qs and up to 100%? In a cosmetic formula

Hope you don’t mind but I’m going to ask anyway. Nothing to lose :) What does qs mean and up to one 100% ? I’m trying to learn the basics on how to write a cosmetic formula. I’ve grasped the % but never come across these other terms before 

Thanks 
Olivia 

Comments

  • PharmaPharma Member, Pharmacist
    qs is short for Latin 'quantum satis' which means 'as much as needed' or 'sufficient amounts'. This is mostly used to adjust pH: Add acid or base until you reach a certain pH; the amount may vary from batch to batch. Or for base formulations wherein the preservative or fragrance is unknown.
    Up to 100% means that you fill up to the final volume. This is not just to avoid having to sum up all ingredients and then get some fancy 3 digit odd number for the main ingredient (which is often water) but it allows for using more should some evaporate. A formulation with 20 g water asks for exactly that, one with up to 100% and 80 g other ingredients gives some flexibility and adjustability.
  • Olivia_76Olivia_76 Member
    Thank you for explaining 
  • gfeldmangfeldman Member
    edited June 3
    A lot of people use QS for the volume of water, myself included. So if I write QS where the water is on the formula sheet, that means that I brought the final volume back up to 100% (because water evaporates off while batching). 
    This is the same as "up to 100%" but much shorter to write. When you are batching on a daily basis, like I do, shorter is better. 
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