Home Cosmetic Science Talk Formulating General Vitamin C (derivatives) and ferrous utensils

  • Vitamin C (derivatives) and ferrous utensils

    Posted by Doreen on June 28, 2019 at 11:18 am

    I’ve read that you shouldn’t use ferrous utensils, like metallic spatulas, spoons etc. with L-ascorbic acid.
    But does that also count for the derivatives?
    Example: I use 2-3% sodium ascorbyl phosphate in an emulsion. Can I use my ferrous spatulas during the preparation of the emulsion?

    Doreen replied 5 years, 4 months ago 4 Members · 15 Replies
  • 15 Replies
  • Doreen

    Member
    June 29, 2019 at 1:42 pm

    I don’t know if the word that I used is the right translation.  :#

    But what I mean is this. Standard pharmacy utensils:

    I am used to preparing emulsions, ointments etc. with a metallic spatula and ‘mortar scrape cards’:

    I tried to work with plastic spatulas, but I can’t work as precise with those as I can with metallic spatulas (plastic ones are too thick, too much loss of product and thus active ingredient).

    I sincerely hope that I can keep on using the metallic kind with vitamin C derivatives! Thanks in advance for answers!

  • Pharma

    Member
    June 29, 2019 at 7:44 pm
    Ascorbyl phosphate is not oxidising and hence, no corrosion/discolouration of your spatula.
    We learn that too but there’s not a really good answer why. Trace amounts of iron and other heavy metals of the alloy might be freed but that’s so small traces that adding an unrefined plant oil to your cream would be a dangerous endeavour :) . The staining/spots though is not aesthetic and can even cause rusting.
  • Dtdang

    Member
    June 30, 2019 at 1:00 am

    @Pharma, the best material to be used is stainless steel?

  • Doreen

    Member
    June 30, 2019 at 8:31 am

    @Pharma
    Thanks so much for your answers!
    Glad to read I can keep on using them. :)

    @Dtdang
    The spatulas are made of stainless steel, but even stainless steel can oxidize over time, especially when (strong) oxidizers are used.
    One of the stainless steel laminar airflow (downflow) benches at my work needs to be neutralized with a sodium hypochlorite 5% solution every time when Botox injections are prepared in it (even when there hasn’t been clearly visible spillage). The bench looks awful now, all rusty!
    After a while it is replaced by a new one. The costs must be enormous…
    To think about all the precautions we take and there are even ‘Botox parties’ by (mostly) women at home! They obviously have no idea what they’re dealing with!  :#

    Edit: typo

  • Fekher

    Member
    June 30, 2019 at 10:35 am

    @Doreen wood will be good choice .

  • Pharma

    Member
    June 30, 2019 at 12:09 pm
    @Doreen It’s chlorine which causes rusting ;) .
    Me, I prefer using stainless steel and get new stuff if necessary. Plastic is often not very practical for the reasons you mentioned. Wood on the other hand is more of a one time usage thing, terrible to really clean.
  • Doreen

    Member
    June 30, 2019 at 3:44 pm

    @Fekher
    A wooden spatula? 

    @Pharma
    Yes it is, because we use sodium hypochlorite. Or did you think that I thought that Botox causes rust? :joy:

  • Pharma

    Member
    June 30, 2019 at 4:07 pm
    LoL! No, botox doesn’t corrode metal but brain cells :blush: .
    The way you wrote it I was under the assumption that you probably might not know why it corrodes or think that it’s hypochlorite as is. Doesn’t really matter… I prefer hydrogen peroxide or in situ generated performic or persulfuric acid if I really have to get something clean. Although, I have to admit, the air gets somewhat unbreathable when using 30% H2O2 or performic acid.
    You could try out an ozone generator. It doesn’t affect the steel work bench (it only annihilates everything else in the room, but not the steel work bench). A doctorate student made that experience… except metal things, EVERYTHING else crumbled to dust when touched! It was like in a Hollywood movie when sunlight hits a vampire. It was hilarious (for those who hadn’t their work ozonised).
  • Fekher

    Member
    June 30, 2019 at 4:16 pm

     yes @Doreen   i guess it is secure .

  • Dtdang

    Member
    July 1, 2019 at 8:31 pm

    @Doreen @Fekher @Pharma Thank you. 

  • Dtdang

    Member
    July 1, 2019 at 8:34 pm

    Stainless steel 304??

  • Fekher

    Member
    July 1, 2019 at 9:46 pm

    you are welcome @dtdang

  • Pharma

    Member
    July 2, 2019 at 7:29 pm

    @Dtdang Use 316 for increased chemical resistance

  • Dtdang

    Member
    July 2, 2019 at 8:39 pm

    Thank @Pharma

  • Doreen

    Member
    July 3, 2019 at 9:36 pm

    Pharma said:

    LoL! No, botox doesn’t corrode metal but brain cells :blush: .
    The way you wrote it I was under the assumption that you probably might not know why it corrodes or think that it’s hypochlorite as is. Doesn’t really matter… I prefer hydrogen peroxide or in situ generated performic or persulfuric acid if I really have to get something clean. Although, I have to admit, the air gets somewhat unbreathable when using 30% H2O2 or performic acid.
    You could try out an ozone generator. It doesn’t affect the steel work bench (it only annihilates everything else in the room, but not the steel work bench). A doctorate student made that experience… except metal things, EVERYTHING else crumbled to dust when touched! It was like in a Hollywood movie when sunlight hits a vampire. It was hilarious (for those who hadn’t their work ozonised).

    Thanks for thinking along! An ozone generator… reminds me somehow of a neutron bomb, destroying living tissue but leaving buildings intact. Yes I know, stupid comparison, but I watched a documentary about it not long ago.

    I know from higher up they’re busy changing protocols on i.a. the Na hypochlorite causing corrosion. And yes, due to the chlorine! Weird right? I mean if you get a whiff of sodium hypochlorite, you’d never guess chlorine! Totally free from odour! :yum: ;) ;)
    Also a change on the 70% IPA we use to sanitize the whole benches (I indeed have heard rumours of using H202 one week then IPA the other).

    Another shitty thing regarding nasties. The lab recently has found a fungus in this particular clean room where toxic steriles are made (mostly chemos). Fungi are the biggest horror scenario here as you can imagine.
    No idea what the plans are yet…

    @Fekher
    Ok, thanks for mentioning! I think I’ll stick with my metallic spatulas as I love to use these!

    @Dtdang
    You’re welcome!

Log in to reply.

Chemists Corner