While everyone is familiar with the need for antifreeze to keep their car’s engines at the right temperature, did you know that the same ingredients are used in HVAC systems to protect your system from temperature fluctuations?
We are referring to the primary ingredient of antifreeze, glycol. Available in two primary forms, ethylene glycol and propylene glycol, this odorless, sweet-tasting, toxic liquid can be found in your car, HVAC units, as well as commercial products like stamp pad inks, ballpoint pens, solvents, paints, plastics, films, and cosmetics.
Our guide to glycol disposal explores the differences between ethylene glycol and propylene glycol and how to dispose of it if you’re an automotive shop, HVAC repair company, or other industry that handles large volumes of glycol.
What is Glycol?
Glycol encompasses a group of organic compounds from the alcohol family, notable for their wide range of industrial, commercial, and consumer applications. There are two commonly used forms of glycol, ethylene glycol and propylene glycol, each used for different purposes based on their chemical properties.
Ethylene glycol is best known for its use in antifreeze and coolant formulations for automotive and heating systems. This version leverages its low freezing point and high boiling point to regulate temperature effectively in your engine and HVAC units.
Ingestion of ethylene glycol is toxic and dangerous.
The other popular version of the chemical, propylene glycol, is often used as a food additive. Propylene glycol helps maintain the consistency, moisture, and texture of food products. Normal amounts of propylene glycol are not hazardous, but many nutritionists and doctors recommend limiting your intake due to unknown long-term effects.
Regulations for Glycol
Various government agencies put together regulations for ethylene glycol:
“In the workplace, The National Institute for Occupational Safety and Health (NIOSH) provided a recommended ethylene glycol exposure limit (REL) of 50 ppm (ceiling limit), and The American Conference of Governmental Industrial Hygienists (ACGIH) has established threshold limit values (TLVs) for workplace exposure.”
The Occupational Safety and Health Administration did not set an exposure limit.
The EPA classifies ethylene glycol as a hazardous air pollutant under the Clean Air Act, and “recommends that children not be exposed to more than 20 mg/L (20 ppm) ethylene glycol in drinking water for 1 day, or 6 mg/L (6 ppm) per day over 10 days. The EPA also recommends that adults not be exposed to more than a daily total of 7 mg/L (7 ppm) for a lifetime.”
The FDA has approved ethylene glycol as an indirect food additive for use only as a component of packaging adhesives.
Is Glycol a Hazardous Waste?
Classifying glycol as hazardous waste hinges on how it has been used and whether it has been contaminated with other substances.
The United States Environmental Protection Agency (EPA) provides guidelines for managing and disposing hazardous waste under the Resource Conservation and Recovery Act (RCRA).
According to the EPA and similar regulatory bodies in other countries, waste is considered hazardous if it poses a substantial or potential threat to public health or the environment.
There are four main hazardous waste characteristics defined by the RCRA: ignitability, corrosivity, reactivity, and toxicity.
Ethylene glycol is on the Right to Know hazardous substances list, meaning it must be labeled appropriately if you have ethylene glycol within your building.
Ethylene glycol becomes a concern when contaminated with heavy metals, such as lead or chromium, often due to its use in industrial or automotive coolants.
If glycol-containing products are used to introduce hazardous substances into the glycol, the resulting waste may be classified as hazardous. For instance, used antifreeze from vehicles, which may contain metals and other contaminants, could be considered hazardous waste.
Ultimately, whether or not glycol classifies as a hazardous waste is up to your local state regulations and what other materials may have interacted with it. You should avoid contamination at all costs.
How Do You Dispose of Glycol?
Whether ethylene glycol or propylene glycol, disposing of this liquid requires specific tools to mitigate its impact on the environment and human health.
The first step in properly disposing of glycol is to determine whether it can be recycled. Dumping glycol products like antifreeze is illegal as they may contain heavy metals that turn them into hazardous waste. Never pour ethylene glycol down the drain or into water, as you may be liable to fines and penalties.
Recycling ethylene glycol enables its reuse or conversion into new products, thereby reducing environmental pollution.
If recycling is not an option, follow local regulations and guidelines for disposing of hazardous waste. These guidelines often dictate that glycol must be taken to a designated hazardous waste facility, where it can be disposed of to minimize its environmental impact.
HWH Environmental collaborates with automotive facilities and HVAC companies to safely dispose of glycol, helping them avoid costly regulatory penalties.
When preparing glycol for disposal, storing it in leak-proof, clearly labeled containers as hazardous waste is required.
For businesses and industries that generate large quantities of glycol waste, it is crucial to collaborate with a hazardous waste disposal company to develop a comprehensive waste management plan that meets all relevant regulatory requirements.
By adhering to these practices, individuals and organizations can contribute to the prevention of environmental contamination and protect public health from the risks associated with improper glycol disposal.
What Happens When You Improperly Dispose of Glycol?
When glycol is released into the environment—whether through industrial runoff, improper waste management, or accidental spills—it quickly contaminates soil and waterways.
Ethylene glycol is toxic to aquatic life, causing damage even with small amounts, which can lead to the death of fish and other organisms. Improper disposal can seep into groundwater, posing a risk to the quality of drinking water. Even in small quantities, ingesting ethylene glycol causes symptoms such as nausea and vomiting to severe metabolic acidosis, and renal failure.
Propylene glycol, while less toxic than ethylene glycol, contributes to oxygen depletion in water bodies. The CDC and world organizations recommend limiting your exposure to propylene glycol as much as possible.
Ethylene vs. Propylene Glycol Disposal
When it comes to disposal, the primary concern for both ethylene and propylene glycol is contamination.
As these fluids circulate within an engine or an HVAC system, they pick up heavy metals like lead, cadmium, and chromium, as well as other contaminants like benzene from fuel residue.
This contamination can cause either type of used glycol to be classified as a hazardous waste under the Resource Conservation and Recovery Act (RCRA), meaning it is subject to strict disposal regulations.
The main difference between the two lies in their unused state.
Propylene glycol is significantly less toxic and is even used as a food additive, so in its pure form, it is not considered hazardous.
However, this distinction becomes irrelevant once the fluid has been used.
Because it can be contaminated with the very same hazardous materials as ethylene glycol, used propylene glycol must often be tested, handled, and disposed of with the same level of care and regulatory oversight.
A Step-by-Step Guide to Glycol Disposal Compliance
Under federal and state law, the business that creates, or “generates,” industrial waste is legally responsible for its management from “cradle to grave.”
This places full liability on your company to ensure your used glycol is characterized, stored, transported, and disposed of in complete accordance with all regulations.
Following a transparent, systematic process is the only way to ensure compliance and protect your business.
1. Characterize Your Waste
The first and most crucial step is to determine if your used glycol is a hazardous waste formally.
This is not a judgment call; it is a scientific determination that often requires laboratory analysis.
The most common method is the Toxicity Characteristic Leaching Procedure (TCLP), which simulates landfill conditions to determine if heavy metals or other toxic constituents could leach into groundwater.
The results of this test will dictate the specific handling, labeling, and disposal methods you are legally required to use.
2. Proper Labeling and Accumulation
Once characterized as hazardous, your used glycol must be stored in containers that are properly labeled in accordance with RCRA standards.
Each container must be marked with the words “Hazardous Waste,” your business’s name and address, and the date on which you first began adding waste to that container–the “accumulation start date”.
You must also adhere to strict accumulation time limits, which can be 90, 180, or 270 days, depending on your hazardous waste generator status, before the waste must be shipped to a licensed facility.
3. Use a Hazardous Waste Manifest
When your hazardous glycol waste is ready to be transported off-site, it must be accompanied by a Uniform Hazardous Waste Manifest.
This is a multi-part legal document that acts as a chain-of-custody form, tracking the waste from your facility to its final destination.
Each party—the generator (your business), the transporter, and the final Treatment, Storage, and Disposal Facility (TSDF)—must sign and retain a copy.
This manifest serves as your legal proof that the waste was managed and disposed of in a responsible manner.
Need Help with Glycol Disposal? Call HWH Environmental Today.
HWH Environmental offers unparalleled customer service for your glycol disposal needs. Rest assured that when you call, you’ll speak with a live representative who will assist you in disposing of any hazardous waste you may have in your building.
To learn more about HWH Environmental’s hazardous waste disposal services, contact us online or call us at 877-777-6708.
