Only citric acid-based descalers are suitable for descaling the SENSEO coffee machine.
Philips has developed a special SENSEO descaler for this which is available under type numbers HD7006, HD7011 and HD7012.
This type of descaler descales the appliance without damaging it.
Note: Never use a descaling agent based on mineral acids such as sulfuric acid, hydrochloric acid, sulfamic acid and acetic acid (e.g. vinegar). These descaling agents may damage your SENSEO coffee machine.