There are 5 main types of fire extinguisher. These are Water, AFF Foam, ABC Powder, CO2 and Wet Chemical. Each have their own strengths and weaknesses. Water extinguishers can be used on class A fires. AFF Foam extinguishers can be used on class A and B fires. ABC Powder fire extinguishers can be used on class A, B, C and Electrical fires. CO2 extinguishers can be used on class B and Electrical fires. Wet Chemical fire extinguishers can be used on class A and F fires.