Why even bakeries must observe explosion protection

Did you know that explosion protection in bakeries is of great importance?
But what is the danger of explosion in bakeries? The answer is flour. To be more precise, we are talking about a potential dust explosion. This can occur when finely dispersed material particles are ignited in the air.

Besides flour, all other organic ground substances in dust form can also explode, for example coffee or coal. The risk of explosion increases as the size of the individual particles decreases. If the particles fall below the threshold of approx. 0.5 mm in size, they become explosive. The smaller the particles, the larger the surface area that can react with an ignition source or the air. Due to its fine grinding degree, flour has a particularly large surface area and thus an increased explosion potential.

Even a single electric spark can ignite a grain of flour dust. The explosion of the dust grain whirls up further flour dust, which can also ignite and explode. This chain reaction was the downfall of the Bremen Roland Mill in February 1979 and resulted in the largest flour dust explosion in Germany. This caused 14 deaths and left behind material damage of about 100 million marks (116 million euros).

When baking privately at home, there is no need to worry, as you tend to use small quantities of flour. The flour dust that is whirled up would have to be so dense to pose a danger that your own hand is no longer visible in front of your eyes. However, bakeries that work with large quantities of flour or have larger flour silos need an explosion protection document as part of the risk assessment that answers the following questions:

• Can an explosive atmosphere occur in the area of the plant to be evaluated or inside equipment?
• What quantities of explosive atmosphere may be present or arise due to local and operational conditions and where can they occur?
• Are the expected quantities of explosive atmosphere hazardous due to local and operational conditions? Only in this case a zoning is necessary.
• Which effective ignition sources are present?
• What is the probability that these will be effective?
• What effects of explosions can be expected?

Do you have any questions about explosion protection? Please do not hesitate to contact us:

Ralf Schiffel
weyer group / horst weyer und partner gmbh
Leiter Explosionsschutz
+49 (0) 491 – 20 66 96 60
r.schiffel@weyer-gruppe.com