Using an Oxygen based bleaching action, Hotspot Fireplace Cleaner removes smoke, soot and tar stains caused by wood, coal and gas fires from brick, stone, concrete, marble and other hard surfaces. Fireplace cleaner eliminates the need for harsh acids. Cleans straight down to the pores without damage. This action will not normally remove discolouration caused by weathering or natural impurities. Do not use on any decorated or painted slate or stone. Always test on a small discreet area firs as the natural colour will be restored and this may differ from the expected colour.