The singer, 39, was encouraged to share the snap after Simpson posted a photo of her seven-year-old daughter Maxwell’s new purple and pink locks – inspired, she said, by an actress in The Descendants.
Simpson’s post received backlash from some of her fans – who said it was “irresponsible” and criticised her parenting choices.
A few days later, Pink posted a photo of her daughter Willow with blue hair. “I heard people were bummed on Jessica Simpson for letting her seven year old get her hair coloured,” Pink wrote.
“So we thought we’d share what we did yesterday.”
She included the captions #bluehairdontcare and #getyourownkids – before disabling comments on the photo.
Is there an age limit on dying your children’s hair? Parents do need to be aware of the potential risks before they let their children experiment, a doctor previously told HuffPost UK – particularly when a product contains one of the most commonly used dye chemicals, Para-phenylenediamine (PPD).
This can cause skin reactions, worsen asthma and, on rare occasions, result in systemic illness (one that affects the entire body), said Dr Rahul Chodhari, spokesperson for the Royal College of Paediatrics and Child Health (RCPCH).
Hair dyes containing PPD are safe to use on adults, he said, providing the supplier’s instructions are followed, but until further research is conducted into the potential risks of PPD, the extent of risk to kids is unclear.
This is why you’re advised not to apply dye with this chemical to the hair of children under 16. Dr Chodhari said darker shades of dyes pose a greater risk of an allergic reaction as these colours can contain higher concentrations of PPD.
But there are safer alternatives, he added. Natural or vegetable-based hair dyes are becoming increasingly available. “But you must read the packaging carefully as some products marketed as ‘natural’ hair dye may still contain the PPD chemical,” he said. “If in doubt, don’t use the product.”