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Flammable And Combustible Liquids Fall Into Which Fire Classification?

Written by Larry Burton | Apr 4, 2024 5:33:00 PM

Fire safety is a critical aspect of industrial and everyday life, and it involves classifying materials based on their flammability and combustibility. Understanding their fire classification is crucial for ensuring safety in your work environment.

 

Unsurprisingly, many facilities that regularly deal with dangerous substances ask: Flammable and combustible liquids fall into which fire classification?

 

The National Fire Protection Association (NFPA) classifies flammable and combustible liquids in six classes: I-A, I-B, I-C, II, III-A and III-B.

 

For the safety of your employees and the protection of your facilities, companies must be aware of the specific classification of liquids you use, ensuring proper storage, handling, disposal and adherence to safety protocols.



NFPA Hazard Classifications

 

 

Flammable liquids are substances that can easily ignite and burn rapidly at normal temperatures. They have a low flash point, which is the lowest temperature at which a liquid can produce enough vapor to form an ignitable mixture in the air.

 

Combustible liquids, while still capable of catching fire, have a higher flash point compared to flammable liquids. They require higher temperatures to ignite, but once ignited, they can burn and sustain a fire.

 

The National Fire Protection Association hazard classifications for flammable and combustible materials are listed below:

 

Hazard classification for flammable liquids

 

Class

Flash Point

Boiling Point

Examples

I-A

below 73°F (23°C)

below 100°F (38°C)

diethyl ether, pentane, ligroin, petroleum ether

I-B

below 73°F (23°C)

at or above 100°F (38°C)

acetone, benzene, cyclohexane, ethanol

I-C

73-100°F (24-38°C)

----

p-xylene



Hazard classification for combustible liquids

 

Class

Flash Point

Boiling Point

Examples

II

101-140°F (39-60°C)

----

diesel fuel, motor oil, kerosene, cleaning solvents

III-A

141-199°F (61-93°C)

----

paints (oil base), linseed oil, mineral oil

III-B

200°F (93°C) or above

----

paints (oil base), neatsfoot oil




Why You Need To Know Fire Classifications

 

 

Understanding the different flash points and boiling points of flammable and combustible liquids is essential for businesses that handle dangerous substances for these reasons:

 

  • Safety Compliance: Knowledge of flash points and boiling points is critical for compliance with safety regulations and standards set by organizations such as the Occupational Safety and Health Administration (OSHA). Adhering to these guidelines helps businesses create and maintain a safe working environment.
  • Fire Prevention: Awareness of flash points enables businesses to implement effective fire prevention measures. Proper storage, handling and separation of flammable and combustible liquids based on their classifications help minimize the fire risks in the workplace.
  • Emergency Response Planning: Knowing the flash points assists in developing robust emergency response plans. In the event of a spill or fire, understanding the characteristics of the liquids involved allows businesses to implement swift and appropriate response actions to mitigate potential hazards.
  • Storage and Handling Practices: Different flash points require specific storage and handling practices. Businesses can design storage facilities and processes that align with the characteristics of the liquids they use, preventing accidents and ensuring the overall safety of their operations.
  • Risk Mitigation: Recognizing the varying ignition temperatures of flammable and combustible liquids allows businesses to identify and mitigate potential risks associated with these materials. This proactive approach is essential for preventing accidents, protecting employees and safeguarding valuable assets.
  • Employee Training: Employee training on the properties of flammable and combustible liquids, including flash points and boiling points, is crucial for fostering a safety-conscious workplace. Well-informed employees are better equipped to handle these materials responsibly, reducing the likelihood of accidents.
  • Regulatory Compliance: Compliance with regulatory requirements is vital for avoiding penalties and legal consequences. Businesses that understand and adhere to the specified flash points and boiling points demonstrate their commitment to safety and regulatory compliance.
  • Safe Disposal Practices: Knowledge of the specific flash points and boiling points of flammable and combustible liquids is crucial when developing disposal procedures. Implementing safe disposal practices ensures that these liquids are handled and disposed of in a manner that minimizes environmental impact and mitigates potential hazards. Adhering to proper disposal guidelines is not only environmentally responsible but also contributes to overall workplace safety and regulatory compliance.

 

A comprehensive understanding of the flash points and boiling points of flammable and combustible liquids empowers businesses to implement effective safety measures, prevent fires and ensure the well-being of employees and the integrity of their operations. This knowledge forms the foundation for a robust safety culture within the organization.



Flammable And Combustible Liquids Storage Guidelines

 

 

While there are some general best practices all companies that store flammable and combustible liquids should follow, there are specific requirements for each subclassification listed in the chart above.



Type

Class I-A

Class I-B

Class I-C

Class II

Class III-A – B

Glass or approved plastic containers 

1 pint (0.47L)

1 quart (0.94L)

1 gallon (3.79L)

1 gallon (3.79L)

1 gallon (3.79L)

Metal containers

1 gallon (3.79L)

5 gallon (18.95L)

5 gallon (18.95L)

5 gallon (18.95L)

5 gallon (18.95L)

OSHA compliant safety cans

2 gallon (7.58L)

5 gallon (18.95L)

5 gallon (18.95L)

5 gallon (18.95L)

5 gallon (18.95L)

       

 

Source: UC San Diego

 

There are a few exceptions to the above guidelines. For example, glass or approved plastic containers up to 1 gallon may be used for flammable liquids when the liquid may corrode metal containers or when the metal container could affect the analytical standard of the liquid.

 

It is important for a company to determine the type and size of storage containers allowed based on how that particular liquid is classified so that you can meet all state and federal regulations. 

 

Other best practices for storing flammable and combustible liquids to help prevent fires and other types of accidents include: 

 

  • Safe location: Storage containers should always be well out of the way, never blocking stairwells or exits and always located in a safe, secure location. Most local regulations require that companies keep flammable and combustible liquids in a fire-proof storage cabinet.
  • Away from ignition sources: Flammable liquids should also be stored away from any ignition sources, which include sparks from electrical tools, open flames, hot surfaces, static electricity and embers or sparks from incinerators. 
  • Sealed: Flammable liquid containers also must be sealed so that they cannot release vapors.
  • Properly labeled: Containers that hold hazardous waste flammable and combustible liquids should always be properly labeled. That means including the start date of accumulation for waste, the type of liquid, the appropriate hazard logo and any additional information on the label mandated by your state/local authorities. It’s also important to note that containers must be labeled as soon as the waste goes in.
  • Grounded containers: Metal containers must be grounded, especially if static electricity is possible. This lowers the risk of the formation of sparks.

 

It’s also critical to make sure every employee is trained in properly stacking, transporting and storing any flammable or combustible liquids on site, as well as to create a Hazardous Material Business Plan (HMBP). This plan provides important information about the hazardous materials on site and is critical for when first responders arrive on site in the event an emergency occurs.

 

 

Disposal Of Flammable And Combustible Liquids

 

 

The safe transportation and disposal of chemicals relies on knowing the fire classification of flammable and combustible liquids. For example, regulatory agencies, including the Department of Transportation (DOT), have specific regulations governing the transportation of hazardous materials, including flammable and combustible liquids. Understanding the fire classification ensures compliance with transportation guidelines, which include proper labeling, packaging and documentation.

 

Any company you partner with should be licensed to transport hazardous wastes in your state. Samex Environmental only accepts waste from brokers that work with licensed hazardous waste transporters in the United States. 

 

Another significant decision you must make is where to send your waste. Solvent distillation offers businesses an opportunity to meet their sustainability objectives while safely disposing of flammable or combustible spent solvents.  

 

The solvent distillation process takes a liquid or vapor mixture of two or more substances and separates it into its component fractions of desired purity. Through the application of heat, this process separates the solvents from other substances. By heating a liquid mixture containing solvents, the solvent vaporizes. The vapor is then condensed back into a liquid form, resulting in the separation and recovery of the solvent.

 

At Samex, we focus on ensuring nothing is wasted so that companies achieve the highest level of sustainability possible for the waste that they generate. Any still bottoms that are generated during the solvent distillation process are transferred to our fuel blending area where they are blended with other flammable liquids. This process meets the specifications of the cement kiln that will use the blend as an alternative fuel source. 

 

Samex also operates a water treatment plant on the same site where commercially clean nonhazardous water is repurposed to brick manufacturing. Solid byproducts from the treatment process are sent to the fuel blending area where they become part of the repurposed waste destined to the cement kiln to be used as an alternative fuel. 

 

By choosing this sustainable option for your flammable or combustible waste, you not only benefit from efficient waste management but also contribute to creating a better environment through responsible waste disposal practices.