The incense will burn/melt and release a scent and produce a lot of smoke after a few minutes the incense/herb will turn into ash and you will want to re-apply the material. It is advisable sometimes to remove spent frankincense ash or some herbal ash with tongs or a heat proof spoon or knife as it may not smell appealing then re-apply. Tongs are handy to move the disc around in the censer: never use your fingers. The disc should be allowed to burn out and cool in the censer before disposing. These disks stay lit for about an hour. Then they turn to ash and can be disposed of easily.
Be careful when using charcoal disks as they get very hot. Do not touch the vessel holding the disk once the disk is lit. Use only in a heatproof container.
They are not safe for use with glass.
Please note: these discs can reach temperatures up to 800 degrees C. Do not dispose of ash in a rubbish bin as it may cause a fire. Just like lit candles never leave charcoal to burn discs un attended. Always use discs on a fire proof surface safely while you work your rituals. Do not ignite the disc in your hand
as it lights instantly.