The project has focused on the risks of dust explosions and any fire that may arise in various manufacturing processes where metal dust is formed. The work has included studying available statistics to get a better picture of frequency, cause and effect in connection with explosions that occurred, but also to study some real incidents in detail to give examples of events and in some cases also measures taken to reduce the risk of similar events occurring again. In the project, a limited literature review has also been conducted.

Nationally, incidents reported to the Swedish Work Environment Authority have been studied as well as statistics based on the incident reports provided by the Swedish Fire and Rescue Services to the Swedish Civil Contingency Agency (MSB). Internationally, we have mainly studied statistics from the US compiled by CSB (U.S. Chemical Safety and Hazard Investigation Board) and from the database "Combustible Dust Incident Database". Studying metal dust explosions specifically, these constitute about 20-25 % of all explosion incidents. It is also clear that the explosions usually occur in dust extraction systems and associated equipment. In several of the incidents, these have also been associated with some form of manual work in the plant, for example cleaning. In many cases, explosions have also been associated with ignorance, e.g. by lack of control of the equipment. The report gives some examples of this type of incident.

Although Sweden has been spared from fatal accidents related to dust explosions, the international statistics show that this is a very common consequence. During the last 15-year period, CSB statistics show that this in average resulted in 0,3 fatalities per reported metal dust incident. It can also be noted that some very serious accidents have occurred in China within the metal industry caused a large number of fatalities. This indicates that dust explosions in the metal industry can be very violent.

Increased knowledge and exchange of experience between metal working industries could result in risk mitigation measures and improved working procedures and are perhaps the most important measures to reduce the risk of serious explosion incidents. There is also a need for more basic knowledge about the explosion processes for different types of metals in order to ensure that different types of protection systems are dimensioned in a correct manner. Today, it cannot be assumed that this is the case as standards for different protection systems are not always adapted for metal dust.

The report also presents some recommendations that form a basis for minimizing the risks for dust explosions.