What Qualifies as Hazardous Waste Materials?

What Qualifies as Hazardous Waste Materials? 

In our last blog, we discussed employers in the business of managing hazardous or non-hazardous solid wasteand the importance of knowing the framework of the Resource Conservation and Recovery Actcommonly known as RCRA, which are found in the Environmental Protection Agency (EPA) Title 40 of the Code of Federal Regulations, Parts 239 through 282A complete list of these regulations can be accessed online

Let us now address a common question which isWhat qualifies as hazardous waste materials? This question is broadly applicable regarding a variety of hazardous waste operations, including: 

  • Manufacturing 
  • Handling 
  • Transport 
  • Disposal 
  • Storage 
  • Recycling 
  • Treatment 


A good starting point is to first define hazardous material and hazardous waste as they are listed within a publication from the U.S. Department of Transportation (DOT) Pipeline and Hazardous Materials Safety Administration (PHMSA): How to Use the Hazardous Materials Regulations CFR 49 Parts 100-189. 

  • Hazardous Material- A substance or material capable of posing an unreasonable risk to health, safety, or property when transported in commerce. 
  • Hazardous Waste- Any material that is subject to the Hazardous Waste Manifest requirements of the EPA. Refer to 40 CFR Part 262Standards Applicable to Generators of Hazardous Waste 

With the latter definition pointing to EPA/RCRA regulations, another key resource is the EPA’s Hazardous Waste website. 

Hazardous waste is subject to a variety of criteria, but as simply defined by the EPAis a waste with properties that make it dangerous or capable of having a harmful effect on human health or the environment. However, the EPA further expands the definition of hazardous waste when the waste in question conforms to at least one of the following characteristics: 

  • Ignitability – The EPA classifies as hazardous a variety of solid materials that can ignite under certain conditions. Liquids with a flashpoint under 60°C (140°F) are hazardous under EPA guidelines. Non-liquid solids that ignite under “standard temperatures” due to friction, chemical changes, or absorbing moisture are to be considered hazardous as well. In addition, all oxidizers and ignitable compressed gases are classified as hazardous. Examples of materials in this category include methanol and ethyl acetate. 
  • Corrosivity – Materials can be classified as hazardous due to their corrosive properties. Specifically, an aqueous material is hazardous if its pH is (a) less than or equal to 2 or (b) more than or equal to 12.5, while a liquid falls under this classification if it is capable of corroding steel at a rate exceeding 6.35 millimeters per year at a temperature of 55°C (130°F). 
  • Reactivity – Materials are to be classified as hazardous if they react to contact with water by generating toxic fumes, creating an explosive mixture, or demonstrating another kind of violent response. Additionally, materials that can detonate also fall under this category. 
  • Toxicity – Any solid industrial waste is hazardous if it contains a level of contaminants that exceed EPA guidelines. The specific concentration of maximum allowable contaminants depends on the particular material in question 

The EPA developed a regulatory definition and process that identifies specific substances known to be hazardous exampled by using the series of questions described in their flowchart. However, the identification process can be very complex, and ultimately should never be left to unqualified personnel to determine.  


 There are two significant exclusion categories.

1. Wastes which are not considered solid waste, and

2. Wastes excluded from hazardous waste regulation.

For more information, please review Criteria for the Definition of Solid Waste and Solid and Hazardous Waste Exclusions.

Hazardous Waste Management

Once a waste does become officially identified as hazardous waste, employers must then follow RCRA guidelines for managing hazardous waste, officially known as Subtitle C. Employers can become familiar with these requirements using the helpful RCRA orientation manual PDF. 

To reiterate, hazardous waste identification and management is a complex issue which should be left to qualified personnel. Employers are bound to have more questions regarding hazardous waste identification, many of which might already be answered within the EPA’s Hazardous Waste Identification FAQ landing page.