Propylene Glycol - Chemists Corner

Starting a cosmetic line

Propylene Glycol

Posted by Dtdang on October 17, 2020 at 12:10 am

Propylene Glycol is from petroleum. Is it safe for cosmetics?
Anyone has experience to use it?

Thanks in advance any sharing.

Pharma replied 4 years ago 6 Members · 16 Replies
16 Replies

ngarayeva001

Member
October 17, 2020 at 10:49 pm

Propylene Glycol has GRAS status. You won’t get safer than that.
Dtdang

Member
October 18, 2020 at 12:12 am

@ngarayeva001, thank you!
Dtdang

Member
October 18, 2020 at 10:16 pm

@ngarayeva001, what you think about the comparison between propylene glycol and glycerin?
ngarayeva001

Member
October 18, 2020 at 11:40 pm

In what sense? They both are safe.
jemolian

Member
October 19, 2020 at 12:58 am

I believe they are edible, if they are food grade. Not sure what you are comparing?
Dtdang

Member
October 19, 2020 at 1:06 am

Humectant, helping active ingredients to absorb into skin, etc.
jemolian

Member
October 19, 2020 at 1:22 am

I’d say it depends on the type of ingredient you are intending to aid the penetration. You might be able to find a test online. For example, for Ethyl Ascorbic Acid, Glycerin is only second to Propylene Glycol. It depends if you want to have the additional benefits of glycols or diols in your formulation as well.
Dtdang

Member
October 19, 2020 at 12:13 pm

@jemolian, thank you so much.

You mean it is depending on molecular weight of ingredients that I need to use propylene glycol to help ingredients penetrating into skin;
molecular weight of ethyl ascorbic acid is about 204 g per mol so it needs propylene glycol?
Dtdang

Member
October 19, 2020 at 7:21 pm

i found propanediol having same formula with propylene glycol but structure is different
Karenbo

Member
October 27, 2020 at 7:01 pm

Which is better: butylene glycol or propylene? I see formulations call for propylene and seldom butylene and despite my research can’t understand why
emma1985

Member
November 3, 2020 at 9:20 pm

I prefer Butylene Glycol as a humectant but Propylene as a solvent. It’s a more effective solvent than the others (for example when solubilizing Ferulic Acid.)
emma1985

Member
November 3, 2020 at 9:21 pm

For penetration enhancement, Dimethyl Isosorbide outperforms PG imo.
Dtdang

Member
November 9, 2020 at 1:11 am

@emma1985 thanks a lot for your sharing. I google and found that butylene is banned many countries due to its toxic and propylene glycol is very safe.
ngarayeva001

Member
November 9, 2020 at 9:51 am

This is the first time I’ve heard that butylene glycol is toxic and banned. Do you have links/references?
Pharma

Member
November 9, 2020 at 12:22 pm

Which butanediol are we referring to here? 1,3-butanediol, although by proper definition not a glycol, is the most often used isomer but by far not the only one. Apart from that, butanediols also come as stereoisomers which complicates things even further.

1,4-butanediol certainly is problematic because it’s quickly metabolised to GHB. Therefore, it is a prodrug or at least a precursor and therefore regulated.
Dtdang

Member
November 9, 2020 at 7:56 pm

@Pharma Thanks a lot!