Propylene glycol, butanediol, pentanediol, hexanediol, commonly known as polyols, are often positioned as small molecule moisturizers.
But the media often discuss that propylene glycol is bad, butanediol is a rape drug, and pentanediol & hexanediol is an antiseptic alternative in a preservative-free formula. It is a moisturizer and has a natural antiseptic effect.
Is the above cognition correct? In fact, the "object (chemical structure) " you have to talk about is correct in order to discuss whether it is right or wrong. You can't be considered a thief with the same name, and you can't be wronged with the same name and surname!
Let's have a "simple chemistry class" today to communicate, in addition to no longer misunderstanding others, you can also know what kind of polyols are safer.
According to the INCI standard, the naming of cosmetic ingredients is common on the label of full ingredients:
In fact, they each have several different chemical structures. They can be used as cosmetics and skin care products, and there are some insider secrets.
Propylene glycol - three carbons (C), two alcohols (OH). So, there can be 1,2-propylene glycol/1,3-propylene glycol, two.
Butanediol - four carbons (C), two (OH). So there can be 1,2-butanediol/1,3-butanediol/1,4-butanediol, three.
Pentanediol - five carbons (C), two (OH). So more pentanediols can be combined. Like n-1,2-pentanediol/n-1,3-pentanediol/n-1,4-pentanediol/n-1,5-pentanediol, and branched-chain pentanediol (e.g. neopentanediol 2,2-Dimethyl-1,3-propanediol)
Hexanediol - six carbons (C), two (OH), so more hexanediol can be combined. Like n-1,2-hexanediol/n-1,3-hexanediol/n-1,4-hexanediol/n-1,5-hexanediol, and branched hexanediol
Propylene glycol, two kinds, is currently widely used. But 1,2-propylene glycol has a primary irritating effect on the skin. 1,3-propylene glycol does not. 1,2-propylene glycol has better penetration assistance than 1,3-propylene glycol. In some formulations, 1,3-propylene glycol cannot replace the efficacy of 1,2-propylene glycol.
Butanediol, only 1,3-butanediol. No 1,4-butanediol (15 times more toxic than type 1,3, used by gangsters as a rape drug.)
Pentanediol, only n-1,2-pentanediol. Others that are toxic should not be used.
Hexanediol, mainly n-1,2-hexanediol; less 1,6-hexanediol; other irritants are not used.
Does the cosmetics factory know? Theoretically should know.
| Polyol | Source |
|---|---|
| 1,3-Propanediol | The source is candy corn. |
| 1,2-Propanediol | The source is petrochemical-derived propylene oxide. |
| butanediol | The cosmetic industry uses 1,3-butanediol. |
| pentanediol | The cosmetics industry uses n-1,2-pentanediol (1,2-pentanediol), and others are irritating to the skin. |
| hexanediol | The cosmetics industry uses n-1,2-hexanediol and 1,6-hexanediol. Among them, n-1,2-hexanediol is helpful for the antiseptic effect, and it is also used more. For skin safety, it is equivalent to 1,2-propanediol and 1,3-butanediol. |
These polyols also have many applications in industry. Therefore, on the raw material supply side, there are also low-priced industrial-grade polyols and high-priced daily chemical-grade (cosmetic) polyols.
Consumers on the consumer side have no way of knowing these inside stories. Therefore, no matter how you (consumers) interpret the full ingredients, you are unable to interpret the purity of the raw materials used in the factory. Therefore, stop self-righteous criticism of "such a formula composition, how much does it cost", which only highlights your shallow point of view.
