Fire risk varies from one material to another, even when both materials can burn. For facilities that work with chemicals, understanding the differences between combustible and flammable materials can make those hazards easier to evaluate.
One major distinction involves the amount of heat a liquid needs before its vapor presents an ignition hazard. Keep reading to understand when a facility needs to decide how to manage a material after use.
What Makes a Material Flammable?
Some liquids can present an ignition hazard at relatively low temperatures. Their ability to produce ignitable vapor under those conditions is one reason facilities need to understand their properties before handling them.
Flash point provides useful information here. As flash point decreases, the temperature needed for the liquid to produce ignitable vapor also decreases.
A Safety Data Sheet (SDS) can help facility personnel review a product’s fire hazards. It may also contain flash point data that helps personnel understand how the material behaves.
How Are Combustible Materials Different?
A combustible material can burn, although it may need greater heat exposure before its vapor reaches ignitable conditions.
The terminology isn’t always straightforward. Regulatory standards have changed over time, and some sources use “combustible” differently. Current OSHA rules group liquids with flash points at or below 199.4°F (93°C) into flammable-liquid categories.
Facilities may still encounter combustible classifications in other standards or older records. Reviewing the material’s actual properties can provide better context than relying on the label alone.
What Can Flash Point Tell a Facility?
Flash point indicates the temperature at which a liquid begins producing vapor that can ignite when an ignition source is present.
Consider two liquids stored under the same temperature conditions. The liquid with the lower flash point may reach ignitable conditions sooner than one with a higher flash point.
Facility teams can use this information when evaluating potential fire hazards. Flash point doesn’t indicate how severe a fire is after ignition.
How Does Ignitability Affect Hazardous Waste?
Waste rules introduce another consideration. EPA regulations identify ignitability as a hazardous waste characteristic.
Certain liquid wastes can receive the D001 hazardous waste code when their flash point falls below 140°F (60°C). Other criteria can apply depending on the waste involved.
A facility shouldn’t assume that the information associated with the original product settles its waste classification. Facility processes may alter a material before disposal. Contact with another waste stream can also affect its characteristics.
What Information Should Facilities Review?
Waste evaluation starts with material-specific information. Depending on the waste stream, facility personnel may review:
- Safety Data Sheets
- Available flash point information
- Waste characterization records
- Process information
These records can help personnel understand what entered the waste stream. Testing or further characterization may still apply when available information doesn’t establish the waste’s properties.
Managing Flammable and Combustible Waste
Fire hazards can become a waste management concern after a chemical spill or other release. Businesses that need hazardous waste cleanup services can work with an environmental services provider to evaluate the resulting waste and determine the next steps for disposal.
Understanding how flammable and combustible materials differ gives facility personnel better context when evaluating materials with fire hazards. Once a material becomes waste, its current characteristics should guide the waste management decision.
