Before replacing the blade, make sure the tool is clean and dry and handle the new blade with care, holding it by the sides without touching the cutting edge. Remove the used blade and insert the new one, checking that it is firmly fixed before use. Replace the blade when it no longer cuts well or is damaged and, in a professional setting, for each new client. Dispose of used blades in a rigid, safe container, without throwing them directly into the rubbish. Keep spare blades in their original packaging in a dry place. Keep out of the reach of children. Do not reuse blades on different people without proper sterilisation.