Do I Need a Class D Fire Extinguisher?

Portable fire extinguishers have specific letters to designate what type of fires they can be used on. Choosing the right type of extinguisher to fit your needs is essential since using the wrong type could be ineffective in putting out a fire or could even make it worse, placing lives and property at greater risk.

What Is a Class D Fire Extinguisher and When Is It Used?

A class D fire extinguisher is used on fires that involve combustible metals. This type of fire, which can cause significant damage, often occurs when small pieces of metal or dust that are generated during processes in a manufacturing, industrial, or laboratory setting ignite. A class D fire extinguisher is needed to put out a combustible metal fire. Other extinguishing agents, including water, are ineffective or can actually make the fire worse. Look for a five-point star containing the letter “D” to identify an extinguisher that’s manufactured to combat combustible metal fires.

The following are some of the combustible metals a class D fire extinguisher can be used on:

• Magnesium
• Aluminum
• Titanium
• Lithium
• Potassium
• Sodium
• Zirconium

What Is a Class D Fire Extinguisher Made Of?

The best way to extinguish a combustible metal fire is by smothering it, which separates it from oxygen and absorbs its heat. The class D fire extinguisher uses a dry powder, either powdered graphite, granular sodium chloride, or a copper-based powder, to accomplish this.

How Is a Class D Fire Extinguisher Maintained and Replaced?

A class D fire extinguisher should be visually inspected monthly to make sure it’s in its proper location, can be easily seen and accessed, is fully charged and operational, and has adequate pressure, as seen on its pressure gauges. This inspection should also ensure its pins and seals are in place and its nozzle is unblocked.

Maintenance of a class D fire extinguisher should be conducted at least once a year, or more often if your visual inspection detects a problem. This maintenance includes an inspection of the extinguisher’s mechanical parts, extinguishing agent, and expelling means and must be performed by an approved fire extinguisher servicing company.

Every 6 years, class D fire extinguishers must be emptied and maintained by the servicing company. And every 12 years, the company should perform hydrostatic testing, which uses water to pressure-test the extinguisher. This helps prevent cylinder failure or rupture.

If a class D fire extinguisher is used to put out a fire, it should be checked by a professional and recharged immediately to ensure it has the proper amount of dispensing agent left and maintains the right pressure levels. It should be replaced if it is damaged or expired based on a servicing tag date or an expiration date that’s stamped on the cylinder. 

Taking Care of Your Fire Safety Needs

If your business could have combustible metal fires, you’ll need to have dry powder (class D) fire extinguishers available to help keep your employees and assets safe. These extinguishers need to be professionally serviced and maintained to ensure that they’ll be ready if and when you need them. Contact Brothers Fire & Security today to partner with a company that can design, install, test, and maintain your fire suppression systems and take care of your other fire safety needs, including sprinkler systems.