12. Significance for E-glass fabric, calcium silicate, mineral wool and aerogel insulation systems

The designation of a product class is not a statement about the chemical harmlessness of the individual product. What is decisive are the raw materials, fibres, carriers, binders and fillers actually used.

If E-glass fabrics, calcium silicate products, mineral wool products or aerogel-based insulation systems demonstrably contain basic oxide fractions, in particular calcium and/or sodium fractions, these must be assessed, when used on chromium-alloyed hot components, as an indication of a chromate formation risk that cannot be ruled out. Reactive availability, temperature, time and oxygen determine the specific extent. The material-related suspicion must be included in the risk assessment irrespective of a prior positive rapid test. [19]

This also applies to aerogel-based products. An aerogel core does not change the assessment if the marketed overall system contains, for example, glass fibre carriers, fabrics, binders, fillers or coatings with basic oxide fractions. What is decisive is the composition of the specific insulation product in the intended application system, not its advertising designation.

Test objective: material resistance or formation of hazardous substances?

Morgan's Superwool Technical Manual contains its own Contamination / Pollution Study. Chromium powder was placed between insulation mats; after six hours at 1,000, 1,100 and 1,150 °C, powdering, melting, discolouration and visible signs of reaction were assessed. For the four fibre products investigated, including calcium and calcium/magnesium silicate fibres, the chromium row is shown as without observed reaction. A Cr(VI) determination with a detection limit is not described. [27]

The technical consequence lies in the test objective: an outwardly resistant fibre can carry a small quantity of a hazardous reaction product. The finding described therefore does not answer the question of chromate formation. Temperature and duration also differ considerably from Sayano's long-term tests at 500 and 600 °C respectively. [11, 27]

At the same time, the manual advertises the absence of a hazardous substance classification and non-hazardous waste. Such statements on fibre chemistry do not replace an assessment of the insulation system contaminated after use. This is a public group document with a European legal reference. A reliable date of first publication cannot be derived from the extract examined. [27]