A fire in a car or garage is always a stressful situation that requires an instant reaction, and it is in such seconds that the driver grabs the first fire extinguishing agent available. Most often this means powder fire extinguisher, which is valued for its versatility and low cost, but few people think about its side effects. A cloud of fine dust emitted by a high-pressure jet can instantly reduce visibility to zero and create conditions dangerous to the human respiratory system.
Many car owners mistakenly believe that the main risk is associated only with the flame itself, ignoring the chemical composition and physical properties of the fire extinguishing agent. When sprayed in a confined space in a cabin or small box, the concentration of particles reaches critical values, which can lead to panic, loss of orientation and even suffocation. Phosphorus-ammonium salts, which form the basis of most powders, are not inert for the body upon direct contact with mucous membranes.
In this article we will analyze in detail exactly what threats the use of OP (powder fire extinguisher) for humans and how to minimize the consequences. It is important to understand the difference between short-term use outdoors and trying to extinguish a fire inside a vehicle where air volume is limited. Life safety should always take precedence over property safety.
Chemical composition and toxicity of the powder
The basis of the fire extinguishing powder is finely ground mineral salts, most often ammonium phosphates and sulfates, mixed with hydrophobic additives. These components themselves belong to low-hazard substances (4th hazard class according to GOST), but this does not mean they are completely harmless. When heated in a fire zone, the chemical structure of a substance can change, releasing volatile compounds that, if inhaled, cause irritation to the upper respiratory tract.
Of particular danger is the finely dispersed fraction of the powder, which can penetrate deep into the lungs, reaching the alveoli.
⚠️ Warning: Inhaling a cloud of powder may cause severe bronchospasm, especially in people prone to asthma or allergic reactions.A long stay in a dusty room without personal respiratory protection equipment (RPP) is fraught with the development of acute respiratory failure.
It is also worth considering that upon contact with the moist surface of the mucous membranes of the eyes and nose, the powder forms an aggressive environment. This leads to a chemical burn, severe lacrimation and temporary loss of vision, which in a smoky room critically reduces the chances of evacuation. Toxicity The combustion product also depends on what exactly is burning in the car - plastic, rubber or technical fluids.
Composition of P-AB powder
P-AB powder is based on monoammonium ammonium phosphate. During thermal decomposition, it releases ammonia, which in high concentrations is toxic to the nervous system.
Physical risks: “dust curtain” effect
One of the main problems with using a dry powder fire extinguisher in a confined space is the sudden and catastrophic drop in visibility. The powder jet creates a dense dust curtain, which scatters light and makes visual control of the situation impossible. For a driver trying to leave a burning car, this means loss of orientation in space.
In conditions of panic, a person instinctively begins to breathe quickly and deeply, which leads to the rapid filling of the lungs with irritating dust. Loss of vision due to powder getting into the eyes aggravates the situation, turning evacuation into chaotic movements. Psychological factor here it plays no less a role than the physical one: the feeling of impenetrable darkness provokes fear and stupor.
In addition, a layer of powder, settling on the floor and surfaces, creates a sliding effect similar to ice. This increases the risk of injury when trying to quickly get out of the car or move around the garage. The mechanical impact of solid particles under jet pressure can also damage the skin or mucous membranes of the eyes upon close contact.
If you are using a fire extinguisher indoors, try to position yourself against the wind or air flow so that the cloud of powder is blown away from you.
Effect on the respiratory system and lungs
The entry of fire extinguishing powder into the respiratory tract causes an immediate protective reaction of the body - coughing, sneezing and sore throat. However, at high aerosol concentrations, these mechanisms fail, and particles begin to settle on the walls of the bronchi. This may lead to the development acute bronchitis or chemical pneumonitis.
The most vulnerable are people with chronic lung diseases, smokers and children. For them, even short-term exposure to powder suspension can become a trigger for a serious attack of suffocation. Doctors note that symptoms of poisoning may not appear immediately, but several hours after the incident.
The table below shows the main symptoms of damage to the respiratory system when inhaling the powder:
| Symptom | Degree of manifestation | Appearance time |
|---|---|---|
| Sore throat | Lightweight | Instantly |
| Dry cough | Average | 1-5 minutes |
| Shortness of breath | Heavy | 5-15 minutes |
| Chemical burn | Critical | With direct contact |
Risks when extinguishing in a confined space
Using a dry powder fire extinguisher inside a car or small garage is a last resort and should only be used if escape is impossible. The volume of air in a passenger car is only a few cubic meters, so the concentration of harmful substances increases exponentially. Interior sealing in this case, it works against the person, preventing the cloud from dissipating.
When the device is activated, the pressure in the jet can reach 10-15 atmospheres, which creates a powerful shock flow. In a confined space, this flow ricochets off walls and glass, lifting dust from all surfaces and creating an additional volume of suspension. This phenomenon is known as secondary dust.
⚠️ Attention: Never extinguish a fire in a car with a powder fire extinguisher if there are people inside. Ensure their evacuation first!
If a fire occurs under the hood, opening the hood without prior preparation is also dangerous. A sudden influx of oxygen can cause a flare-up, and a stream of powder directed into the engine compartment can be thrown by the wind directly into the face of the extinguisher. Distance and angle of attack must be maintained to minimize the risk of blowback.
☑️Safety when extinguishing in the garage
Comparison with other types of fire extinguishers
To understand the dangers of a dry powder fire extinguisher, it is necessary to compare it with alternatives. Carbon dioxide (Op-amp) and air-foam (ORP) devices have their pros and cons. Carbon dioxide, for example, leaves no traces, but when evaporated, it sharply reduces the temperature and can cause frostbite on the hands, and also displaces oxygen, creating a risk of suffocation in small volumes.
Powder models benefit in cost and operating temperature range, but lose in environmental friendliness and cleanliness of use. Aerosol fire extinguishers, popular among car enthusiasts, create less smoke, but their effectiveness against large fires is much lower. The choice of protective equipment should depend on the likely fire scenario.
For a car, the optimal solution is often considered to be a combination: a small powder fire extinguisher for the engine compartment (where no person is present) and an aerosol or carbon dioxide one for the interior. However, regulations often require a powder device of a certain volume, which is dictated by fire safety rules.
A powder extinguisher is effective against flames, but creates a hazardous breathing environment in a confined space, requiring immediate ventilation.
First aid and actions after use
If you or someone nearby has to inhale the powder, the best action is to go out into the fresh air. You must immediately leave the dusty area to stop contact with the irritant. Flushing your eyes and nasopharynx with plenty of clean water will help flush away any remaining chemicals and reduce the risk of burns.
You should not rub your eyes with dirty hands, as this can lead to mechanical damage to the cornea from abrasive powder particles. It is better to remove clothing soaked in fire extinguishing agent or shake it thoroughly in the open air to avoid re-introduction of dust into the respiratory tract. Symptoms of poisoning may include dizziness and nausea.
If you experience a persistent cough, difficulty breathing, or severe eye pain, seek medical attention. The doctor should be told that a powder fire extinguisher was used so that he can prescribe appropriate antihistamines or anti-inflammatory drugs. Self-medication in such cases is unacceptable.
Is it possible to use a powder fire extinguisher in an apartment?
Using a powder fire extinguisher in a residential apartment is highly discouraged. The powder penetrates into all crevices, is difficult to remove and can damage electronics. In addition, in the confined space of an apartment there is a high risk of suffocation. It is better to purchase a carbon dioxide fire extinguisher or a special aerosol fire generator.
How long does it take for powder to disappear from the car interior?
Complete removal of fine dust from the car interior can take from several hours to several days, especially if active ventilation is not used. Particles settle on the upholstery and in the air conditioning system, so after using OP, professional dry cleaning of the interior is required.
Is the powder harmful to car electronics?
Yes, the powder can be harmful to electronics. It conducts current when wet and can cause short circuits in open contacts. In addition, abrasive particles can damage moving mechanisms and instrument screens. After use, complete cleaning of the engine compartment is required.