-3

My parents always caution me to not use their hair brushes or combs as they apply dyes (to dye their hair black) on a regular basis. According to them, my hair will start whitening. I am very insecure about my white hair as I am still young for white hair, but I am skeptical about this unfounded claim.

Composition of the hair dye my mom uses. I am not directly applying the dye but just mistakenly use her comb or brush sometimes. I don't see any reason why it can't lead to whitening of my hair.

JRE
  • 5,088
  • 3
  • 29
  • 22
Samardeep singh
  • 113
  • 3
  • 3
    sounds like a variation of the one my mother used to tell me which was to never use other peoples' hairbrushes or combs to prevent getting lice. Which was a real thing back in the 1970s, less so now but still wise advise out of simple sanitary logic. – jwenting Sep 22 '21 at 08:12
  • 6
    Does what your parents say constitute a "[notable claim](https://skeptics.meta.stackexchange.com/questions/2506/what-is-a-notable-claim)"? – Weather Vane Sep 22 '21 at 09:04
  • @WeatherVane well it somewhat makes sense, that the chemical gets transferred to their hairs to mines and as the composition I have mentioned contains hydrogen peroxide it could bleach my hair isnt it? – Samardeep singh Sep 22 '21 at 09:53
  • 2
    Uh, why would black hair dye contain bleach? Anyway, hydrogen peroxide decomposes quite quickly in air. – Weather Vane Sep 22 '21 at 11:41
  • 1
    @WeatherVane while it is counterintuitive because the dye is black, it contains hydrogen peroxide and ammonium hydroxide to make the hair porous (facilitating the penetration of the pigment) and partially bleach it (to achieve a more reliable tone) – Juliana Karasawa Souza Sep 22 '21 at 13:29
  • 4
    It would probably be most polite to not use the brushes/combs of people who don't want you to use them, even family, regardless of whether the specific reason they give is valid or not. – Bryan Krause Sep 22 '21 at 14:08
  • 1
    ... very good point. Perhaps your parents are trying to politely ask: don't leave *your* greasy hairs on *our* combs and brushes. – Weather Vane Sep 22 '21 at 15:26

1 Answers1

6

Let's do a play-by-play of what is happening, using the composition and the instructions as a guide:

Mix equal amounts of colorant and the developer into the bowl and mix them well

I'd like to draw your attention to two ingredients: hydrogen peroxide (in the developer) and ammonium hydroxide (in the colorant).

To properly color hair in a permanent fashion, you need to open the hair cuticles and strip the hair of old pigment so the new pigment can bond in. Think about trying to paint a wall that was already painted before - you need to strip off the previous layer of paint, otherwise, it will interfere in the color that you want to apply.

So, the ammonium hydroxide opens the hair cuticles so the hydrogen peroxide can move in and destroy the old pigment. Since this is designed for gray coverage and not radical color change, I'm expecting the developer to be the garden variety 20 volume developer, which is not very strong.

Keep in mind that it is mixed with the pigment, not just decolorant / bleach.

Now, apply the color wherever necessary, with gloves or the applicator comb. Keep for 30-45 minutes. Wash off with cool water.

Now the color is being applied to the hair with gloves or with the applicator comb (not the brush or comb she uses to style her hair, or so I hope) and it will be left there for 30-45 minutes.

The thing with ammonium hydroxide and hydrogen peroxide is that they're unstable. Hydrogen peroxide is even more unstable in alkaline conditions. For crying out loud, when peroxide degrades the pigment, it is also degrading itself, making it useless for another round of "pigment-eating"

Furthermore, both compounds that bleach hair are very soluble in water, so when the colorant is washed off, they'll be fully removed from the hair, leaving effectively nothing to be picked up by the styling comb or brush.

Even if there was residue on the comb / brush to begin with, if it was enough to bleach hair, it should be bleaching YOUR MOM's hair, since she uses the comb / brush more often than you.

TL, DR: no, it can't

Juliana Karasawa Souza
  • 1,011
  • 1
  • 3
  • 9