BC dry chemical fire extinguishers are rated for class B and Class C fires.
Class B fires involve flammable liquids.
Class C fires are electrically energized.
These extinguishers are more effective against class B and C fires than an ABC rated extinguisher.
Purple K fire extinguishers are best at fighting class B fires. They can also be used on class C fires.
Class D fire extinguishers are for use against fires involving combustible metals. Such metals include potassium, magnesium, and titanium. These units use a class D dry powder to handle high temperature fires in this class.