This fire extinguisher sign should be used to highlight P50 fire extinguishers. P50 extinguishers can be used on wood, paper, textiles, flammable liquids and electrical fires however they should not be used on flammable metal fires. Many members of the public do not know which fire extinguishers can be used on which type of fire, that's why using this sign is extremely important. Under the Regulatory Reform - Fire Safety Order 2005 any non-automatic fire fighting equipment should be identified with an appropriate sign. The signs should be positioned and designed in accordance with BS EN ISO 722 to ensure maximum levels of comprehension.