US-headquartered Innospec has developed a way to replace cyclic siloxane D5 (Decamethylcyclopentasiloxane) in personal care formulations, using a combination of low and high molecular weight silicones.
D4, D5, D6 upcoming ECHA ban
Dr. Tony Gough, technical services director for personal care at Innospec, said this was an important development given the European Chemicals Agency ECHA had recently identified these cyclic siloxanes “substances of high concern”.
ECHA currently had an open public consultation out on its proposal for restricted use of D4, D5 and D6 cyclic siloxanes in consumer and professional products and while no enforcement date was in place, suggestions indicate a ban within the next three years, likely 2021. Restrictions on D4 and D5 in wash-off cosmetic products were already enforced in January 2018 and will apply from January 31 2020.
Speaking to CosmeticsDesign-Europe at the SEPAWA Congress in Berlin two weeks ago, Gough said use of these substances in an array of personal care formulations, including rinse-off and leave-on formulas, would soon no longer be allowed so it was important industry looked to alternatives now.
“There’s a lot of movement now to going D5- and cyclic-free, not just in Europe but globally as well because a lot of the formulators in the USA formulate for the European market too,” he said.
“…This is an area that people are definitely going to be interested in because D5 is a fantastic, unique material – it’s used in antiperspirants and deodorants, sun care – and hitherto there’s not been anything that can replace it because of its unique spreadabilty and volatility characteristics.”
Drop in replacement for D5 cyclic siloxane?
Asked if there was a drop-in replacement for D5, Gough said: “There’s no kind of ‘one-size-fits-all’ for a D5 replacement; manufacturers have to work on a formulation-by-formulation basis.”
Innospec’s proprietary blend was a strong starting point, he said, that could be tweaked according to formulation needs – something Innospec could assist with.
“We’re strong in silicones, we’ve got good research facilities looking at silicones and we’ve got expert silicone chemists.”
Gough told attendees at his presentation during the SEPAWA Congress the blend developed by Innospec provided the right combination of volatility, lubricity and spreadability for a range of formulations, including sun care, skin care, hair care, serums and sprays.
“Anything you want from a cyclic silicone you can get from a cyclic silicone-free formulation,” he said.
“…We’ve got products with the right combination and importantly we’ve got the technical know-how and a very good methodology for developing testing capabilities to test these cyclic-free systems to make sure they match the performance of cyclic systems.”
The biggest challenge for industry would be going completely silicone-free but that, Gough said, was not on the horizon.