The world produces about 13 tons of hazardous waste per second. This kind of modern human-produced waste must be treated, stored, and disposed of effectively to preserve planet Earth for future generations.
Humans are constantly creating such toxic waste. The amount that’s produced is based on the scope of different human activities, including industrial, agricultural, and residential. Today the issue is becoming more serious and affecting not only the entire planet but even individual communities.
This universe of dangerous waste is gigantic and very diverse. For example, it can exist in different forms like gas, liquid, and solid. There are also different types and features of hazardous waste. The definition “hazardous waste” is also defined by different organizations including the United States Environmental Protection Agency (EPA).
What is a Hazardous Waste?
According to the EPA, “Simply defined, a hazardous waste is a waste with properties that make it dangerous or capable of having a harmful effect on human health or the environment.” Hazardous waste also includes different physical forms, including: solids, liquids, and gases.
Dangerous wastes can also be produced through different means. From manufacturing methods, and discarded substances like unused commercial products (i.e., pesticides and cleaning fluids), and used materials, according to the University of California-Irvine.
The hazardous toxic waste can also be defined in regulatory terms. This includes one or a combination of the features in the EPA’s Resource Conservation and Recovery Act (RCRA) which includes the following characteristics:
In addition to these strict definitions, waste products can still be considered “hazardous” even if they don’t have any technical features of this kind of dangerous waste. Some examples include soil produced from large clean-up projects and used oil.
EPA Regulatory Definition
The EPA has created a regulatory hazardous waste definition. It has defined various substances that have been scientifically proven to be hazardous. The EPA has also created objective requirements that allow for a particular material to be regulated as “hazardous waste.”
While this hazardous waste definition is objective, it can be extremely complex. This has resulted in the US agency creating a list of questions that waste-generators can ask to determine whether or not they are indeed producing “hazardous” waste:
1. Is it solid waste?
The EPA always defines hazardous-type waste as solid waste. Other organizations use a broader definition that can include liquid or gas, but the EPA strictly defines such toxic waste as having a solid form.
2. Is the solid waste exempt from being regulated?
It’s possible for a particular solid waste to not be classified/regulated as hazardous. In other words, not all solid wastes are “hazardous” based on the EPA’s standards, but all hazardous wastes are solid wastes.
The EPA then requires waste generators to check if they’re producing waste with features that classify it as “hazardous.”
It’s also possible for waste generators to request the EPA to de-list their waste as hazardous. This is based on the EPA’s RCRA’s lists. The EPA also maintains a list of waste generators that have successfully been delisted from the EPA’s list of facilities producing dangerous waste.
The EPA provides not only strict guidelines for classifying this toxic waste but also provides other guidelines about how much waste must be Stored, Treated, Disposed, and Recycled.
This kind of hazardous waste is typically classified differently from other kinds of toxic wastes. Scientists have approached the issue differently from other waste management.
Radioactive waste is typically made from radioactivity, although in some cases, this isn’t the cause. However, this kind of waste always has levels of “radionuclide” contaminants that are higher than legal levels set by regulatory bodies like the USA’s EPA.
This type of waste produces a greater health risk due to the measured concentration of radionuclides contained in a substance. Another factor is that various radionuclides pose different hazard levels.
Main Causes of Hazardous Waste
Hazardous materials produced by industrial and technological advances are the main causes of these toxic substances. The situation became exponentially worse due to events like the Industrial Revolution, which took place during the 1700s and 1800s.
In recent decades one of the main developments has been nuclear technology. Various nuclear applications have increased in popularity around the globe. This has triggered a spike in the effects of radioactive materials released into the Earth’s environment. That, in turn, has caused major problems in Earth’s biological systems.
Hazardous Waste Types
Just as defining what is hazardous waste can be done in different ways, there are different ways to classify dangerous waste as different types.
Wastes might be classified as “hazardous” if they show particular characteristics, including:
This kind of waste results in chemical reactions in particular conditions. This can trigger explosions or give off different gases, fumes, or vapors. The activity happens when the substance is mixed with H2O or compressed. Some examples include unused explosives and lithium/sulfur batteries.
It’s important to note that no test methods exist to test a waste for reactivity. There are other methods to test for this feature that are based on regulations for hazardous waste.
Corrosive wastes are various materials like solids that are either acids/bases or make acidic/alkaline solutions. A corrosive waste is one with a pH level at/under 2.0 or at/above 12.5.
Liquid wastes can also be corrosive in the case it’s able to corrode various metal containers like drums, storage tanks, and barrels. Examples include used battery acid. There are various EPA methods to test if waste is corrosive.
In certain situations, these wastes can spark fires, have a flash point under 60°C (140°F), or blow up (spontaneous combustion). Some examples include used solvents and waste oil.
Various test methods can be done to figure out if the waste has the ignitability characteristic. There are different methods used, including the USA EPA’s test methods.
Toxic waste is dangerous or deadly when it’s absorbed or indigested. This involves different substances, including lead, mercury, Dichlorodiphenyltrichloroethane (DDT), etc. The disposal of toxic wastes can cause groundwater to become polluted.
“Toxic” is a wide category that can be defined when a substance has 1+ of the following features:
1. Acute Dermal Toxicity
This is a test that’s related to a substance being slightly toxic or having a slightly toxic substance that’s triggered through skin contact. It involves a certain level of dermal toxicity.
In this situation, the waste contains a certain level of cancer-causing substance that classifies it as being dangerous. This is a major issue since cancer is one of the most common causes of death, according to the World Health Organization (WHO).
3. Waste Extraction Test
The Waste Extraction Test (WET) is related to another procedure known as “total digestion.” Each lab test is compared with various regulations for toxic waste to determine whether or not a particular substance should be defined as such.
4. Toxicity Characteristic Leaching Procedure
Toxicity Characteristic Leaching Procedure (TCLP) is related to the definition “hazardous waste” and is defined by the EPA as wastes that can release dangerous substances into the environment.
TELP test results are compared with regulations for hazardous waste. This doesn’t include wastes that aren’t regulated by the EPA’s RCRA.
5. Acute Oral Toxicity
This type of toxic waste is due to slightly toxic substances or becomes slightly toxic when consumed. A particular waste is toxic if it has a certain level of oral toxicity.
6. Acute Aquatic Toxicity
This toxicity is related to waste being toxic when fish are exposed to it. A test procedure is done to determine if the aquatic toxicity is high enough for the waste to be classified as toxic.
Some specific kinds of wastes are defined as hazardous wastes based on created lists. There are various ways that the wastes are categorized including:
This list includes wastes that are created from particular industries like pesticides and petroleum. Some other examples of these dangerous wastes include wastewater and sludge from production/treatment processes.
This list includes several manufacturing/industrial processes like solvents used for cleaning/degreasing. The processes that make these wastes exist in several industry sectors.
Thus, these wastes are from sources that are non-specific. In other words, the wastes aren’t from one particular manufacturing or industrial process.
These are certain wastes with mercury, including mercury switches, fluorescent lamps, and products that house such switches. They’re related to the issue of what is hazardous waste.
These products with mercury can provide several benefits for people. However, the problem is when the products are discarded, they become waste.
Commercial Chemical Products
This can include chemical products that weren’t used yet but will be discarded. There are different examples, including commercial pesticides, industrial chemicals, and prescription drugs. The chemical products actually become hazardous items when they’re tossed.
RCRA Hazardous Waste Management System
Based on the EPA’s Resource Conservation and Recovery Act (RCRA), hazardous waste generators are the first link within the waste management system. The first goal of generators is to determine if the waste they are producing is indeed hazardous, and then figure out how to handle it.
Another goal of generators is to guarantee, and document that produced hazardous waste is correctly:
These steps must be taken before disposal or recycling takes place.
The amount of EPA regulation that applies to individual generators is based on how much waste the generator creates. The EPA provides info about which regulations apply to hazardous waste generators.
Following the generators’ production of the toxic waste, transporters might move the produced waste to a facility that treats, disposes of, or recycles the waste. Various EPA and US Department of Transportation (DoT) regulations apply since the waste is moved through roads/highways, railroads, and waterways.
Treatment and Storage
The EPA has attempted to create federal regulations for hazardous waste that are able to balance the goal of protecting public health and Earths’ environment, while sustaining resource conservation. This involves different processes, including treating/disposing of waste to incinerators or landfills, or recycling the waste in a safe and effective manner.
RCRA requirements are related to companies creating, storing, or disposing of toxic wastes in the USA. The RCRA requires US-located facilities that engage in treating, storing, or disposing of hazardous-type waste to secure a permit. Specific requirements must be met for handling, tracking, and managing waste.
The disposal of dangerous waste has historically been done in traditional landfills. However, this resulted in large amounts of toxic materials seeping down into the soil. Over time the waste started contaminating ground-water and underground water systems.
Today, several landfills require counter steps that are used to prevent ground-water contamination. One example is an installed barrier along the landfill’s foundation. This is installed to contain toxic substances that might stay in the landfill’s disposed waste.
Treatment, Storage, and Disposal Facilities (TSDFs) provide short-term storage, and treatment or disposal of hazardous wastes. One possible drawback is a higher amount of risk due to the enormous quantities of waste and activities performed at such facilities.
This issue explains why TSDFs are strictly regulated. In fact, TSDF regulations are set for issues like:
The recycling of hazardous waste provides several benefits, including reducing the volume of treated/disposed of waste materials and the use of raw materials.
It’s critical to ensure proper storage of the materials. This can prevent events like leaks, spills, fires, and contamination of drinking water and soil. The EPA has created official regulations to make sure recycling is done safely.
Developments in industry and technology during the past quarter-millennium or so have caused the creation of hazardous materials to skyrocket. This has resulted in a surge in various industries like hazardous waste handling automation.
It’s important to know the definition of “hazardous waste” in particular situations like owning/operating waste generators. This can provide such parties with critical information about how bodies like the UN, EPA, and local states define and regulate the dangerous waste material.
Another key issue is knowing how such regulators categorize various types of hazardous waste. It includes different approaches involving the waste’s source, characteristics, and “toxic” status. This can result in the proper handling, transport, and disposal of hazardous waste based on global, national, and local industry standards.