What defines Class 2, Division 2 in terms of combustible dust?

Class 2, Division 2 is defined by the presence of combustible dust in a way that it is not suspended in the air in hazardous quantities. This means that while dust may be present, it does not accumulate in sufficient concentrations to create a hazard for explosion or fire. This classification is important in ensuring safety in industrial environments where dust can be a byproduct of various processes but is managed appropriately to prevent hazardous conditions.

The other choices denote scenarios that do not fit the definition. For instance, if dust were suspended constantly in the air, that would make it a Class 2, Division 1 hazard, where there is a risk of an explosion due to persistent dust presence. Dust being generated only from chemical reactions or appearing solely during manufacturing does not accurately capture the criteria for Class 2, Division 2, which focuses specifically on the quantity of dust present in the atmosphere.