How young is too young to dye your child's hair?

It’s predictable that young girls will want to change their hairstyle over time.

But how young is too young to dye your child’s hair? If an eight-year-old “hates her hair”, should she be allowed to change it?

It’s a debate that has one online mums group fired up.

Dr Michael Gannon, Australian Medical Association (AMA) President says he would advise parents to “exercise caution” and question whether it’s really necessary.

“Children have developing bodies and it’s at least plausible that there might be a level of risk exposing young children to these kind of chemicals,” he told Mamamia.

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“I would question the need for it in most circumstances. If it’s for a theatrical performance at primary school then there are plenty of spray on alternatives,” he added.

“There’s is evidence that these chemicals get into the bloodstream so it’s plausible there could be some sort of risk.”

Sydney Toni & Guy salon owner, Marie Poggi, says 15 or 16 is a good age to start experimenting with hair colours.

“We have teenage clients aged 15 or 16 that want tint pastels. It is semi-permanent and very soft and subtle,” she said.

“I think it’s good age to start, especially with the trends and fashion. Girls just want to be on point with the way they look – quite young now. It’s not a problem.”

Poggi’s Surry Hills salon offers 48-hour allergy test for first time clients to test for allergic reactions.

“I will always give my opinion. Also it is my business, so if I think it’s too trashy or too much I will refuse to do it because the little girl would walk out of the shop with my name on her head. I need to agree,” said the hairdresser.

Mamamia mum, Rebecca Jacobs, started dyeing her daughter Ruby’s hair when she was 10 years old.

"We coloured her hair last year for her 11th birthday. It was her one pleading request," said Jacobs.

"I was in two minds about her wanting to colour her hair," she added.

"She is wanting to express herself in that way which is totally legitimate and I support that. My husband was concerned about her inviting comment on her appearance, which is not important. I definitely saw his point."

Ruby's birthday salon treat was a semi-permanent colour that cost around $150.

"She wanted to colour her hair so bad - for a long time - and the more I thought about it the harder I found it to think of a good reason why not. Because other people might judge her? That’s a terrible reason," said Jacobs.

The mother of one says the home dyes are now a shared fun experience she can have with her daughter.

"She could have been like me and just bought the colour from the chemist myself and did it without telling my mum then it becomes a whole big thing."