Home Cosmetic Science Talk Formulating Why hair dye packs don’t include an acid ammonia neutralizer?

  • Why hair dye packs don’t include an acid ammonia neutralizer?

    Posted by Gunther on June 16, 2018 at 8:17 pm

    They add ammonia to open the hair cuticle and allow dyes to penetrate better.

    But why they don’t include a separate acid-containing neutralizer, to be used when rinsing off excess dye?

    Duncan replied 5 years, 11 months ago 3 Members · 4 Replies
  • 4 Replies
  • OldPerry

    Member
    June 16, 2018 at 8:19 pm

    Because you can rinse it off with water.

  • Gunther

    Member
    June 16, 2018 at 8:26 pm

    Thanks @Perry  but wouldn’t it be be better to both

    lower hair pH beyond what water rinsing can (for a smooth feeling hair)
    and provide a quicker and more complete neutralization, as to avoid further hair damage?

  • OldPerry

    Member
    June 16, 2018 at 9:42 pm

    I just don’t think there is much evidence that using an acid rinse would provide significant benefits over just using water.  The amount of water used in rinsing would overwhelm any residual ammonia left on the hair. And if they use a shampoo after, those will usually have an acidic pH (5.0). So, no I don’t think it would be measurably better to use both. (Perhaps theoretically it might be better).

  • Duncan

    Member
    June 19, 2018 at 12:59 pm

    They usually contain a conditioner for application post rinse. (Ones I’ve applied anyway. These are typically acidic and will neutralise any ammonia residues

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