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CHEMINFO Record Number: 783
CCOHS Chemical Name: Polyalkylene glycol monobutyl ether, molecular weight 970

EO/PO co-polymer (non-specific name)
Polyalkylene glycol monobutyl ether (non-specific name)
Ethylene oxide/propylene oxide co-polymer (non-specific name)
Oxirane, methyl-, polymer with oxirane, monobutyl ether, molecular weight 970
Oxirane, methyl-, polymer with oxirane, monobutyl ether (non-specific name)
Poly(ethylene oxide-propylene oxide) butyl ether

Trade Name(s):
UCON 50-HB-260
UCON Lubricant 50-HB-260
Poly G WS

CAS Registry Number: 9038-95-3
RTECS Number(s): YP8400000
Chemical Family: Aliphatic ether alcohol / aliphatic glycol ether / polyalkylene glycol monoether
Molecular Formula: Complex polymer
Structural Formula: CH3-(CH2)3-(OCH2CH2)x[OCH2CH(CH3)]yOH


Appearance and Odour:
Essentially colourless liquid.(5)

Odour Threshold:
Information not available.

Warning Properties:
Information not available for evaluation.

Polyalkylene glycol monobutyl ether (PAGMBE) compounds are butyl alcohol started, random linear co-polymers of ethylene oxide and propylene oxide. They contain equal amounts by weight of oxyethylene and oxypropylene groups. These compounds are available in a range of molecular weights from 270 to approximately 4000, and have viscosities from 55 to 5100 Saybolt Universal Seconds (SUS) (8.9 to 1104 centistokes) at 37.8 deg C (100 deg F).(6,7) All of the polyalkylene glycol monobutyl ethers have the same CAS Registry Number (6), but the toxicity increases with increasing molecular weight. Therefore, this CHEMINFO record specifically reviews the hazards and control measures for the polyalkylene glycol monobutyl ether (PAGMBE) with an average molecular weight of 970 (mw 970). The CHEMINFO database contains records for 8 other PAGMBE compounds with different molecular weights.

Uses and Occurrences:
PAGMBEs are mainly used as lubricants and fluids in a wide variety of industrial processes and applications. They are also used as chemical intermediates, ink and dye solvents, nonvolatile solvents, softeners and plasticizers, foam control agents; in cosmetic applications, skin creams and lotions, bath oils, antiperspirants, deodorants and other lotions and creams; and as demulsifiers.(6,7)


Essentially colourless liquid. No unusual hazard in a fire situation. Can burn if strongly heated. Expected to be essentially non-toxic following short-term exposure.


Effects of Short-Term (Acute) Exposure

Polyalkylene glycol monobutyl ether with a molecular weight of 970 (PAGMBE (mw 970)) does not readily form a vapour at room temperature. Therefore, inhalation exposures are unlikely to occur unless the material is heated or misted. One animal study suggests that exposure to very high aerosol concentrations may cause minor changes, but not the lung injury that has been observed in animals exposed to higher molecular weight PAGMBEs. There is no human information available.

Skin Contact:
PAGMBE (mw 970) is probably a mild irritant, based on comparison to other PAGMBEs and one unconfirmed animal study. There is no human information available.
PAGMBE (mw 970) is not expected to produce toxic effects if absorbed through the skin, based on an animal toxicity value.

Eye Contact:
PAGMBE (mw 970) is probably not an eye irritant, based on comparison to other PAGMBE compounds. There is no human or animal information available.

Animal toxicity values indicate that PAGMBE (mw 970) is not very toxic following ingestion. One animal study indicates that signs and symptoms of central nervous system (CNS) depression, such as lack of coordination, nausea, dizziness and vomiting, may develop following ingestion of very large amounts. There is no human information available. Ingestion is not a typical route of occupational exposure.

Effects of Long-Term (Chronic) Exposure

There is no relevant information available.


No human information was located. In one mouse study, negative results were obtained following long-term skin application of PAGMBE (mw 970).

The International Agency for Research on Cancer (IARC) has not evaluated the carcinogenicity of this chemical.

The American Conference of Governmental Industrial Hygienists (ACGIH) has no listing for this chemical.

The US National Toxicology Program (NTP) has not listed this chemical in its report on carcinogens.

Teratogenicity and Embryotoxicity:
No human or animal information was located.

Reproductive Toxicity:
No human or animal information was located.

No information was located.

Toxicologically Synergistic Materials:
No information was located.

Potential for Accumulation:
No information was located.


If symptoms are experienced, remove source of contamination or move victim to fresh air and obtain medical advice.

Skin Contact:
No health effects are expected. If irritation does occur, flush with lukewarm, gently flowing water for 5 minutes. If irritation persists, obtain medical advice.

Eye Contact:
No health effects are expected. Immediately flush the contaminated eye(s) with lukewarm, gently flowing water for 5 minutes, while holding the eyelid(s) open. Obtain medical advice.

If irritation or discomfort occur, obtain medical advice.

First Aid Comments:
All first aid procedures should be periodically reviewed by a doctor familiar with the material and its conditions of use in the workplace.


Flash Point:
194 deg C (381 deg F) (Pensky-Martens closed cup) (7)

Lower Flammable (Explosive) Limit (LFL/LEL):
Not available

Upper Flammable (Explosive) Limit (UFL/UEL):
Not available

Autoignition (Ignition) Temperature:
Not available

Sensitivity to Mechanical Impact:
Not sensitive. Stable material.

Sensitivity to Static Charge:
No information is available on the electrical conductivity of polyalkylene glycol monobutyl ethers (PAGMBEs). PAGMBE vapours will not be ignited by a static discharge because of the high flash point.

Electrical Conductivity:
Not available

Combustion and Thermal Decomposition Products:
The main products of combustion are carbon monoxide, carbon dioxide. Incomplete combustion may also produce irritating smoke and toxic and/or irritating gases or fumes.

Fire Hazard Summary:
This material can burn if strongly heated. During a fire, irritating/toxic gases and fumes may be formed.

Extinguishing Media:
SMALL FIRES: Carbon dioxide or dry chemical powder. LARGE FIRES: Alcohol or all-purpose-type foam, water spray or fog. Foam manufacturers should be consulted for recommendations regarding types of foams and application rates.

Fire Fighting Instructions:
Evacuate area and fight fire from a safe distance or a protected location. Approach fire from upwind to avoid potentially toxic decomposition products.
Water or foam may cause frothing. The frothing may be violent and could endanger personnel close to the fire. However, a water spray or fog that is carefully applied to the surface of the liquid, preferably with a fine spray or fog nozzle, will cause frothing that will blanket and extinguish the fire. DO NOT direct a solid stream of water or foam into hot, burning pools, since this may cause frothing and increase fire intensity. In addition, water can be used in the form of spray or fog to absorb heat, keep containers cool and protect fire-exposed material. Solid streams of water may be ineffective and spread material. If a leak or spill has not ignited, use water spray to disperse the vapours, dilute the spill to a nonflammable mixture and protect personnel attempting to stop a leak. Water spray may be used to flush spills away from ignition sources.

Protection of Fire Fighters:
This material is only slightly hazardous to health. Firefighters may enter the area if positive pressure self-contained breathing apparatus (NIOSH approved or equivalent) and full Bunker Gear is worn.


NFPA - Comments:
NFPA has no listing for this chemical in Codes 49 or 325.


Molecular Weight: 970 (average)

Conversion Factor:
Not applicable

Physical State: Liquid
Melting Point: Not applicable. See Other Physical Properties for POUR POINT.
Boiling Point: Not applicable; decomposes slightly at elevated temperatures.(7)
Relative Density (Specific Gravity): 1.036 at 20 deg C (7); 1.017 at 40 deg C (7) (water = 1)
Solubility in Water: Soluble in cold water (7)
Solubility in Other Liquids: Soluble in a wide variety of organic solvents, including acetone, methanol, isopropanol, other aliphatic alcohols, propylene glycol, butyl cellosolve, butyl ether and toluene; insoluble in saturated hydrocarbons, such as cyclohexane, heptane, kerosene, petroleum ether, and diethylene glycol and ethylene glycol.(7)
Coefficient of Oil/Water Distribution (Partition Coefficient): Not available
pH Value: Not available
Viscosity-Kinematic: 56.2 mm2/s (56.2 centistokes) at 38 deg C (100 deg F) (6)
Saybolt Universal Viscosity: 260 Saybolt Universal seconds at 38 deg C (100 deg F) (6,7)
Surface Tension: 35-40 mN/m (35-40 dynes/cm) at 20 deg C (7)
Vapour Density: Not applicable
Vapour Pressure: Very low; less than 0.00013 kPa (0.001 mm Hg) at 20 deg C (7)
Saturation Vapour Concentration: Very low; less than 1.3 ppm (less than 0.00013%) (calculated)
Evaporation Rate: Essentially zero.
Henry's Law Constant: Not available

Other Physical Properties:
POUR POINT: -40 deg C (-40 deg F) (6); -38 deg C (-36 deg F) (7)


Normally stable. PAGMBEs decompose slightly at elevated temperatures to form low molecular weight products.(7)

Hazardous Polymerization:
Does not occur.

Incompatibility - Materials to Avoid:

NOTE: Chemical reactions that could result in a hazardous situation (e.g. generation of flammable or toxic chemicals, fire or detonation) are listed here. Many of these reactions can be done safely if specific control measures (e.g. cooling of the reaction) are in place. Although not intended to be complete, an overview of important reactions involving common chemicals is provided to assist in the development of safe work practices.

PAGMBEs are chemically stable.(7) Strong oxidants, like chlorine, hydrogen peroxide, permanganates or persulfates can cause degradation.(6) Strong acids (e.g. sulfuric acid) at high temperatures, strong bases (e.g. potassium or sodium hydroxide), and materials reactive with hydroxyl compounds (e.g. active metals such as sodium and magnesium) can react with PAGMBEs.

Hazardous Decomposition Products:
None reported

Conditions to Avoid:
Temperatures above 194 deg C.

Corrosivity to Metals:
PAGMBEs are not corrosive to iron, carbon steel, brass, bronze, and aluminum under normal operating conditions.(7)

Corrosivity to Non-Metals:
PAGMBE (mw 970) does not attack elastomers, like Viton A, and other fluorocarbons, like Kalrez and Fluoraz, neoprene, ethylene-propylene-diene (EPDM), natural rubber, butyl rubber, Buna N and S, silicone, and fluorosilicone.(7) PAGMBEs soften and lift many industrial coatings, like alkyd and vinyl coatings.(7) Catalyzed epoxy, epoxy-phenolic and modified phenolic coatings are not attacked by PAGMBEs.(7)


LC50 (rat): 4770 mg/m3 (4-hour aerosol exposure) (1)

LD50 (oral, female rat): 4640 mg/kg (cited as 4.49 mL/kg) (2)
LD50 (oral, male rabbit): 1830 mg/kg (cited as 1.77 mL/kg) (2)

LD50 (dermal, rabbit): greater than 20660 mg/kg (cited as greater than 20 mL/kg) (3, unconfirmed)

Eye Irritation:

There is no specific information available for polyalkylene glycol monobutyl ether with a molecular weight of 970 (PAGMBE (mw 970)). In general, PAGMBEs are not irritating in rabbit tests.

Skin Irritation:

In one unconfirmed report, application of 500 mg of PAGMBE (mw 970) produced mild irritation in rabbits.(3) In general, application of PAGMBEs has produced no or minimal irritation.

Effects of Short-Term (Acute) Exposure:

Rats were exposed to 5, 50 or 500 mg/m3 PAGMBE (mw 970) aerosols for 9 exposures. Decreased body weight was observed at the 2 high exposures and increased kidney weights were observed at 500 mg/m3. Also at 500 mg/m3, exposure-related effects were observed in several blood parameters. There was no lung toxicity even at 500 mg/m3.(1)

The only non-fatal effects observed in rats, female mice and male rabbits following oral exposure to high doses of PAGMBE (mw 970) were signs of central nervous system (CNS) depression.(2)

Effects of Long-Term (Chronic) Exposure:

No differences were observed in rats exposed to PAGMBE (mw 970) in the diet at levels up to 500 mg/kg/day for 2 years. Negative results were also found with dogs exposed to up to 1670 mg/kg/day.(2)

Skin Sensitization:
Negative results were obtained in guinea pigs tested with a PAGMBE of unspecified molecular weight (Bel- Ray Syncom 1400 (CAS 9038-95-3)).(4)

PAGMBE (mw 970) was painted without dilution on the clipped skin of mice, 3 times/week until death. No papillomas or carcinomas developed.(2)


Selected Bibliography:
(1) Klonne, D.R., et al. Acute and 2-week aerosol inhalation studies on 970 and 1700 molecular weight ethylene oxide/propylene oxide (EO/PO) polymers. Inhalation Toxicology. Vol. 5, no. 2 (Apr.-June 1993). p. 189-201
(2) Smyth, H., Jr., et al. Oral toxicity and excretion of four commercial polyoxyalkylene glycol compounds. Toxicology and Applied Pharmacology. Vol. 16, no. 3 (May 1970). p. 675-680
(3) MDL Information Systems, Inc. Ucon 50-HB-260. Last updated: 1997-10. In: Registry of Toxic Effects of Chemical Substances (RTECS(R)). [CD-ROM]. Canadian Centre for Occupational Health and Safety (CCOHS). Also available at: <> {Subscription required}
(4) Kinkead, E.R., et al. Acute irritation and sensitization potential of Bel-Ray Syncom 1400. Acute Toxicity Data. Vol. 1, no. 3 (1992). p. 221
(5) Bailey, F.E., et al. Polyoxyalkylenes. In: Ullmann's encyclopedia of industrial chemistry. 7th ed. John Wiley and Sons, 2005. Available at: <> (Subscription required)
(6) Clinton, N., et al. 1,2-Epoxide polymers: ethylene oxide polymers and copolymers. In: Encyclopedia of polymer science and engineering. Vol. 6. John Wiley and Sons, 1986. p. 225-273
(7) UCON fluids and lubricants. Union Carbide Corporation, 1996

Information on chemicals reviewed in the CHEMINFO database is drawn from a number of publicly available sources. A list of general references used to compile CHEMINFO records is available in the database Help.

Review/Preparation Date: 2005-03-10

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