Formaldehyde is not banned in “professional use” hair products in California. It is regulated by the CA Air Resources Department and the limit is no greater than 6%. They comply with OSHA’s regulations in regards to their products and Hazard Warning under CA state law. The Hazard Warning is indicated on the back of each bottle for both True and True+ products.
For a Formaldehyde-free alternative, try Trissola Solo.