To avoid the negative effects of hair coloring, you should understand how to dye hair safely. By following the correct hair coloring procedure, negative effects can be minimized. The side effects of using hair dye products are caused by the chemical content in hair dyes. For example, the content of paraphenylenediamine (PPD) can trigger allergic reactions in the form of scalp irritation. That's why it's important to follow the rules for coloring hair properly. Rules to Look For Hair coloring can not be done haphazardly. The use of hair dye needs to be done according to the recommended hair coloring rules, namely by: Pay attention to the rules of use on the packaging Read the rules of use and safety of use in detail on the packaging of hair dye products, and use according to the rules of use. Conduct patch test Before it is applied to the hair, it is recommended to do a patch test on the skin first. If the itchy area feels itchy, rashes appear, the skin feels blister