Fire and flammable liquids can be a dangerous combination, threatening the lives of employees, a company’s property and the community.

To say a company must be careful about the disposal of flammable and combustible liquids is an understatement. Not following proper safety protocols and regulations can lead to disastrous consequences.

The National Fire Protection Association (NFPA) publishes a Flammable and Combustible Liquids Code. This code includes a system that categorizes flammable or combustible liquids.

In environments where flammable liquids are present, it is critical to understand how each flammable liquids class differs because each type requires a different approach to storage and disposal. 

Below is an overview of how flammable liquids are classified, and what these classifications mean for your business.


Why Flammable Liquids Are Classified


flammable liquids classBecause flammable and combustible liquids pose a significant threat, strict requirements are in place for the storage and disposal of these liquids. 

While many substances can pose a fire risk, flammable and combustible liquids, in particular, ignite easily and burn very quickly. 

The NFPA classification system is based on a liquid’s flash point. A flash point is defined as, “the lowest temperature at which a substance generates a sufficient amount of vapor to form a vapor/air mixture that can be ignited.” 

While flammable liquids have a flash point under 100 degrees F, combustible liquids have a flashpoint at or above 100 degrees F. The lower the flash point, the easier the vapors of the liquid will ignite.

It is important to note that under some guidelines, numbers may vary. For example, according to Resource Conservation and Recovery Act regulations, the regulatory cutoff for D001 ignitable liquids is 140 degrees F. (D001 is the EPA characteristic waste code that designates a waste stream as ignitable.) This is why it is important to check to make sure you are meeting all local, state and federal regulations.

To make matters worse, as the temperature increases, so does the vaporization rate. Understanding the flash points for individual types of hazardous liquids is critical in putting the right procedures in place for storage, removal and disposal.


How Flammable Liquids Are Classified


The NFPA classifies all flammable liquids as Class I. However, based on the risk of fire, these liquids are sub-classified, with six main sub-classifications. 


Flammable Liquids

Class IA have flash points below 73 degrees F and boiling points below 100 degrees F. Unstable flammable liquids also fall under the class IA sub-classification.

Examples of Class IA liquids: ethylene oxide, pentane, propylene oxide, vinyl chloride

Class IB liquids have flash points below 73 degrees F, but unlike Class IA, have boiling points at or above 100 degrees F.

Examples of Class IB liquids: acetone, ethyl alcohol, isopropyl alcohol, benzene, octane, methanol, heptane

Class IC liquids have flash points at or above 73 degrees F, but below 100 degrees F. 

Examples of IC liquids: diethyl glycol, turpentine, xylene, isobutyl alcohol and mineral spirits

Note: According to the NFPA, because Class IA liquids are so volatile, boiling points are used only to distinguish between IA and IB.


Combustible Liquids

Class II combustible liquids have a flash point at or above 100 degrees F, but below 140 degrees F. 

Examples of Class II liquids: camphor oil, diesel fuel, pine tar, motor oil, kerosene

Class IIIA liquids have a flash point at or above 140 degrees F, but below 200 degrees F. 

Examples of IIIA liquids: formaldehyde, creosote oil, linseed oil, oil-based paints, mineral oil

Class IIIB liquids have a flash point at or above 200 degrees F.

Examples of Class IIIB liquids: castor oil, coconut oil, fish oil, olive oil, ethylene glycol, glycerine, neatsfoot oil


How Flammable Liquids Should Be Stored


While there are some general procedures all companies that store flammable liquids should follow, there are specific requirements for each sub-classification of flammable and combustible liquids as well.

For example, the state of California enforces specific requirements for the container size and quantities of flammable and combustible liquids in a laboratory.

A glass container, for instance, can hold 1 pint of a Class IA liquid, but can hold 1 gallon of a Class II 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 proper procedures to keep in mind, no matter the classification, include the following.


Where Flammable Liquids Are Stored

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.

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. 

Flammable liquid containers also must be sealed so that they cannot release vapors.


flammable liquids class Storage cabinetHow Flammable Liquids Are Labeled

Containers that hold hazardous waste flammable and combustible liquids should always be properly labeled. That means noting the following: 

  • The start date of accumulation for waste
  • The type of liquid
  • A Hazard Class 3 flammable (or other appropriate) logo, which is a picture of a raging fire
  • 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.


What Best Practices Are In Place

When flammable liquids must be moved from one location to another in a facility, it is critical that a system of best practices is in place to ensure all safety measures are followed. 

Some examples of best practices include:

  • Proper training: Make sure every employee is trained in properly stacking, transporting and storing any flammable or combustible liquids on site.
  • Halt work: Stop work when moving liquids through an area to ensure no known ignition sources are present.
  • Thorough documentation: Always maintain thorough documentation so management can refer back to it in the event an emergency occurs.
  • Segregate chemicals: Ensure all incompatible chemicals are stored separately and by hazard class codes.
  • Maintain proper storage: Use the proper storage cabinets, in particular, for flammable materials. Liquids should also be stored in unbreakable or double-contained packaging, or in a storage cabinet that can hold the liquids if a container breaks. Metal containers must be grounded, especially if static electricity is possible. This lowers the risk of the formation of sparks.
  • Label chemicals: All chemicals should be labeled using Material Safety Data Sheets (MSDS). These sheets allow those who are handling these liquids to be aware of their chemical properties and any associated risks.
  • Inspect regularly: Look for leaks or deteriorating containers, as well as any spills, broken fire equipment and conditions that can cause concern such as temperature extremes and blocked exits.

It is also important to create a Hazardous Material Business Plan (HMBP), which provides important information about the hazardous materials on site. This plan is critical for when first responders arrive on site in the event an emergency occurs since it provides information regarding what chemicals are present.

In fact, in the state of California, the Health and Safety Code establishes standards that must be included in the HMBP. These include:

  • Business activities and owner identification
  • An inventory of any hazardous materials on site
  • A site map
  • An emergency response plan and employee training

It is important to note that these requirements differ based on the size of the company and amount of hazardous materials that are on site. 


How Flammable Liquids Should Be Disposed Of


When it comes time to dispose of a flammable liquid, hazardous waste disposal codes often dictate the proper disposal methods for that liquid. 

Where you send your waste is often just as important as how you have stored it. Before you sign on with a company that accepts your liquid waste, make sure it follows best practices for the disposal of flammable liquids in a sustainable way. 

This may mean partnering with a company like Temarry Recycling, which recycles solvents at its solvent distillation unit

At Temarry, the solvent distillation process is part of a Closed Loop Recycling system that ensures nothing is wasted. Here’s how the process works: 

  • The waste to energy process converts high BTU organic solids to steam to be used as energy onsite.
  • The solvent distillation process uses the steam from the waste to energy process as energy to power the solvent recovery stills. Spent solvents are re-manufactured and sold back into industry for their original solvent properties.
  • A water treatment process then extracts usable water from industrial hazardous wastes. This treated water is used onsite for industrial needs, including the waste to energy equipment and a cooling tower.

You can read more about this process, which keeps materials at their highest utility and returns solvents back to industry, in our article, Solvent Distillation And The Energy Recovery Process Explained.


How To Increase Your Sustainability


It is critically important for any company to ensure that all flammable and combustible liquids have been properly identified and stored based on their classification … not only to make sure all federal, state and local laws have been followed, but to ensure the safety of employees and the community as well. 

Companies can take their disposal process one step further, however, and create a more sustainable solution for their hazardous waste streams by working with a recycling facility like Temarry Recycling that utilizes a Closed Loop Recycling system so that zero waste is achieved.


Are you Recycling or Fuel Blending

Larry Burton

Larry Burton

Larry Burton has over 25 years of experience in the hazardous waste and chemical industries. He has worked for several major corporations, including Honeywell, and can speak on a variety of industry-related topics. He has specialized knowledge in Circular Economy, Solvent Distillation, Closed Loop Recycling Technology, Waste to Energy, and the H061 Paradigm. Larry has extensive knowledge of the latest technologies that allow businesses to explore real-world sustainable solutions. These solutions will help reduce their carbon footprint and improve their profitability. Larry is currently the CEO of Temarry Recycling.

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