Home Cosmetic Science Talk Formulating General Preservatives if refrigerating

  • Preservatives if refrigerating

    Posted by DaveStone on August 26, 2021 at 1:31 am

    I don’t understand why a small amount of say, a toner/tonic can’t be refrigerated without a preservative yet you can make a pitcher of iced tea without it. Yeah, I know one is a food but I would think the same principle would apply in this case, seeing as both are aqueous solutions. 

    Pattsi replied 2 years, 11 months ago 4 Members · 5 Replies
  • 5 Replies
  • Paprik

    Member
    August 26, 2021 at 3:09 am

    How long would you keep the iced tea in the fridge? One, two days? That’s cool. If you drink it, your stomach acids will destroy any microorganism. If you leave it for a week, I don’t think you would drink that.  

    If you leave a toner for one two days in a fridge, you might not get any microbial growth, but you might. So if you want, you can use it on YOUR skin and see. 
    Unfortunately on your skin there is no (hydrochloride acid) stomach acids to destroy any pathogens. 

    We can’t stress enough how much preservatives are important.

  • DaveStone

    Member
    August 26, 2021 at 3:35 am

    Paprik said:

    How long would you keep the iced tea in the fridge? One, two days? That’s cool. If you drink it, your stomach acids will destroy any microorganism. If you leave it for a week, I don’t think you would drink that.  

    If you leave a toner for one two days in a fridge, you might not get any microbial growth, but you might. So if you want, you can use it on YOUR skin and see. 
    Unfortunately on your skin there is no (hydrochloride acid) stomach acids to destroy any pathogens. 

    We can’t stress enough how much preservatives are important.

    When I make iced tea, it usually lasts about a week. I wouldn’t know if it had gone bad by then because it still tastes and smells fine.
    Wouldn’t the stomach acid only have minimal effect? I mean, doesn’t botulism get around that? You eat contaminated food and it still kills you. Maybe it absorbs through your mouth.
    I’d use a preservative regardless. Just wondering why you can get away with it when Iced Tea or other homemade drink is concerned. I could see it not mattering with Lemonade because it’s very acidic.
  • DaveStone

    Member
    August 26, 2021 at 9:31 am

    I wonder if the citric acid (from the lemon juice) helps preserve it. Although I also add sugar.

  • PhilGeis

    Member
    August 26, 2021 at 10:24 am

    Food products and tap water often include a lot of microbes.  We consume and breathe in billions of bugs a day - the issue is less the number than specific bugs.  For healthy folks, most micro problems are minor and transient - just as you’d find with exposure to cosmetic contamination.  Compromised folks are at greatest risk for both - adding to cosmetic risk eye exposure.

    Tea might be around for a few days - cosmetics have effective use lives of years.   So the bugs can be at high numbers and each use is an opportunity for ’em to cause problems.
    have Stomach acid pH is in the 1-3 range - pretty effective in killing most not all bugs.   Botulism is due to a toxin (not the bacterium itself)  and is not an issue for tea.  The bug is anaerobic (sensitive to oxygen) so canned foods are  at  risk.  They’re effectively sterilized in retort and for the same reason nitrites are added to bacon.

  • Pattsi

    Member
    August 27, 2021 at 12:18 pm

    DaveStone said:

    Wouldn’t the stomach acid only have minimal effect?

    Where do you get this information?

    Oh I just saw @PhilGeis ‘s already explained. 

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