TRİETHYLENE GLYCOL (TEG)

Introduction

Triethylene Glycol (TEG) is a colorless, odorless, and viscous liquid belonging to the family of glycols. It is a linear homologue of polyethylene glycol, containing three oxyethylene repeats. In food processing, TEG is primarily used for indirect food contact applications rather than as a direct additive.

Its primary food-related role is as a processing aid or a component in materials that contact food. Its most significant historical use has been as a humectant and plasticizer in the manufacture of adhesives, printing inks, and coatings used on food packaging. It is also used in some food processing equipment lubricants. However, it is not approved as a direct food additive and has very limited direct use.

CAS Number

112-27-6

Synonyms

• TEG
• Triglycol
• 2,2'-ethylenedioxybis(ethanol)
• Triethylene glycol

Topic Headings

1. Primary Indirect Food Contact Applications (list form)

• Adhesives — Used as a humectant and plasticizer in adhesives for food packaging laminates.
• Printing inks — Employed as a solvent and humectant in inks used on flexible food packaging.
• Coatings — Used as a plasticizer in coatings applied to food-contact surfaces.
• Lubricants — A component in certain food-grade lubricants used in food processing equipment.
• Dehydration solvent — Used in natural gas processing to remove water, but this is not a food application.

2. Mechanism of Indirect Contact Migration (paragraph form)

As a component of an adhesive, ink, or coating used on the non-food side of a package, TEG can potentially migrate through the packaging material and into the food. This process is governed by the principles of mass transfer, where the concentration gradient drives the additive from the packaging material to the food. To ensure safety, its use in food contact materials is strictly regulated, and migration limits are established. The potential for migration depends on factors like the thickness of the packaging layer, the type of food (e.g., high-fat foods are more likely to absorb migrants), and the storage conditions (temperature and time).

3. Physical and chemical properties (list form)

• Appearance — Clear, colorless liquid.
• Odor — Odorless.
• Molecular weight — 150.17 g/mol.
• Boiling point — Approximately 285-288°C.
• Viscosity — High (about 47.8 cP at 25°C).
• Solubility — Very soluble in water and many organic solvents.
• Hygroscopicity — Highly hygroscopic, attracting and retaining water.

4. Safety and Regulatory Status (paragraph form)

Triethylene Glycol is not listed as a direct food additive by the FDA. Its use in food packaging materials is permissible under 21 CFR as an indirect food additive, often adhering to specific regulations for adhesives and coatings. It is also on the EU's list of substances that can be used in plastic food contact materials, subject to a specific migration limit. TEG has relatively low acute toxicity; however, chronic exposure to high levels can have health effects. It is not listed as a carcinogen by major agencies like ACGIH, IARC, or NTP.