What is Polyethyleneglycol?
Polyethyleneglycol, or PEG for short, is a polyether consisting of a (-O-CH2-CH2-) backbone that is commonly used in many fields of academic research, industrial processing and commercial applications. PEGs can also commonly be referred to as polyoxyethylene (POE) and polyethyleneoxide (PEO), but regardless of the name that is used, the simple structure of PEGs (which consists of solely carbon, hydrogen and oxygen, see image below) affords safe compounds that are used throughout everyday life.
Synthesized via the polymerization of ethylene oxide, PEGs have a polymeric structure, giving a different set of properties as compared to their unimolecular counterpart, ethylene glycol (see figure below).
Due to these structural differences (ethylene glycol vs. polyethyleneglycol), comparisons between physical properties, additive qualities and overall safety may not always be appropriate.
Additionally, it is this simple structure that separates PEGs from similar compounds like propylene glycol and polypropyleneglycol. The two aforementioned compounds (polyethyleneglycol vs. propylene glycol) are derivatives of propylene oxide, which, when polymerized, bestows a completely different set of physical characteristics to the compound as compared to PEG.
The method in which PEGs are created allows for a wide variability in their physical attributes, allowing them to be utilized by many commercial markets. By controlling a PEG’s size (i.e. molecular weight) and its size distribution, a wide variety of physical properties can be achieved, which sets Oxiteno’s line of PEG products, the ULTRAPEG® series, apart from other name brands of polyethyleneglycols.
Due to the vast number of product types offered by Oxiteno’s ULTRAPEG® products (click here for a full listing), many physical forms (liquids, pastes, solids, flakes, powder, etc.) and viscosities of PEGs are available. It is the numerous attributes of PEGs that allow for their inclusion in a vast array of applications, ranging from the pharmaceutical industry to cosmetic markets. While the structure of PEG is simple, it is this compound’s solubility in water is what makes it such a versatile additive to enhance many industrial applications.
Because Oxiteno’s line of ULTRAPEG® products are non-toxic and hydrophilic (water-loving), these polymers are used in the home (i.e. to treat surfaces in cleaning agents made by cleaning chemicals manufacturers) as well as in the food production industry (to reduce the amount of foam during the processing of food products). PEGs are generally considered to be biologically inert, making them safe to use throughout the medical and food-processing industries.
What is Polyethyleneglycol Used For?
Due to the variety of physical properties that can be achieved through Oxiteno’s ULTRAPEG® series, formulators in nearly all industries can benefit from this line of PEG products. A PEG’s unique ability to enhance a dye’s solubility in aqueous formulations causes it to be used throughout the textile industry as dye carriers. PEGs are also exceptional at retaining moisture in complex formulations, as well as to an applied surface, making them excellent humectants and anti-caking agents for cosmetic chemical suppliers and coatings chemical suppliers.
This unique relationship with water is further exploited by many other markets as PEGs can help to stabilize emulsions and act as water-miscible co-solvents for aqueous formulations. The food industry uses these compounds as additives to reduce the amount of foam during food processing. Additionally, PEGs find themselves very useful in the pharmaceutical industry due to their ability to act as rheological modifiers, thus being used as excipients.
New research techniques are increasingly incorporating PEG compounds via the use of ‘pegylation’ onto protein and peptide therapeutics, thus improving their pharmacokinetics and leading to safer and more effective drugs1-2. Many of Oxiteno’s ULTRAPEG® series meet the requirements set forth by the National Formulary (NF) guidelines for safe preparation, manufacture and use of a variety of PEG compounds that can be used as excipients, botanicals and other similar products.
Is Polyethyleneglycol Safe?
PEGs are generally considered to be a biologically inert substance, meaning that this class of oligomers and polymers are recognized to be safe for use in food, cosmetic and pharmaceutical applications. So, is polyethyleneglycol toxic? Due to the PEG’s structure and its water solubility, these compounds are generally considered to be non-toxic, as studies of demonstrated their safety for use within the field of drug delivery1-2, for application to the skin in cosmetics3 and as additives in the food and vitamin processing industry4.
Where applicable, Oxiteno’s line of PEGs, ULTRAPEG®, adhere to the guidelines for the manufacturing set forth by the National Formulary (NF). Having initially been established by the U.S. Federal Food, Drug, and Cosmetics Act of 1938, these guidelines are currently recognized by the U.S. Food and Drug Administration (FDA). These manufacturing and production guidelines are annually reviewed, requiring Oxiteno to not only adhere to these strict standards, but maintain constant surveillance over the preparation of these non-toxic additives. Additionally, many of Oxiteno’s ULTRAPEG® products that are used in agricultural applications are safe for the environment and are on the Environmental Protection Agencies’ (EPA) inert ingredient list, meeting the requirements set forth in 40 CFR 180.910 and 40 CFR 180.930. This makes Oxiteno’s PEGs attractive for agrochemical companies.
The ability to manufacture these products to conform to the necessary regulations to ensure a safe product that has minimal impact on the environment requires a company that has the manufacturing capabilities and correct mindset to safely engineer these compounds that affect our everyday lives. Oxiteno recognizes that having the global infrastructure is not enough to ensure the sustainability and well-being of our planet, which is why the people of Oxiteno are committed to making safer, more environmentally friendly products for all markets served.
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1-Harris, J. Milton, and Robert B. Chess. “Effect of pegylation on pharmaceuticals.” Nature reviews Drug discovery 2.3 (2003): 214.
2-Webster, Rob, et al. “PEG and PEG conjugates toxicity: towards an understanding of the toxicity of PEG and its relevance to PEGylated biologicals.” PEGylated protein drugs: Basic science and clinical applications. Birkhäuser Basel, 2009. 127-146.
3-Fruijtier-Pölloth, Claudia. “Safety assessment on polyethylene glycols (PEGs) and their derivatives as used in cosmetic products.” Toxicology 214.1-2 (2005): 1-38.
4-EFSA Panel on Food Additives and Nutrient Sources added to Food (EFSA ANS Panel), et al. “Refined exposure assessment of polyethylene glycol (E 1521) from its use as a food additive.” EFSA Journal 16.6 (2018): e05293.