We describe the formation of the carcinogenic chromium (VI) compounds calcium chromate (CaCrO4), sodium chromate (Na2CrO4) and other alkali or alkaline earth chromates as "dangerous dust"; in high-temperature insulation of steam and gas turbines, but also of CHP engines. These chromates are classified as "Carcinogen 1B" - "May cause cancer (H350)" and "Very toxic to aquatic life with long lasting effects (H410), it's a "substances of very high concern (SVHC)".

In particular, calcium chromate, which is frequently mentioned in the blog texts, can arise if, in an unfortunate thermochemical reaction, the actually harmless calcium oxides (CaO) contained in common insulating materials with a mass content of up to 40% with actually harmless chromium oxides, which can be found e.g. B. in stainless steel alloys on the hot parts to be insulated (e.g. Cr (III); Cr2O3), at high temperatures (between approx. 300°C-800°C) in the presence of oxygen (O2) to the toxic hexavalent chromium compounds (high-oxidation process)