"Thank you for your interest in silicones.
As you already aware, it is easy to find a lot of nonsense on the
Internet, and it is not easy to find authoritative sources.
Regarding silicones, one thing to be aware of is that "silicones" is a
generic term that covers many different types of silicones, from
volatile solvents to high molecular weight liquids or solids. In
addition, some silicones carry functional groups which increase their
substantivity to skin or hair, meaning that even very low amounts in the
cosmetic formulations will be attracted and will deposit on skin or
hair. That is why in some cases they can prevent hair dyes from working
properly. I've heard that silicones are actually added to hair dyes. I
speculate that they are used because they can assist in getting around
this potential problem, by displacing whatever is left on the hair.
The first silicone to be applied in cosmetics is PDMS or dimethicone
(INCI name). It is a straight polydimethylsiloxane with no functional
groups. You will find more silicones in the INCI list with the suffix
"methicone" or "siloxane".
I speculate that some of the early formulations containing PDMS might
have created problems such as build-up and stickiness on hair. The same
problem took place with the early hair conditioners based on tallow
quaternary ammonium compounds, so there might have been confusion as
both are used for hair conditioning. You may remember that in the past
shampoos and conditioners were packaged separately, because they were
incompatible. Now thanks to silicones, "all in one" shampoos are
possible. To my knowledge due to the fine-tuning done by cosmetics
producers the build-up issue has disappeared.
With respect to skin ageing: the most important factor is protection
against the sun. I'm sure you know that. Despite all the hype, no
cosmetic product can reverse ageing. However, some products can mask the
effect of age. The most common trick is to have a water barrier on the
skin, such as a fatty product (a paraffin, a vegetable or an animal fat
derivative) or a silicone. Silicones are often preferred because they
apply well and they are not sticky.
Silicones are preferred also because of their inertness. I would be
extremely surprised if there is evidence that they accelerate skin
ageing!
CES members are all telling me that the cosmetics market keeps growing
for silicones. I guess that this is because consumers appreciate the
benefits they bring. I am therefore somewhat sceptical when I hear about
their alleged deficiencies.
I hope this helps. Note that none of these statements have been
validated with the CES members and are purely based on my personal
knowledge.
Best regards,
Michel De Poortere
Dr. M. De Poortere
Secretary General, CES
Cefic
Av. E. Van Nieuwenhuyse 4
B-1160 Brussels
Belgium
Phone +32-2-676 73 69
Fax +32-2-676 73 01"
Wie ihr sehen könnt, hat der Sekretär der Vereinigung selber geschrieben, da ich ihn angeschrieben habe. Er räumt auch ein, dass es früher Probleme gab. Ich persönlich finde, dass es einen Unterschied gibt. Seit kurzem nutze ich wieder Silikonshampoos (ca. 2 Monate) und bin überaus zufrieden.
Wenn es jemanden interessiert, werde ich auch noch Forschungsstellen anschreiben und deren Antworten ebenso hier veröffentlichen.
Ich hoffe, dass jeder mit Englisch klar kommt, sonst übersetze ich gerne.
LG.