All you need to know before dyeing/coloring your hair!

 Do you also wish to color your hair? And end up saying no, because you think it’s harmful? Then read this post.

Hair dyeing is a common trend in today’s world. But do you know the chemicals involved in the process are harmful or not,if yes then to what extent? These questions come to your mind at least once,before dyeing or coloring your hair. This blog post will resolve all your doubts.

To understand hair coloring, you must understand a few terms. The terms involved are easy to understand.

They are as follow:-

1. Cuticle- Outer layer of hair or can be called as protective shield.

2. Hair shaft- Part of hair that can be seen above scalp.

3. Cortex- Thickest layer containing colour pigment called melanin.

Hair dyes are classified in the following types based on colour resistance.

1.Temporary Non oxidative dyeing

This dye only remains at the surface of hair i.e. cuticle.As it is formed from dyes having higher molecular mass it cannot penetrate into cortex and thus can be removed in one wash.This dye cannot whiten your hairs.

2.Semipermanent Non oxidative dyeing

Semi Permanent dye penetrates slightly into cortex[1] i.e little more below the surface.It is formed from dyes having lower molecular mass and can be removed from six washes.

3.Demipermanent oxidative dyeing

It is formed from semipermanent oxidative dyes and hydrogen peroxide (H₂O₂) and in the other method aniline is used with basic or acid dyes.It can be removed after 20 washes.

Other dyes-

Vegetable and metallic derivatives such as chamomile(vegetable)and silver,lead and bismuth(metallic)[1]

A disadvantage of the metallic dyeing process is the lack of control in the color progression because of the composition of hair, which is based on keratin. The keratin reduction will result in different colors, so after the first applications, hair can present greenish or yellowish shades. However, the final result is natural because the color develops progressively to more usual shades, such as brown and black, and coverage of 100% of white hair strands is impossible.[1]

Permanent Oxidative Hair dyeing

This is the most common method used for dyeing.It requires ammonia or ethanolamine and is carried out at higher pH(~10),causing cuticle swelling and facilitating entry of the dye intermediates into the fiber structure as well as to decompose hydrogen peroxide so that the dyes can be activated [2].

By looking at the number of washes and chemicals used,  you must have got a slight idea of how dye works. 

Conclusion 

Frequent hair dye weakens hair shaft which results in hair loss.if a pre bleach process is conducted prior to the hair dyeing process,cracks and holes are observed at cuticle.The hair surface becomes more hydrophilic during the dyeing process. The dyeing procedure removes most lipids from the hair surface since it is generally performed under alkaline conditions[2].Long term health effects are unknown till now.

In a nutshell, Proper care after dyeing your hair null the chances of damage.

References-

1.https://www.mdpi.com/2079-9284/2/2/110/htm [Google scholar]

 

2. https://www.researchgate.net/publication/306230328_Investigation_of_hair_dye_deposition_hair_color_loss_and_hair_damage_during_multiple_oxidative_dyeing_and_shampooing_cycles [Google scholar ]

3. https://books.google.co.in/books?id=nbr-BAAAQBAJ&printsec=frontcover&dq=hair+dye+chemistry&hl=en&newbks=1&newbks_redir=1&sa=X&ved=2ahUKEwiAoY2ZxanyAhXT62EKHbEdAtMQ6AEwAHoECAcQAg