Home Cosmetic Science Talk Formulating General Is it worse to put something acidic or alkaline on your face?

  • Is it worse to put something acidic or alkaline on your face?

    Posted by DaveStone on April 19, 2023 at 12:05 am

    I was wondering why just putting a niacinimide+water solution on a shaven area of your face makes it sting. I didn’t think Vitamin B3 would cause that sensation, so I assume its acidic in nature hence why it would sting. I also notice it stings when washing with soap, which is alkaline (not synthetic like Dove soap, which is fine). So that just got me thinking which would have worse effect on the skin in general.

    chemicalmatt replied 1 year ago 5 Members · 4 Replies
  • 4 Replies
  • jemolian

    April 19, 2023 at 12:52 am

    Both might sting perhaps because it’s a shaven area, so it’s easily sensitizing.

    Whether which is worse would also depend on the pH and also if it’s a rinse off / leave on product.

  • Unknown Member

    April 24, 2023 at 11:00 pm

    Both might hurt because the area has been shaved, which is readily sensitizing. idle breakout

  • Pharma

    April 25, 2023 at 2:46 pm

    If it stings due to pH, it may just do that without any actual damage.

    Regarding damage: human skin can deal with acids more easily than with bases. Alkali burns are easier to get than burns with acids (unless you’re useing concentrated sulphuric acid which does half the damage by abstracting water and half by getting super hot when doing so -> you basically char and burn, not etch, your skin *fun fact off*).

  • chemicalmatt

    April 25, 2023 at 3:20 pm

    @Pharma is right on point there. Alkali are strongly keratolytic whereas acids are weakly keratolytic, excepting that nasty sulfuric acid mentioned. Fun “don’t try this at home” story. I once did a demo for the ACS for some high school kids, trying to peak their interest in STEM. I placed a copper penny into a small beaker of HCl 36% and they watched it fume and dissolve. Then I placed drops of the same acid onto my bare hand (HCl is non-keratolytic) while they gaped in awe. “See kids, I am Superman, even acid doesn’t hurt me.” Now, had I an open cut on that hand at the time, my painful cry would have been even funnier. Hemoglobin is an iron complex, reacts with HCl big-time. 😃

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