A UK woman died after an apparent allergic reaction to her hair dye.
Julie McCabe, 38, fell into a coma 13 months ago after dyeing her hair with L'Oreal Preference last October.
After dyeing her hair, the woman's breathing shortened and she suffered heart failure.
The family thinks that the chemical may have built up in her system after regular use.
They are now campaigning to have the chemical banned in the UK.
L'Oreal has apparently offered to help with the investigation despite a lack of evidence pointing to the hair dye as the culprit.
The Daily Mail reported that the woman had regularly dyed her hair.
McCabe worked as a real estate agent in West Yorkshire.