Deals with silicone liquids to be used as insulating liquids in transformers and other electrical equipment. It comprises three sections as follows: section one describes the silicone liquids and gives general guidance on their properties, safety, storage and disposal; section two describes the test methods that shall be employed to test the properties of silicone liquids; section three specifies the required characteristics of a liquid polydimethylsiloxane primarily intended for use in transformers.