As every year, the high temperatures and the dryness of the vegetation increase the risk of fires in summer. This combination of factors can become an added danger when parking a car on a flammable surface. For example, on a bed of dry herbs. This irresponsible action carried out by some drivers can trigger a fire due to the high temperatures given off by some parts of the car in contact with dry vegetation, especially during heat waves.
Vehicles equipped with a catalyst present an additional risk of fire. This device, which has become the object of desire for criminals due to its high economic value, can reach extremely high temperatures during operation. Hence, when it comes into contact with a highly flammable surface, it can cause a fire that burns the car and leads to a fire.
In recent years, some forest fires registered in the Catalan forests have been caused by a vehicle parked on dry vegetation. This is confirmed by Lourdes Casademont, senior agent in the area of fire prevention and investigation of the Rural Agents body of the Generalitat de Catalunya, in a telephone conversation with Moveo. "It happens, above all, with older cars, from 10 to 20 years old, which have catalytic converters made of ceramic parts."
As the rural agent explains, these pieces are more fragile than those fitted to the catalytic converters of the most modern cars, which are made of more resistant metallic materials. Ceramic pieces deteriorate more easily when the car drives on stone roads and rural tracks, confirms Casademont. "The ceramic material crumbles on the inside and when the car does some kind of acceleration, at a junction or when entering a road, it is easier for them to come off."
This situation is especially compromising when the car is parked on dry vegetation. “It must be taken into account that all fires start with dead and dry herbaceous material. This material, known as dead fine fuel, has the ability to dehydrate faster than any other plant material. When this ceramic particle, which is at a temperature between 450 and 700 degrees, falls on the fine dead material, it catches fire, since its autoignition temperature is about 300 degrees and does not need a flame.
For this incandescent material to end up igniting on a dry vegetable surface, it needs to be in contact with it for a certain time. “Any fine dead material that touches the underside of the car when it is at a high temperature is susceptible to starting a fire. Making an estimate of time is complicated. It depends on the ambient temperature, humidity, etc.” In any case, the rural agent assures that there is no risk of fire when the car simply passes over the weeds. “For it to turn on, you need time, how much? We don't know, but it takes time”, insists Casademont.
Regardless of the fire danger associated with the older catalytic converters, the source consulted by Moveo points out that the lack of vehicle maintenance is related to the increase in car fires that Agents Rurals has detected. “Every time we are finding that due to lack of maintenance there are more cars that burn. And burning cars start fires. It is not only about the safety of people, but we also find more cases of cars that start to smoke and park on the shoulder next to the vegetation. So, in some cases, a fire breaks out.”
Casademont points out that in rural areas, where maintenance is usually less, is where more fires of this type occur. "Many fires occur because cars, trucks and tractors have poor carburetion and sparks."
Likewise, the senior agent of the Rural Agents stresses that despite the fact that the new Traffic Law punishes more severely people who throw cigarette butts from the car, fires still occur due to actions like these. "It is very worrying that at this point we are still like this," she admits a few hours after confirming that a forest fire along the C-31 highway was caused by a cigarette butt. “As if all this were not enough, current cars are designed without ashtrays, which constitutes an added risk factor”, laments Lourdes Casademont.
