Portable fire extinguishers are your first line of firefighting equipment, and are available in different classes and sizes for different types of fire hazards. The most used type of portable fire extinguishers are dry chemical class ABC that can be used on most fires. Other types of fire extinguishers are available for special uses, such as for grease fires in kitchens or clean agent extinguishers for computer rooms. Local fire inspectors determine minimum number and types of fire extinguishers required for their businesses.  The use, installation, maintenance and service of the fire extinguishers are regulated by the state and local fire authorities, and fire extinguishers are required in all locations where public safety is concerned.