Alkaline Earth Silicate (AES) Wool

  • Developed in the 1980s
  • Commercially available since the early 1990s
  • Used in domestic appliances, fire protection and industrial applications
  • Low biopersistence
  • Can be used up to 1200 °C

AES wools consist of amorphous fibres, which are produced by melting a combination of CaO-, MgO- and SiO2 (see also EN 1094-1; VDI-recommendation 3469, Parts 1 and 5).

Key features are:

  • low thermal conductivity
  • low biopersistence
  • low linear shrinkage up to their use limit

Fibre properties can be adjusted by varying the quantity of alkaline-earth for different application areas. The fibres are manufactured using high purity raw materials.

Products made from AES wools are generally used at application temperatures > 600 °C in industrial equipment, fire protection, automotive exhaust systems and domestic appliances. Their usage has grown significantly since their commercial production began in the early 1990s.

Specific product technical information is available from your supplier.

diagramm polycrystalline wool

Regulatory Classification Status

AES wools have been exempted from classification after scientific assessment. They fulfil the Exoneration Criteria of Note Q of the European Dangerous Substances Directive based on biopersistance tests or long-term animal studies. (See Annex 1 of the Dangerous Substance Directive and Annex VI part 3 table 3.1 of CLP, reference group EU index number 650-016-00-2.)


Regulation (EC) No 1907/2006 of the European Parliament and the Council of 18 December 2006 concerning the Registration, Evaluation, Authorization and Restriction of Chemicals (REACH) requires manufacturers, importers and or the exclusive representative of non-European manufacturers to share data on potential health and environmental hazard and provide data to the European Chemicals Agency (ECHA) in a formalized registration process.

AES was registered before the first deadline of 1 December 2010 and can therefore be used on the European market.

Handling AES

Care should be taken to minimise the generation of workplace dusts when handling any High Temperature Insulation Wool (HTIW) product. The following link gives an overview of good working practices when handling AES: [Download Information]

Further specific information can be found on your supplier’s MSDS.

All relevant local, state, regional and national regulations should be observed at all times when using these products .