The current nosology and etiology of silicosis were officially adopted by the 1930 International Labor Office (ILO) Conference on silicosis in Johannesburg. Convened by the International Labor Office and by the Transvaal Chamber of Mines, it paved the way to the adoption of a 1934 ILO convention which recognized silicosis as an occupational disease. Even though it constituted a social and sanitary turning point, the Johannesburg conference, strongly influenced by South African physicians working for the gold mining industry, reduced silica hazards to silicosis, an equation which is questioned nowadays. While the definition of silicosis adopted in 1930 was a major step in the recognition of occupational pneumoconioses, it also led to the under-identification of some pathogenic effects of silica. Going back to history opens new avenues for contemporary medical research.