The dust concentrations of different work phases in iron foundries of different sizes were studied. The results of the total dust measurements made during the Finnish Foundry Project were considered according to the eight main work phases, and the 51 iron foundries were divided into four groups according to the number of foundry workers. The division between the groups at 25, 50, and 100 workers is related to the degree of mechanization in Finnish foundries. The total dust concentration clearly increased in sand making and melting as the size of the foundry increased. The concentration decreased in molding, coremaking, knock-out, and cleaning as the number of workers increased. No significant differences between the foundry groups could be found during casting. The factors affecting the differences in dust concentrations are discussed.

Key terms concentration; dust; dust concentration; dust measurement; foundry size; foundry work; iron foundry; work phase