Some customers are left with severe burns and reactions to chemicals which could be life threatening.
25-year-old Vanessa Bolzon just wanted some lighter streaks put in her hair with foils - a simple every day procedure generally costing around $130.
Instead she was left with a deep burn on her scalp which will never heal.More stories from Today Tonight
"I was in intense pain. I had to put an ice brick on my head and had to take pain killers," Bolzon said.
Grace was another young woman to have been scarred after having her hair bleached by a hairdresser who worked from home. It was meant to be an all-natural bleach with no chemicals added, but it affected her within seconds.
"It started burning. It started ripping through my scalp. That's when I said 'I need to wash this off now'," she said.
This reporter is on Twitter at @RichoTT7