As a safety professional, it’s crucial to be familiar with all types of fires that may occur in your workplace or community. One important class of fires to be aware of is Class D fire, which involve combustible metals and can require specialized equipment and techniques to extinguish.
Class D fires are fires that involve combustible metals, such as magnesium, titanium, potassium, and sodium. These types of fires can be difficult to extinguish because they burn at extremely high temperatures and do not respond well to traditional fire extinguishers.
Instead, specialized extinguishing agents such as dry powder extinguishers or specially designed smothering agents must be used. Additionally, Class D fires should not be sprayed with water, as water reacts with many of these metals to produce hydrogen gas, which can further fuel the fire.
Types of Class D fires and their causes
There are several types of Class D fires, each caused by a specific type of metal. Some common examples include:
- Magnesium fires: Magnesium is a highly reactive metal and can ignite when exposed to oxygen. It is often used in industrial applications, such as in the production of aluminum and in the aerospace industry.
- Titanium fires: Titanium is a strong and lightweight metal that is used in many industrial applications, including aerospace and chemical production. It can ignite in powder form or when in contact with chlorine.
- Sodium fires: Sodium is a highly reactive metal that is used in the production of chemicals and in the refining of petroleum. It can ignite when in contact with water or when exposed to air.
- Potassium fires: Potassium is another highly reactive metal that can ignite when in contact with water or when exposed to air. It is commonly used in fertilizers, pyrotechnics, and some types of batteries.
- Aluminum fires: Aluminum is a metal that is widely used and not as reactive as previous metals mentioned, but it can still fuel a fire with high intensity. It is used in various industries such as construction, transportation, and electrical.
These types of fires typically start due to mishandling of the metal, accidental contact with a heat source, or chemical reactions. Safety precautions like proper storage, handling, and ventilation is important to prevent these types of fires.
How to put out a Class D fire
Putting out a Class D fire requires specialized equipment and techniques. The first step in extinguishing a Class D fire is to isolate the source of the fire by removing any fuel or oxygen. This includes shutting off any gas lines or electrical power and moving combustible materials away from the fire.
The next step is to use a Class D fire extinguisher. These extinguishers are filled with a specialized dry powder that smothers the fire by separating the fuel (the metal) from the oxygen. This powder is designed to stick to the burning metal, effectively suffocating the fire. It is also designed to be non-reactive, meaning it will not cause an exothermic reaction.
It is important to note that water and foam should not be used to extinguish Class D fires as they can react with the burning metal and create hazardous gases. Also, the heat generated by the fire can cause an explosion if water is used.
In the case of larger fires or where access is restricted, special smothering agents can be used, which will smother the fire by creating a barrier between the burning metal and oxygen. These agents can also cool down the burning metal, lower its ignition temperature, and prevent reignition.
After the fire is out, it’s important to ventilate the area to remove any smoke or toxic fumes. The fire scene should also be inspected for any remaining hot spots or areas of rekindling, and a fire watch should be established to ensure that the fire does not reignite.
It’s very important to note that tackling a Class D fire should only be attempted by properly trained and equipped safety personnel. In case of a class D fire, you should call the fire department immediately, evacuate the area, and follow the emergency protocol.
Proper use of Class D fire extinguishers
Proper use of a Class D fire extinguisher requires the correct training, knowledge of the specific type of metal involved, and understanding of the chemical properties of the extinguishing agent. Here are some guidelines for using a Class D fire extinguisher:
- Identify the type of metal involved: It is crucial to know the specific type of metal involved in the fire so that the appropriate extinguishing agent can be used. Each type of metal has different chemical properties and requires a specific type of extinguishing agent.
- Remove sources of fuel and oxygen: Before using the extinguisher, it’s important to isolate the source of the fire by removing any fuel or oxygen. This includes shutting off any gas lines or electrical power and moving combustible materials away from the fire.
- Use the correct extinguisher: Always use a Class D fire extinguisher specifically designed for the metal involved in the fire. It’s important to use the correct extinguisher to avoid causing a chemical reaction that could make the fire worse.
- Follow the manufacturer’s instructions: Read and follow the manufacturer’s instructions for using the extinguisher. This will typically include information on the proper distance to hold the extinguisher from the fire, the appropriate amount of powder to use, and the duration of use.
- Avoid breathing in the powder: When using a Class D fire extinguisher, it’s important to avoid breathing in the powder, as it can be harmful. Wear a respirator mask or other protective equipment as necessary.
- Keep the fire department informed: In case of a class D fire, Call the fire department immediately and keep them informed about the situation. In case of a larger fire or where access is restricted, fire department assistance might be needed.
- Inspect and clean up: Once the fire is out, inspect the area for any remaining hot spots or areas of rekindling, and establish a fire watch to ensure that the fire does not reignite.
It is important to remember that Class D fire extinguishers are specialized equipment and should only be used by safety personnel who have been properly trained and certified.
Safety precautions for Class D fires in the workplace
Preventing Class D fires in the workplace is essential to ensure the safety of employees and minimize damage to property and equipment.
Here are some safety precautions that can be taken to reduce the risk of Class D fires:
- Proper storage and handling: Store combustible metals in a cool, dry place and away from any potential ignition sources. Metal shavings and dust should be cleaned up regularly, and all containers should be properly labeled and sealed.
- Training: Properly train employees on the hazards associated with Class D fires and the correct procedures for handling, storing, and using these metals. This should also include training on how to operate and use the appropriate fire extinguishing equipment.
- Proper ventilation: Ensure that areas, where combustible metals are stored or used have adequate ventilation to reduce the risk of fires caused by chemical reactions.
- Regular inspections: Conduct regular inspections of equipment and facilities to ensure that they are in good working order and to identify any potential hazards.
- Fire suppression system: install fire suppression systems in areas where combustible metals are stored or used or have portable extinguishers readily available.
- Follow OSHA regulations: Comply with OSHA regulations related to the handling and storage of combustible metals, including OSHA’s standard for fire protection in shipyard employment.
- Emergency plan: Develop an emergency plan that includes evacuation procedures, emergency contact information, and procedures for calling the fire department.
- Fire drills: Conduct fire drills periodically to ensure that employees are familiar with emergency procedures and can evacuate quickly in case of a fire.
By taking these precautions, employers can significantly reduce the risk of Class D fires in the workplace and ensure that their employees are prepared to respond to a fire emergency if one occurs.
How to identify Class D fire hazards
Identifying Class D fire hazards in the workplace is crucial in order to minimize the risk of a fire occurring.
Here are some steps that can be taken to identify Class D fire hazards:
- Conduct a risk assessment: Identify areas in the workplace where combustible metals are stored or used and assess the risks associated with these materials. This should include an examination of the type of metal, the quantity of metal present, and the potential ignition sources in the area.
- Look for specific hazards: Inspect the area for specific hazards such as metal dust, shavings, or debris. These materials can be highly combustible and should be cleaned up regularly.
- Evaluate the storage conditions: Check the conditions under which the metals are stored. Are they kept in a cool, dry place? Are they properly sealed and labeled? Are they away from potential ignition sources?
- Check the ventilation: Make sure that there is adequate ventilation in areas where combustible metals are stored or used. This can prevent fires caused by chemical reactions.
- Evaluate the equipment: Inspect the equipment used in the handling, storage, and processing of combustible metals. Make sure that they are in good working order and that the electrical and mechanical components are grounded properly.
- Evaluate the emergency plans: Make sure that the emergency plans for the workplace are adequate and include procedures for responding to a Class D fire.
- Employee training: Ensure that all employees are trained on the hazards of Class D fires and how to use the appropriate fire extinguishing equipment.
By taking these steps, employers can identify and minimize the risk of Class D fires in the workplace and ensure the safety of their employees and property.
Class D fire suppression system
A Class D fire suppression system is a specialized fire protection system that is designed to extinguish fires involving combustible metals. These types of fires require specialized extinguishing agents that are not typically found in traditional fire suppression systems.
There are several types of Class D fire suppression systems available, including dry powder suppression systems and smothering agents suppression systems.
- Dry powder suppression systems: These systems use a specialized dry powder, which is designed to stick to the burning metal, suffocating the fire by separating the fuel from the oxygen. The dry powder is also designed to be non-reactive, meaning it will not cause an exothermic reaction.
- Smothering agents suppression systems: These systems use specialized smothering agents that create a barrier between the burning metal and oxygen, smothering the fire. These agents can also cool down the burning metal, lower its ignition temperature, and prevent re-ignition.
The systems can be either manual or automatic and can be designed to protect a specific area or an entire facility.
Proper design, installation, and maintenance of Class D fire suppression systems are critical to ensure they will function correctly in case of fire. Regular inspection, testing, and maintenance should be done by professionals to ensure the system is in good working condition.
It’s important to consult with experts in Class D fire suppression systems, who can help determine the best solution for your facility and specific needs and ensure that the system is properly installed and maintained.
Class D fire ratings for buildings and structures
Class D fire ratings are a measure of a building or structure’s ability to contain and extinguish a Class D fire. These ratings are established by organizations such as the National Fire Protection Association (NFPA) and Underwriters Laboratories (UL) to evaluate the performance of various materials and systems in containing and extinguishing a Class D fire.
There are several ratings that are used to evaluate Class D fire performance:
- UL Class D: This is a rating established by Underwriters Laboratories that measures the ability of a material or system to contain and extinguish a Class D fire. It is based on a series of tests, including the ability of the material or system to maintain its integrity in the face of a Class D fire and the ability of the material or system to extinguish a Class D fire.
- NFPA 484: This is a standard established by the National Fire Protection Association that covers the safe use, handling, and storage of combustible metals. It includes guidelines for fire protection systems, emergency planning, and employee training for facilities that use or store combustible metals.
- FM Global Class D: This is a standard developed by FM Global which covers the fire protection of facilities that store or use combustible metals. It focuses on fire detection and suppression systems and hazard mitigation design for specific industries and settings.
- ASTM E 891: This is a standard established by the American Society for Testing and Materials (ASTM) that covers the fire performance of materials and systems in the presence of combustible metals. It includes fire resistance and fire-propagation testing methods that evaluate the ability of materials and systems to contain and extinguish a Class D fire.
It’s important to consult with the relevant authorities and experts to understand the regulations and standards that apply to your building or structure and to ensure that your building or structure meets the appropriate Class D fire ratings.
How to train employees on Class D fire safety
Properly training employees on Class D fire safety is essential to minimize the risk of fires and ensure the safety of employees and property. Here are some steps that can be taken to train employees on Class D fire safety:
- Identify the hazards: Identify the specific hazards associated with the use, storage, and handling of combustible metals in your workplace and explain the risks involved.
- Provide information on the materials: Give employees detailed information about the properties of the combustible metals they will be working with, including how they burn and how to extinguish them.
- Fire safety instruction: Train employees on the procedures for responding to a Class D fire, including how to use the appropriate fire extinguishing equipment, how to evacuate the building, and how to properly call for emergency services.
- Hands-on training: Provide hands-on training in the proper use of fire extinguishers, and give employees the opportunity to practice using the extinguishers in simulated fire scenarios.
- Review emergency procedures: Review the emergency procedures with the employees regularly and conduct drills so that they are familiar with the procedures and can act quickly in case of a fire.
- Safety protocols: Explain the protocols and procedures that should be followed to prevent Class D fires, and make sure that employees understand the importance of following these protocols.
- Safety reminders and signages: Place reminder posters and signs in strategic locations around the workplace to remind employees of proper procedures and emergency contact information.
It is important to make sure that all employees are properly trained on Class D fire safety and that refresher training is conducted on a regular basis. The safety of employees and the workplace should be the primary concern, and regular training and drills can ensure that employees are prepared to respond to a fire emergency if one occurs.
Common materials that can fuel Class D fires
There are several types of materials that can fuel a Class D fire, which is a fire that involves combustible metals. Here are some common examples of materials that can fuel a Class D fire:
- Magnesium: Magnesium is a highly reactive metal that can ignite when exposed to oxygen. It is used in many industrial applications, including the production of aluminum and the aerospace industry.
- Titanium: Titanium is a strong and lightweight metal that is used in many industrial applications, including aerospace and chemical production. It can ignite in powder form or when in contact with chlorine.
- Sodium: Sodium is a highly reactive metal that is used in the production of chemicals and in the refining of petroleum. It can ignite when in contact with water or when exposed to air.
- Potassium: Potassium is another highly reactive metal that can ignite when in contact with water or when exposed to air. It is commonly used in fertilizers, pyrotechnics, and some types of batteries.
- Aluminum: Although not as reactive as the previously listed metals, aluminum can still be a source of intense fire due to its thermal properties. It is used in various industries such as construction, transportation, and electrical.
- Lithium: Lithium is a metal that is used in many industrial applications, particularly in batteries. It can ignite when in contact with water or oxygen and can cause a thermal runaway reaction when it gets damaged and heats up, leading to fire.
- Zirconium: Zirconium is a metal that is widely used in the nuclear industry, aerospace, and ceramics. It can ignite when in contact with air, especially when in powdered form.
It’s important to note that this list is not exhaustive; other metals such as thorium, yttrium, ytterbium, dysprosium, and many others can also fuel a Class D fire. It’s important to understand the specific type of combustible metal present in the workplace, and to properly store, handle and use these metals to prevent the risk of fire.
The dangers of inhaling Class D fire smoke
Inhaling smoke from a Class D fire can be dangerous due to the release of toxic and corrosive gases. Here are some of the dangers of inhaling Class D fire smoke:
- Metal fumes: When a combustible metal burns, it releases fumes that contain particles of the metal. Inhaling these fumes can lead to metal fume fever, which is characterized by symptoms such as fever, chills, nausea, and muscle aches. Long-term exposure to metal fumes can also lead to lung damage.
- Hydrogen gas: Many combustible metals will react with water to produce hydrogen gas, which can further fuel a fire and release large amounts of heat and toxic gases. Inhaling hydrogen gas can cause respiratory problems, as well as damage to the eyes, skin, and other organs.
- Chlorine gas: Inhalation of chlorine gas can cause irritation to the eyes, nose, throat, and lungs and can cause difficulty in breathing and coughing. Also, it can lead to pneumonia-like symptoms.
- Carbon Monoxide: Carbon monoxide is a toxic gas that can be produced in a fire, which can lead to headaches, nausea, dizziness, confusion, and ultimately unconsciousness or death.
- Smoke inhalation: Smoke from a fire can contain a variety of toxic gases, including carbon monoxide, nitrogen oxides, and other particulate matter that can irritate the eyes and respiratory system and cause lung damage.
It’s important to avoid inhaling smoke from a Class D fire, as well as the dry powder extinguisher or smothering agents used to put out the fire.
Wearing personal protective equipment such as respirator masks or fire suits can help protect against the dangers of inhaling smoke. If a person has inhaled smoke, they should be moved to fresh air, and medical attention should be sought immediately.
Class D fire extinguisher inspection and maintenance
Class D fire extinguishers are used to extinguish fires that involve combustible metals, such as magnesium, titanium, and sodium. They should be inspected and maintained according to the manufacturer’s instructions and local regulations. Some general guidelines for inspection and maintenance include:
- Make sure the extinguisher is easily accessible and visible.
- Check the extinguisher’s pressure gauge to ensure that it is in the proper range.
- Check for any physical damage to the extinguisher, such as dents or corrosion.
- Check for any signs of leakage.
- Ensure that the safety seal is intact and the tamper indicator is in the proper position.
- Check the expiration date if the extinguisher is a water-based or foam-type extinguisher.
- Make sure the operating instructions are legible and in the proper position.
- Check the weight or heft of the extinguisher; if it seems to be light, it might be empty or close to it.
- Regularly check the fire extinguisher and make sure it remains in good condition.
- If an extinguisher is found to be damaged or empty, it should be serviced or replaced as soon as possible.
It’s best to have these inspections performed by a qualified technician or the maintenance team. They will be able to follow the specific instructions in the product manual and local regulations to ensure that the extinguisher is in good working condition and ready for use in case of emergency.
Class D fire extinguishers are an essential tool for fighting fires that involve combustible metals, such as magnesium, titanium, and sodium. They are designed to extinguish such fires quickly and effectively, preventing damage and injury.
Regular inspection and maintenance of Class D fire extinguishers are crucial in ensuring that they are in good working condition and ready for use in case of emergency. Inspections should be performed according to the manufacturer’s instructions and local regulations, and it is best to have them done by a qualified technician or maintenance team.