The danger of explosion can be determined by means of the explosion limits, the point of ignition (of fluids), the temperature at which spontaneous ignition occurs and the grain size distribution (of dust), the ignition temperature and the minimum ignition energy of an ignition source. These data can be found in the Safety Data Sheet. Explosive atmospheres may form at workplaces due to: concentration within the explosion limits, excessively high processing or storage temperatures (minimum 5° C below the point of ignition), deposits of dust, leakage of substances from containers, or unfavourable local conditions, such as pits or sewers. Appropriate measures have to be taken for explosion protection. The Regulation relating to Explosive Atmospheres (Verordnung explosionsfähige Atmosphären, VEXAT) defines the required action for the protection of workers against the danger of explosions.