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CHEMINFO Record Number: 785
CCOHS Chemical Name: Polyalkylene glycol monobutyl ether, molecular weight 1590

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 1590
Oxirane, methyl-, polymer with oxirane, monobutyl ether (non-specific name)
Poly(ethylene oxide-propylene oxide) butyl ether

Trade Name(s):
UCON 50-HB-660
UCON Lubricant 50-HB-660
Poly G WS

CAS Registry Number: 9038-95-3
RTECS Number(s): YP8420000
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.(7)

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).(8,9) All of the polyalkylene glycol monobutyl ethers have the same CAS Registry Number (8), 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 1590 (mw 1590). 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.(8,9)


Essentially colourless liquid. No unusual hazard in a fire situation. Can burn if strongly heated. May cause lung injury at extremely high aerosol concentrations.


Effects of Short-Term (Acute) Exposure

Polyalkylene glycol monobutyl ether with a molecular weight of 1590 (PAGMBE (mw 1590)) does not readily form a vapour at room temperature. Therefore, inhalation exposures are unlikely to occur unless the material is heated or misted. Animal studies suggest that relatively short-term exposure to extremely high aerosol concentrations can cause severe lung injury. It is unlikely that such high concentrations would be achieved in an occupational setting. There is no human information available.

Skin Contact:
PAGMBE (mw 1590) is probably not irritating or mildly irritating to the skin, based on animal information. There is no human information available.
An animal toxicity value suggests that PAGMBE (mw 1590) will not cause harmful effects if absorbed through the skin.

Eye Contact:
PAGMBE (mw 1590) is probably not an eye irritant, based on an animal study. There is no human information available.

Animal toxicity information indicates that PAGMBE (mw 1590) 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 or animal information was located for PAGMBE (mw 1590). Negative results were obtained in one mouse study following skin application of two other PAGMBEs.

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:
202 deg C (396 deg F) (Pensky-Martens closed cup) (9)

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: 1590 (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.(9)
Relative Density (Specific Gravity): 1.046 at 20 deg C (8); 1.051 at 20 deg C (9); 1.028 at 40 deg C (9) (water = 1)
Solubility in Water: Soluble in cold water (7,9)
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.(9)
Coefficient of Oil/Water Distribution (Partition Coefficient): Not available
pH Value: Not available
Viscosity-Kinematic: 143 mm2/s (143 centistokes) at 38 deg C (100 deg F) (8)
Saybolt Universal Viscosity: 660 Saybolt Universal seconds at 38 deg C (100 deg F) (8,9)
Surface Tension: 35-40 mN/m (35-40 dynes/cm) at 20 deg C (9)
Vapour Density: Not applicable
Vapour Pressure: Very low; less than 0.00013 kPa (0.001 mm Hg) at 20 deg C (9)
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: -39 deg C (-38 deg F) (8); -43 deg C (-45 deg F) (9)


Normally stable. PAGMBEs decompose slightly at elevated temperatures to form low molecular weight products.(9)

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.(9) Strong oxidants, like chlorine, hydrogen peroxide, permanganates or persulfates can cause degradation.(8) 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 202 deg C.

Corrosivity to Metals:
PAGMBEs are not corrosive to iron, carbon steel, brass, bronze, and aluminum under normal operating conditions.(9)

Corrosivity to Non-Metals:
PAGMBE (mw 1590) 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, silicone, and fluorosilicone. It can attack Buna S.(9) PAGMBEs soften and lift many industrial coatings, like alkyd and vinyl coatings.(9) Catalyzed epoxy, epoxy-phenolic and modified phenolic coatings are not attacked by PAGMBEs.(9)


LC50 (male, rat): 4670 mg/m3 (4-hour aerosol exposure) (1)

LD50 (oral, rat): 18300 mg/kg (1,2)

LD50 (dermal, rabbit): greater than 21000 mg/kg (1/4 deaths) (1)

Eye Irritation:

Application of 0.1 mL of polyalkylene glycol with a molecular weight of 1590 (PAGMBE (mw 1590)) produced no irritation in rabbits.(1)

Skin Irritation:

Application of 0.5 ml of PAGMBE (mw 1590), under occlusive cover, for 4 hours, produced no irritation in rabbits.(1) In another unconfirmed report, application of 500 mg of PAGMBE (mw 1590) produced mild irritation in rabbits.(3)

Effects of Short-Term (Acute) Exposure:

Exposure to very high aerosol concentrations of PAGMBE (mw 1590) has produced lung injury and deaths in rats.

During LC50 testing with PAGMBE (mw 1590) (2590-5230 mg/m3) increased respiratory rate and reduced activity were observed following exposure to PAGMBE (mw 1590) at the highest concentration. Mortality was delayed to 2-5 days following exposure.(1) Rats were exposed to 500, 1000 or 2500 mg/m3 PAGMBE (mw 1590) aerosols for 9 exposures. All animals exposed to 2500 mg/m3 died. Symptoms included incoordination, prostration and respiratory difficulties. Some animals also showed nose and eye irritation. Lung weights were increased in the 500 and 1000 mg/m3 groups. At 2500 mg/m3, signs of lung injury (congestion, pneumonitis, bronchopneumonia) were observed. In the 500 mg/m3 group, less severe lung injury was observed.(4) Due to complete mortality at the highest exposure, the above study was repeated with rats exposed to PAGMBE (mw 1590) aerosols at 5, 50, 100 or 500 mg/m3 for 9 exposures. During this study, a separate group was treated and held for a 6-week recovery period. Decreases in absolute body weight and body weight gain were noted in high exposure animals. Concentration-related increases in absolute and relative lung weights were noted in males of all exposure groups and females at the two higher exposures. Autopsy showed lung injury in animals exposed to the high dose. No exposure related lesions were observed in animals allowed to recover for 6 weeks.(4)

Exposure to high oral doses of some PAGMBEs has produced signs of central nervous system (CNS) depression and deaths in mice, rats and rabbits.

Effects of Long-Term (Chronic) Exposure:

No differences were observed in rats exposed to 2 different PAGMBEs 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.(5)

Skin Sensitization:
Negative results were obtained in guinea pigs with a PAGMBE of unspecified molecular weight (Bel- Ray Syncom 1400 (CAS 9038-95-3)).(6)

There is no specific information for PAGMBE (mw 1590). Negative results were obtained in mice following the skin application of 2 other PAGMBEs.


Selected Bibliography:
(1) Klonne, D.R., et al. Acute and 2-week inhalation toxicity studies on aerosols of selected ethylene oxide/propylene oxide polymers in rats. Fundamental and Applied Toxicology. Vol. 9, no. 4 (Nov. 1987). p. 773- 784
(2) Mellon Institute of Industrial Research. Work in progress. Report 15-54. Union Carbide Corporation, June 30, 1952
(3) MDL Information Systems, Inc. Ucon 50-HB-660. Last updated: 2000-09. 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) 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
(5) 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
(6) 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
(7) Bailey, F.E., et al. Polyoxyalkylenes. In: Ullmann's encyclopedia of industrial chemistry. 7th ed. John Wiley and Sons, 2005. Available at: <> (Subscription required)
(8) 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
(9) 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

Revision Indicators:
Passive Sampling Devices 2005-03-22

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