The Overlooked Ingredient, It is not sulphur

Expert analysis · Version 1.11

The Overlooked Ingredient

Chromium(VI) from thermal insulation (high-temperature insulation) and in combustion ashes

High temperature insulation contains basic oxides, above all calcium oxide and sodium oxide. Neither is classified as carcinogenic, and neither appears in any assessment of chromium(VI). Above about 300 °C they react with the chromium oxide layer of chromium alloyed hot components to form calcium chromate and sodium chromate; sodium chromate already from about 200 °C. In the delivered state no chromate is present; it forms at the interface between insulation and component and forms again after every start up. It is released during maintenance, removal, cleaning, overhaul and dismantling, as dust that leaves the work area on tools, clothing, gloves and removed components.

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The Overlooked Use Ban

Expert analysis · Version 0.18

The Overlooked Use Ban

Reinstalling chromate-contaminated mineral wool as an authorisation-required use (REACH) of the chromium(VI) compound sodium chromate

Anyone working on a thermally stressed chromium-alloyed component under insulation that contains alkali or alkaline earth metal oxides has to check whether sodium chromate is being handled. If it is present, that handling has been prohibited since 21 September 2017 without a granted authorisation. Certainty exists only where the presence of sodium chromate can be ruled out on a sound basis, and ruling it out requires knowledge of the oxide composition of the installed insulation over the entire service history, together with a method whose recovery rate for this matrix has been established. In most cases neither is available.

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The first guide

It is not sulphur

After more than four years of research into the formation of carcinogenic and environmentally toxic chromium(VI) compounds (chromates, in particular calcium chromate) when insulation materials containing alkali and/or alkaline earth metals are used, the guide “It is not sulphur, chromates in the workplace” gives an overview of the history and the state of knowledge at the time, with scientific studies, practical examples, notes on occupational and environmental protection, prevention (substitution) and health consequences. Over 60 pages, more than twenty studies and a hundred illustrations. Authors: Stephan Effinowicz, Lloyd Hopes, Markus Sommer.

Download the guide Case study “Chromates in the workplace”

The two works