It is widely known that cosmetic ingredients are managed under the Cosmetic Regulation 1223/2009 however, what is less well known is that other regulatory changes can impact, and in some cases override, the restrictions laid down in the Cosmetic Regulation.
Cyclopentasiloxane (D5) is commonly used in cosmetic products to provide an array of functions (antistatic, emollient, humectant etc.). Currently this ingredient is subject to restrictions laid down in Annex III of the Cosmetic Regulation following an opinion published by the Scientific Committee on Consumer Safety (SCCS) in 2015 which can be found here: http://ec.europa.eu/health/scientific_committees/consumer_safety/docs/sccs_o_174.pdf
This update found that D5 is safe except when used in body lotions and hair styling formulations, meaning there was no usage restriction in rinse-off products or other leave-ons.
However, D5 may be subject to an update under the REACH regulation. An opinion is under development which looks to limit the use of D5 in all wash-off cosmetics to 0.1% due to potential effects on the environment. If this limit is to come into force it will be binding across cosmetics, regardless of the SCCS opinion that the ingredient is toxologically safe.
You can view the update here: https://echa.europa.eu/previous-consultations-on-restriction-proposals/-/substance-rev/9444/term
This change highlights the need to be vigilant of changes across the regulatory landscape and not just updates to the Cosmetic Regulation.