Triethylene Glycol (TEG)

Overview

Triethylene Glycol (TEG, CAS No: 112-27-6), is a colorless, odorless, hygroscopic and viscous liquid. It is an important member of the ethylene glycol family and is widely used especially in the dehydration of natural gas and other gases due to its strong water absorption properties.

TEG is completely soluble in water and miscible with most organic solvents. Due to its high boiling point, low vapor pressure and stable chemical structure, it is preferred in various applications in the industry. It is commonly used as a gas processing agent, plasticizer, solvent and chemical intermediate.

Applications

Triethylene Glycol has a wide range of industrial and chemical applications:

Technical Specifications

Safety Information

Hazard Symbols and Statements

Eye and skin irritation Health hazard

Personal Protective Equipment (PPE)

• Chemical-resistant gloves (nitrile or neoprene)
• Chemical safety goggles or face shield
• Appropriate respiratory protection (dust/vapor mask)
• Chemical-resistant apron or work clothing
• Proper ventilation or local exhaust system

Storage Conditions

• Store in a cool, dry, well-ventilated place
• Store in original closed containers, protected from sunlight
• Store separately from oxidizing agents
• Storage temperature: 10-30°C
• Protect from moisture
• Store in stainless steel, polyethylene or glass containers

Fire Fighting

• Suitable extinguishing agents: Dry chemical, CO₂, alcohol-resistant foam
• Cooling can be done using water spray
• Intervention by trained personnel with appropriate respiratory protection
• Cool containers with water during fire fighting

Handling and Storage

Handling

• Ensure containers are tightly closed during transport
• Provide adequate ventilation in transport vehicles
• Avoid eating, drinking or smoking while handling
• Appropriate labeling required on transport containers
• Have emergency equipment in transport vehicles

Storage

• Store in stainless steel, polyethylene or glass containers
• Maintain appropriate signage in storage area
• Use appropriate breathing vents on storage tanks
• Prohibit smoking in storage areas
• Store separately from acids and oxidizers

Spill Response Measures

• Use appropriate respiratory protection
• Absorb spills with sand, chemical sponge or other absorbent materials
• Dispose of absorbed material appropriately
• Wash spill area thoroughly with water and detergent
• Call professional cleaning service for large spills
• Prevent spills from entering sewers or water sources

Regulatory Information

GHS Classification

• Skin Irritation Category 2
• Eye Irritation Category 2A
• Specific Target Organ Toxicity (Single Exposure) Category 3

Important Regulations

• REACH: Registered
• CLP: Compliant
• OSHA: Subject to hazard communication standard
• NFPA 704: Health 1, Flammability 1, Reactivity 0
• FDA: Approved for certain applications

International Legislation

• European Union: Subject to Directive 2008/58/EC
• USA: Subject to EPA regulations
• China: Listed in IECSC
• Japan: Listed in ISHL

Environmental Information

Environmental Impact

Triethylene Glycol is moderately toxic in aquatic environments but is biodegradable. It degrades through photochemical reactions in the atmosphere. It undergoes microbial degradation in soil and can persist in groundwater if infiltrated.

Biological Degradation

• Air: Degrades through photochemical reactions
• Water: Degrades within 10-20 days through microbial activity
• Soil: Moderate degradation through microbial activity
• Biological Oxygen Demand (BOD): 0.8-1.0 g O₂/g TEG
• Chemical Oxygen Demand (COD): 1.5-1.7 g O₂/g TEG

Waste Management

• Classified as hazardous waste
• Small quantities can be disposed of through biological treatment in licensed facilities
• Large quantities should be incinerated in licensed hazardous waste disposal facilities
• Dispose according to local regulations
• Prevent entry into wastewater

Frequently Asked Questions

How is Triethylene Glycol produced?

Triethylene Glycol is produced by the reaction of ethylene oxide with water. During this process, a mixture of monoethylene glycol (MEG), diethylene glycol (DEG) and triethylene glycol (TEG) is formed. This mixture is separated by distillation to obtain pure TEG.

What is the difference between TEG and DEG?

Diethylene Glycol (DEG) consists of two ethylene glycol units while Triethylene Glycol (TEG) consists of three units. TEG has a higher boiling point (285-290°C vs 245°C) and lower vapor pressure. TEG has stronger hygroscopic properties and is more effective in gas dehydration.

How does TEG work in gas dehydration?

TEG physically absorbs water vapor from natural gas. The gas passes through a column containing TEG. TEG retains the water while the gas exits dehydrated. The TEG is then heated to remove the water and made reusable.

What is the shelf life of Triethylene Glycol?

When stored in properly sealed containers, Triethylene Glycol has a shelf life of approximately 2 years. It should be tightly closed to prevent water absorption and oxidation. Stability testing is recommended before long-term storage.

What should I do if TEG contacts my skin?

Remove contaminated clothing immediately and wash with plenty of water and soap. Prolonged contact may cause dryness and irritation to the skin. Seek medical attention if irritation persists. For eye contact, rinse with plenty of water for at least 15 minutes and consult an ophthalmologist. If swallowed, do not induce vomiting, seek immediate medical attention.

Is TEG compatible with other chemicals?

TEG is miscible with most organic solvents. It is miscible with water in all proportions. It may react with strong oxidizers, acids and bases. It forms complexes with metal ions. Compatibility tables should be consulted during storage and use.