In recent years, the cyclic silicones D4 (Octamethylcyclotetrasiloxane) and D5 (Decamethylcyclopentasiloxane) started to gain attention by national as well as European authorities. Several regulatory activities have been carried out and cyclic siloxanes can be found in various Restricted Substances Lists.
Against this background, TEGEWA member companies reported of increasing requests for measures of D4 and further cyclosiloxanes in silicone products being used in textile finishing industry. Until recently, there had been no universally valid analysis specification available, with the result that different methods with differing results had been applied.
This is why the TEGEWA Working Group “Finishing” developed a uniform, universally applicable and validated measuring method : the „TEGEWA method for determining cyclic siloxane levels in silicon oils or aqueous silicone emulsions”. This method had been reviewed and refined in 2021 by the TEGEWA Working Group Leather Auxiliaries. This optimized test method should now serve as first choice when looking for the determination of residual contents of D4, D5 and D6 in chemicals.
Please find the refined method below:
D4-Siloxane_test_method_2021-06_TEGEWA_revision_final_EN