Thread: Glycerin shelf life

Glycerin can go bad in as little as a year's time. If you're concerned about the short shelf life of your glycerin, keep your main supply in the refrigerator and just a small container of it in your shaving area -- then you can refill the smaller container as needed.

I would be interested in learning more about this, particularly about the source of the info. As far as I know, pure glycerin (this is the key here) is a fairly stable compound at room temperature. Clearly, at high temperatures and/or in the presence of other chemicals, and depending on the pH, it can oxidize. I would imagine that this is slow but feasible over long periods of time at room temperature. Since glycerin (a.k.a glycerol) is a widely used chemical in the food, pharmaceutical and cosmetics industries, the stability of glycerin has been studied extensively. Typically the effects are related to color and flavor degradation. For an example, take a look at this: http://www.pgchemicals.com/resources...elf%20Life.pdf

However, I do not think that storing glycerin in the fridge would hurt it either ;-). Probably the key here is to buy high grade (USP) glycerin:

http://www.cleaning101.com/oleo/USPGlycerin.pdf

Please keep me posted, by PM if you prefer, as I am interested in refreshing my knowledge.

Al raz.

Originally Posted by sffone

Glycerin can go bad in as little as a year's time. If you're concerned about the short shelf life of your glycerin, keep your main supply in the refrigerator and just a small container of it in your shaving area -- then you can refill the smaller container as needed.

I can tell you I have a well sealed bottle in my chemistry lab that lasted over 10 years with no signs of deterioration at all.
Mike

All I know about it is what I was told at the health food store where I bought the stuff. The clerk said that if I was opening the bottle (16 fl. oz.) a couple of times a day and storing it in an enclosed, warm, humid area, it could go bad in as little as a year's time.

Originally Posted by sffone

All I know about it is what I was told at the health food store where I bought the stuff. The clerk said that if I was opening the bottle (16 fl. oz.) a couple of times a day and storing it in an enclosed, warm, humid area, it could go bad in as little as a year's time.

I figured since many of us use this stuff you could use this information.Here is a MSDS on Glycerine, enjoy. http://www.sciencelab.com/xMSDS-Glycerin-9927350. Note that it is chemcally stable, but is Hygroscopic which means that if not properly sealed it will pick up moisture from the atmosphere and in time become more and more dilluted. From my experience in South Florida which is a very humid environment I have never seen glycerine decompose because it has become too dilluted or from chemical instability.
Having said that if your sample has an off color or smell then I would get rid of it, but I doubt that will happen if sealed and not contaminated with other stuff.
Mike