Healthy air, always with the Philips Anti-bacterial Cartridge for Air Humidifier Water Tank! The unique anti-bacterial agent effectively prevents the growth of bacteria and other organisms inside the water tank of Philips humidifiers, ensuring extra safety for you and your family. Philips humidifier comes with an addition to the advanced humification filtering system: an anti-bacterial agent that prevents bacteria of growing inside the water tank. Add it to the water regularly to ensure your water tank is extra safe. Anti-bacterial agent for safe & clean humidifiers!