1 Brief digression
The problem of respirable crystalline silica is not really one anymore! At least, this is the case in Germany and particularly in the German ceramics industry! The Employer’s Liability Insurance Association for the ceramics industry introduced limits back in the early 1950s. These led to increased efforts in the industry to avoid dust, the result was a substantial reduction of silicosis in the industry. Further progress came with the replacement of annular kilns with tunnel kilns and the introduction of the maximum workplace concentration of 0.15 mg per cubic metre respirable...