hot to the touch), don't use it - Cool in the shade for 1-2 hours. If there are signs of swelling or deformation leave the area immediately and call the Ministry of Emergency Situations.
7. Attempt to extinguish burning metals (Class D)
Carbon dioxide not only does it not extinguish burning metals (magnesium, aluminum, titanium), but also enhances combustion. Upon contact CO₂ a reaction occurs with hot metal:
2Mg + CO₂ → 2MgO + C (soot) + Q (heat release)Result:
- 🔥 Thermite reaction - the temperature rises to 2000°C.
- 💥 Release of hot particles.
- 🚫 The fire extinguisher becomes fire catalyst.
What to do if there is a metal fire:
- 🛑 Immediately leave the area - extinguishing with water or CO₂ will only make the situation worse.
- 📞 Call firefighters (they have special grade D powders).
- 🚗 There are burning metal parts in a car (for example, after an accident), you can try cover with sand or cover asbestos blanket.
8. Use a fire extinguisher with a damaged cylinder
Cracks, dents or corrosion on the carbon dioxide fire extinguisher body - direct threat of explosion. Signs of malfunction:
- 🔍 Visible dents more than 1 mm deep.
- 🟠 Rust on welds or neck.
- 💨 Gas leak (you can hear hissing or ice on the cylinder).
What to do with a damaged fire extinguisher:
- 🚫 Don't touch with his bare hands - there may be frostbite.
- 📦 Place in tight box (if possible).
- 🚛 Take it to recycling point (do not throw it in the trash container!).
What happens if a carbon dioxide fire extinguisher explodes?
When a balloon ruptures OU-3 (weighing ~5 kg) fragments scatter at speeds up to 200 m/s, punching through metal 2–3 mm thick. In a confined space (garage, car interior) this will lead to fatal outcome for people within a radius of 3–5 meters.
FAQ: Frequently asked questions about carbon dioxide fire extinguishers
Is it possible to use a carbon dioxide fire extinguisher to extinguish a person's clothes that are on fire?
❌ No! Jet CO₂ will cause frostbite and suffocation. To extinguish clothes, use water or powder fire extinguisher, or cover with thick cloth (for example, a blanket).
How does OU-2 differ from OU-3? Which one is better for a car?
OU-2 (2 kg CO₂) is more compact and cheaper, but it lasts for 3–5 seconds extinguishing. OU-3 (3 kg) works 6–8 seconds and is more effective for large fires (for example, a fire in the engine compartment). Optimal for car OU-2, if the car is a passenger car, and OU-3 - for SUVs or minibuses.
Can I carry a carbon dioxide fire extinguisher on an airplane?
✅ Yes, but only in luggage (not in hand luggage) and provided that:
- Cylinder new or tested (not older than 5 years).
- The pressure is normal (pressure gauge in the green zone).
- Fire extinguisher packed in a durable case.
Before flying, check the airline's rules - some prohibit transportation any fire extinguishers.
How often should you check the fire extinguisher in your car?
According to Traffic regulations (clause 7.7) and GOST R 51057-2001, the fire extinguisher in the car is checked:
- 🔹 Visual inspection - every 6 months (checking pressure, integrity, seals).
- 🔹 Reload - every 5 years (even if the fire extinguisher was not used).
- 🔹 Replacement - upon expiration expiration date (10–15 years).
What to do if the fire extinguisher goes off spontaneously in the car?
If CO₂ escaped from the balloon without your participation:
- 🚗 Immediately leave the car — high concentrations of gas are dangerous.
- 🪟 Open all doors and windows for ventilation (at least 10 minutes).
- 🔧 Check the cylinder for damage (if it is intact, it may have been triggered by heating).
- 📞 Report to Ministry of Emergency Situationsif the fire extinguisher explodes or becomes deformed.
⚠️ Do not attempt to reuse this type of fire extinguisher! Even if the gas did not escape completely, the cylinder could lose its seal.
A carbon dioxide fire extinguisher is not a universal remedy. It is only effective against class fires B (liquids) and E (electrical equipment). For other cases, you need a powder or water fire extinguisher.