The most eco-friendly extinguisher available out there are the Clean Agent Based Fire Extinguishers, they contain a special chemical that evaporates after usage leaving behind zero residue suiting best for sensitive equipment and areas like computers & server rooms that would undergo malfunction if powder based fire extinguishers were used. This special range can extinguish all classes of fire and can be used under any circumstance. It is indeed the most effective all-rounder. Its working action is similar to that of any other fire extinguisher.