Cyclic silicones are solvents frequently used for fragrance, essential oils + carrier fluids (a fluid or gel to dilute essential oils).
Cyclic silicones are found in a wide range of beauty and personal care products such as lotions, serums, moisturizers, foundations, primers, hair care products, and more.
There are growing concerns about chronic exposure for humans and animals as cyclic silicones are building up in the environment. They are known to be highly volatile and reactive when mixed with other chemicals in landfills.
Cyclic silicones encourage dead skin, dirt, sweat, bacteria, and oil to impact pores, leaving blackheads and other acne issues. While cyclic silicones “seal” things into the skin, they also seal things out – most importantly, water. This can leave your skin dull and dehydrated. Silicones also inhibit the production of new skin cells and the shedding of old skin cells.
The European Commission restricted the use of silicones octamethylcyclotetrasiloxane (D4) and decamethylcyclopentasiloxane (D5) to 0.1% in wash-off personal care products. One of the concerns listed was the long term damage to the environment .
 European Commission. REACH Act. (2018). https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=uriserv:OJ.L_.2018.006.01.0045.01.ENG&toc=OJ:L:2018:006:TOC
 ECHA (European Chemicals Agency). ANNEX XV RESTRICTION REPORT PROPOSAL FOR A RESTRICTION. (2019). https://echa.europa.eu/documents/10162/13641/rest_d4d5d6_axvreport_en.pdf/c4463b07-79a3-7abe-b7a7-5c816e45bb98
 NIH. NCBI. Induction of the Estrogenic Marker Calbindn-D9k by Octamethylcyclotetrasiloxane. (2017). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4661670
 Systems Biology in Toxicology and Environmental Health. Page 149. (2015). https://books.google.com/books?id=J-ucBAAAQBAJ&pg=PA149&lpg=PA149&dq=D4+and+D5+are+known+to+induce+liver+cytochrome+P450+(CYP)+enzymes+and+CAR+expression+in+rodents,+indicating+that+both+compounds+are+potentially+regulators+of+important+xenobiotic+metabolic+pathways&source=bl&ots=IiPJJsGClK&sig=ACfU3U1UINtEqT_t7A2kJrUvvx9MXuVg8A&hl=en&sa=X&ved=2ahUKEwjqkOW3nPjoAhWXvJ4KHc8BAR0Q6AEwAHoECA0QKA#v=onepage&q=D4%20and%20D5%20are%20known%20to%20induce%20liver%20cytochrome%20P450%20(CYP)%20enzymes%20and%20CAR%20expression%20in%20rodents%2C%20indicating%20that%20both%20compounds%20are%20potentially%20regulators%20of%20important%20xenobiotic%20metabolic%20pathways&f=false
 Science Daily. How everyday products are supercharging landfill gas, and what that means. (2019). https://www.sciencedaily.com/releases/2019/11/191113153029.htm