GlyEco Inc

Glossary of Glycol Terms

Green Chemistry:

The design of chemical products and processes that reduce or eliminate the use or generation of hazardous substances. Green chemistry technologies provide a number of benefits, such as reducing waste and the use of natural resources.  

Hazardous Waste:

A waste that is dangerous or potentially harmful to our health or the environment.


Man-made liquid chemicals derived from crude oil and natural gas. Glycols are used as a base chemical in many industrial applications.

Ethylene Oxide: A colorless, flammable gas derived from petroleum and natural gas used to produce various chemicals, including ethylene glycol.
Diethylene Glycol:

A colorless, nearly odorless, sweet-tasting liquid chemical widely used as a solvent for resins, dyes, oils, and other organic compounds.  Diethylene glycol is toxic, and ingestion can result in death.

Triethylene Glycol:

A colorless, odorless liquid chemical commonly used as a dehumidifying agent for air and natural gas.

Propylene Glycol: A colorless, nearly odorless, slightly-syrupy liquid chemical commonly used as an humectant (a substance used to help products retain water), solvent, and preservative in food and tobacco products.  It is also commonly used in pharmaceutical and personal care products.  The U.S. Food and Drug Administration (FDA) has classified propylene as “Generally Recognized as Safe.”
Polyethylene Glycol: A compound of ethylene oxide and water, available in either a liquid form or as a waxy solid, used in various pharmaceutical preparations.
ASTM: The American Society for Testing and Materials (“ASTM”) is an international standards organization that develops and publishes technical standards for a wide range of materials and products, including glycol.
ASTM E1177 Type 1:     

Ethylene glycol and propylene glycol with a purity level equivalent to virgin glycol.

ASTM E1177 Type 2: Ethylene glycol and propylene glycol meeting purity levels regarded as safe for use in automotive engine coolant formulas
Virgin Glycol: Glycol containing new raw materials.

Spent (also referred to as “waste” or “used”) glycol from various sources, such as antifreeze, heat transfer fluids, and aircraft deicing fluids, which is capable of being recycled.


A substance added to a solvent, such as water, to lower its freezing point. Antifreeze is typically added to water in the cooling system of an internal-combustion engine of an automobile so that it can be cooled below the freezing point of water. Ethylene glycol is the most widely used automotive antifreeze.  

Common Contaminants of Antifreeze: Lead, cadmium, and chromium.
OEM Specifications: The specifications required of an original equipment manufacturer (“OEM”) in manufacturing a replacement automotive part.
Heat Transfer Fluid: Also referred to as a “coolant,” a liquid that flows through or around a device to prevent it from overheating.
Aircraft Deicing Fluid: A liquid used to prevent and remove snow, ice, or frost build-up on the critical surfaces of an aircraft, such as the wings and fuselage. The main component of aircraft deicing fluid is typically propylene glycol or ethylene glycol.
Ethylene Oxide (EO) Sterilization: The use of ethylene oxide to sterilize medical and pharmaceutical products.
Polyester Fiber:

A quick-drying resilient synthetic fiber consisting primarily of polyester.  Ethylene glycol is used in the production of polyester fibers. 

Distillation: The process of purifying a liquid mixture by successive evaporation and condensation.
Vacuum Distillation: A method of distillation whereby the pressure above the liquid mixture to be distilled is reduced to less than its vapor pressure causing evaporation of the most volatile liquids.

The process of removing particles from a liquid mixture by forcing the liquid mixture through a porous media.

Ultrafiltration: Filtration using a semipermeable medium that allows only the passage of small molecules.
Nanofiltration: Pressure-driven filtration through a membrane that removes particles of about two nanometres or larger.
Reverse Osmosis:

A filtration process by which a solvent passes through a semipermeable membrane in the direction opposite to that for natural osmosis.  

Quality Control Assurance Program (QCAP):

GlyEco’s quality control procedures and quality criteria for incoming feedstock, goods in process, and finished product.

EPA Hazardous WasteManifest System:

A set of forms, reports, and procedures designed to seamlessly track hazardous waste from the time that it leaves the place where it was produced until it reaches the place where it will be stored, treated, or disposed of.