### Technical Review of Ethylene Glycol mono Butyl Ether (EGBE): Chemistry, Environmental Fate and Ecological Toxicity

CAS Registry Number 111
- 76
- 2
September 9, 2009

Office of Environmental Information Office of Information Access and Analysis Environmental Analysis Division U.S. Environmental Protection Agency 1200 Pennsylvania Avenue, N.W. Washington, DC 20460Table of Contents

Chapter One

– Chemistry and Environmental Fate

....................................... ...... 1 1.1 Summary................................................................................ 1 1.2 Synonyms/Identification.............................................................

. 3 1.3 Physical and Chemical Properties................................................... 4 1.4 Production Methods................................................................... 5 1.5 Use Properties.......................................................................... 5 1.6 Environmental Fate..................................................................... 6 1.6.1 Environmental Transport................................................... 6 1.6.2 Abiotic Degradation

........................................................ 7 1.6.3 Biotic Degradation......................................................... 8 1.6.4 Environmental Distribution............................................... 9 1.6.5 Toxic Transformation Products Assessment........................... 10 1.7 References............................................................................... 11 Chapter Two

– Ecological Hazard Assessment................................................ 15 2.1 Summary............................................................................... 15 2.2 Ecological Toxicity................................................

................... 1 5 2.2.1 Acute Toxicity............................................................... 19 2.2.2 Chronic Toxicity............................................................ 20 2.2.3 Terrestrial Toxicity and Phytotoxicity................................... 20 2.2.4 Population Effects.......................................................... 21 2.2.5 Bioaccumulation Potenti al................................................ 21 2.3 References.............................................................................. 211 CHAPTER ONE CHEMISTRY AND ENVIRONMENTAL FATE

1.1. SUMMARY Ethylene glycol mono butyl ether (EGBE) (CAS Registry No. 111

- 76

- 2) is a member of the glycol ethers chemical clas s. The technical

- grade product is a clear, combustible liquid with
a mild ether odor (Dow , 2006). The molecular formula is C 6 H 14 O 2 and the molecular weight is 118.2. EGBE is described as miscible in water ( Stoye and Aktiengesellschaft, 2005 ). It is also miscible with mineral oil and most organic solvents (O'Neil, 2006). EGBE's major use is as an ingredient in many coati ng formulations, inks, and cleaning fo rmulations (Dow , 1990). The major use of EGBE is as an ingredient in both solvent and water based coating formulations such as emulsions, dispersions, varnishes, enamels, an d lacquers (Dow , 1990, 2006). It is used as an ingredient in many cleaning formulations including household/industrial cleaners, liquid soaps, dry cleaning soaps, rug cleaners, spotting fluids, phosphoric acid rust removers, aluminum brighteners, metal cleaners, carbon and grease removers, paint/var nish/silicone removers, ink removers, hard surface cleaners, white wall tire cleaners, and disinfectants/ germicides (Dow , 1990). EGBE is produced through the reaction of ethylene oxide with n

- butanol in the presence of a catalyst (Dow , 1990, 2006). Acc ording to industrial reports provided to the U.S. Environmental Protection Agency (U.S. EPA) under the Invent ory Update Rule (U.S. EPA,
2007 ), EGBE has had a production volume of 100 million to 500 million pounds per year during reporting years 1986, 1990, 1994, 1998, and 2002. The reported U.S. production capacity for glycol ethers in 2007 was 1,623 mill ion pounds (SRI, 2007).2

In 200 7 , releases of glycol ethers reported to the Toxic Release Inventory (TRI) (U.S. EPA, 200 9 ) under the “certain glycol ethe rs” category totaled approximately 18,476,000 pounds. Reported releases to air, surface water, and land were approximately 16,416,000 , 87 ,000, and 1,3 11 ,000 pounds, respectively. Approximately 126 ,000 pounds were released via underground injection. App roximately 7,902, 000 pounds were transferred to publicly

- owned treatment works (POTWs). EGBE is one of the glycol ethers reportable under the “certain glycol ethers” category (s pecific release informa tion for EGBE is not available in the TRI database) . I t is not known how much of these amounts are attributable to EGBE releases; however, this may be a large percentage since EGBE is the single most widely produced glycol ether (Dow, 2006). EGBE is expected to volatilize slowly into the atmosphere from terrestrial and aquatic surfaces based on its Henry’s law constant and a classification scheme (HSDB, 2007 ; Kim et al. 2000; Lyman, 1990 ). Estimated volatilization half

- lives of EGBE are 17 days for a model rive r and 185 days for a model lake (U.S. EPA 200 8 ). When EGBE does volatilize, it is expected to exist primarily as a vapor in the atmosphere ( EPI Suite, 2007; Bidleman, 1988). EGBE released to soils and sediments is not expected to strongly absorb and has the potential to migrate into underlying groundwater systems (Hansch et al., 1995; HSDB, 2007; Staples et al., 1998 ; U.S.EPA, 2008 ). For EGBE in the atmosphere, t he predicted half

- life for the indirect photodegradation of this substance is 9.2 hours due to reaction with hydroxyl radicals (Atkinson, 1989; Leifer, 1993).
EGBE may contribute to the formation of tropospheric ozone (Derwent et al., 1996; U.S. EPA,
2006 ). Atmospheric d egradation products can result in the formation of 2

- butoxyacetic acid (BAA) (see section 1.6.5) as well as peroxyacyl nitrates, (Atkinson, 2000; LOOP, 2003). In mammals 2

- butoxyacetic acid is thought to be responsible for EGBE’s toxic he matological effects (U.S. EPA, 1999). P eroxyacyl nitrates (PAN) have been reported to be eye irritants,3

mutagenic, phytotoxic, and possible agents of skin cancer (Singh and Salas, 1989; Williams et al. 1993). PAN has been shown to be mutagenic in Salmone lla and in the lungs of mice exposed

nose - only to PAN generated from non

- mutagenic precursors (DeMarini et al., 2000). Based upon a level III fugacity model calculation (see Section 2.6.4), soil and water are the environmental compartments where the largest mass of EGBE will distribute, assuming equal releases of EGBE to air, water, and soil (U.S. EPA, 200 8 ). Limited biod egradation data are available for this substance; however, EGBE is considered to be readily biodegrada dable in soil and water based on screening level test data (CITI, 1992; Devillers et al., 2001; NITE 2002; OECD, 199 7 ; S taples et al., 1998; Price et al., 1974; Waggy et al., 1994 ). EGBE is expected to be highly mobile in soil, and has the potential to move from soil to groundwater (HSDB 2007; Staples et al., 1998). The chemistry and environmental fate of EGBE are discussed in this chapter. Synonym and physical

- chemical property information was obtained during a search of the on

- line source ChemID Plus Advanced, handbook references, the Syracuse Research Corporation (SRC) PHYSPROP database, and the SRC Environmental Fate Data Base. Manufacturing and us e information was obtained from the Ullmann's encyclopedia article on solvents ( Stoye and Aktiengesellschaft, 2005 ) and the Glycol Ethers Handbook p ublished by Dow Chemical Company (1990). Environmental fate data were obtained through a se arch of the lite rature compiled in SRC's Environmental Fate Data Base, the Hazardous Substances Data Bank (HSDB) record for EGBE (available on

- line), and estimations performed using the EPI Suite v 4.00 software.

1 .2. SYNONYMS/IDENTIF IERS ( CAS Registry, 2007; ChemID Plus Advanced, 2007): Butoxyethanol4

2

- Butoxy

- 1

- ethanol 2

- Butoxyethanol 2

- n - Butoxyethanol 3

- Oxa

- 1

- heptanol Butyl Cellosolve Butyl glycol Butyl monoether glycol Butyl oxitol Dowanol EB EGBE Ethanol, 2

- butoxy Ethylene glycol butyl ether Ethylene glycol monobutyl ether Ethylene glycol n

- butyl ether Glycol butyl ether Monobutyl glycol ether 1.3. PHYSICAL AND CH EMICAL PROPERTIES Table 1

- 1 provides selected chemical and physical properties for EGBE. Table 1

- 1. Physical and Chemical Prope rties of Ethylene glycol mono butyl ether (EGBE) (CAS Reg. No. 111

- 76

- 2) Property Value a Conditions Reference Molecular f

ormula C 6 H 14 O 2 - O’Neil, 2006 Molecular w eight 118.18

- O’Neil, 2006 Melting point (°C)

- 74.8

- Lide, 2005 Boiling point (°C) 171

- 172

- O'Neil, 2006 Vapor pressure (mm Hg) 0.88 25 °C Dow , 1990 Water solubility (mg/L) Infinite

- Riddick et al., 1986 Log K ow 0.83

- Hansch et al., 1995 Henry’s l aw constant (atm

m 3 /mol) 8. 16×10 - 7 25 °C Kim et al. 2000 Hydroxyl radical reaction rate constant (cm 3 /molec

- sec) 1.4×10 - 11 25 °C Atkinson, 1989 Density (g/cm 3 ) 0.9015 20 °C Lide, 2005 Flash Point (°C) 60 closed cup O'Neil, 2006 Autoignition temperature (°C) 244

- Lewis, 2001

a Values are experimental unless otherwise indicated.5

1.4. PRODUCTION METHODS According to Dow Chemical Company (1990, 2006), EGBE is produced via the reaction of ethylene oxide with n

- butanol in the presence of a catalyst. Di

- and tri

- ethylene glycol monoethers are also produced in this reaction if the ratio of ethylene oxide to n

- butanol is greater than 1. 1.5. USE PROPERTIES EGBE is miscible with water and most organic solvents (O'Neil, 2006; Stoye and Aktiengesellschaft, 2005 ). It is used as a solvent for cellulose nitrate, cellulose ethers,
colo phony, shellac, chlorinated rubber, polyacrylates, polymethacrylates, alkyd resins, formaldehyde resins, synthetic resins, oils, and fats ( Stoye and Aktiengesellschaft, 2005 ). The major use of EGBE is as an ingredient in both solvent and water based coating formulations such as emul sions, dispersions, varnishes, enamels, an d lacquers (Dow , 1990, 2006). It serves as a solvent, a coalescent, or a coupling agent in these coatings which are designed for automotive, industrial, metal coil, architectural, and wood surface s (Dow , 1990). E GBE is used as a solvent in gravure, flexographic, and silk screen inks and as a reactive diluent in radiation cu rable inks (Dow , 1990). EGBE is an ingredient in many cleaning formulations including household/industrial cleaners, liquid soaps, dry cleanin g soaps, rug cleaners, spotting fluids, phosphoric acid rust removers, aluminum brighteners, metal cleaners, carbon and grease removers, paint/varnish/silicone removers, ink removers, hard surface cleaners, white wall tire cleaners, and disinfectants/ germi cides (Dow , 1990). EGBE has also been used in the manufacture of pl asticizers (Dow , 1990). According to Dow Chemical Company (2006), relative percentages of the different market applications for EGBE are as follows: paints, coatings, and inks (53%), meta l cleaning and household cleaning (15%), raw material for the6

production of 2

- butoxyethyl acetate (5%), raw material for production of other chemicals (5%), other uses (21%).

1.6. ENVIRONMENTAL F ATE
1 .6.1. Environmental Transport. EGBE is expected to volatilize slowly from moist soil and water surfaces, based on a Henry's l aw constant of 8. 16×10 - 7 atm

- m 3 /mol at 25 °C and a classification scheme ( HSDB, 2007; Kim et al. 2000; Lyman et al., 1990). Using this Henry's l aw constant and the EPI Suite estimation software (U.S. EPA, 200 8 ), the volatilization half

- lives of EGBE are calculated to be
33 days for a model river 1 and 360 days for a model lake 2 . A vapor pressure of 0.88 mm Hg at 25 °C (Dow , 1990) indicates that EGBE will vola tilize slowly from dry soil surfaces (HSDB, 2007). Using t his vapor pressure value, a calculated particle/gas partition coefficient of
2.05×10 - 6 indicates that any EGBE that is released into the air will exist primarily as a vapor (Bidleman, 1988 ; U.S. EPA, 2008 ). Based on a bioconcentration factor ( BCF ) value of 3, calculated using regression

- derived equations and the experimental log K ow value, EGBE is not expected to bioaccumulate in aquatic organisms. (Hansch et al., 1995; HSDB, 2007; Meylan, 1999; Staples et al., 1998). Based on a K oc value of 67, calculated using regression derived equations and the experimental log K ow value, EGBE is not expected to adsorb strongly to soils and sediments and will have high mobility in soil and the potential to mo ve from soil to groundwater (Hansch et al., 1995; HSDB, 2007; Staples et al., 1998 ; U.S.EPA, 2008 ). Additional data regarding the transport of EGBE through soil, sur face water, and groundwater
ha ve not been located in the available literature.

1 Parameters for the model river are 1 m deep, flowing 1 m/sec, wind velocity of 5 m/sec. 2 Parameters for the model lake are 1 m deep, flowing 0.05 m/sec, wind velocity of 0.5 m/sec.7

1 .6. 2 . Ab iotic Degradation. EGBE is not expected to undergo direct photolysis since it does not absorb radiation in the environmentally available region of the electromagnetic spectrum that has the potential to cause molecular degradation (HSDB, 2007). EGBE wil l be degraded in the atmosphere by reaction with photochemically produced hydroxyl radicals. Atkinson (1989) has reported a measured rate constant of 1.4×10 - 11 cm 3 /molecule

- sec at 25 °C for this reaction, which corresponds to a half

- life of 9.2 hours assu ming an atmospheric hydroxyl radical concentration of 1.5×10 6 molecules/cm 3 and a 12

- hour day (Leifer, 1993). Stemmler et al. (1997) and Tuazon et al. (1998) reported that three formate esters, two aldehydes, and one organic nitrate were the major product s of EGBE atmospheric photooxidation: butyl formate, 2

- hydroxyethyl formate, 3

- hydroxybutyl formate, butoxyacetaldehyde, propionaldehyde, and the organic nitrate
CH 3 CH 2 CH 2 CH 2 OCH(ONO 2 )CH 2 OH. In the atmosphere, aldehydes react with photochemically produce d hydroxy radicals to form acyl peroxy radicals (Atkinson, 2000). In the presence of O 2 and NO 2 , acyl peroxy radicals undergo transformation to form peroxyacyl nitrates, which are analogs of peroxyacetyl nitrate (PAN) (Atkinson, 2000; LOOP, 2003). Follow ing this mechanism, atmospheric photooxidation of butoxyacetaldehyde and propionaldehyde can result in the formation of peroxybutoxyacetyl nitrate and peroxypropionyl nitrate (PPN), respectively. With a vapor pressure of 0.88 mm Hg at 25 °C, EGBE will ex ist almost entirely in the vapor phase in the atmosphere

. EGBE may contribut e to the formation of tropospheric ozone (Derwent, 1996; U.S. EPA, 2006 ). EGBE is not expected to undergo hydrolysis in the environment since this substance lacks hydrolyzable functional groups (HSDB, 2007).8

1 .6.3. Biotic Degradation. Limited information is available regarding the aerobic biodegradation of EGBE. Screenin g level data indicate that EGBE is readily biodegradable under aerobic conditions (CITI, 1992; Devillers et al., 2001; NITE 2002; OECD, 1997 ; Price et al., 1974; Staples et al., 1998; Waggy et al., 1994). Price et al. (1974) reported 88% and 75% biodegrad ation after 20 days in

non - acclimated fresh water and synthetic salt water, respectively, measured by biochemical oxygen demand ( BOD ) . A similar result was reported by Waggy et al. (1994), who measured 88% biodegradation by Johanson (1988) after 20 days. Waggy et al. (1994) also performed a
closed

- bottle screening test following OECD Guideline 301D and measured 75% biodegradation after 28 days. EGBE was biodegraded by 96% after 14 days in a sewage sludge inoculum during a Modified MITI screening test (CI TI, 1992). Based on the results of the closed bottle and Modified MITI screening tests, this substance meets the criteria specified within OECD Guidelines for a readily biodegradable substance (Staples et al., 1998 ). Specific information regarding transf

ormation products of EGBE in water and soil was not located in the available literature. Results from a pure

- culture biodegradation study indicate that ethylene glycol monoalkyl ethers like EGBE undergo microbial oxidation at their terminal alcohol groups (Kawai 1995). In this study, degradation of ethylene glycol monoethyl ether and diethylene glycol monoethyl ether by an isolated microbial culture resulted in the formation of ethoxyacetic acid and ethoxyglycoxyacetic ac id, respectively (Kawai 1995) . Fo llowing this pathway, the microbial degradation of EGBE in the environment is expected to form 2

- butoxyacetic acid. Information regarding t he biodegradation of EGBE under anaerobic conditions, such as in groundwater, is not currently available.9

1 .6.4. E nvironmental Distribution Assessment. A model (U.S. EPA, 200 8 ) estimate was conducted of how, on a percentage basis, EGBE
may distribute when it is released in to the environment. Measured physical

- chemical properties (melting point, boiling point, vapor pressure, octanol

- water partition coefficient, water solubility, and Henry's l aw constant) were used as model input parameters. Emission inputs (82% to air, 8% to water, and 7% to soil) were based on the assumption that TRI release data for the “certain glycol ethers” category are representative of EGBE releases. Model half

- life input values were assigned based on the photooxidation half

- life for air and biodegrad ation screening test data for water, soil, and sediment 3

. The advective flow rate was set to zero by selecting very large advection times (1×10 20 hours) for the air, water, and sediment environmental compartments. Based upon the model results, soil is th e environmental compartment where the largest mass of EGBE will accumulate ( 47%), with less partitioning to water (33%) and air ( 20% ). The model partitioning results, half

- life inputs, and emissions inputs for each environmental compartment are shown in T able 1

- 2.

Table 1

- 2, Environmental Distribution of EGBE Compartment Mass amount

(percent) Half
- life Values (hours) Emissions

(kg/hr) Air 47% 9.2 820 Water 33% 120 80 Soil 20% 240 70 Sediment 0% 1080 0
Source: EPI Suite, (U.S. EPA, 2008)

3 The half

- life value used for water was determined by applying a classification scheme developed by Aronson et al. (2006) to the measured screening test data located in the literature for EGBE. Half

- lives in soil and sediment were set equal to the derived half

- life in water multiplied by factors of 2 and 9, respectively, which follows the methodology used within the EPI Suite model.10

1 .6.5. Toxic Transformation Products. According to Stemmler et al. (1997) and Tuazon et al. (1998), two of the major products of EGBE photooxidation are the aldehydes, butoxyacetaldehyde and propionaldehyde ; the two aldehydes result in a combined quantity approximately equal to 30 to 40 percent of the EGBE reacted ( Stemmler et al. 1997; Tuazon et al. 1998). As discussed in Section 1.6.2., these aldehydes can react with photochemically produced hydroxy radica ls in air resulting in the formation of acyl peroxy radicals, which can then combine with O 2 and NO 2 to form the peroxyacyl nitrates, peroxybutoxyacetyl nitrate , and peroxylpropionyl nitrate (analogs of PAN) (Atkinson, 2000; LOOP, 2003). No information re garding actual yields of peroxyacyl nitrates that result from the atmosph eric photooxidation of EGBE was located in the literature. Peroxyacyl nitrates have a lifetime that is temperature dependent, approximately 30 minutes at room temperature (Atkinson, 2000), to over a year at upper troposphere temperatures (Atkinson, 2000; LOOP, 2003; Roberts, 1990). Peroxyacyl nitrates have been reported to be eye irritants, mutagenic, phytotoxic, and possible agents of skin cancer (Singh and Salas, 1989; Williams et al. 1993). PAN has been shown to be mutagenic in Salmonella and in the lungs of mice exposed

nose - only to PAN generated from non

- mutagenic precursors (DeMarini et al., 2000). With respect to the formation of toxic biodegradation products in soil and water, no EGBE specific literature was available. Results from a pure

- culture biodegradation study indicate that ethylene glycol monoalkyl ethers like EGBE undergo microbial oxidation at their terminal alcohol groups (Kawai 1995). In this study, degradat ion of ethylene glycol monoethyl ether and diethylene glycol monoethyl ether by an isolated microbial culture resulted in the formation of ethoxyacetic acid and ethoxyglycoxyacetic acid, respectively (Kawai 1995). Following this pathway, the microbial deg radation of EGBE in the environment is expected to11

form 2

- butoxyacetic acid

. In mammals, 2

- butoxyacetic acid is a principal EGBE metabolite, which is thought to be responsible for EGBE’s toxic hematolog ical effects (U.S. EPA, 1999)

.

1 .7. REFERENCES
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- 879.15 CHAPTER TWO ECOLOGICAL HAZARD ASSESSMENT
2.1 SUMMARY Based upon available acute toxicity data, EGBE does not appear to present a sig nificant concern for adverse effects on the aquatic environment since effects occur at relatively high concentrations i ndicating low toxicity . Such high concentrations ar e not expected to be observed under typ ical environmental conditions. Experimental acute toxicity LC 50 ((i.e., the concentration that is lethal to 50% of test organisms ) or EC 50 ( (i.e., the concentration that is effective in producing a sublethal response in 50% of test organisms ) values range from 900 to
1 , 840 mg/L for green algae, 164 to 1 , 815 mg/L for freshwater invertebrates, and 1 , 395 to 2 , 137 mg/L for freshwater fish. Available experimental acute toxicity LC 50 values for saltwater invertebrates and saltwater fish were 1 , 000 and 1 , 250 mg/L, respectively; a 24

- hour lowest

observed

- effect concentration ( LOEC ) (embryotoxicity) of 1 , 000 mg/L was av ailable for Japanese oyster eggs. These acute experimental toxicity values indicate low aquatic toxicity. Experimental chronic toxicity values range from 35 to >1 , 000 mg/L for algae and from 100 to 297 mg/L for daphnids. Also, a 21

- day no - observed

- effec t

- c oncentration ( NOEC ) of >100 mg/L was available for freshwater fish. These chronic experimental toxicity values i ndicat e low to moderate aquatic toxicity (Table 2

- 1). For terrestrial toxicity, an ECOSAR

- predicted 14

- day
LC 50 of 1 , 666 mg/kg dry weight soil for earthworms was available. EGBE is not expected to bioaccumulate significantly in aqu atic organisms ( the BCF is 3 based on a log K ow of 0.83 ).

2.2. ECOLOGICAL TOXICITY Databases searched to identify studies on ecological toxici ty were ECOTOX (2007) (which contains three databases: AQUIRE, PHYTOTOX, and TERRETOX), the Office of Pesticide Programs (OPP) Environmental Fate and Effects Division (EFED) Pesticide16

Ecotoxicity Database, and the Hazardous Substances Databank (HSDB). In addition, the TOXLINE database was searched to identify additional aquatic toxicity studies and population effects studies

. No experimental chronic toxicity data for fish or aquatic inv ertebrates were found for EGBE. Limited experimental toxicity data we re available for all other endpoints. Quantitative Structure

- Activity Relationships (QSARs) were considered for some ecological toxicity endpoints for EGBE; however, QSAR models were not available to predict the chronic toxicity of EGBE to estuarine/marin e fish or invertebrates. EPA’s Ecological Structure Activity Relationship Program (ECOSAR) (U.S. EPA, 200 8 ) was used to supplement available experimental data . ECOSAR is a regression

- based model developed by the EPA Office of Pollution Prevention and Toxics and was used to predict the acute and chronic toxicity of EGBE based on structural similarities to chemicals for which aquatic toxicity has been measure d experimentally. ECOSAR

- derived acute aquatic toxicity values were generated for estuarine/marine fish and invertebrates (mysid shrimp), and ECOSAR

derived chronic aquatic toxicity values were generated for green algae and freshwater fish. The predicted 96

- hour LC 50 values for estuarine/marine fish and invertebrates were 1 , 481 and 2 , 2 40 mg/L, respectively . The predicted chronic toxicity values for green algae and freshwater fish

were 42 and 94 mg/L , respectively. Table 2

- 1 presents the measured and predicted values indicating acute and chronic toxicity of EGBE to aquatic organisms an d toxicity to terrestrial organisms.17

Table 2
- 1 . Ecological Toxicity Values for EGB E Species Duration and Test Endpoint Experimental

Type a,b Value

(mg/L) c Reference Acute aquatic toxicity Algae Green algae ( Scenedesmus quadricauda ) Toxicity threshold value S, U h 900 Bringmann & Kuhn, 1977a f Green algae ( Pseudokirchneriella subcapitata ) 72

- hr EC 50 (biomass) S, M e,i 911 Devillers et al., 2002a, 2002b Green algae ( Pseudokirchneriella subcapitata ) 72

- hr EC 50 (growth) S, M e,i 1 , 840 Devillers et al., 2002a, 2002b Green algae ( Pseudokirchneriella subcapitata ) 72

- hr NOEC (growth rate) S, M 286 INERIS, 1999 d , as cited in ECB, 2006 Green algae ( Pseudokirchneriella subcapitata ) 72

- hr NOEC (biomass) S, M 88 INERIS, 1999 d , as cited in ECB, 2006 Freshwater invertebrate Water flea ( Daphnia magna ) 24

- h r EC 50 S, U, O g 1 , 720 Bringmann & Kuhn, 1977b f Water flea ( Daphnia magna ) 48

- h r EC 50 S, U, O e 1 , 815 Bringmann & Kuhn, 1982
Water flea ( Daphnia magna ) 48

- hr EC 50 S, O k 835 Dow Chemical Company, 1979, as cited in ECB, 2006 Water flea ( Daphnia magna ) 48

- hr EC 50 S m 1 , 550 INERIS, 1999a, as cited in ECB, 2006 Water flea ( Daphnia magna ) 48

- hr EC 50 S, M o 1 , 600 Devillers et al., 2002a, 2002b Rotifer ( Brachionus calyciflorus ) 48

- hr EC 50 (reproduction) S, M p 164 Devillers et al., 2002a, 2002b Freshwater fish Bluegill ( Lepomis macrochirus ) 96

- hr LC 50 S, U 1 , 490 Dawson et al., 1975 Golden orfe ( Leuciscus idus ) LC 50 d NS e 1 , 575 Juhnke & Luedemann, 1978 f Golden orfe ( Leuciscus idus ) LC 50 d NS e 1 , 395 Juhnke & Luedemann, 1978 f Goldfish ( Carassius auratus ) 24

- hr LC 50 S, M e 1 , 700 Bridie et al., 1979 Rainbow trout ( Oncorhynchus mykiss ) 96

- hr LC 50 M k,q 1 , 700 Devillers et al., 2002a, 2002b Rainbow trout ( Oncorhynchus mykiss ) 96

- hr LC 50 NS k,m 1 , 474 INERIS, 1999b, as cited in ECB, 200618

Species Duration and Test Endpoint Experimental

Type a,b Value

(mg/L) c Reference
Fathead minnow ( Pimephales promelas ) 96

- hr LC 50 S, O k 2 , 137 Dow Chemical Company, 1979, as cited in ECB, 2006 Estuarine/marine invertebrate Brine shrimp (

Artemia salina ) 24

- hr LC 50 S, U, C 1 , 000 Price et al., 1974 Japanese oyster eggs ( Crassostrea gigas ) 24

- hr LOEC (embryotoxicity) S k 1 , 000 Devillers et al., 2002a, 2002b Mysid shrimp predicted value 96

- hr LC 50 predicted 2 , 240 ECOSAR v. 1.00, U.S. EPA, 2008 Estuarine/marine fish Silverside ( Menidia beryllina ) 96

- hr LC 50 S, U 1 , 250 Dawson et al., 1975 Saltwater fish predicted value 96

- hr LC 50 predicted 1 , 481 ECOSAR v. 1.00, U.S. EPA, 2008 Chronic aquatic toxicity Algae Green algae ( Scenedesmus quadricauda ) 8

- d LOEC (cell multiplication inhibition) S, U e 900 Bringmann & Kuhn, 1978a f and 1978b Blue

- green algae ( Microcystis aeruginosa ) 8

- d LOEC (cell multiplication inhibition) S, U e 35 Bringmann & Kuhn, 1978a f and 1978b Green algae ( Selenastrum capricornutum ) 7

- d EC 50 (growth rate) S, U e >1 , 000 Dill & Milazzo, 1988
Green algae predicted value Chronic Value predicted 42 ECOSAR v. 1.00, U.S. EPA, 2008 Freshwater invertebrate Water flea (Ceriodaphnia dubia) 7

- day EC 10 (reproduction) R, N 134.9 Devillers et al., 2003
Water flea ( Daphnia magna ) 21

- d NOEC (reproduction) R, M 100 Devillers et al., 2002a, 2002b Water flea ( Daphnia magna ) 21

- d NOEC n R, M 100 INERIS, 1999 c , as cited in ECB, 2006 Water flea ( Daphnia magna ) 21

- d EC 50 n R, M 297 INERIS, 1999 c , as cited in ECB, 2006 Freshwater fish Zebrafish ( Brachydanio rerio ) 21

- d NOEC (mortality) NS l >100 INERIS, 2001, as cited in ECB, 2006 Freshwater fish predicted value 30

- d Chronic Value predicted 94 ECOSAR v. 1.00, U.S. EPA, 2008 Estuarine/marine invertebrate

- No data Estuarine/marine fish

- No data Terrestrial toxicity and phytotoxicity Avian species

- No data19

Species Duration and Test Endpoint Experimental

Type a,b Value

(mg/L) c Reference Terrestrial invertebrate Earthworm predicted value 14

- d LC 50 predicted 272 mg/kg dry weight soil ECOSAR v. 1.00, U.S.

EPA, 2008 Plants

- No data

a For freshwater tests, pH and water hardness were within accepted ranges (6

- 8.5 and 50

- 250 mg/L as CaCO 3 , respectively) unless noted otherwise b Experiment type: S = static, R = renewal, M = measured, U = unmeasured, O = open test system, NS = not specified
c mg/L = ppm d Test duration w as not noted in the study report.
e Water hardness was not reported. f Most of the study report was in German and a full English translation was not available. g Water hardness was reported as 16° dH, equivalent to 285.76 mg/L as CaCO 3 . h It was unclear from the study report whether test concentrations were measured. ECOTOX reported that the test was static and that test concentrations were nominal. i pH was not reported. j Water hardness was reported as 25 mg/L as CaCO 3 . k It was not indicated whether test concentrations were nominal or measured. l Water hardness, pH, test type, and whether test concentrations were nominal or measured were not indicated.
m Test type was unclear from the report.
n The effect on which the endpoint value was based (e.g., reproduct ion? mortality?) was not indicated in the report.
o Water hardness was reported as 250±20 mg/L as CaCO 3 . p Water hardness was described as “moderately hard.” q Water hardness was reported as 250±25 mg/L as CaCO 3 . 2.2.1. Acute Toxicity. Acute toxicity val ues are presented in Table 2

- 1

. For green algae , a toxicity threshold value (duration not specified) of 900 mg/L and 72

- hour EC 50 values of 911 and 1 , 840 mg/L for biomass and growth rate, respectively, were reported (corresponding 72

- hr NOEC values for bi omass and growth rate were 88 and 286 mg/L). For daphnids, 24

- or 48

- hour EC 50 values ranged from 835 to 1 , 815 mg/L, and a 48

- hr EC 50 (reproduction) of 164 mg/L in rotifers was reported. A 96

- hour LC 50 value of 1 , 490 mg/L was available for bluegill sunfish and 96

- hour
LC 50 values for rainbow trout were 1 , 474 and 1 , 700 mg/L. A 96

- hour LC 50 value of 2 , 137 mg/L for fathead minnows was also reported. LC 50 values (duration not specified) of 1 , 575 and 1 , 395 mg/L were available for golden orfe ( Leuciscus idus ), and a 24

- hour LC 50 value of 1 , 700 mg/L was available for goldfish ( Carassius auratus ). A study of a lacustrine invertebrate (brine20

shrimp) reported a 24

- hour LC 50 value of 1 , 000 mg/L, but the brine shrimp is not a standard test species and the test duration was only 24 hours

. Also, an embryo

- larval test in which Japanese oyster eggs were incubated with the test material for 24 hours and then examined for abnormalities produced a 24

- hr LOEC of 1 , 000 mg/L. ECOSAR predicted a 96

- hour LC 50 value of 2 , 240 mg/L for mysid shrimp. A study of an estuarine/marine fish (silverside, Menidia beryllina ) reported a 96

- hour LC 50 value of 1 , 250 mg/L. Additionally, ECOSAR predicted a 96

- hour LC 50 value of 1 , 481 mg/L for estuarine/marine fish.

2.2.2. Chronic Toxicity. Chronic toxicity values are presented in Table 2

- 1. Eight

- day LOEC values (cell multiplication inhibition) of 900 and 35 mg/L were available for green algae and blue

- green algae, respectively, and a 7

- day EC 50 value of >1 , 000 mg/L was available for green algae. ECOSAR predicted a chronic value of 42 mg/L for green algae (ECOSAR chronic values are indicative of lowest adverse effect levels associated with the ability to survive, grow, and/or reproduce). For daphnids, the following end point values were available: a 7

- day EC 10 (reproduction) of 134 mg/L, a 21

- day NOEC (reproduction) of 100 mg/L, and a 21

- day EC 50 (effect not specified) of 297 mg/L. For freshwater fish, a 21

- day NOEC (mortality) of >100 mg/L was available, and ECOSAR pre dicted a 30

- day chronic value of 94 mg/L. There were no measured or predicted chronic estuarine/marine fish or invertebrate toxicity data available.

2.2.3. Terrestrial Toxicity and Phytotoxicity. Ecological toxicity values are presented in Table 2

- 1; no avian toxicity or phytotoxicity data were available. ECOSAR predicted a 14

- day LC 50 of 272 mg/kg dry weight soil for earthworms

.21

2.2.4. Population Effects. No data on population effects were located.

2.2.5. Bioaccumulation Potenti al. Bioaccumulat ion in aquatic organisms can be estimated using the BCF , which describes the degree to which a chemical can be concentrated in the tissues of an organism. Measured BCFs were not available; thus, a BCF was calculated using EPIWIN v. 3.2 (U.S. EPA, 2008 ). Based on a calculated BCF of 3 , EGBE is not expected to bioaccumulate significantly in the
tissue s of aquatic organisms.

2.3. REFERENCES Bridie, A.L., Wolff, C.J.M., & M. Winter. 1979. The acute toxicity of some petrochemicals to goldfish. Water Res, 13(7): 623

- 626. Bringmann, G. & R. Kuhn. 1977a. Limiting values for the damaging action of water pollutants to bacteria ( Pseudomonas putida ) and green algae ( Scenedesmus quadricauda ) in the cell multiplication inhibition test.

. Z. Wasser Abwasser F orsch, 10(3/4 ): 87

- 98 . (In German) Bringmann, G. & R. Kuhn. 1977b. The effects of water pollutants on Daphnia magna. Z. W asser Abwasser Forsch, 10(5): 161

- 166. (In German)
Br ingmann, G. & R. Kuhn. 1978a. Threshold Values of Substances Harmful to Water for Blue Algae ( Microcystis aeruginosa ) and Green Algae ( Scenedesmus quadricauda ) in Tests Measuring the Inhibition of Cellular Propagation. Vom Wasser 50:45

- 60 (GER) (ENG ABS), Tr

- 80

- 02 01, Literature Research Company : 22 p. Bringmann, G. & R. Kuhn . 1978b. Testing of Substances for Their Toxicity Threshold: Model Organisms Microcystis (Diplocystis) aeruginosa and Scenedesmus quadricauda . Mitt. Int. Ver. Theor. Angew. Limnol. 21: 2 75

- 284. Bringmann, G. & R . Kuhn. 1982. Results of the toxic act ion of water pollutants on Daphnia magna in an improved standardized procedure. Z. Wasser Abwasser Forsch, 15(1): 1

- 6. (In German) Dawson, G.W., Jennings, A.L., Drozdowski, D., & E. Rider. 1975. The acute toxicity of 47 industrial chemicals to fresh a nd saltwater fishes. Journal of Hazardous Materials, 1: 303

- 318.22

Devillers, J., Chezeau, A., Poulsen, V. & E. Thybaud. 2003. Effects of ethylene glycol ethers on the reproduction of Ceriodaphnia dubia . Chemosphere, 50: 373

- 376. Devillers, J., Chezeau, A., Thybaud, E., Poulsen, V., Procher, J.

- M., Graff, L., Vasseur, P., Mouchet, F., Ferrier, V. & F. Quiniou. 2002a. Ecotoxicity of ethylene glycol monobutyl ether and its acetate. Toxicology Mechanisms and Methods, 12: 255

- 263. Devillers, J., Chezeau, A., Thybaud, E., Poulsen, J.

- M., Graff, L., Vasseur, P., Chenon, P., Mouchet, F., Ferrier, V. & F. Quiniou. 2002b. Ecotoxicity of ethylene glycol monomethyl ether and its acetate. Toxicology Mechanisms and Methods, 12: 241

- 254. Dill, D.C. & D. P. Milazzo. 1988. Dowanol PM Glycol Ether: Evaluation of the toxicity to the green alga, Selenastrum capricornutum printz. July 18, 1988. Dow Chemical Company. EPA Document Control Number 86

- 890001160. 18 pages. Dow Chemical Co. 1979. Toxicity of Dowanol EB to freshwater organisms (redactor: Bartlett), 31 August 1979. As cited in ECB, 2006. ECB (European Chemicals Bureau). 2006. European Union Risk Assessment Report for 2

- Butoxyethanol (EGBE). Vol. 68. European Commission. ECOSAR (v. 1.00h, p art of the EPIWIN Suite v.3.2, see U.S. EPA 2008). 2008. Syracuse Research Corporation. Available at http://www.epa.gov/opptintr/newchems/tools/21ecosar.htm

. ECOTOX. 2007. ECOTOX User Guide: ECOTOXicology Database System. Version 4.0, Released February 2007. Available at http://www.epa.gov/ecotox/. HSDB (Hazardous Substances Databank)

. National Library of Medicine. Available at: http://toxnet.nlm.nih.gov. Toxicology Data Network (TOXNET 7 ). Bethesda, MD. Available at http://toxnet.nlm.nih.gov/cgi

- bin/sis/htmlgen?HSDB

. INERIS. 2001. Essai poisson 21 jours, Dani o rerio, unpublished report, N° 22685, 05.11.2001. As cited in ECB, 2006. INERIS. 1999a. Détermination de la toxicité aïgue du 2

- butoxyethanol vis

- à

- vis de Daphnia Magna, Ba746b

- CGR21427. Verneuil

- en - Halatte, France, 14 décembre 1999, INERIS: 10. As c ited in ECB, 2006. INERIS. 1999b. Détermination de la toxicité aiguë du 2

- butoxyethanol vis

- à

- vis de Oncorhynchus Mykiss, unpublished, Ba746f

- CGR21427. Verneuil

- en - Halatte, France, 14 décembre 1999, INERIS: 10. As cited in ECB, 2006. INERIS (1999 c ) Dé termination de la toxicité chronique du 2

- butoxyethanol vis

- à

- vis de Daphnia Magna, Ba746a

- CGR21427. Verneuil

- en - Halatte, France, 15 décembre 1999, INERIS: 13. As cited in ECB, 2006.23

INERIS (1999 d ) Détermination de la toxicité chronique du 2

- butoxyethano l vis

- à

- vis de l'algue d'eau douce Pseudokirchneriella Subcapitata, Ba746d

- CGR21427. Verneuil

- en - Halatte, France, 14 décembre 1999, INERIS: 14. As cited in ECB, 2006. Juhnke, I. & D. Luedemann. 1978. Results of the study of 200 chemical compounds on acute fish toxicity using the Golden Orfe test. Z. Wasser Abwasser Forsch., 11(5): 161

- 164. (In German) Price, K.S., Waggy, G.T., & R.A. Conway. 1974. Brine shrimp bioassay and seawater BOD of petrochemicals. Journal WPCF, 46(1): 63

- 76.

TOXLINE. Par t of the National Library of Medicine's Toxicology Data Network (TOXNET 7 ). Bethesda, MD. Available at http://toxnet.nlm.nih.gov/cgi

- bin/sis/htmlgen?TOXLINE

. U.S. EPA. 2008

. ECOSAR v .1.00. Available within the EPI SuiteTM v. 4.00

. program ©2008 U.S. Environmental Protection Agency. Available as part of the EPI Suite program v 4.00 at http://www.epa.gov/oppt/exposure/pu bs/episuite.htm

.