Mono Propylene Glycol (MPG)

Overview

Mono Propylene Glycol (MPG, CAS No: 57-55-6), is a colorless, odorless, slightly sweet-tasting liquid. This dihydric alcohol produced by hydration of propylene oxide is completely soluble in water and miscible with most organic solvents. Due to its low toxicity and versatility, it has a wide range of industrial applications.

MPG is an excellent humectant and solvent due to its hygroscopic properties. FDA, USP and EP grade versions are available for pharmaceutical and food applications. It is widely used in cosmetics, pharmaceuticals, food, animal feed and industrial applications.

Applications

Mono Propylene Glycol has a wide range of industrial and consumer applications:

Technical Specifications

Safety Information

Hazard Symbols and Statements

Low Hazard Eye Irritation

Personal Protective Equipment (PPE)

• Chemical-resistant gloves (nitrile or neoprene)
• Chemical safety goggles or face shield (for high splash risk)
• General ventilation is sufficient, local exhaust not required
• Protective apron or work clothes (for prolonged contact)
• Use organic vapor filter respirator for high temperature applications

Storage Conditions

• Store in cool, dry, well-ventilated area
• Protect from excessive heat and direct sunlight
• Store in stainless steel, polyethylene or glass containers
• Store separately from oxidizing agents
• Storage temperature: 10-30°C
• No special moisture protection measures required

Fire Fighting

• Suitable extinguishing media: Water spray, dry chemical, CO₂, foam
• May form flammable vapors at high temperatures
• Use appropriate respiratory protection during fire fighting
• Use dry chemical or CO₂ for small fires
• Use water spray or alcohol-resistant foam for large fires
• 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 during handling
• Proper labeling required on transport containers
• Grounding to prevent static electricity buildup
• Use appropriate packaging to prevent spills

Storage

• Store in stainless steel, polyethylene or glass containers
• Provide appropriate signage in storage area
• Use appropriate breathing vents on storage tanks
• Provide secondary containment measures for large quantities
• Prohibit smoking in storage areas
• Store separately from acids and oxidizers
• Provide spill control equipment in storage areas

Spill Response Measures

• Isolate the spill area
• Use appropriate protective equipment
• Absorb spills with sand, chemical absorbent or other absorbent materials
• Dispose of absorbed material appropriately
• Wash spill area with plenty of 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
• FDA: GRAS status under 21 CFR 184.1666
• EFSA: Approved as food additive (E1520)
• USP: Pharmaceutical grade specifications available
• EP: European Pharmacopoeia compliant

International Legislation

• European Union: Subject to Directive 2008/58/EC
• USA: Compliant with FDA and EPA regulations
• China: Listed in IECSC
• Japan: Listed in ISHL
• Global: Evaluated by JECFA
• IMO: Not classified as marine pollutant

Environmental Information

Environmental Impact

Mono Propylene Glycol degrades rapidly in the environment (>90% within 28 days). When mixed with water sources, it shows low toxicity to aquatic organisms. It degrades rapidly in soil through biological processes. It does not deplete the ozone layer and has minimal contribution to global warming.

Biological Degradation

• Air: 1-3 day half-life through photochemical reactions
• Water: Complete degradation within 7-14 days through microbial activity
• Soil: Rapid degradation through microbial activity
• Biological Oxygen Demand (BOD): 1.0-1.2 g O₂/g MPG
• Chemical Oxygen Demand (COD): 1.5-1.7 g O₂/g MPG

Waste Management

• Not classified as hazardous waste
• Small quantities can be disposed 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
• Prevent seepage into soil and groundwater

Frequently Asked Questions

How is Mono Propylene Glycol produced?

MPG is mainly produced by two methods: 1) Hydration of propylene oxide with water, 2) Catalytic hydrogenolysis of glycerol. Industrial-scale continuous distillation processes are used with annual global production exceeding 2 million tons.

What is the difference between Mono Propylene Glycol and Diethylene Glycol?

MPG (C₃H₈O₂) is a single propylene glycol molecule, while Diethylene Glycol (DEG, C₄H₁₀O₃) is formed by the combination of two ethylene glycol molecules. MPG has lower toxicity and is widely used in food/pharmaceutical applications, while DEG is preferred for industrial applications.

Is Mono Propylene Glycol safe for use in food?

Yes, it has FDA "Generally Recognized as Safe" (GRAS) status and is used as a food additive with E1520 code. Acceptable Daily Intake (ADI) has not been specified, meaning reasonable consumption is safe.

What is the shelf life of Mono Propylene Glycol?

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

What should I do if Mono Propylene Glycol contacts my skin?

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

Can Mono Propylene Glycol be mixed with other solvents?

Yes, MPG is miscible with water, alcohols, ketones, esters and most organic solvents in all proportions. It is immiscible with oils and hydrocarbons. It has excellent compatibility especially with water and ethylene glycol. However, it may react with strong oxidizers and acids.