Sometimes the most seemingly harmless ingredients in our pantries can become… explosion fuel if they are subject to certain conditions. This is the case, for example, with some nuts, such as pistachios. They are so flammable that they are considered dangerous goods and must be transported to their destination under very strict safety conditions. Another very interesting case involves flour. In fact, this soft dust was responsible for several of the deadliest explosions in history.
One of the worst happened in 1878 at a mill in the city Washburn, near Minneapolis. Improper handling of flour led to an explosion that killed 18 people. Therefore, since then, security conditions in this sector of the industry have been significantly strengthened.
It is known that for flour to lead to an explosion, there must be five specific conditions. Therefore, it is important to make at least one of them disappear. But let’s start from the beginning. Why does flour burn?
Origin of the danger of flour
Actually, we are talking about flour, but any powder rich in carbohydrates can be flammable. For example, the same thing happens with coffee or sugar. However, more explosions have been reported with flour because the five factors we’ll see later are easier to combine.
Carbohydrates, as their name suggests, consist of carbon and hydrogen, mostly. They are also two of the main components of hydrocarbons that are so often used as fuel. It’s not for nothing that carbohydrates are the fuel for our cells.
In any case, cells aside, burning both hydrocarbons and carbohydrates requires oxygen. Thus, a combustion reaction occurs in which carbon and hydrogen react with oxygen to form carbon dioxide, water vapor and a large release of energy.
If this fuel is in the form suspended dust They are even more flammable, since in air the particles have a large surface area of contact with oxygen. Moreover, when they form clouds, the particles remain very close to each other and are lighter chain reaction.
So if we have flour on the kitchen counter ready to make pizza dough, there is no danger. In this case it is not enough contact surface with air so it can burn. But even if there are clouds of dust hanging in the air, a spark is still needed to ignite the reaction. A spark flying from two millstones or machines used in factories or professional kitchens would be enough.
We already have four of the five factors we mentioned here: airborne dust, cloud, air and spark. All this would favor a fire rather than an explosion. To do this, a fifth factor is needed: to enclose the dust in closed space.
How to avoid an explosion?
It is important to remember that unless we bake or make flour professionally, we should not be afraid of the risks associated with flour. In a traditional home there is not enough airborne dust to create this risk. However, it is worth knowing in case more industrial uses of this ingredient.
The most common safety precaution is to regularly vacuum up airborne flour. Storage in very closed areas should also be avoided. You can even work with flour concentration,
This was noticed in 2019 by two researchers from Beijing Institute of Technology. They noticed that the flame expands at its maximum speed when the concentration of flour in a confined space is equal to 800 grams per cubic meter. However, if it increases to 1000 grams per cubic meter, the flame weakens. There may not be much room for dust clouds to form.
In short, the risks of flour in general should not be feared, but they need to be taken into account in some very specific conditions. It seems like the most harmless ingredient, but it can hide risks that we are not even aware of. Maybe it’s the zombies Last of us This may be an exaggeration, but the explosion is somewhat plausible. Sometimes real life is almost as amazing as fiction.
Source: Hiper Textual
