A former hairdresser claims she has been left with breathing difficulties and unable to work after years of carrying out Brazilian blow-drying treatments. She did not know why her health was deteriorating but said her GP had recently linked her long-term symptoms to these treatments. Brazilian blow-drying treatments, which involve applying keratin formula to the hair, are widely used to reduce frizz and strengthen hair. Curtis recalled how she was taken to hospital with breathing difficulties after carrying out a hair-smoothing treatment in March. "The law ensures that cosmetic products are made in a hygienic and well-controlled environment and they must not be likely to experience harmful microbial contamination.