What happens to a Class D combustible metal fire when water is applied?

When water is applied to a Class D combustible metal fire, the fire will intensify. This is because Class D fires involve metals like magnesium, titanium, and sodium, which react violently with water. The reaction typically generates heat and can create flammable gases, leading to a larger and more dangerous fire. Water is ineffective and potentially hazardous in this scenario, as it does not suppress the fire but rather exacerbates it, causing the flames to spread further and possibly leading to explosions.

Extinguishing a Class D fire requires specialized agents specifically designed to handle metal fires, such as dry powder extinguishers made from materials like sodium chloride or calcium carbonate, which can smother the fire without reacting adversely.