DOWANOL DPM

DOWANOL DPM

CAS No. : 34590-94-8
EC No. : 252-104-2

Synonyms:
DOWANOL DPM Glycol Ether; Dipropylene glycol mono methyl ether; DPGME; Dipropylene glycol methyl ether; Propylene Glycol n-Butyl Ether; Di Methoxy Propanol; DPM; Methoxy Propoxy Propanol; Oxybispropanol; Methoxypropoxypropanol; Dipropylene Glycol Methyl Ether Acetate Reagent Grade; Di(propylene glycol) butyl ether, mixture of isomers; 1-Propanol,3-(3-methoxypropoxy)-; Dowanol DPG; DPG-FC; DCOIT Dowanol DPM; Propylene glycol monomethyl ether acetate, 99%; Dipropylene glycol methyl ether; 2-(2-methoxypropoxy)propan-1-ol; 13588-28-8; Dowanol DPM; 1-Propanol, 2-(2-methoxypropoxy)-; 2-(2-methoxypropoxy)propanol; 2-(2-METHOXYPROPOXY)-1-PROPANOL; 12002-25-4; 2-(2-methoxy-propoxy)-propan-1-ol; Glycol Ether DPM; ACMC-1AH7V; SCHEMBL16073; Glycol Ether DPM Reagent Grade; CTK4B1641; dipropyleneglycol monomethyl ether; DTXSID80864425; NCGC00090688-04; BS-15252; 2-(2Methoxypropoxy) propan-1-ol 13588-28-8; Dipropylene glycol methyl propyl ether; DPGME; 2-(2-methoxypropoxy)-1-propoxypropane; Dipropylene glycol butyl methyl ether; 1-[2-(2-methoxypropoxy)propoxy]butane; 1-(3-methoxypropoxy)propyl acetate; Glycol Ether DPM Acetate; 2,4,5-T Dipropylene glycol isobutyl ether ester; 53535-31-2; Acetic acid, (2,4,5-trichlorophenoxy)-, methyl-2-[methyl-2-(2-methylpropoxy)ethoxy]ethyl ester; dipropylene glycol methyl ether acetate; Acetic acid 2-(2-methoxypropoxy)propyl ester; 2-(2-methoxypropoxy)propyl acetate; Propanol, 1(or2)-(2-methoxymethylethoxy)-, acetate; 1-(2-Butoxy-1-methylethoxy)propan-2-ol; Stabilene; PPG-2 Butyl ether; 2-Propanol, 1-(2-butoxy-1-methylethoxy)-; PPG-14 Butyl ether; Crag fly repellent; Dowanol 54B; OPSB; PPG-5 Butyl ether; PPG-9 Butyl ether; Ambiflo L-317; Caswell No. 122; Unilube MB-370; Stabilene fly repellent; Newpol LB3000; PPG-12 Butyl ether; Exp. miticide No. 7; Butoxypropanediol polymer; BUTOXYPOLYPROPYLENE GLYCOL; Ucon fluid LB-3000; Ucon LB-250; Butoxy polypropylene glycol; Ucon LB 1145; 1-((1-Butoxypropan-2-yl)oxy)propan-2-ol; Polypropylene glycol monobutyl ether; Ucon Lubricant LB-1145; Fluid-AP; Poly(oxypropylene) butyl ether; Dipropylene glycol butoxy ether; DOWANOL DPM; Butoxypolypropylene glycol 400; Polyoxypropylene monobutyl ether; PPG-4 Butyl ether; Polypropylene glycol butyl ether; 9003-13-8; HSDB 1524; Polyoxypropylene(40) butyl ether; Polypropylene glycol monobutylether; Dipropylene glycol mono butyl ether; Polypropylene glycol (5) butyl ether; 1-(2-BUTOXY-1-METHYLETHOXY)-2-PROPANOL; Polyoxypropylene glycol butyl monoether; Ucon LB-1145; EPA Pesticide Chemical Code 011901; Poly(propylene oxide), monobutyl ether; BRN 1743918; Ucon LB-3000 (fluid); 1-(1-butoxypropan-2-yloxy)propan-2-ol; Polyoxypropylene (2) butyl ether; Di(propylene glycol)butyl ether; dipropylene glycol monombutyl ether; 1-[(1-butoxypropan-2-yl)oxy]propan-2-ol; Poly(oxy(methyl-1,2-ethanediyl)), alpha-butyl-omega-hydroxy-; DOWANOL DPM Glycol Ether; Dipropylene glycol mono methyl ether; Dipropylene glycol methyl ether; Propylene Glycol n-Butyl Ether; Di Methoxy Propanol; DPM; Methoxy Propoxy Propanol; Oxybispropanol; Methoxypropoxypropanol; Dipropylene Glycol Methyl Ether Acetate Reagent Grade; Di(propylene glycol) butyl ether, mixture of isomers; 1-Propanol,3-(3-methoxypropoxy)-; Dowanol DPG; DPG-FC; DCOIT Dowanol DPM; Propylene glycol monomethyl ether acetate, 99%; Dipropylene glycol methyl ether; 2-(2-methoxypropoxy)propan-1-ol; 13588-28-8; Dowanol DPM; 1-Propanol, 2-(2-methoxypropoxy)-; 2-(2-methoxypropoxy)propanol; 2-(2-METHOXYPROPOXY)-1-PROPANOL; 12002-25-4; 2-(2-methoxy-propoxy)-propan-1-ol; Glycol Ether DPM; ACMC-1AH7V; SCHEMBL16073; Glycol Ether DPM Reagent Grade; CTK4B1641; dipropyleneglycol monomethyl ether; 2-(2-Methoxypropoxy)propan-1-ol 13588-28-8; Dipropylene glycol methyl propyl ether; 2-(2-methoxypropoxy)-1-propoxypropane 3-(3-methoxypropoxy)propan-1-ol; 1-Propanol, 3-(3-methoxypropoxy)-; 112-28-7; 3-(3-Methoxypropoxy)-1-propanol; Di(propylene glycol) methyl ether, mixture of isomers; Caswell No. 551D; 3-(3-Methoxypropoxy)propanol; Propanol, methoxypropoxy-; Poloxalene; Poloxamer 188; POLOXAMER; Pluronic; Poloxalkol; 2594628; Pluronic L 61; Pluronic L-81; Detalan; Pluracare; Therabloat; 1-Methoxy-2-propyl acetate; 108-65-6; PGMEA; 2-Acetoxy-1-methoxypropane; Propylene glycol methyl ether acetate; 1-methoxypropan-2-yl acetate; Propylene glycol monomethyl ether acetate; 1-Methoxy-2-acetoxypropane; 2-Methoxy-1-methylethyl acetate; 2-Propanol, 1-methoxy-, acetate; METHOXYISOPROPYL ACETATE; Propyleneglycol monomethyl ether acetate; NSC 2207; 1-METHOXY-2-PROPANOL ACETATE; Acetic acid, 2-methoxy-1-methylethyl ester; 2-Propanol, 1-methoxy-, 2-acetate; EINECS 203-603-9; Dowanol (R) PMA glycol ether acetate; PROPYLENEGLYCOLMETHYLETHERACETATE; BRN 1751656; 2-(1-Methoxy)propyl acetate; AI3-18548; MFCD00038500; Propylene glycol 1-methyl ether 2-acetate; 2-(1-Methoxy)propyl acetate, 99%; Arcosolv PMA; Dowanol PMA; 2-Propanol, acetate; Ektasolve PM Acetate

Dowanol DPM

Mid-to slow evaporating solvent. Has 100% water solubility and is ideally suited as a coupling agent in a wide range of solvent systems. Has a higher flash point than Dowanol DPM glycol ether making it easier to handle, store, and ship. Often incorporated into latex emulsion coatings; can be used to prevent shocking (coagulation of emulsion) when hydrophobic solvents are used. More broadly, its hydrophilic nature makes Dowanol DPM an ideal coupling aid in water reducible coatings, and cleaning applications. Used with cleaners because they offer an extensive combination of basic physical and performance properties for cleaning formulations. The intermediate evaporation rate allow Dowanol DPM to be used in a potentially wider range of systems than many other solvents.

Uses of Dowanol DPM:
Cleaners, Resins, Coating formulation and application
Industrial, automotive and architectural coatings
Benefits of Dowanol DPM:
Versatile, Wide range of applications, Extensive combination of physical and performance properties

Product Description of Dowanol DPM
DOWANOL DPM glycol ether is a mid-to slow evaporating solvent. This hydrophilic solvent has 100% water solubility and is ideally suited as a coupling agent in a wide range of solvent systems. DOWANOL DPM glycol ether has a higher flash point than DOWANOL PM glycol ether making it easier to handle, store, and ship. Often incorporated into latex emulsion coatings DOWANOL DPM glycol ether can be used to prevent shocking (coagulation of emulsion) when hydrophobic solvents are used. More broadly, its hydrophilic nature makes it an ideal coupling aid in water reducible coatings, and cleaning applications. DOWANOL DPM glycol ether’s intermediate evaporation rate allow it to be used in a potentially wider range of systems than many other solvents.

USES of Dowanol DPM
• Coupling agent (often in blends) for water-based dilutable coatings.
• Active solvent for solvent-based coatings.
• Coupling agent and solvent in household and industrial cleaners, grease and paint removers, metal cleaners, and hard surface cleaners.
• Tail solvent for solvent-based gravure and flexographic printing inks.
• Primary solvent in solvent-based silk screen printing inks.
• Coupling agent in solvent blends for water-based gravure, flexographic, and Silk screen, printing inks.
• Coupling agent and solvent for vat dyeing fabrics.
• Mutual solvent, coupling agent, and emollient in cosmetic formulations.
• Stabilizer for agricultural herbicides.
• Coalescent for floor polishes and finishes.
Features of Dowanol DPM
• Powerful solvency
• Moderate evaporation rate
• Low viscosity
• High dilution ratio
• Low surface tension
• Coupling ability
• Wide range of applications

DOWANOL DPM is a dipropylene glycol methyl ether. Used as coupling agent (often in blends) for water-based dilutable coatings, active solvent for solvent-based coatings, tail solvent for solvent-based gravure and flexographic printing inks, primary solvent in solvent- based silk screen printing inks, coupling agent in solvent blends for water-based gravure, flexographic, and silk screen printing inks. DOWANOL DPM offers moderate evaporation rate, very good coupling abilities and low viscosity. DOWANOL DPM Exhibits high dilution rate and low surface tension.

What is Dowanol DPM?
Dowanol DPM (also known as Methoxy Propoxy Propanol, Oxybispropanol, dipropylene glycol methyl ether, DPM, and Dipropylene glycol monomethyl ether) is a propylene oxide-based/P series glycol ether and has the formula C7H16O3. Dowanol DPM is a clear, colourless, viscous liquid which has a slight ether odour. 
Dowanol DPM is completely soluble in water and is miscible with a number of organic solvents, for example ethanol, carbon tetrachloride, benzene, petroleum ether and monochlorobenzene. Dowanol DPM is also practically non- toxic and hygroscopic, and thus lends itself well to commercial and industrial use.

USES of DOWANOL DPM
Often incorporated into latex emulsion coatings DOWANOL DPM glycol ether can be used to prevent shocking (coagulation of emulsion) when hydrophobic solvents are used. More broadly, its hydrophilic nature makes it an ideal coupling aid in water reducible coatings, and cleaning applications.
Use Summary: The predominant use of this chemical is in consumer products, including paints, varnishes, inks, and cleaning products. Dowanol DPM is also has limited use as an  inert ingredient in pesticide products as a stabilizer in pesticide formulations applied to growing crops only; and/or a surfactant in pesticide formulations applied to animals.
DOWANOL DPM is used as a stabilizer.
Other Uses of Dowanol DPM
Dowanol DPM is used in the manufacture of a wide variety of industrial arid commercial products including paints, varnishes, inks and cleaners. Dowanol DPM is used as a solvent in the manufacture of water-based coatings and as a coalescing agent for water-based paints and inks. Dowanol DPM is also an intermediate in the production of dipropylene glycol methyl ether acetate (Dowanol DPMA). It is widely used in industrial, commercial, automotive and household cleaners. Consumer products containing Dowanol DPM include: glass, surface, and all-purpose cleaners; floor polish and carpet cleaners; paints and paintbrush cleaners; inks and dyes; rust remover and aluminum brightener; and cosmetic agents and their residues in packaging. Most products contain levels of Dowanol DPM between 1-10%, although some industrial products may have levels as high as
50% (SUA, 1995 as cited in DECO SIOS).

USAGES
Dowanol DPM is a very useful industrial and commercial chemical.  One of its main commercial uses is as a solvent for paints, varnishes, inks, strippers, and degreasers.  It is also utilised as a coalescing agent for water-based paints and inks where it promotes polymer fusing during the drying process. Dowanol DPM is also a component of wood and coil coatings, as well as coatings used in the automotive industry, industrial maintainence, and metal finishing. Dowanol DPM is also a component of hydraulic fluids and industrial degreasers and is a chemical additive in the oil production and drilling industry.

Dowanol DPM is a very useful chemical building block in the manufacture of many products. This is due to its reaction with acids, forming esters and oxidising agents which produce aldehydes, carboxylic acids and alkali metals therefore creating alcoholates and acetals.
It is this flexibility that supports the use of DPM across a range of industries and therefore makes it a component of many household items that people use every day.  It is found in ceiling and wall paints and in many common cleaners including glass and surface cleaners, paint-brush cleaners, all-purpose cleaners, carpet cleaners and disinfectant cleaners.  Dowanol DPM is also found in cosmetics where it provides emollient properties and product stabilisation as well as floor and aluminium polish, leather and textile dyes, rust removers and pesticides where it acts as a stabiliser.
Dipropylene glycol methyl ether is also a chemical intermediate in the production of Dipropylene glycol monomethyl ether acetate or DPMA.

How is Dowanol DPM produced?
Dowanol DPM (dipropylene glycol monomethyl ether) is produced by the reaction of propylene oxide with methanol using a catalyst.
How is Dowanol DPM stored and distributed?
Dowanol DPM is stored in mild steel and /or stainless steel tanks and/or drums and can be transported by bulk vessels or tank trucks. Dowanol DPM should be stored away from heat and sources of ignition in a cool and well-ventilated area. Dowanol DPM has a specific gravity of 0.95 and a flashpoint of 75oC (closed cup) and is not regulated for any form of transport.

What is Dowanol DPM Used For?
Dowanol DPM is a very useful industrial and commercial chemical. One of its main commercial uses is as a solvent for paints, varnishes, inks, strippers, and degreasers. Dowanol DPM is also utilised as a coalescing agent for water-based paints and inks where it promotes polymer fusing during the drying process. Dowanol DPM is also a component of wood and coil coatings, as well as coatings used in the automotive industry, industrial maintainence, and metal finishing. Dowanol DPM is also a component of hydraulic fluids and industrial degreasers and is a chemical additive in the oil production and drilling industry.
Dowanol DPM is a very useful chemical building block in the manufacture of many products. This is due to its reaction with acids, forming esters and oxidising agents which produce aldehydes, carboxylic acids and alkali metals therefore creating alcoholates and acetals.
Dowanol DPM is this flexibility that supports the use of DPM across a range of industries and therefore makes it a component of many household items that people use every day. It is found in ceiling and wall paints and in many common cleaners including glass and surface cleaners, paint-brush cleaners, all-purpose cleaners, carpet cleaners and disinfectant cleaners. It is also found in cosmetics where it provides emollient properties and product stabilisation as well as floor and aluminium polish, leather and textile dyes, rust removers and pesticides where it acts as a stabiliser.
Dowanol DPM is also a chemical intermediate in the production of Dipropylene glycol monomethyl ether acetate or DPMA.

Dowanol DPM may react violently with strong oxidizing agents. May generate flammable and/or toxic gases with alkali metals, nitrides, and other strong reducing agents. May initiate the polymerization of isocyanates and epoxides.
Dowanol DPM is a colorless liquid with a weak odor.
Dowanol DPM is a clear, colorless, combustible liquid with a slight ether odor. Dowanol DPM is completely soluble in water, and has moderate volatility. DPM is a propylene oxide-based, or P-series, glycol ether.

What is Dowanol DPM?
Dowanol DPM is a glycol ether based on propylene oxide and methanol. Dowanol DPM is a speciality solvent having a bi-functional nature (ether-alcohol). It is a clear liquid with an ether-like odour.
How is Dowanol DPM Used? 
Dowanol DPM is used as an intermediate and in formulations in industrial, professional or consumer applications. Mainly in surface coatings and printing inks and paints, cleaners and agrochemical formulations. Health, Safety and Environmental Considerations Dowanol DPM is not flammable, but a combustible liquid with a flashpoint of 1670 F/750C. Typically, the concentration of Dowanol DPM is 99%; 2-Methoxypropanol-1 can be present as an impurity at max. 0.1%.
If large quantities are ingested or high vapour concentrations inhaled, Dowanol DPM may cause central nervous system depression including headaches, nausea, dizziness, drowsiness, and coma, but not to an extent that it would trigger a classification. To a certain extent, Dowanol DPM can cause slight eye, skin or respiratory tract irritations, but effects do not cause classification according to the Globally Harmonized System (GHS) criteria. Dowanol DPM is not classified as a carcinogen or mutagen; it is not expected to cause cancer in humans, nor does it impair fertility or damage the developing fetus. Occupational exposure limits exist for Dowanol DPM in the range of 50 –100 ppm. Dowanol DPM is of low toxicity towards aquatic organisms. Dowanol DPM is completely miscible with water, biodegradable and not expected to bio-accumulate.

Storing and Transporting Dowanol DPM
Dowanol DPM is transported by tank truck, rail car and vessel, primarily in bulk quantities, but also as a packed product. Dowanol DPM is not classified as hazardous for transport under transport regulations. Glycol ethers should be stored at ambient temperatures away from sources of ignition and substances with oxidizing or corrosive properties. PROXITOLs are stabilized with a certain amount of inhibitor to prevent the formation of peroxides.
Risk Characterization Summary of Dowanol DPM
Risks associated with exposure to these products have been evaluated for the following “chain-ofcommerce” activities: manufacture, storage, product transfer, transportation, and customers/markets. They are manufactured, stored and transported to customers in closed systems. Depending on the customer, end uses may vary from use as an intermediate for the manufacture other chemicals, as commercial products or as formulated consumer products. Proper equipment design and handling procedures maintain low risk from exposure where used as an intermediate. Exposures may be higher in commercial and consumer applications. To minimize risk, additional controls, such as special handling procedures and protective packaging, are implemented. 

Human Health
Commercial Dipropylene Glycol Methyl Ether (Dowanol DPM) is a mixture of four isomers. Dowanol DPM exhibits low acute toxicity by the oral, dermal, and inhalation routes. The oral LD50 ranges 5180-5400 mg/kg b.w. in rats to 7500 mg/kg b.w. in dogs. Dermal LD50 values were reported to range from 9500 to >19000 mg/kg b.w. in rabbits. Acute inhalation exposures to 500 ppm (3000 mg/m 3 , highest attainable concentration) Dowanol DPM produced no lethality and mild, but reversible narcosis in rats. In animal and human studies, Dowanol DPM is neither a skin sensitizer nor a skin irritant, and was only slightly irritating to the eye. In repeated dose inhalation studies, NOAELs of >50 ppm to 200 ppm (> 303 mg/m3  to 1212 mg/m3 ) have been observed using rats, mice, rabbits, guinea pigs, and monkeys. Effects observed at higher dose levels (1818 mg/m3  to 2424 mg/m3; 300 – 400 ppm) showed signs of central nervous system depression and adaptive liver changes. In rats exposed to up to 1000 mg/kg-day Dowanol DPM via gavage for 4 weeks, tentative salivation (immediately after dosing) and adaptive liver changes were observed in animals exposed to the highest dose. No effects were observed in rats exposed to 200 mg/kg-day. Studies in rats and rabbits showed that Dowanol DPM is not teratogenic (two inhalation studies with NOAELs of 1818 mg/m3 ; 300 ppm). It should be noted that the beta isomer of PGME is known developmental toxicant. This isomer is unlikely to be a metabolite of Dowanol DPM. The available data indicate that Dowanol DPM is not genotoxic. Information collected for a structurally similar chemical (PGME) suggests that Dowanol DPM is not a reproductive toxicant, and is not carcinogenic. Additionally, no effects were seen on the testes and ovaries in a 90-day repeat dose inhalation toxicity study on Dowanol DPM.

Environment
Dowanol DPM is not persistent in the environment and is not expected to bioaccumulate in food webs. Dowanol DPM has a water solubility value of 1000 mg/L, a vapor pressure of 0.37 hPa and a log Kow of 0.0061. The half-life of Dowanol DPM in air was measured at 5.3 hours and is estimated to be 3.4 hours due to direct reactions with photochemically generated hydroxyl radicals. Dowanol DPM is readily biodegraded under aerobic conditions, but only slightly degraded under anaerobic conditions. Although environmental monitoring data are not available for Dowanol DPM, fugacity-based modelling indicates that Dowanol DPM is likely to partition to water compartments in the environment (surface water, groundwater). Acute toxicity testing in fish, invertebrates, and algae indicate a low order of toxicity with effect concentrations exceeding 1000 mg/L. Applying an uncertainty factor of 100 to the 48- hour LC50 value of 1919 mg/L for Daphnia, a PNEC of 19 mg/L was derived.

Exposure
Production in the U.S. was estimated at 35 million pounds (16 thousand tonnes) for 2000. Dowanol DPM is used in the manufacture of a wide variety of industrial and commercial products, including paints, varnishes, inks, and cleaners. In the US in 1999, Dowanol DPM was used as follows: 58% paints/coatings/inks, 28% cleaners, 10% Dowanol DPM acetate production, and 3% miscellaneous production.

Uses and Functions
Dowanol DPM is a powerful solvent for a vast range of organic compounds. It is used as a solvent in the manufacture of water-based coatings and Dowanol DPM is also used as a coalescing agent for water based paints and inks. Dowanol DPM is an ingredient in a wide variety of industrial products including cleaning agents, cosmetic agents, detergent/wetting agents, sanitary/disinfectant cleaners, solvent for paints/varnished/inks, and stripper/degreasers. Dowanol DPM is also used in a wide variety of household and commercial cleaning products including glass, surface, paintbrush, carpet, and all-purpose cleaners, floor polish, industrial degreasers, aluminium brighteners, and rust removers. It is also used in chemicals for the oil production and drilling industry. In the U.S. in 1999, Dowanol DPM was used as follows: 58% paints/coatings/inks, 28% cleaners, 10% Dowanol DPM acetate production, and 3 % miscellaneous production (Appendix A).
Form of Marketed Product
Dowanol DPM is used in a variety of domestic, commercial, and industrial cleaners. The majority of these products may contain less than 1%-5% Dowanol DPM, however, some products contain as much as 10-25% Dowanol DPM (GDCh-Advisory Committee, 1995). A more detailed list of products and their Dowanol DPM content is provided in the SIDS Dossier for Dowanol DPM.

Toxicokinetics and Metabolism
In a study by Miller et al. (1985), male Fischer 344 rats were given a single oral dose of carbon-14 labelled Dowanol DPM. Approximately 60% of the administered 14C activity was excreted in the urine, while 27% was eliminated as 14CO2 within 48 hours after dosing. Dowanol DPM, PGME, as well as sulfate and glucuronide conjugates of Dowanol DPM were identified in urine of animals given (14C) Dowanol DPM.Major metabolic pathways for Dowanol DPM include conjugation with glucuronic acid and sulfate and hydrolysis of the methoxy group to form dipropylene glycol. Hydrolysis of the dipropylene glycol backbone of Dowanol DPM to form PGME (propylene glycol methyl ether) and propylene glycol is considered a minor metabolic pathway as indicated by the fact that conjugates of Dowanol DPM, dipropylene glycol and the parent compound accounted for more than half of the total radiolabel in the urine (Miller et al, 1985). Hence like PGME and other propylene based glycol ethers, microsomal O-demethylation is a significant route of biotransformation of Dowanol DPM. The glucuronide and sulfate conjugates of Dowanol DPM are essentially non-toxic and rapidly eliminated from the body. Dowanol DPM is less volatile and has been shown in comparable studies to be similar to, or less toxic than dipropylene glycol, PGME and propylene glycol, each of which are themselves of low toxicity. Although tests on commercial PGME have indicated a low potential for toxicity the pure beta isomer of PGME (present at levels £ 0.5% in commerical PGME) has produced developmental effects in animals (BASF, 1988; Hellwig et al., 1994). Unlike the alpha PGME isomer, the beta PGME isomer is an excellent substrate for alcohol/aldehyde dehydrogenases and is oxidized primarily to 2-methoxypropionic acid (2- MPA) (Miller et al., 1986). It is this alkoxyacid metabolite that is the likely mediator of developmental toxicity (Carney et al., 2000). 
Dowanol DPM differs from PGME in that it does not contain beta isomer and hence the formation of the primary alcohol, beta PGME, from Dowanol DPM is dependent upon the potential to hydrolyze the central ether linkage in certain isomers of Dowanol DPM. Only two of the 4 Dowanol DPM isomers have the potential to be hydrolyzed to beta PGME. If one assumes that 100% cleavage of the ether bridge occurs, only 0.6 mmol of 2-MPA can be theoretically produced for every mmol of Dowanol DPM. Although Dowanol DPM has not been studied directly for the ability to produce beta PGME, a pharmacokinetic study with a structurally similar dipropylene glycol ether, dipropylene glycol dimethyl ether (DPGDME) showed a very low potential for cleavage of the glycol ether backbone with only 4.3% of the theoretical maximum of 2-MPA recovered at low doses and 13% of the theoretical maximum at higher doses (Mendrala et al., 1993). In an in vitro liver slice metabolism assay used to investigate the formation of 2-MPA from six propylene glycol ethers including beta PGME and DPGDME, none of the di- or triether substrates evaluated were metabolized to 2- MPA as effectively as beta-PGME. 
The in vitro formation of 2-MPA from beta PGME ranged from 3-170- fold higher than from any of the diethers tested (Pottenger et al., 1995). The in vivo metabolism study with Dowanol DPM taken together with the in vivo and in vitro studies with structurally analogous diglycol ethers indicate that hydrolysis of the central ether linkage to form the primary alcohol beta PGME and subsequent hydrolysis to the alkoxyacid metabolite is a minor metabolic pathway for Dowanol DPM. This minor pathway is likely to result in levels of MPA that are well below the levels that produce toxicologically significant effects even at high doses of Dowanol DPM. The database on the metabolites of Dowanol DPM also includes studies that have not been conducted with Dowanol DPM such as reproductive and chronic toxicity/oncogenicity studies. Based upon the the low probability to form beta PGME, similarities in metabolism and modes of action of Dowanol DPM and its metabolites, it is highly probable that Dowanol DPM will be similar to or less toxic than its metabolites in reproductive, chronic toxicity and carcinogenicity studies. 

Although tests on commercial Dowanol DPM and PGME have been negative in developmental studies the pure beta isomer of PGME (present at levels £ 0.5% in commerical PGME) has produced developmental effects in animals (BASF, 1988; Hellwig et al., 1994). Unlike the alpha PGME isomer, the beta PGME isomer is an excellent substrate for alcohol/aldehyde dehydrogenases and is oxidized primarily to 2-methoxypropionic acid (2-MPA) (Miller et al., 1986). It is this alkoxyacid metabolite that is the likely mediator of developmental toxicity (Carney et al., 2000). Dowanol DPM differs from PGME in that it does not contain beta isomer thus the formation of the primary alcohol, beta PGME, from Dowanol DPM is dependent upon the potential to hydrolyze the central ether linkage in certain isomers of Dowanol DPM. Only two of the 4 Dowanol DPM isomers have the potential be hydrolyzed to beta PGME. In vivo and in vitro studies provide support that significant cleavage of the dipropylene glycol backbone does not occur (Mendrala et al., 1993; Pottenger et al., 1995) precluding the formation of levels of beta PGME capable of producing toxicologically significant effects even at very high doses of Dowanol DPM. The low potential to generate the beta PGME isomer taken together with negative results in developmental toxicity studies in multiple species indicate it is unlikely that Dowanol DPM would be teratogenic of fetoxic by oral ingestion or inhalation.

Dowanol DPM is currently of low priority for further work.
Commercial Dipropylene Glycol Methyl Ether (Dowanol DPM) is a mixture of four isomers. Dowanol DPM exhibits low acute toxicity by the oral, dermal, and inhalation routes. The oral LD50 ranges 5180-5400 mg/kg in rats to 7500 mg/kg in dogs. Dermal LD50 values were reported to range from 9500 to >19000 mg/kg in rabbits. Acute inhalation exposures to 500 ppm Dowanol DPM produced mild, but reversible narcosis in rats. Dowanol DPM is not a skin sensitizer or skin irritant, and was only slightly irritating to the eye. In repeated dose studies, NOAELs of >50 ppm to 3000 ppm have been observed in inhalation studies using rats, mice, rabbits, guinea pigs, and monkeys. Observations included central nervous system (CNS) effects, adaptive hepatic changes, and decreases in body weight gain. In rats exposed to either 0, 40, 200, or 1000 mg/kg-day Dowanol DPM via gavage for 4 weeks, tentative salivation (immediately after dosing) and liver effects (increased relative liver weight, centrilobular hypertrophy) was observed in animals exposed to the highest dose. No effects were observed in rats exposed to 200 mg/kg-day. Studies in rats and rabbits showed that Dowanol DPM is not teratogenic (two inhalation studies with NOAELs of 300 ppm). 
The weight of the evidence indicates that Dowanol DPM is not genotoxic. Information collected for a structurally similar chemical (PGME) suggests that Dowanol DPM is not a reproductive toxicant, and is not carcinogenic. Additionally, no effects were seen on the testes and ovaries in a 28-day repeat dose oral toxicity study on Dowanol DPM. In humans, concentrations of 35-75 ppm may be expected to produce irritation to the eyes, nose, throat, and respiratory tract. Therefore, human exposures to concentrations of Dowanol DPM greater than 75 ppm are expected to be self-limiting. Dowanol DPM is not persistent in the environment and is not expected to bioaccumulate in food webs. The half-life of Dowanol DPM in air was measured at 5.3 hours and is estimated to be 3.4 hours due to direct reactions with photochemically generated hydroxyl radicals. Dowanol DPM is readily biodegraded under aerobic conditions, but only slightly degraded under anaerobic conditions. Although environmental monitoring data are not available for Dowanol DPM, fugacity-based modeling indicates that PGME is likely to partition to water compartments in the environment (surface water, groundwater). Acute toxicity testing in fish, invertebrates and algae indicate a very low order of toxicity with effect concentrations exceeding 1000 mg/L. A PNEC of 19 mg/L was derived by applying an uncertainty factor of 100 to the 48-hour LC50 value of 1919 mg/L for daphnids.

Approximately 38 million pounds (17 thousand tons) of Dowanol DPM were produced in the U.S. in 1999 (Appendix A). Approximately 12,000 tons of Dowanol DPM were consumed in the U.S. in 1995 (Staples and Davis, 2001). Production in the U.S. was estimated at 35 million pounds (16 thousand tons) for 2000 (Chemical Economics Handbook on Glycol Ethers (1996), SRI International). Dowanol DPM occurred in 123 products present on the Swedish market in July 1989. Dowanol DPM is used in the manufacture of a wide variety of industrial and commercial products, including paints, varnishes, inks, and cleaners. In the US in 1999, Dowanol DPM was used as follows: 58% paints/coatings/inks, 28% cleaners, 10% Dowanol DPM acetate production and 3% miscellaneous production. Exposures to Dowanol DPM are likely to occur for workers and consumers. Inhalation exposures to relatively high concentrations of Dowanol DPM are believed to be self-limiting due to the irritant effects of the chemical. Use of protective gloves to minimize absorption is recommended when prolonged dermal exposures to Dowanol DPM are anticipated.

Dowanol DPM (34590-94-8) may react violently with strong oxidizing agents. May generate flammable and/or toxic gases with alkali metals, nitrides, and other strong reducing agents. May initiate the polymerization of isocyanates and epoxides.
Dowanol DPM is colorless liquid with a mild, pleasant odor. Because of its structure Dowanol DPM is completely miscible with water and a wide variety of organic substances, and has the combined solubility characteristics of an alcohol, on ether and a hydrocarbon. Dowanol DPM is used in formulations of brake fluids, lacquers, paints, varnishes, dye and ink solvents, wood stains, textile processes, dry cleaning soaps and cleaning compounds.
Dowanol DPM is often used in combination with propylene glycol in cosmetics.

About Dowanol DPM
Helpful information
Dowanol DPM is registered under the REACH Regulation and is manufactured in and / or imported to the European Economic Area, at ≥ 10 000 to < 100 000 per annum.
Dowanol DPM is used by consumers, in articles, by professional workers (widespread uses), in formulation or re-packing, at industrial sites and in manufacturing.

Consumer Uses of Dowanol DPM
Dowanol DPM is used in the following products: coating products, anti-freeze products, lubricants and greases, inks and toners and biocides (e.g. disinfectants, pest control products).
Other release to the environment of Dowanol DPM is likely to occur from: outdoor use, indoor use (e.g. machine wash liquids/detergents, automotive care products, paints and coating or adhesives, fragrances and air fresheners), outdoor use in close systems with minimal release (e.g. hydraulic liquids in automotive suspension, lubricants in motor oil and break fluids) and indoor use in close systems with minimal release (e.g. cooling liquids in refrigerators, oil-based electric heaters).

Article service life of Dowanol DPM
Other release to the environment of Dowanol DPM is likely to occur from: outdoor use in long-life materials with low release rate (e.g. metal, wooden and plastic construction and building materials), outdoor use in long-life materials with high release rate (e.g. tyres, treated wooden products, treated textile and fabric, brake pads in trucks or cars, sanding of buildings (bridges, facades) or vehicles (ships)), indoor use in long-life materials with low release rate (e.g. flooring, furniture, toys, construction materials, curtains, foot-wear, leather products, paper and cardboard products, electronic equipment) and indoor use in long-life materials with high release rate (e.g. release from fabrics, textiles during washing, removal of indoor paints).
Dowanol DPM can be found in complex articles, with no release intended: vehicles.
Dowanol DPM can be found in products with material based on: metal (e.g. cutlery, pots, toys, jewellery), wood (e.g. floors, furniture, toys), paper (e.g. tissues, feminine hygiene products, nappies, books, magazines, wallpaper) and plastic (e.g. food packaging and storage, toys, mobile phones).

Widespread uses by professional workers
Dowanol DPM is used in the following products: fuels, laboratory chemicals and plant protection products.
Dowanol DPM is used in the following areas: building & construction work, printing and recorded media reproduction and agriculture, forestry and fishing.
Dowanol DPM is used for the manufacture of: machinery and vehicles, furniture, plastic products and mineral products (e.g. plasters, cement).
Other release to the environment of Dowanol DPM is likely to occur from: indoor use (e.g. machine wash liquids/detergents, automotive care products, paints and coating or adhesives, fragrances and air fresheners), outdoor use, indoor use in close systems with minimal release (e.g. cooling liquids in refrigerators, oil-based electric heaters) and outdoor use in close systems with minimal release (e.g. hydraulic liquids in automotive suspension, lubricants in motor oil and break fluids).

Formulation or re-packing
Dowanol DPM is used in the following products: air care products, plant protection products, washing & cleaning products, biocides (e.g. disinfectants, pest control products), lubricants and greases, perfumes and fragrances, polishes and waxes and cosmetics and personal care products.
Release to the environment of Dowanol DPM can occur from industrial use: formulation of mixtures, manufacturing of the substance, in processing aids at industrial sites and formulation in materials.

Uses at industrial sites
Dowanol DPM is used in the following products: coating products, lubricants and greases, inks and toners and polishes and waxes.
Dowanol DPM is used for the manufacture of: chemicals.
Release to the environment of Dowanol DPM can occur from industrial use: in processing aids at industrial sites, as an intermediate step in further manufacturing of another substance (use of intermediates) and of substances in closed systems with minimal release.

Manufacture
Release to the environment of Dowanol DPM can occur from industrial use: manufacturing of the substance, in processing aids at industrial sites, formulation of mixtures, as an intermediate step in further manufacturing of another substance (use of intermediates), formulation in materials, in the production of articles, as processing aid, for thermoplastic manufacture, as processing aid and of substances in closed systems with minimal release.