Diethylene glycol (DEG) plays a key role in various industries, including antifreeze, adhesives, solvents, fiber softeners, gas dehydrators, brake fluids, plasticizers, raw materials for plastics, and printing inks. As a vital chemical intermediate, DEG is widely used in chemical processing. However, it is both flammable and toxic. Improper storage or transport can lead to serious safety risks. This article will help you understand the primary applications and hazards of DEG, along with practical storage precautions.

1.   What is Diethylene Glycol (DEG)? Classification and Uses

Diethylene glycol (DEG), chemical formula: (C₂H₄OH)₂O, HS Code: 2909 4100 009, is also known as diglycol.

• IMDG Classification : Not listed as a regulated dangerous good
• UN Number : None
• Danger Class : None

Physical Properties :

• Appearance: Colorless hygroscopic liquid
• Boiling Point: 224°C
• Melting Point: -6°C
• Density: 1.118 g/cm³ (at 25°C, water = 1)
• Solubility: Fully miscible with water, alcohols, ethers, acetone, and other organic solvents
• Volatility: Low vapor pressure, not easily volatile

Chemical Properties :

• DEG is chemically stable but reacts violently with strong acids, bases, and oxidizing agents, posing an explosion risk.
• It can corrode aluminum materials.
• As a glycol ether, DEG exhibits both viscosity and hygroscopicity.

Synthesis : DEG is derived from ethylene glycol and ethylene oxide.
Chemical Reaction : Ethylene glycol + Ethylene oxide → DEG

DEG is also used to manufacture various derivatives and polymers. Key applications include:

(1) Explosives

Diethylene Glycol Dinitrate (DEGDN) : Created by reacting DEG with nitric acid and sulfuric acid, replacing hydroxyl groups (-OH) with nitro groups (-NO₂). It is used as a substitute for nitroglycerin in rocket propellants and explosives.

(2) Antifreeze

DEG’s water solutions have lower freezing points and higher boiling points than pure water. Its high specific heat allows it to absorb or release large amounts of heat with minimal temperature fluctuation. Therefore, DEG is ideal as an antifreeze to prevent freezing and crystal formation that can damage tanks and pipes. It also protects against metal corrosion in cooling systems.

(3) Industrial Solvent & Chemical Intermediate

DEG is an excellent organic solvent that dissolves grease, nitrocellulose, dyes, resins, and plastics. It also absorbs moisture effectively, making it useful in inks, adhesives, dehumidifiers, and gas dehydrators. Additionally, it serves as an intermediate for synthesizing 1,4-dioxane, morpholine, deodorants, cosmetics, foaming agents, dyes, preservatives, and fumigants.

2.   Understanding the Hazards of DEG

Although DEG is not classified as a dangerous good under IMDG, it still poses serious health and safety risks if mishandled:

• Inhalation: Can cause headaches, dizziness, throat irritation, and even shock
• Eye Contact: May lead to irritation, inflammation, and potential blindness
• Ingestion: Can cause unconsciousness, vomiting, shock, dizziness, respiratory and cardiovascular failure, and is potentially fatal
• Skin Contact: Can cause irritation

If exposed to DEG, seek immediate medical attention.

3.   Proper Storage Guidelines for DEG

(1) Store in a Cool, Well-Ventilated Area

Keep DEG containers sealed in a shaded, ventilated space away from direct sunlight. Use opaque, airtight containers to avoid degradation due to light or air exposure. DEG should not be stored near incompatible substances like oxidizers (e.g., perchlorates, nitrates, chromic acid), peroxides, strong acids (e.g., sulfuric acid, fuming sulfuric acid, hydrochloric acid, nitric acid, chlorosulfonic acid), strong bases (e.g., sodium hydroxide, potassium hydroxide), aluminum, or phosphorus sulfide. These combinations can cause combustion, heat generation, or explosions.

(2) Ensure Airtight Packaging

Exposure to air, light, or heat can cause DEG to degrade and release toxic substances. Containers should be securely sealed to prevent reactions and accidents.

(3) Label Containers Clearly

Clearly label all DEG containers with chemical identifiers and handling precautions. Proper labeling helps workers and transporters understand how to safely manage the chemical. In the event of an incident, responders can use this information to take appropriate emergency action.

Further Reading : What Are Dangerous Goods? A Quick Guide to Hazard Classification and Transport Regulations

(4) Use Personal Protective Equipment (PPE)

Because DEG is hazardous upon contact or inhalation, workers must wear gloves, protective clothing, goggles, and gas masks. Proper training is essential.

(5) Avoid Spark-Producing Tools

DEG is flammable and may explode when exposed to open flames, high heat, static electricity, or strong light. Use plastic tools instead of metal ones to prevent sparks. Ensure the area is free of ignition sources during handling or transport.

(6) Install Emergency Equipment

Storage areas should be equipped with emergency response equipment in case of spills or exposure. Safety data sheets (MSDS) and emergency kits must be placed in visible, easily accessible locations.

Further Reading : How to Understand the MSDS (Material Safety Data Sheet) and Key Details to Watch For

Published Date : January 9, 2025