machin Glass MachineSafe is a product family of vision panels for use in CNC, milling and other metalworking machines that require machine safety glass. esearch has shown that metalworking fluids and lubricants will degrade the polycarbonate in vision panels after relatively short periods of time resulting in significant reduction in the impact resistance of the material. In the later stages, the polycarbonate can also discolour. Mitigation of this degradation in the quality of the machine safety glass is now a requirement in many countries.