Dr. Hoang Manh Hung, former Deputy Director of the Institute of Criminal Science of the Ministry of Public Security, proposed to set up a task force to investigate the cause of the vehicle fires. He said that fuel quality is the number one suspect.

- There are currently many hypotheses about the cause of the fire such as electrical short circuit, traffic jam, low gas tank... As someone who has spent many years investigating car fire cases, what is your assessment?

- All of the above scenarios are possible. From a criminal perspective, we are inclined to believe that methanol or acetone was added to the gasoline to increase profits, which is the cause of the fire.

Methanol is a highly reactive chemical, highly flammable and soluble in gasoline. Meanwhile, the materials that make up the vehicle's body and fuel system include plastic, rubber, copper, and aluminum. Leaks from fuel pipes and fuel rubber gaskets such as copper, zinc, and aluminum can occur because they corrode when the methanol concentration reaches 15% or more.

When the fuel has a place to spread out, it encounters the high heat of the engine, or just a collision or electrical spark, an explosion or fire will occur.

In addition, methanol is a weak acid that reacts with nitrous oxide, and during the reaction, hydrogen gas is produced. The light hydrogen gas is released through the gaps in the plastic. When the car stops, the hydrogen concentration in the air is from 4% to 76%, which is within the range of hydrogen's spontaneous combustion concentration. We used to work at the Institute of Forensic Science and found many fires caused by hydrogen.

For machines, people often think about fuel. Regarding the hypothesis of fire caused by machine defects, maintenance or broken gaskets, or exhaust pipes, electrical short circuits, we rank them next.

- But the results of testing some gasoline and oil samples nationwide by the General Department of Standards, Metrology and Quality recently announced that most of the tested gasoline samples are of good quality. What do you think?

- That result made me very sad and disappointed. I think we need to review the sampling method, sampling time, and testing method. If we take 1-2 liters of gasoline at each location and then test it normally, it is not okay.

Previously, the same authorities announced that the vast majority of gasoline samples in the southern region were contaminated.Maledoes not meet the octane index standards. The problem is that to bypass the inspection agency, increase the octane index, and cheat on quality, people just need to add a small amount of acetone. To increase profits, people can mix in methanol, because it is cheap. Previously, in Hanoi, a location was discovered selling gasoline with a methanol content of up to 15.3% by volume. This is too high a ratio and can be an important factor leading to fire and explosion.

- If it's due to fuel, when the car catches fire, it will flare up into a huge fire, but in reality, many fires start slowly and then spread?

- Fire and explosion are consecutive processes, in which conditions there is only fire, in which conditions there is only explosion. Therefore, a burning car in an open environment (ie on the road) will almost certainly not explode. Unlike the case in Bac Ninh, because the car was placed with explosives, it exploded first and then burned.

- What do you think about the possibility that the alloy used to make car engine cases is now being mixed a lot to save costs?

- It is true that the alloy composition determines much of the heat dissipation mechanism and affects whether the fuel system is leaky or not. But how it affects, when, for how long, or what fuel will wear out quickly… requires more comprehensive and careful research.

There have been a series of motor vehicle fires recently, and all parties need to get involved and find the cause as soon as possible. Every day we delay, the more panic the people will have.

- What do you think needs to be done to find the culprit causing the series of car fires and explosions?

- Finding the cause of a fire or explosion is very difficult and requires the cooperation of many specialized agencies.

In a case, one investigation can produce results, but another cannot. The same is true for testing the quality of gasoline and oil, requiring the participation of many specialized components to have the capacity to produce the most accurate results.

Therefore, I proposed that the Hanoi Department of Science and Technology establish a scientific task force to investigate hot phenomena in society, including vehicle fires. This task force has the right to request all gas stations to provide samples, and if there is any violation, their operations will be permanently suspended.

Fuel-saving devices must also be registered and licensed, and products of unknown origin must be confiscated. In addition, each burned vehicle must have a record stating the date of purchase, warranty, location of gasoline purchase... so that within a year the cause of the fire must be found.

According to Express