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Polyethylene Glycol 8000, known in Turkish as polietilen glikol 8000, is a white, waxy solid polyethylene glycol with an average molecular weight of about 8000, obtained by the ring-opening polymerization of ethylene oxide in the presence of water or ethylene glycol with a basic catalyst. Identified by CAS No 25322-68-3 and represented by the formula HO(CH₂CH₂O)ₙH, this polymer has an average number of repeating units of about 181. It is supplied in flake, granule or powder form; it dissolves readily in water, melts in the range of about 55–62 °C and is known in cosmetics as PEG-180. The chain carries one hydroxyl group at each end and numerous ether oxygens along its backbone; this structure gives the polymer both water solubility and alcohol-like reactivity.
Macrogol 8000, this substance is used as a pharmaceutical excipient in ointment and suppository bases and as a tablet binder and coating plasticizer, thanks to its low toxicity and broad compatibility. The same polymer is evaluated as a humectant, carrier and thickener in cosmetics and, in the food field, as an additive under the number E 1521 in certain uses. In industry it serves as a binder and plasticizer in ceramic production, as a mold release agent and lubricant in rubber and plastics processing, as a water-soluble lubricating component in metalworking fluids and as a reactive diol in polyester and polyurethane resins. In molecular biology laboratories it is a widely used reagent in processes such as the precipitation of DNA, proteins and viruses, cell fusion and protein crystallization.
Polyoxyethylene glycol 8000, is not a single uniform substance. Parameters such as average molecular weight, hydroxyl value, freezing point, residual ethylene oxide and 1,4-dioxane content, ethylene glycol and diethylene glycol content and the presence of antioxidants vary by grade; pharmacopoeial, food, cosmetic, molecular biology and technical grades are offered with different limits and documents. For this reason, product selection should not rely on the average molecular weight alone; the grade, TDS, SDS and COA documents should be evaluated together. This product can be supplied from ATAMAN KİMYA; contacting ATAMAN KİMYA is recommended for product selection, technical information and supply requests.
WHAT IS POLYETHYLENE GLYCOL 8000?
Polyethylene Glycol 8000 is one of the solid, high-molecular-weight members of the polyethylene glycol family. Polyethylene glycols are linear polyethers formed by the addition polymerization of ethylene oxide with water or ethylene glycol, and their general structure is written as H−(O−CH₂−CH₂)ₙ−OH. The number in their names corresponds to the average molecular weight; thus grades between 200 and 600 are free-flowing liquids, while grades of 1000 and above are solid at room temperature.
Grades of about 4000 and above exist as waxy solids, while grades of 6000 and above are supplied as free-flowing ground powders.
The names polyethylene glycol and polyethylene oxide are close to each other. According to industry sources, the term polyethylene glycol is used for products with an average molecular weight between 200 and about 35,000, while products obtained by polymerizing ethylene oxide in a solvent medium and reaching molecular weights in the millions are called polyethylene oxide. The product with a molecular weight of eight thousand belongs to the polyethylene glycol group in this distinction, and its chain length consists of about 181 ethylene oxide units.
The commercial product is mostly one hundred percent active polymer; that is, it contains no water or solvent and carries only a low level of moisture. However, the average molecular weight does not mean that the polymer consists of chains of a single value. Chain lengths show a statistical distribution during the reaction; for this reason pharmacopoeias define a range such as 7000–9000 for the average molecular weight. Two products sold under the same name may differ somewhat from each other in hydroxyl value, viscosity and impurity profile.
Different forms exist on the market, namely flake, granule and fine powder.
The flake form provides ease of storage and dosing and can be weighed without heating; fine powder, because of its high dissolution rate, is preferred in dry blends and in applications requiring rapid dissolution. Grades include pharmacopoeial grade (Ph. Eur., USP-NF, BP), food grade, cosmetic grade, molecular biology grade and technical grade. Although these have the same chemical structure, they differ in impurity limits, production conditions and documentation.
Polyethylene glycols have long been among the basic components of pharmaceutical, cosmetic and industrial formulations. The repeating ether bonds of the structure form hydrogen bonds with water and make the polymer miscible with water in all proportions; the terminal hydroxyl groups, in turn, take part in reactions specific to alcohols such as esterification, etherification and urethane formation. These two properties are the basis of the polymer's use both as a formulation aid and as a chemical intermediate.
COMMON PRODUCT AND CHEMICAL NAMES OF POLYETHYLENE GLYCOL 8000:
Polyethylene Glycol 8000
Polyethylene Glycol 8000 NF
Poly(ethylene glycol) 8000
Polyethylene glycol, average molecular weight 8000
Macrogol 8000
Macrogolum 8000
Polyoxyethylene glycol 8000
Poly(oxy-1,2-ethanediyl), α-hydro-ω-hydroxy-
α-Hydro-ω-hydroxypoly(oxy-1,2-ethanediyl)
Ethylene glycol polymer 8000
PEG 8000
PEG-8000
PEG-180
Carbowax 8000
Carbowax PEG 8000
Polyglykol 8000
Polyglykol 8000 S
Polyglykol 8000 P
Polyglykol 8000 PF
Lipoxol 8000
POLIkol 8000
T-Det PEG 8000 P
Polietilen glikol 8000
Polioksietilen glikol 8000
Makrogol 8000
Etilen glikol polimeri 8000
HO(CH₂CH₂O)ₙH
Some of these names express the chemical identification, some the abbreviation and cosmetic use, and some a trademark. Polyethylene Glycol 8000 and Poly(ethylene glycol) 8000 are different spellings of the same product; Macrogol 8000 is the name used particularly in the European pharmacopoeia and the pharmaceutical sector. PEG-180 is the INCI name used in cosmetic products, and the number indicates the average number of ethylene oxide units in the chain.
Carbowax, Polyglykol, Lipoxol, POLIkol and T-Det are trade names belonging to different manufacturers; Polyglykol 8000 S denotes the flake form, and P and PF denote the powder forms. Trade names belong to the respective companies, and products carrying the same name should not be assumed always to have the same specification.
The similarity in product names can be misleading. Other molecular-weight grades of polyethylene glycol and other polymers containing ethylene oxide, such as polyethylene oxide, polypropylene glycol and poloxamers, can also be seen side by side in product lists. These products have different physical properties and usage limits. In addition, some SDS documents may contain synonyms for Polyethylene Glycol 8000 that include a different number, such as PEG-150; in such differences, the product's CAS number, average molecular weight and grade should be checked against the documents.
CAS NO, EC / EINECS NO AND CHEMICAL IDENTIFICATION OF POLYETHYLENE GLYCOL 8000
Product name: Polyethylene Glycol 8000 / Polietilen Glikol 8000
Common abbreviation: PEG 8000
Chemical name: Poly(oxy-1,2-ethanediyl), α-hydro-ω-hydroxy-; polyethylene glycol, average molecular weight 8000
INCI name: PEG-180
Food additive number: E 1521 / INS 1521 (polyethylene glycol)
CAS No: 25322-68-3
EC / EINECS No: 500-038-2
Molecular formula: HO(CH₂CH₂O)ₙH, average n about 181
Molecular weight: Average about 8000 g/mol; pharmacopoeial range 7000–9000
Chemical class: Polyether polyol, polyethylene glycol
Main functions: Binder, plasticizer, lubricant, mold release agent, humectant, carrier, thickener, solvent, precipitant and reactive diol component
Polyethylene Glycol 8000 is a polymer with a defined repeating unit; however, its molecular weight is not a single value but a distribution.
Products supplied under the same CAS number may differ not only in average molecular weight but also in residual ethylene oxide, 1,4-dioxane, ethylene glycol, diethylene glycol, formaldehyde and water content. The CAS number is necessary for matching the product with the correct substance; however, on its own it does not show that the product is suitable for a specific application.
CAS No 25322-68-3 is used for polyethylene glycol in general and covers products ranging in molecular weight from 200 to 35,000. For this reason, different grades such as PEG 400, PEG 3350, PEG 6000 and PEG 8000 carry the same CAS number, and the information that distinguishes the grade is the number in the product name and the average molecular weight value. As the EC number, 500-038-2 is given in many supplier documents; since a different number may be encountered in some catalog records, the current number should also be checked from the supplier's SDS document.
The INCI name PEG-180 indicates that the product can be used in cosmetics, and the presence of the E 1521 number indicates that it can be used as a food additive under certain conditions; however, this does not mean that every grade can be used in every application. A product to be used for cosmetic or food purposes must be of the relevant grade, documented and compliant with legislation.
CHEMICAL STRUCTURE AND MOLECULAR PROPERTIES OF POLYETHYLENE GLYCOL 8000
Polyethylene Glycol 8000 is a linear polyether formed by the ring-opening polymerization of ethylene oxide and made up of repeating −CH₂−CH₂−O− units. There is one hydroxyl group at each chain end. Since the average molecular weight is about 8000, the chain contains on average about 181 ethylene oxide units; this value can also be followed from the hydroxyl value of the product. A product with a hydroxyl value in the range of about 12–16 mg KOH/g corresponds to a polymer with an average molecular weight of about 7000–9000.
The structural and chemical properties of the molecule can be summarized as follows:
• Linear and unbranched structure: The polymer has a simple repeating unit carrying no methyl or other side groups. The regular structure allows the chains to pack in an orderly way, and for this reason the product is a partially crystalline, waxy solid at room temperature.
• Ether oxygens and hydrophilicity: The ether oxygen in each repeating unit forms hydrogen bonds with water. This bonding ensures the complete dissolution of the polymer in water and the formation of a hydrated chain structure in solution. The two-carbon distance between the ethylene units is a suitable spacing for maintaining solubility.
• Terminal hydroxyl groups: The −OH groups at the chain ends react like primary alcohols. They form surface-active ester derivatives by esterification with fatty acids, urethanes with isocyanates and polyesters with carboxylic acids. This property enables the polymer to be used as a reactive diol component.
• Non-ionic character: The chain carries no charge. For this reason it is largely independent of the pH of the solution, does not precipitate through charge interactions in the presence of electrolytes and is compatible with a wide variety of substances.
• Low volatility: Because of its high molecular weight, its vapor pressure is very low. Some manufacturers state that the evaporation rate of the product is very low.
• Solubility profile: It dissolves in polar solvents such as water, ethanol, glycols, acetone and methanol; it does not dissolve in pure hydrocarbons, oils and ether. In the molten state it can be mixed with many polar organic substances.
• Oxidative sensitivity: Ether bonds can slowly oxidize in air under the influence of heat, light and traces of metals. As a result of chain scission, small molecules such as formaldehyde, formic acid and formyl ester derivatives can form. This property should be taken into account during storage and heating of the product.
The crystalline structure of the polymer determines its physical properties.
The product with a molecular weight of eight thousand freezes or melts in the range of about 55–62 °C; this range is higher than for low-molecular-weight grades, and the melting point continues to increase at higher chain lengths. The polymer, which is a viscous liquid in the molten state, dissolves rapidly when mixed with water, and the solution viscosity increases markedly with concentration.
Another consequence of the structure is that hygroscopicity decreases as the chain length of the polymer increases. While low-molecular-weight polyethylene glycols are very hygroscopic, solid grades of 4000 and above take up moisture much more slowly. Nevertheless, in a humid environment the product can absorb moisture over time, and caking may be seen in powder or flake forms.
PHYSICAL AND CHEMICAL PROPERTIES OF POLYETHYLENE GLYCOL 8000
Polyethylene Glycol 8000 is generally a white or off-white, odorless or very slightly odored solid with a waxy appearance. It is available in flake, granule or fine powder form. The values below are general ranges from different manufacturers and pharmacopoeial grades; they are not a binding specification.
General technical properties:
Physical appearance: White or off-white, waxy solid; flake, granule or powder
Chemical character: Non-ionic, hydrophilic polyether diol
Molecular formula: HO(CH₂CH₂O)ₙH
Molecular weight: Average about 8000 g/mol; pharmacopoeial range 7000–9000
CAS No: 25322-68-3
EC / EINECS No: 500-038-2
Purity (assay): Generally supplied as one hundred percent active polymer; the grade is defined by average molecular weight, hydroxyl value and impurity limits
Density: In the molten state about 1.0845 g/mL (70 °C) and 1.0689 g/mL (90 °C)
Water solubility: High; solutions of up to 50% by weight are prepared in pharmacopoeial tests; a 50 mg/mL solution at 20 °C is clear and colorless
pH (aqueous solution): About 4.5–7.5 in a 5% solution by weight
Decomposition: Decomposes oxidatively when heated in air for a long time; according to one manufacturer the decomposition temperature is at least about 150 °C
Moisture: Generally at most 1.0%
Heavy metals (Pb, Cu, etc.): In pharmacopoeial grades at most about 5 ppm
Reactivity: Incompatible with strong oxidizing agents; because of its terminal hydroxyl groups it undergoes alcohol reactions such as esterification and urethane formation; it may soften or liquefy with phenol, tannic acid and salicylic acid
Short Description of Physical Properties
Polyethylene Glycol 8000 freezes in the range of about 55–62 °C and is therefore solid at room temperature. According to pharmacopoeial properties, the viscosity of its 50% by weight aqueous solution is about 260–510 mPa·s at 20 °C, and the viscosity in the molten state at 98.9 °C is in the range of about 470–900 cSt. The hydroxyl value is about 12–16 mg KOH/g and is a practical way of verifying the average molecular weight. The acid value may be limited to at most about 1 mg KOH/g, and the color of the 25% solution to at most about 25 on the Pt-Co scale.
The product melts readily as the temperature rises; in the molten state the flash point is high and, according to one manufacturer, is at least about 100 °C. In the solid state it is not flammable; however, it may carry a dust explosion risk when it forms a dust cloud suspended in air.
Parameters such as active oxygen, bulk density, iron and chloride content are not given as standard for polyethylene glycol in every grade. These values should be checked from the manufacturer's TDS and COA documents according to grade and application.
HOW DOES POLYETHYLENE GLYCOL 8000 WORK AT THE MOLECULAR LEVEL?
The effect of Polyethylene Glycol 8000 arises from the behavior of its chain structure in water, in the solid state and at surfaces. The same molecule can work through several different mechanisms in different systems.
Dissolution in water and humectancy: Each ether oxygen in the chain and the terminal hydroxyl groups bind to water molecules through hydrogen bonds. When the polymer dissolves, a hydration shell forms around it; this shell increases the viscosity of the solution, keeps the polymer stable in solution and provides a humectant effect by holding water vapor. Because high-molecular-weight solid grades are much less hygroscopic than low-molecular-weight liquids, the humectant effect is more limited and more controlled.
Plasticizing and binding: In ceramic, coating and film applications, the polymer chains insert themselves between the main polymer or the particle surfaces. By reducing interactions between chains they make the material more flexible, and in green pressed parts and granules they hold the particles together and provide green strength. During firing they burn off at a low temperature without leaving residue, which is an advantage in ceramic applications.
Lubrication and mold release: The water-soluble waxy structure forms a thin, slippery film on the surface. In rubber, plastic and elastomer processing it acts as a release layer between the mold and the material; in metalworking fluids it works as a water-soluble lubricating component. Because the film can be easily washed off with water, it leaves no oily residue on the surface.
Macromolecular crowding and precipitation: Because a high-molecular-weight polyethylene glycol solution binds a large part of the water molecules to itself, it reduces the solvent volume accessible to macromolecules such as dissolved proteins, nucleic acids and viruses. This excluded-volume effect lowers the solubility of the macromolecules and causes them to precipitate readily in the presence of salt. This is the function of the polymer in DNA precipitation, in the concentration of bacteriophages and viruses and in protein crystallization. The same effect can increase yield in ligation and polymerase reactions by making it easier for macromolecules to approach each other.
Cell fusion: By removing the water at the surface of cell membranes, the polymer makes it easier for membranes to approach and fuse with each other. For this reason it is used in processes such as hybridoma production and protoplast fusion.
As a reactive diol: The terminal hydroxyl groups react with groups such as isocyanate, carboxylic acid or epoxide. In polyester and polyurethane resins these ends are incorporated into the structure as chain extenders or flexible segments.
Oxidative degradation: Ether bonds can undergo radical reactions in air with oxygen, heat and traces of metals. Through hydroperoxide intermediates the chain breaks and low-molecular-weight products form; formic acid, formaldehyde and formyl esters are the prominent products. Antioxidants slow this degradation; in vacuum or an inert atmosphere the polymer is much more stable than in air. For this reason heating time, temperature and oxygen contact are kept under control in process design.
The performance of the polymer is not determined by molecular weight alone. Solution concentration, salt amount, temperature, co-used polymers and additives affect the result. For this reason product quality and dose should be verified by laboratory trials.
IN WHICH SECTORS IS POLYETHYLENE GLYCOL 8000 USED?
Thanks to its water solubility, waxy solid structure, low toxicity and terminal hydroxyl groups, this polymer is used in many sectors as an auxiliary material, process chemical or reactant. The purpose of use varies with the grade and physical form of the product.
Main areas of use:
• Pharmaceuticals and biotechnology: In ointment and suppository bases, as a tablet binder and coating plasticizer, in controlled-release matrices and as a solid dispersion carrier
• Cosmetics and personal care: As a humectant, carrier and thickener in hair conditioners, shampoos, hair styling products, creams and lip products; use in transparent toothpastes has also been reported
• Ceramics: As a binder, plasticizer and mold release agent in green pressed parts; because it burns off without leaving residue during firing
• Rubber, plastic and elastomer processing: As a water-soluble mold release agent and lubricant
• Metalworking and lubricants: As a lubricating component in water-soluble synthetic metalworking fluids, and also as a component in heat transfer fluids
• Polyester and polyurethane resins: As a reactive diol or polyether component
• Textile, leather and fiber processing: As a component of auxiliary chemicals
• Paper, wood, cellulose film, ink, coating, adhesive, putty and concrete: As a solvent, humectant or plasticizer
• Detergents and cleaning: As a binder in tablet-form detergents
• Packaging: As a plasticizer and binder in the production of biopolymer-based packaging
• Food and food supplements: Under E 1521, in certain uses as a coating and carrier
• Laboratory and research: In DNA, protein and virus precipitation, macromolecular crowding, protein crystallization and aqueous two-phase separation systems
The expectations of each sector are different. A pharmaceutical manufacturer may focus on pharmacopoeial compliance and low residual ethylene oxide and dioxane limits, a cosmetic manufacturer on the INCI name and documentation, a ceramic manufacturer on combustion residue and binding strength, a metalworking user on solubility and lubrication performance, and a laboratory user on the absence of nucleases and high purity. For this reason, a product suitable for one sector should not be assumed to be suitable for another sector as well.
IS POLYETHYLENE GLYCOL 8000 USED IN COSMETIC, FOOD AND PHARMACEUTICAL APPLICATIONS?
Cosmetic applications
Yes. Polyethylene glycol 8000 is used in cosmetic products under the INCI name PEG-180. In cosmetic ingredient databases the functions of humectant, solvent and fragrance carrier are indicated for this ingredient. Solid polyethylene glycols are used as thickeners in lip products and creams, and in hair care in hair conditioners and styling products. Some manufacturers recommend the product as a thickener in shampoos, body washes and bubble baths, and as a moisture balancer in moisturizing creams.
The polymer is not an emulsifier; therefore it does not form an emulsion on its own.
In terms of safety, a scientific safety assessment of the cosmetic use of polyethylene glycols has been published. This assessment is consistent with sources stating that the polymer is well tolerated by the skin and that solid grades are not microbiologically susceptible.
Because of impurities such as ethylene oxide and 1,4-dioxane that come from the production chain, documented, cosmetic-grade raw material must be used in cosmetic applications. Conditions of use, labeling and the safety assessment of the final product should be checked against current cosmetic legislation. Molecular biology or industrial technical grades should not be used directly as cosmetic raw materials.
Food applications
Polyethylene glycol is defined in the European Union as a food additive under the number E 1521. In Commission Regulation 231/2012, the average molecular weight of the product is defined as between 380 and 9000, and the upper limit for the sum of ethylene glycol and diethylene glycol is 0.25% by weight. An average molecular weight of eight thousand falls within this range.
Its use is possible only within permitted food categories and quantity limits; industry sources state that the polymer is used particularly in technological functions such as coating, carrying and glazing. It appears in the Codex system under the number INS 1521.
In the USA, polyethylene glycol (average molecular weight 200–9500) is among the additives that may be added directly to food under 21 CFR 172.820 and is permitted as a component of food-contact materials under 21 CFR 178.3750. In these provisions a limit of 0.2% by weight applies to the sum of ethylene glycol and diethylene glycol.
Some manufacturers state that in packaging and adhesive applications the product is evaluated as an indirect food additive. Since the legislation of each market is different, the current legislation of the target market and the product's food-grade documents should be checked before any food-related use. Products of molecular biology grade are generally not suitable for food and pharmaceutical use.
Pharmaceutical applications
Yes. Polyethylene glycol 8000 is a pharmaceutical excipient listed in the European Pharmacopoeia under the name Macrogol 8000 and in the USP-NF and the British Pharmacopoeia. In pharmaceutical formulations, different polyethylene glycol grades are used for topical, oral, rectal and parenteral uses.
High-molecular-weight solid grades are used in ointment and suppository bases in mixtures with liquid polyethylene glycols, as tablet binders, as plasticizers and carriers in film coatings, and in coating suspensions carrying active substances of low solubility. In pharmacopoeial grade the average molecular weight must be 7000–9000; limits are also defined separately for ethylene oxide, 1,4-dioxane, ethylene glycol, diethylene glycol and formaldehyde.
In pharmaceutical formulations, polyethylene glycol may be incompatible with some active substances. The antibacterial effect of antibiotics such as penicillin and bacitracin may decrease in polyethylene glycol bases; softening or liquefaction may be seen in mixtures with phenol, tannic acid and salicylic acid, and migration from tablet film coatings to core components may be observed.
Since small molecules such as formaldehyde and formic acid formed as a result of the oxidation of the polymer in air can react with some amine-containing active substances, stability studies are required in solid dosage forms. The product to be used in pharmaceuticals must be of pharmacopoeial grade and have the relevant documents.
INDUSTRIAL APPLICATIONS OF POLYETHYLENE GLYCOL 8000
The industrial use of this polymer rests on a few common functions: being a water-soluble binder and plasticizer, forming a slippery and washable film, being a non-evaporating humectant and being incorporated into the structure as a reactive diol. The main applications are discussed below in terms of purpose, function and limitations.
Ceramics and construction materials
The purpose is to preserve the shape and strength of the pressed or shaped green ceramic part until firing. As a binder, plasticizer and carrier, the polymer settles between the particles of the ceramic powder; where it contacts the mold and tooling it acts as a lubricant and facilitates mold release.
It is stated that the product disperses easily and homogeneously, increases green strength and burns off during firing without leaving residue. The same polymer is also recommended as a plasticizer and binder in concrete and cement-based production. As a limitation, excessive use of the polymer can lead to loosening in the green part and to cracks related to gas release during burn-off; for this reason the ratio and the firing program should be determined by trials.
Rubber, plastic and elastomer processing
The purpose is to prevent sticking during demolding and to provide lubrication during processing. The water-soluble structure leaves a thin film on the mold surface; because the film can be washed off with water, it does not cause oily-residue problems on the product surface. Compared with silicone- and wax-based release agents, it may disturb subsequent processes such as painting, bonding and coating less. The main limitation is that in processes in contact with water the film dissolves and continuous protection cannot be maintained on the mold surface.
Metalworking and lubricant formulations
The purpose is to provide a lubricating effect in water-soluble metalworking fluids. The polymer is used as the lubricating component of synthetic fluid formulations and is also evaluated as a component in heat transfer fluids. Compared with mineral oils, its advantages are complete miscibility with water and easy cleanability. Among its limitations are degradation through oxidation at high temperature and use together with other components that are not resistant to microbial contamination; solid polyethylene glycols themselves are not microbially susceptible.
Polyester and polyurethane resins
The purpose is to add a hydrophilic and flexible segment to the polymer chain. The hydroxyl groups at the chain ends react with isocyanates or carboxylic acids, and the polyether segment is placed into the urethane and polyester structure. In this use the moisture content of the product is important, because water reacts with isocyanate to form gas and urea bonds. For this reason low-moisture grades are preferred for reactive applications.
Textile, leather, paper, wood and ink
Solid polyethylene glycols are used as a component of fiber, textile and leather processing auxiliary chemicals and as humectants and plasticizers in paper, wood and cellulose films. In paint and ink formulations they act as solvent and humectant; in adhesives and putties they are used as plasticizers. There are also recommended uses as a modifier in regenerated viscose production. In these applications, high-molecular-weight solid products provide low volatility and fast hardening; however, in a humid environment they can create slipperiness and tackiness on the surface.
Detergent tablets and packaging
It is used as a binder and carrier in dishwashing and laundry detergent tablets and in bath salts. It is being evaluated as a plasticizer and binder in the production of biopolymer-based food packaging. In these uses, the migration of the product into the final material and food-contact legislation must be checked separately.
Molecular biology and laboratory applications
The purpose is to separate nucleic acids, proteins and viruses from solution or to facilitate reactions. The polymer is used, in the presence of salt, to precipitate plasmid DNA and PCR products and to select them by size, to concentrate bacteriophages and viruses from culture and wastewater samples, and to obtain extracellular vesicles from cell culture medium.
It is also used as a precipitating agent in protein crystallization, as a macromolecular crowding agent in ligation and polymerase reactions, as a cell fusion agent in hybridoma production and protoplast fusion, together with lithium acetate in yeast transformation, and in aqueous two-phase systems such as polyethylene glycol/dextran. In these applications, nuclease-free, low-impurity molecular biology grade is used.
Heat storage
Solid polyethylene glycols have been investigated as phase change materials because of their heat storage property during melting and freezing. Since oxidative degradation occurs during heating in air, the addition of antioxidants or limiting contact with air stands out in studies for this use. This field is predominantly research in nature.
THINGS TO CONSIDER WHEN USING POLYETHYLENE GLYCOL 8000
Although polyethylene glycol 8000 is considered a low-hazard substance, product quality, storage conditions, formulation compatibility and processing conditions affect the result.
The main points to be taken into account in use:
• A grade suitable for the intended use should be selected. There are important differences between pharmaceutical, cosmetic, food, molecular biology and technical grades in terms of impurity limits and documentation.
• The average molecular weight and hydroxyl value should be checked. The chain length distribution may differ in products sold under the same name.
• When heating the product until it melts, excessive temperature and prolonged contact with air should be avoided. Heating in air can lead to degradation products such as formaldehyde, formic acid and formyl esters; the use of antioxidants or an inert atmosphere slows this degradation.
• When working in the molten state, the risk of burns and scalding should be taken into account.
• The presence of peroxide, metal ions and water can accelerate degradation. Contact with strong oxidizing agents should be avoided.
• Incompatibility may be seen with phenol, tannic acid, salicylic acid, some dyes and some antibiotics; formulation compatibility tests should be performed.
• In solutions with high salt concentration the polymer may precipitate. This property is used in precipitation applications, but it can be an undesirable result in other formulations.
• Its effect on plastic and rubber materials should be taken into account; some sources state that the polymer may affect the integrity of plastics.
• Dust formation and dust clouds should be controlled. Suspended dust may carry an explosion risk.
• Spilled product makes the floor slippery, especially if it has become damp.
• It should be verified with documents that the product to be used for cosmetics, food or pharmaceuticals meets the relevant grade and legislative requirements.
• Rare allergic reactions should be taken into account. Although rare, immediate-type hypersensitivity to polyethylene glycols has been reported.
• The manufacturer's TDS and SDS documents should be reviewed, and batch-based results should be verified with the COA.
This section has been prepared for general informational purposes and does not replace the official safety data sheet.
STARTING FORMULATION APPROACHES FOR POLYETHYLENE GLYCOL 8000
The examples below are starting approaches prepared to show how Polyethylene Glycol 8000 can be evaluated in the formulation and process development process. They are not verified commercial recipes, production instructions or final formulas compliant with legislation.
The ratios given are example starting levels for preliminary laboratory trials, and the total of each formula is 100%. The average molecular weight, moisture content and form of the product to be used and the other raw materials can change performance significantly. In every application, laboratory trials, performance tests, occupational safety and relevant legislative checks should be carried out.
EXAMPLE 1: EVALUATION OF POLYETHYLENE GLYCOL 8000 BINDER RATIO IN CERAMIC PRESS POWDER
Purpose: To examine the effect of the polyethylene glycol 8000 ratio in ceramic press powder on green part strength, mold release and residue after firing.
Starting approach (Formula A, B and C):
• Ceramic powder (e.g. alumina): about 95.0%, 94.0% and 93.0%
• Polyethylene Glycol 8000: about 1.0%, 2.0% and 3.0%
• Demineralized water: about 4.0%
Application approach:
• Polyethylene Glycol 8000 is dissolved in demineralized water by heating and stirring.
• The solution is added to the ceramic powder little by little under mixing and the mixture is homogenized.
• The mixture is dried and sieved to form granules.
• The granules are pressed in the mold at constant pressure.
• The strength, density and ease of release from the mold of the green part are measured.
• The parts are fired with a controlled program; residue after burn-off, cracks and porosity are evaluated.
• Results are compared with different polyethylene glycol ratios.
• Dust formation and moisture uptake should be controlled, and ventilation should be provided for gases formed during firing.
EXAMPLE 2: EVALUATION OF POLYETHYLENE GLYCOL 8000 RATIO IN A WATER-SOLUBLE MOLD RELEASE AND LUBRICANT SOLUTION
Purpose: To examine the effect of the polyethylene glycol 8000 ratio in a water-soluble release solution prepared for rubber or plastic molding on film formation, release performance and washability.
Starting approach (Formula A, B and C):
• Polyethylene Glycol 8000: about 5.0%, 10.0% and 15.0%
• Preservative: about 0.2%
• Demineralized water: about 94.8%, 89.8% and 84.8%
Application approach:
• Demineralized water is placed in a suitable container and stirred while being heated.
• Polyethylene Glycol 8000 in flake or powder form is added under stirring and completely dissolved.
• The solution is cooled to room temperature and the preservative is added.
• The solution is applied to the mold surface as a thin layer and dried.
• Demolding force, film thickness, surface appearance and residue after washing are measured.
• The viscosity of the solution and its stability during storage are monitored.
• Results are compared with different ratios.
• During application, precautions should be taken against floor slipping due to slipperiness, and the risk of burns should be taken into account when working with hot solutions.
EXAMPLE 3: EVALUATION OF PEG-180 THICKENING RATIO IN A SHAMPOO FORMULATION
Purpose: To examine the effect of the PEG-180 ratio in a shampoo formulation on viscosity, foam and appearance.
Starting approach (Formula A, B and C):
• Sodium laureth sulfate (about 28% active solution): about 30.0%
• Cocamidopropyl betaine (about 30% active solution): about 8.0%
• PEG-180 (Polyethylene Glycol 8000, cosmetic grade): about 0.5%, 1.0% and 1.5%
• Sodium chloride: about 1.0%
• Preservative: about 0.5%
• Water, including citric acid for pH adjustment: about 60.0%, 59.5% and 59.0%
Application approach:
• Water, sodium laureth sulfate and betaine are mixed until homogeneous.
• PEG-180 is added by heating or in flake form under stirring and completely dissolved.
• Sodium chloride and preservative are added, and the pH is adjusted with citric acid.
• Viscosity, clarity, foam and stability are evaluated.
• Results are compared with different ratios.
• Cosmetic-grade raw materials should be used; the safety assessment of the final product, labeling and legislative compliance should be checked separately.
SIMILAR PRODUCTS AND ALTERNATIVES TO POLYETHYLENE GLYCOL 8000
The alternative to this polymer does not consist merely of choosing another type of polyethylene glycol. In determining an alternative, the targeted function, molecular weight, solubility, melting point, hygroscopicity, regulatory requirements and cost should be evaluated together.
POLYETHYLENE GLYCOL 8000 AND OTHER SOLID POLYETHYLENE GLYCOLS
Polyethylene glycol 4000, 6000, 10000 and 20000 grades have the same chemical structure and CAS number; the difference is in chain length. As molecular weight increases, the melting point, solution viscosity and waxy solid structure increase, while hygroscopicity and dissolution rate decrease. The six-thousand grade can provide lower-viscosity solutions and a slightly lower melting point, while the twenty-thousand grade can provide higher viscosity and a longer release time. In suppository and ointment bases, the melting point and hardness are adjusted by mixing different polyethylene glycols. In cosmetics the INCI names vary according to the number.
POLYETHYLENE GLYCOL 8000 AND POLYETHYLENE OXIDE
Polyethylene oxide is an ethylene oxide polymer whose molecular weight reaches hundreds of thousands to millions and which has a different production method. It provides much higher viscosity and a flocculation effect in solution and is used in film-forming and controlled-release matrices. Polyethylene glycol 8000 is a product with lower viscosity, easy melting and a more pronounced plasticizing effect; the two do not replace each other in every application.
POLYETHYLENE GLYCOL 8000 AND POLOXAMERS
Poloxamers are surface-active copolymers made up of ethylene oxide and propylene oxide blocks. They have emulsifier, solubilizer and gel-forming functions. Polyethylene glycol 8000 is not an emulsifier; however, poloxamers may be more expensive and have a different surface-active behavior. They can be evaluated as an alternative for solubilization purposes in pharmaceuticals and cosmetics.
POLYETHYLENE GLYCOL 8000 AND POLYVINYLPYRROLIDONE
Polyvinylpyrrolidone is used as a binder, film former and stabilizer in pharmaceuticals and cosmetics. It can be an alternative to polyethylene glycol in tablet binding and forms a harder film. Polyethylene glycol, on the other hand, provides plasticizing and a soft, flexible structure. The choice is made according to the targeted strength, dissolution rate and compatibility.
POLYETHYLENE GLYCOL 8000 AND POLYVINYL ALCOHOL
Polyvinyl alcohol is a water-soluble film former and binder. It is used as a binder in ceramics and coatings. It can provide higher binding strength, but has less plasticizing effect and is often used together with a plasticizer. In these uses polyethylene glycol is also evaluated together with polyvinyl alcohol as a plasticizer. The graft copolymer of polyvinyl alcohol and polyethylene glycol is separately defined under the number E 1209 for coating in food supplements.
POLYETHYLENE GLYCOL 8000 AND POLYPROPYLENE GLYCOL
Polypropylene glycol is a propylene oxide polymer. It has limited solubility in water or does not dissolve and carries a more hydrophobic character. It is used as a diol in polyurethane synthesis; polyethylene glycol, on the other hand, is preferred for hydrophilic polyurethanes. In mold release applications, polyethylene glycol is preferred when water solubility is required.
ALTERNATIVES IN MOLECULAR BIOLOGY
In precipitation and crowding applications, ethanol, isopropanol and salts such as ammonium sulfate, as well as polymers such as dextran and Ficoll, can be alternatives. These substances work through different mechanisms; polyethylene glycol 8000 is a common choice at low ionic strength, under gentle conditions and for large macromolecules.
It should not be assumed that all of these alternatives can replace each other in every application. The choice should be verified by laboratory and pilot trials.
QUALITY CONTROL AND PURCHASING CRITERIA FOR POLYETHYLENE GLYCOL 8000
Even though polyethylene glycol 8000 is sold under the same name, the level of quality and documentation differs greatly according to the field of use. Pharmaceutical grade is evaluated according to the pharmacopoeial monograph, cosmetic grade according to cosmetic raw material requirements, molecular biology grade according to nuclease and impurity limits, and technical grade mostly according to the manufacturer's internal specification. For this reason, in purchasing and acceptance control the target grade should be determined first, and then the parameters should be selected according to this grade.
The main parameters that can be evaluated in the quality control and purchasing process:
• Average molecular weight: The pharmacopoeial range is 7000–9000; the nominal value and the measured value should be stated separately in the manufacturer's certificate
• Hydroxyl value: It is related to the average molecular weight and is theoretically around 14 mg KOH/g; the method and limits used for verification should be taken from the supplier's document
• Freezing point: It is generally in the range of 55–62 °C
• Physical appearance: White or off-white, waxy solid; flake, granule or powder form should be specified at the order stage
• pH of aqueous solution: It is evaluated together with the measurement concentration; a range of 4.5–7.5 is reported in an approximately 5% solution
• Solution clarity and color: Important particularly in pharmaceutical and cosmetic applications
• Moisture: Generally at most 1.0%; lower values may be required in reactive applications
• Impurity profile: Ethylene oxide, 1,4-dioxane, ethylene glycol, diethylene glycol and formaldehyde; limits depend on the grade and relevant legislation
• Heavy metals: In pharmacopoeial grades at most about 5 ppm; in technical grades it depends on the manufacturer's specification
• Sulfated ash: A parameter controlled in pharmacopoeial and cosmetic grades
• Peroxide and acidity: Can be monitored as an indicator of oxidation during storage
• Nuclease, protease and DNA residue: Applies only to molecular biology grade
• Particle size: Flake or powder size affects dissolution rate and flow properties
• Active oxygen and bulk density: Active oxygen is not a valid parameter for this product; bulk density depends on the form and the manufacturer's line, and should be requested from the supplier if needed
• Documents: Batch-based certificate of analysis, SDS, TDS, regulatory declarations appropriate to the grade and, when necessary, a pharmacopoeial compliance certificate
• Packaging and batch information: Batch number, production date and retest date should be traceable on the packaging
The manufacturer's typical values and binding specification values should be distinguished from each other. The typical value describes the level that the product generally shows; the specification, on the other hand, is the limit that a batch must meet in order to be accepted. When placing an order, limits should be requested in writing and compared with the COA for every batch.
STORAGE AND TRANSPORT OF POLYETHYLENE GLYCOL 8000
Polyethylene glycol 8000 is a chemically stable product; however, it is a waxy solid that attracts moisture, melts at low temperature and can degrade under the effect of long-term heat and oxygen. Storage conditions should be determined according to these properties.
• Temperature: It should be stored in a cool and dry place, clearly below the melting range. The product may cake or block in a hot warehouse
• Moisture: The packaging should be kept tightly closed when not in use. Product that has absorbed moisture cakes, becomes slippery and can cause water-related problems in reactive applications
• Packaging: The product is generally supplied in polyethylene-lined bags or similar closed packaging. The packaging type and net quantity vary according to the manufacturer and the request
• Light and oxygen: It should be kept away from direct sunlight and heat sources. Opened packages should be closed again after use
• Incompatible materials: It should be stored separately from strong oxidizing agents and strong acids and bases
• Ventilation: Normal warehouse ventilation is generally sufficient. In operations where dust is formed, dust control should be provided
• Shelf life: Under suitable conditions a long period of use is generally reported; the exact shelf life and retest date should be taken from the manufacturer's document
• Spillage: Spilled product can make the floor slippery and should be collected immediately
In terms of transport, the product is generally not classified as a dangerous good under ADR, IMDG and IATA in the safety data sheets evaluated and has no UN number. However, the transport classification may depend on the product form, mixture and applicable legislation; before shipment the supplier's current SDS should be checked. During transport, it is important to protect the packaging from moisture and to take into account the risk of caking and melting in hot vehicles and containers.
SAFETY INFORMATION OF POLYETHYLENE GLYCOL 8000
Polyethylene glycol 8000 is generally regarded as a substance of low acute toxicity and low hazard. In the safety data sheets of many manufacturers, the product is not classified as a hazardous substance under GHS and CLP. Nevertheless, because of the product form, purity and conditions of use, each supplier's own SDS should be taken into account. The information below is for general informational purposes and does not replace the manufacturer-specific safety data sheet.
Main safety topics:
• Skin contact: It is generally not irritating; after long-term and repeated contact, slight dryness may occur in sensitive persons. Contact with molten product can cause burns
• Eye contact: Dust or flakes can cause mechanical irritation; in case of contact, rinse with plenty of water
• Inhalation: High dust concentrations can irritate the upper respiratory tract; dust formation should be reduced and, when necessary, suitable respiratory protection should be used
• Ingestion: Low acute toxicity is reported; ingestion of large amounts may cause digestive system discomfort
• Sensitization: Immediate-type hypersensitivity to polyethylene glycols has rarely been reported; persons with known allergies should be careful in pharmaceutical and cosmetic use
• Fire: The product is difficult to ignite; the reported flash points are high. In a fire, water, foam, dry chemical powder or carbon dioxide can be used. During combustion, carbon oxides and irritating fumes may form
• Dust explosion: In operations where a very fine dust cloud forms, ignition sources should be kept under control
• Reactivity: It can react dangerously with strong oxidizers; if heated in air for a long time, degradation products such as formaldehyde and formic acid may form
• Personal protective equipment: Protective gloves, safety glasses and, when necessary, a dust mask are recommended. When working with molten product, heat-resistant gloves and face protection should be used
• Spills and accidents: Spilled product should be collected dry, dust should not be created and precautions should be taken against floor slipperiness. Large amounts should be prevented from reaching drains and waterways
• Environmental risks: The product is reported to be water-soluble and biodegradable; nevertheless, waste management should be carried out according to local legislation
• Waste management: Unused product and waste should be disposed of in accordance with the relevant legislation
• After exposure: If symptoms continue or skin or eye irritation persists, medical help should be sought; the product's SDS and packaging should be shown to health personnel
A country-specific occupational exposure limit value is not expected to have been set for Polyethylene Glycol 8000; general dust limits and good hygiene practices are taken as the basis for dust. In pharmaceutical, cosmetic and food uses, a safety assessment of the final product is also required.
WHAT SHOULD BE CONSIDERED WHEN BUYING POLYETHYLENE GLYCOL 8000?
To choose the right product, the product identity must first be clearly determined. Since the polyethylene glycol family is very broad, a request that says only "polyethylene glycol" or "PEG" is insufficient. In the request, the product name Polyethylene Glycol 8000, the CAS number 25322-68-3 and the average molecular weight should be stated together. Names such as Macrogol 8000 or PEG-180 may refer to the same product in pharmacopoeial and cosmetic contexts; however, quality and documentation requirements are different.
Main points to consider when purchasing:
• Grade: Which of pharmaceutical, cosmetic, food, molecular biology or technical grades is required should be clarified
• Specification: Average molecular weight, hydroxyl value, moisture, pH, freezing point and impurity limits should be requested in writing
• Product form: Flake, granule or powder form affects dissolution rate, dusting and dosing
• Suitability for the intended use: A product to be used as a ceramic binder should not be selected with the same criteria as a pharmaceutical excipient and a molecular biology reagent
• Packaging and logistics: Bag, big bag or similar packaging options, warehouse temperature and shipping conditions should be evaluated
• Batch consistency: Particularly in pharmaceutical and reagent applications, the molecular weight distribution between batches should be consistent
• Documents: TDS, SDS, COA and regulatory documents appropriate to the grade should be obtained before ordering
• Technical support of the supplier: Trial samples, formulation support and documentation support should be evaluated
• Legislation: In food, cosmetic and pharmaceutical use, the current legislation of the relevant country should be checked
• Total cost of supply: In addition to the unit price, packaging, logistics, wastage, documentation, testing and storage costs should be evaluated together
The price may vary according to grade, molecular weight distribution, form, purity, packaging, order quantity, origin, ethylene oxide and energy costs, certification and current market conditions. For this reason, the current price should be evaluated through a quotation together with the product specification and delivery terms.
SUPPLY OF POLYETHYLENE GLYCOL 8000 FROM ATAMAN KİMYA
Polyethylene Glycol 8000 is an important polyethylene glycol type that is evaluated as a binder, plasticizer, lubricant and precipitant in pharmaceuticals, cosmetics, ceramics, rubber and plastics processing, metalworking, molecular biology and various industrial applications. It is important for companies planning to purchase the product to clarify the grade suitable for the field of use, the technical specifications and the necessary documents before ordering.
Companies that want to obtain information about the supply of Polyethylene Glycol 8000 from ATAMAN KİMYA can request information on product suitability, current supply status, packaging options and price quotation by sharing their areas of use and technical needs.
The current stock status, origin, grade, technical properties, packaging and specifications of the product should be confirmed from ATAMAN KİMYA before ordering.
Sharing the following information in the quotation request makes it easier to evaluate the correct Polyethylene Glycol 8000 product:
• Sector of use and final application
• Requested grade: pharmaceutical, cosmetic, food, molecular biology or technical
• Requested product form: flake, granule or powder
• Expectation of average molecular weight and hydroxyl value
• Moisture, impurity and heavy metal limits
• Formulation or process information used
• Estimated order quantity
• Desired packaging type
• Requested technical documents
• If available, TDS or COA information of the current product
FREQUENTLY ASKED QUESTIONS ABOUT POLYETHYLENE GLYCOL 8000
What is Polyethylene Glycol 8000?
Polyethylene Glycol 8000 is a non-ionic polyethylene glycol with an average molecular weight of about 8000 g/mol, in the form of a white waxy solid and very soluble in water. It is referred to as Macrogol 8000 in pharmacopoeias and as PEG-180 in cosmetics. It is used as a binder, plasticizer, lubricant, humectant and precipitant in pharmaceutical, cosmetic, ceramic, rubber processing, metalworking and molecular biology applications.
What does Polyethylene Glycol 8000 mean?
Polyethylene Glycol 8000 refers to the type of polyethylene glycol polymer, derived from ethylene oxide, with an average molecular weight of about 8000. In Turkish it is said as polietilen glikol 8000. The number at the end indicates the average molecular weight of the polymer.
What is the CAS number of Polyethylene Glycol 8000?
The CAS number for polyethylene glycol is 25322-68-3. This number is used for the whole polyethylene glycol family, which varies with molecular weight; to distinguish the product, the average molecular weight must be stated separately.
What is the EC / EINECS number of Polyethylene Glycol 8000?
For polyethylene glycol 8000, the EC number is listed as 500-038-2 in many supplier catalogs. Since some manufacturers may state different EC numbers, the number in the SDS of the ordered product should be checked.
What is the chemical formula of Polyethylene Glycol 8000?
Its general formula is HO(CH₂CH₂O)ₙH. In the type with an average molecular weight of about 8000, the n value is on average about 181.
What is the INCI name of Polyethylene Glycol 8000?
The INCI name used in cosmetic products is PEG-180.
Is Polyethylene Glycol 8000 used in cosmetics?
Yes. Cosmetic-grade product can be used under the INCI name PEG-180 as a humectant, carrier and thickener in hair care products, shampoos, creams and lip products. Conditions of use and the safety assessment of the final product should be checked against current cosmetic legislation. Technical or molecular biology grades should not be used in cosmetics.
Does Polyethylene Glycol 8000 have an E code?
Yes. Polyethylene glycol is defined as a food additive in the European Union under E 1521 and in the Codex system under the number INS 1521. Use is possible only within permitted food categories and limits.
What is the difference between Polyethylene Glycol 8000 and Polyethylene Glycol 4000?
Both are polyethylene glycols with the same chemical structure and the same CAS number. The difference is in chain length. The eight-thousand grade has a higher molecular weight, higher solution viscosity, a harder waxy structure and a slightly higher melting range; the four-thousand grade has a lower molecular weight and dissolves faster. The choice is made according to the hardness, dissolution rate and viscosity required by the application.
For what purpose is Polyethylene Glycol 8000 used?
It is used as a binder, plasticizer, lubricant, mold release agent, humectant, carrier, thickener and precipitant. It is evaluated as a pharmaceutical excipient, a cosmetic ingredient, a ceramic binder, a water-soluble lubricant, a reactive diol in polyurethane and polyester synthesis and a precipitating reagent in molecular biology.
In which sectors is Polyethylene Glycol 8000 used?
It is used in pharmaceuticals, cosmetics and personal care, ceramics, rubber and plastics processing, metalworking, polyurethane and polyester resins, textiles, leather, paper, ink, coatings, adhesives, detergents, packaging, food additive applications and laboratory research.
How does Polyethylene Glycol 8000 carry out DNA and virus precipitation?
The polymer binds water and reduces the free volume available to macromolecules in solution. In the presence of salt, large structures such as DNA, viruses or bacteriophages separate from the solution and precipitate. The precipitation effect depends on the polymer concentration, the salt concentration and the size of the target molecule; for this reason conditions should be tried according to the application.
What is Polyethylene Glycol 8000 good for?
In formulations it balances the solid and plastic structure, forms a slippery and washable film on surfaces, preserves the moisture of the product and carries components. In synthesis, thanks to its hydroxyl ends, it takes part in ester and urethane bonds.
How does Polyethylene Glycol 8000 work in ceramic production?
It acts as a binder and plasticizer between the particles of the ceramic powder. It ensures that the pressed green part keeps its shape and is easily released from the mold. During firing it burns off and leaves the structure; during this, gas release must be controlled.
Is Polyethylene Glycol 8000 soluble in water?
Yes. It dissolves very well in water, and heating and stirring speed up the preparation of the solution. In pharmacopoeial tests, solutions of up to 50% by weight can be prepared. The product also dissolves in some organic solvents; however, it does not dissolve in oils and aliphatic hydrocarbons.
How much Polyethylene Glycol 8000 is used in ceramic production?
The usage rate varies according to the ceramic powder, the shaping method and the targeted green strength. In technical sources, binder ratios are generally worked at the level of a few percent of the dry powder weight. The starting example on this product page is only for laboratory trials; the exact ratio should be determined by the ceramic manufacturer's trials.
Is Polyethylene Glycol 8000 a hazardous substance?
It is generally regarded as a low-hazard substance and is not classified as a hazardous substance in the SDS of many manufacturers. However, there are practical risks such as dust, molten product and slipperiness. The current SDS should always be checked.
Why can Polyethylene Glycol 8000 degrade and form harmful by-products?
When heated in air, or in the presence of peroxides and metal ions, the polyether chain can undergo oxidative chain scission. In this process small molecules such as formaldehyde, formic acid and formyl esters may form. For this reason the product should not be overheated, should not be kept in contact with air for a long time and, when necessary, an antioxidant or inert atmosphere should be used.
Is Polyethylene Glycol 8000 registered under REACH?
Polymers are generally outside the scope of registration obligations under REACH; however, the monomers of the polymer and the status of the impurities used are evaluated separately. The current REACH status of the product should be confirmed from the supplier.
What is the physical appearance of Polyethylene Glycol 8000?
It is a white or off-white, waxy solid. It is supplied in flake, granule or powder form. When it melts, it turns into a clear and colorless liquid.
What is the UN number of Polyethylene Glycol 8000?
Since the product is generally not classified as a hazardous substance in the safety data sheets evaluated, no UN number is stated. Before shipment, the supplier's current SDS should be checked.
Why are ethylene oxide, dioxane and glycol residues important in Polyethylene Glycol 8000?
These substances are residues or by-products from the production process. They are limited in pharmaceutical, cosmetic and food applications, because their presence at high levels can create a toxicological risk. Limits have been set in food and pharmaceutical legislation for ethylene glycol and diethylene glycol. For this reason, it is important to see the residue results on the COA for the relevant grade.
What does the price of Polyethylene Glycol 8000 depend on?
The price varies according to grade, molecular weight distribution, purity, product form, packaging, origin, order quantity, ethylene oxide and energy costs, certification and current market conditions. Pharmaceutical and molecular biology grades may be higher priced than technical grades.
Is there an alternative to Polyethylene Glycol 8000?
There are alternatives depending on the application. Other polyethylene glycol types, polyethylene oxide, poloxamers, polyvinylpyrrolidone, polyvinyl alcohol and polypropylene glycol can be evaluated according to the relevant functions. They do not replace each other in every application.
How should Polyethylene Glycol 8000 be stored?
It should be stored in a cool, dry and well-closed package, away from heat sources and strong oxidizers. To prevent moisture uptake and caking, the package should be closed after use.
Which documents should be requested when buying Polyethylene Glycol 8000?
The technical data sheet, safety data sheet and batch-based certificate of analysis are the basic documents. Depending on the field of use, pharmacopoeial compliance, a cosmetic raw material declaration, a food-grade certificate, a REACH declaration and, for molecular biology grade, nuclease results may be requested.
Which technical specifications are important when buying Polyethylene Glycol 8000?
Average molecular weight, hydroxyl value, moisture, pH, freezing point, impurity limits, heavy metals, product form and grade are important.
POLYETHYLENE GLYCOL 8000 – TECHNICAL SUMMARY
Chemical name: Polyethylene glycol, average molecular weight about 8000
Common name: Polyethylene Glycol 8000, Macrogol 8000, PEG 8000, PEG-180
CAS No: 25322-68-3
EC / EINECS No: 500-038-2
Molecular formula: HO(CH₂CH₂O)ₙH, average n about 181
Molecular weight: Average about 8000 g/mol; pharmacopoeial range 7000–9000
Chemical class: Polyether polyol
Physical appearance: White or off-white, waxy solid; flake, granule or powder
Key properties: Non-ionic, very soluble in water, freezing point about 55–62 °C, hygroscopic, can degrade oxidatively when heated in air
Main functions: Binder, plasticizer, lubricant, mold release agent, humectant, carrier, thickener and precipitant
Important areas of application: Pharmaceuticals, cosmetics, ceramics, rubber and plastics processing, metalworking, polyurethane and polyester synthesis, molecular biology
Critical parameters for quality control: Average molecular weight, hydroxyl value, moisture, pH, freezing point, ethylene oxide, 1,4-dioxane, glycol and formaldehyde residues, heavy metals, documents appropriate to the grade
Storage: In a cool, dry and closed package; away from heat, moisture and strong oxidizers
Legislation: INCI PEG-180; food additive E 1521 / INS 1521; listed in pharmacopoeias under the name Macrogol 8000; REACH and UN status should be confirmed from the supplier.
