explode, thereby releasing the powder. Then, the natural chimney draft will carry the dry chemical powder up the shaft of the chimney, thus coating the creosote and eventually neutralizing the fire. Use of multiple chimney bombs may be necessary, depending on how severe the fire is. Chimney bombs can also be effective if they are opened and then dropped down the chimney. In order for chimney bombs to be effective, it may be necessary to first unclog the chimney. Inappropriate uses ABC dry chemical is inappropriate for chlorine or oxidizer fires. The resulting chemical reaction can cause an explosion or a breakdown of the chemicals releasing toxic gases. Water should be used in that case. ABC dry chemical is inappropriate for certain metal fires (Class-D) and does not possess a saponification characteristic and should therefore not be used on Class K fires. ABC dry chemical has been found to be effective in initially ceasing combustion of oils or fats, however re-application of additional dry chemical may be necessary due to the potential for re-flash of oils or fats heated to near or at their flash point. A Class K extinguisher is more effective in controlling fires involving primarily vegetable oils as it causes a chemical change to the oils or fats making re-flash far less likely. When a Class K extinguisher is not available an ABC dry chemical extinguisher can be carefully used to control a fire involving cooking oils or fats if the operator is aware of the potential need to re-apply more chemical if the oils or fats reignite. (Class-K). Due to the corrosive properties of ABC dry chemical, it is not recommended for use around aircraft or sensitive equipment. Recycling The powder contains monoammonium phosphate, with the phosphate being the most globally valuable material. See the references for links to recycling research projects and companies. References External links MSDS for ABC Dry Chemical Cylinder Disposal Solutions Ltd, UK Extinguisher powder reused in fertilisers and fire retardants (Phys.org NOVEMBER 27, 2018) Fire suppression agents de:Löschpulver