U.S. Environmental Protection Agency
Hazard Characterization Document

December, 2009

SCREENING-LEVEL HAZARD CHARACTERIZATION

1,2-Dibromoethane
(CASRN 106-93-4)

The High Production Volume (HPV) Challenge Program1 was conceived as a voluntary
initiative aimed at developing and making publicly available screening-level health and
environmental effects information on chemicals manufactured in or imported into the United
States in quantities greater than one million pounds per year. In the Challenge Program,
producers and importers of HPV chemicals voluntarily sponsored chemicals; sponsorship
entailed the identification and initial assessment of the adequacy of existing toxicity
data/information, conducting new testing if adequate data did not exist, and making both new
and existing data and information available to the public. Each complete data submission
contains data on 18 internationally agreed to "SIDS" (Screening Information Data Set1'2)
endpoints that are screening-level indicators of potential hazards (toxicity) for humans or the
environment.

The Environmental Protection Agency's Office of Pollution Prevention and Toxics (OPPT) is
evaluating the data submitted in the HPV Challenge Program on approximately 1400 sponsored
chemicals by developing hazard characterizations (HCs). These HCs consist of an evaluation of
the quality and completeness of the data set provided in the Challenge Program submissions.

They are not intended to be definitive statements regarding the possibility of unreasonable risk of
injury to health or the environment.

The evaluation is performed according to established EPA guidance2'3 and is based primarily on
hazard data provided by sponsors; however, in preparing the hazard characterization, EPA
considered its own comments and public comments on the original submission as well as the
sponsor's responses to comments and revisions made to the submission. In order to determine
whether any new hazard information was developed since the time of the HPV submission, a
search of the following databases was made from one year prior to the date of the HPV
Challenge submission to the present: ChemID (to locate available data sources including
Medline/PubMed, Toxline, HSDB, IRIS, NTP, AT SDR, IARC, EXTOXNET, EPA SRS, etc.),
STN/CAS online databases (Registry file for locators, ChemAbs for toxicology data, RTECS,
Merck, etc.) and Science Direct. OPPT's focus on these specific sources is based on their being
of high quality, highly relevant to hazard characterization, and publicly available.

OPPT does not develop HCs for those HPV chemicals which have already been assessed
internationally through the HPV program of the Organization for Economic Cooperation and
Development (OECD) and for which Screening Initial Data Set (SIDS) Initial Assessment
Reports (SIAR) and SIDS Initial Assessment Profiles (SIAP) are available. These documents are
presented in an international forum that involves review and endorsement by governmental
authorities around the world. OPPT is an active participant in these meetings and accepts these
documents as reliable screening-level hazard assessments.

1	U.S. EPA. High Production Volume (HPV) Challenge Program; http://www.epa.gov/chemrtk/index.htm.

2	U.S. EPA. HPV Challenge Program - Information Sources; http://www.epa.gov/chemrtk/pubs/general/guidocs.htm.

3	U.S. EPA. Risk Assessment Guidelines; http://cfpub.epa.gov/ncea/raf/rafguid.cfm.

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These hazard characterizations are technical documents intended to inform subsequent decisions
and actions by OPPT. Accordingly, the documents are not written with the goal of informing the
general public. However, they do provide a vehicle for public access to a concise assessment of
the raw technical data on HPV chemicals and provide information previously not readily
available to the public.

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Chemical Abstracts
Service Registry Number
(CASRN)

106-93-4

Chemical Abstracts
Index Name

Ethane, 1,2-dibromo

Structural Formula

Br

Br

Summary

This chemical is a colorless liquid with high water solubility and high vapor pressure. This
chemical is expected to have high mobility in soil. This chemical did not pass a ready
biodegradation test (OECD 301C); however, it was shown to degrade at varying rates in soils
under aerobic conditions. Persistence can vary greatly from soil to soil. In one laboratory
screening study using 100 soils, half-lives were determined to range from 1.5 to 18 weeks. The
rate of volatilization from water and moist soil is considered moderate based on its Henry's Law
constant. The rate of uncatalyzed hydrolysis is considered negligible, but hydrolysis catalyzed
by the presence of various natural substances (such as HS ion) may be competitive with
biodegradation (half-life of 1-2 months). This chemical is expected to have moderate persistence
(P2) and low bioaccumulation potential (Bl).

Acute oral toxicity to rats is moderate and to rabbits is high. Acute dermal toxicity to rabbits and
acute inhalation toxicity to rats is moderate. CASRN 106-93-4 is irritating to skin and eyes. In
chronic inhalation bioassays with rats and mice, the noncancer effects observed included
testicular and adrenal cortex degeneration, retinal atrophy and hepatic necrosis (rats) or
mortality, inflammation/cellular abnormalities in the respiratory tract and hepatic necrosis (mice)
at 0.077 mg/L; NOAELs for systemic toxicity were not established. Repeated inhalation of this
chemical resulted in fatty degeneration in the liver of monkeys at 0.38 mg/L, mortality in guinea
pigs at 0.19 mg/L and no effects in rabbits at 0.38 mg/L (highest dose tested); the NOAEL for
systemic toxicity was 0.19 mg/L, not established and0.38 mg/L in monkeys, guinea pigs and
rabbits, respectively. Noncancer effects after repeated oral exposures included hepatitis/liver
inflammation, adrenal cortex degeneration and testicular atrophy at 38 mg/kg-bw/day (rats) and
mortality (mice) at 62 mg/kg-bw/day; NOAELs for systemic toxicity were not established. A
reproductive toxicity study in rats via inhalation resulted in effects on male and female
reproductive organs, fewer matings and changes in estrous cycles at 0.61 mg/L; the NOAEL for
reproductive toxicity was 0.30 mg/L. Human epidemiological studies suggest that CASRN 106-
93-4 is associated with male reproductive toxicity. In prenatal inhalation developmental toxicity
studies in rats and mice, maternal toxicity (decreased body weight in rats and mortality in mice)
was seen at 0.29 mg/L. In these developmental studies, fewer viable fetuses and increased
resorptions were seen at 0.29 mg/L in rats, and skeletal anomalies, resorptions and decreased
fetal body weights were seen at 0.15 mg/L in mice. In rats, the NOAEL for maternal and
developmental toxicity was 0.15 mg/L. In mice, the NOAEL for maternal toxicity was 0.15
mg/L and for developmental toxicity was not established. CASRN 106-93-4 induced gene
mutations and chromosomal aberrations in vitro; induced micronuclei in vivo in mice via
inhalation, but did not induce dominant lethal mutations in vivo. Increased DNA adducts have
been observed in vivo and humans have shown increased chromosomal exchanges after exposure

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to this chemical. CASRN 106-93-4 was carcinogenic in rats and mice via the inhalation and oral
routes; human epidemiological studies on carcinogenicity are inconclusive.

The 96-hour LC50S of CASRN 106-93-4 to fish ranged from 136 to 991 mg/L. The predicted 48-
hour EC50 of CASRN 106-93-4 to aquatic invertebrates is 82 mg/L, and the predicted 96-hour
EC50 of CASRN 106-93-4 to aquatic plants is 35.4 mg/L.

A data gap for toxicity to aquatic plants was identified under the HPV Challenge Program.	

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The sponsor, Great Lakes Chemical Corporation, submitted a Test Plan and Robust Summaries
to EPA for CASRN 106-93-4 (CASRN 106-93-4; CA Index Name: ethane, 1,2-dibromo-) on
December 28, 2001. EPA posted the submission on the ChemRTK HPV Challenge website on
February 5, 2002 (http://www.epa.gov/oppt/chemrtk/pubs/summaries/ethanedi/cl3454tc.htm).
EPA comments on the original submission were posted to the website on October 10, 2002.
Public comments were also received and posted to the website.

1 Chemical Identity

1.1	Identification and Purity

It should be noted that although one of the common synonyms for CASRN 106-93-4 is ethylene
dibromide (EDB), there are no double bonds in the compound's structure.

No information on percent purity was provided in the industry sponsor's submission.

1.2	Physical-Chemical Properties

The physical-chemical properties of CASRN 106-93-4 are summarized in Table 1. CASRN 106-
93-4 is a colorless liquid with high water solubility and high vapor pressure.

Table 1. Physical-Chemical Properties of 1,2-Dibromoethane1

Property

Value

CASRN

106-93-4

Molecular Weight

187.9

Physical State

Colorless liquid2

Melting Point

9.3-9.8 °C

Boiling Point

131-131.4 °C

Vapor Pressure

11.7 mm Hg at 25 °C;
14.7 mm Hg at 20 °C;
23.2 mm Hg at 30 °C

Water Solubility

4,030 mg/L at 20 °C;
4,300 mg/L at 30 °C

Dissociation Constant (pKa)

Not applicable

Henry's Law Constant

6.5*10~4 atm-m'/mole2

Log K0w

1.93-2.13

Bold = measured data; (e) = estimated data (i.e., derived from modeling)

1 Great Lakes Chemical Corporation. December 18, 2001. Robust Summary and Test Plan for Ethane, 1,2-Di-
bromo. http://www.epa.gov/chemrtk/pubs/summaries/ethanedi/cl3454tc.htm.

2HSDB. 2008. Hazardous Substances Data Bank. Accessed October 10, 2008. http://toxnet.nlm.nih.gov/cgi-
bin/sis/htmlgen?HSDB.

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2 General Information on Exposure

2.1	Production Volume and Use Pattern

Non-confidential information in the IUR indicated that the industrial processing and uses of the
chemical include "other" for incorporation into formulation, mixture, or reaction product in
petroleum refineries. Non-confidential information in the IUR indicated that the commercial and
consumer products containing the chemical include lubricants, greases, and fuel additives. The
HSDB for this chemical states that the chemical is primarily used as an exhaust system
scavenger in gasoline containing lead, as a catalyst, a chemical intermediate, a fumigant,
insecticide, and as a solvent for resins, gums and waxes.

2.2	Environmental Exposure and Fate

Total releases from all sites reported to U.S. EPA's Toxics Release Inventory (TRI) in 2006 were
10,558 pounds (3,783 pounds to air from on-site fugitive and point sources; 6,594 pounds as on-
site releases to water). Most of the remaining volume of release was injected to deep wells or
sent to off-site landfills.

The environmental fate properties are provided in Table 2. CASRN 106-93-4 is expected to
have high mobility in soil. CASRN 106-93-4 did not pass a ready biodegradation test (OECD
301C); however, it was shown to degrade at varying rates in soils under aerobic conditions.
Persistence can vary greatly from soil to soil. In one laboratory screening study using 100 soils,
half-lives were determined to range from 1.5 to 18 weeks. The rate of volatilization from water
and moist soil is considered moderate based on its Henry's Law constant. The rate of
uncatalyzed hydrolysis is considered negligible, but hydrolysis catalyzed by the presence of
various natural substances (such as HS ion) may be competitive with biodegradation (half-life of
1-2 months). CASRN 106-93-4 is expected to have moderate persistence (P2) and low
bioaccumulation potential (Bl).

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Table 2. Environmental Fate Characteristics of 1,2-Dibromoethane1

Property

Value

Photodegradation Half-life

>1 month (e);
64 days (e)2

Hydrolysis Half-life

0-13%	degraded at pH 5-9 and 25°C after 140 days;
8-13 years at pH 7 and 20°C2

1-	2 months catalyzed by HS"6

Biodegradation

Half-life of <2 days in soil (aerobic) at 100 mg/kg2;
Half-life of 1.5 to 18 weeks in soil2;

0% in 14 days (not readily biodegradable)3
Degraded in soil rapidly at ppb level; degraded
slowly at the ppm level;

Bi oconcentrati on

BCF = 1.6-3.2 (carp; 150 ppb)3;
BCF = <3.5-14.9 (carp; 15 ppb)3

Log Koc

1.6(e)2

Fugacity

(Level III Model)4

Air = 27.1%

Water = 32.1%

Soil = 40.7%
Sediment = 0.11% (e)

Persistence5

P2 (moderate)

Bi oaccumul ati on5

BI (low)

Bold = measured data; (e) = estimated data (i.e., derived from modeling)

1 Great Lakes Chemical Corporation. December 18, 2001. Robust Summary and Test Plan for Ethane,
1,2-Dibromo. http://www.epa.gov/chemrtk/pubs/summaries/ethanedi/cl3454tc.htm.

2HSDB. 2008. Hazardous Substances Data Bank. Accessed October 10, 2008. http://toxnet.nlm.nih.gov/cgi-
bin/sis/htmlgen?HSDB.

3National Institute of Technology and Evaluation. 2002. Biodegradation and Bioaccumulation of the Existing
Chemical Substances under the Chemical Substances Control Law.
http://www.safe.nite.go.ip/english/kizon/KIZON start hazkizon.html.

4U.S. EPA. 2008. Estimation Programs Interface Suite™ for Microsoft® Windows, v 3.20. United States
Environmental Protection Agency, Washington, DC, USA.
http://www.epa.gov/opptintr/exposure/pubs/episuite.htm.

5Federal Register. 1999. Category for Persistent, Bioaccumulative, and Toxic New Chemical Substances.

Federal Register 64, Number 213 (November 4, 1999) pp. 60194-60204.

6EDB Fact Sheet EPA Office of Water : http://www.epa.gov/safewater/dwh/t-soc/edb.html

3. Human Health Effects

A summary of health effects data submitted for SIDS endpoints is provided in the conclusion
below and Table 3. Most data are contained in the IRIS assessment (http://www.epa. gov/iris/)
and are not described in detail below. However, selected studies submitted by the industry
sponsor or available from ATSDR, NTP, HSDB and TSCATS are summarized below.

Acute Oral Toxicity

(1) Fischer 344 rats (6/sex/dose) were administered CASRN 106-93-4 via gavage at 40, 80, 130
(male only), 160 or 320 mg/kg-bw and observed for 2 weeks following dosing. Mortalities were
observed in both females and males at all doses > 80 mg/kg-bw. Four of six males died at 130

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mg/kg-bw, 6/6 males and 5/6 females died at 160 mg/kg-bw and all animals died at the highest

dose. All deaths occurred within 6 days of dosing (TSCATS - OTS0536392 -

http://www.svrres.com/esc/tscats.htm).

LD50 (male) = 116 mg/kg-bw

LD50 (female) = 133 mg/kg-bw

(2)	Albino rats of both sexes (10-20/dose) were administered CASRN 106-93-4 (vehicle: olive
oil) via gastric intubation at six different single doses. After exposure, they were observed until
they recovered from weight loss and gained weight normally, typically a period of two weeks.
LD50 = 140 mg/kg-bw

(3)	Rabbits (1/dose; strain not specified) were administered CASRN 106-93-4 via the oral route
at 20, 25, 30, 50, 100, 250, 500, 1000, 2000 and 3500 mg/kg-bw and were observed for mortality
and clinical signs (number of days not stated). All animals dosed with 50 mg/kg-bw and greater
died within two days. The other animals survived for the duration of the study. (TSCATS -
OTS0516127 - http://www.svrres.com/esc/tscats.htm).

30 < LD50 < 50 mg/kg-bw

(4)	Several species [mouse (20 females), albino rat (60 males/40 females), guinea pig (40
animals of both sexes) and rabbit (55 females)] were administered single oral doses CASRN
106-93-4 (vehicle: olive oil) via gastric intubation. After exposure, they were observed until
they recovered from weight loss and gained weight normally, typically a period of two weeks.
LD50 (male rat) = 146 mg/kg-bw

LD50 (female rat) = 117 mg/kg-bw
LD50 (female mouse) = 420 mg/kg-bw
LD50 (female rabbit) = 55 mg/kg-bw
LD50 (guinea pig) = 110 mg/kg-bw

Acute Inhalation Toxicity

Rats, guinea pigs and rabbits were exposed to CASRN 106-93-4 at 100 to 10,000 ppm
(approximately 0.77 to 77 mg/L; rats at eight concentrations and guinea pigs at two
concentrations) for varying exposure durations of 0.02 - 16 hours. The number of animals (both
sexes) varied depending on the exposure duration and concentration being tested. Two control
populations were used: air-exposed and unexposed. The animals were observed for
approximately 2 weeks post exposure. LC50 values for guinea pigs and rabbits were not
determined. This summary was supplemented with information from the ATSDR Toxicological
Profile for 1,2,-dibromoethane (http://www.atsdr.cdc.gov/toxpro2.htm).

LC50 (rats; 2-h) ~ 3.08 mg/L

Acute Dermal Toxicity

(1) White rabbits (sex not specified) were treated with CASRN 106-93-4 via the dermal route at
210 (15 animals/dose) or 300, 650 and 1100 mg/kg-bw (5 animals/dose) under impervious
sleeves and heavy cloth bandages for 24 hours and observed for 2 weeks following dosing.
Numbers of mortalities were as follows: 1/15 at 210 mg/kg-bw, 2/5 at 300 mg/kg-bw, 4/5 at 650
mg/kg-bw and 5/5 at 1000 mg/kg-bw. All deaths occurred within 4 days of treatment. 1,2-

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Diboromoethane resulted in moderate to severe erythema, edema and necrosis. An LD50 was not
presented in the submitted summary.

300 < LD50 < 650 mg/kg-bw

(2) Rabbits (1/dose; strain not specified) were administered a single application of
CASRN 106-93-4 via the dermal route at 300, 430, 480, 750, 1090 or 2000 mg/kg-bw under
unspecified conditions for an unspecified amount of time. Mortalities were observed at the two
highest doses within two days of administration (TSCATS - OTS0516127 -
http://www.svrres.com/esc/tscats.htm).

750 < LDS0< 1090 mg/kg-bw

Genetic Toxicity — Chromosomal Aberrations

In vivo

In an NTP study, B6C3F1 mice (10 males/concentration) were exposed to CASRN 106-93-4 via
inhalation at 10, 20 or 50 ppm (approximately 0.077, 0.15 and 0.38 mg/L, respectively) for 25
weeks. Peripheral blood samples were evaluated for incidence of micronuclei. A negative
control responded appropriately. Although a positive control was not tested, positive control
slides were included to control for staining and scoring procedures (http://ntp-
apps.niehs.nih.gov/ntp tox/index.cfm?fuseaction=ntpsearch.searchhome).

CASRN 106-93-4 induced micronuclei in this assay.

Additional Information

Skin irritation

CASRN 106-93-4 was irritating to the skin (species not stated) (http://toxnet.nlm.nih.gov/).
Eye irritation

CASRN 106-93-4 was irritating to eyes (species not stated) (http://toxnet.nlm.nih.gov/).

Conclusion: Acute oral toxicity to rats is moderate and to rabbits is high. Acute dermal toxicity
to rabbits and acute inhalation toxicity to rats is moderate. CASRN 106-93-4 is irritating to skin
and eyes. In chronic inhalation bioassays with rats and mice, the noncancer effects observed
included testicular and adrenal cortex degeneration, retinal atrophy and hepatic necrosis (rats) or
mortality, inflammation/cellular abnormalities in the respiratory tract and hepatic necrosis (mice)
at 0.077 mg/L; NOAELs for systemic toxicity were not established. Repeated inhalation of this
chemical resulted in fatty degeneration in the liver of monkeys at 0.38 mg/L, mortality in guinea
pigs at 0.19 mg/L and no effects in rabbits at 0.38 mg/L (highest dose tested); the NOAEL for
systemic toxicity was 0.19 mg/L, not established and 0.38 mg/L in monkeys, guinea pigs and
rabbits, respectively. Noncancer effects after repeated oral exposures included hepatitis/liver
inflammation, adrenal cortex degeneration and testicular atrophy at 38 mg/kg-bw/day (rats) and
mortality (mice) at 62 mg/kg-bw/day; NOAELs for systemic toxicity were not established. A
reproductive toxicity study in rats via inhalation resulted in effects on male and female
reproductive organs, fewer matings and changes in estrous cycles at 0.61 mg/L; the NOAEL for

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reproductive toxicity was 0.30 mg/L. Human epidemiological studies suggest that CASRN 106-
93-4 is associated with male reproductive toxicity. In prenatal inhalation developmental toxicity
studies in rats and mice, maternal toxicity (decreased body weight in rats and mortality in mice)
was seen at 0.29 mg/L. In these developmental studies, fewer viable fetuses and increased
resorptions were seen at 0.29 mg/L in rats, and skeletal anomalies, resorptions and decreased
fetal body weights were seen at 0.15 mg/L in mice. In rats, the NOAEL for maternal and
developmental toxicity was 0.15 mg/L. In mice, the NOAEL for maternal toxicity was 0.15
mg/L and for developmental toxicity was not established. CASRN 106-93-4 induced gene
mutations and chromosomal aberrations in vitro; induced micronuclei in vivo in mice via
inhalation, but did not induce dominant lethal mutations in vivo. Increased DNA adducts have
been observed in vivo and humans have shown increased chromosomal exchanges after exposure
to this chemical. CASRN 106-93-4 was carcinogenic in rats and mice via the inhalation and oral
routes; human epidemiological studies on carcinogenicity are inconclusive.

4. Environmental Effects- Aquatic Toxicity

In addition to data submitted by the industry sponsor to EPA, information from the following
data sources are summarized below:

(1)	Holcombe, G.W., D.A. Benoit, D.E. Hammermeister, E.N. Leonard, and R.D. Johnson,
1995. Acute and Long-Term Effects of Nine Chemicals on the Japanese Medaka (Oryzias
latipes). Ach. Environ. Contam. Toxicol. 28(3):287-297.

(2)	Erickson, S.J., and A. E. Freeman 1978. Toxicity Screening of Fifteen Chlorinated and
Brominated Compounds Using Four Species of Marine Phytoplankton In: R.L. Jolley, H.
Gorchev, and D.H. Hamilton (Eds.), Water Chlorination: Environmental Impact and
Health Effects, Ann Arbor Sci. Publ., Ann Arbor, MI 2:307-310.

(3)	Trenel, J., and R. Kuhn, 1982. Bewertung Wassergefahrdender Stoffe im Hinblick auf
Lagerung, Umschlag und Transport Umweltforschungsplan des Bundesministers des
Innern (OECDG Data File).

(4)	Davis, J.T., and W.S. Hardcastle, 1959. Biological Assay of Herbicides for Fish Toxicity
Weeds 7:397-404.

Acute Toxicity to Fish

(1) Japanese Medaka (iOryzias latipes) were exposed to measured concentrations of CASRN
106-93-4 (dose range not stated) under flow-through conditions for 96 hours with analytical
monitoring. The LC50 was 331 mg/L.

96-h LC50 = 331 mg/L

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(2)	Japanese Medaka (Oryzias latipes) were exposed to measured concentrations of CASRN
106-93-4 (dose range not stated) under flow-through conditions for 96 hours with analytical
monitoring. The LC50 values ranged from 136 to 991 mg/L.

96-h LC50 = 136 - 991 mg/L

(3)	Bluegill sunfish (Lepomis macrochirus) were exposed to CASRN 106-93-4 (dose range not
stated) under static conditions for 48 hours. The LC50 values ranged from 18 to 25 mg/L.
48-h LC50 =18-25 mg/L

Acute Toxicity to Aquatic Invertebrates

Water fleas (Daphnia magna) were exposed to CASRN 106-93-4 under static conditions for 28
hours. Mean measured concentrations and dose range were not reported.

24-h EC5o= 119 mg/L

A standard acute toxicity test for invertebrates was not provided for CASRN 106-93-4. A 48-
hour EC50 for invertebrates, estimated by ECOSAR (v. 1.00a), was provided to evaluate the
acute toxicity of CASRN 106-93-4.

48-h EC5o= 81.908 mg/L (ECOSAR v. 1.00a)

Toxicity to Aquatic Plants

Freshwater algae (Scenedesmus subspicatus) were exposed to CASRN 106-93-4 at nominal
concentrations for seven days. No dose range was reported. An EC03 value of 266 mg/L was
reported.

Chronic EC50 (proliferation) = 266 mg/L

A standard toxicity test for aquatic plants was not provided for CASRN 106-93-4. A 96-hour
EC50 for aquatic plants, estimated by ECOSAR (v. 1.00a), was provided to evaluate the toxicity
to aquatic plants of CASRN 106-93-4.

96-h EC50 = 35.4 mg/L (ECOSAR v. 1.00a)

Conclusion: The 96-hour LC50 of CASRN 106-93-4 to fish ranged from 136 to 991 mg/L. The
predicted 48-hour EC50 of CASRN 106-93-4 to aquatic invertebrates is 82 mg/L, and the
predicted 96-hour EC50 of CASRN 106-93-4 to aquatic plants is 35.4 mg/L.

A data gap for toxicity to aquatic plants was identified under the HPV Challenge Program.

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Table 3. Summary Table of the Screening Information Data Set

Endpoints

SPONSORED CHEMICAL



1,2-Dibromoethane



(CASRN 106-93-4)

Summary of Human Health Data

Acute Oral Toxicity

116 - 133 (rat)

LD50 (mg/kg-bw)

> 30 < 50 (rabbit)

Acute Inhalation Toxicity



LCso (mg/L)

3.08 (2h; rat)

Acute Dermal Toxicity



LD50 (mg/kg-bw)

> 300 < 650 (rabbit)

Repeated-Dose Toxicity



NOAEL/LOAEL



Inhalation (mg/L)

LOAEL ~ 0.077



NOAEL ~ 0.023



(rat; 13 weeks)



LOAEL ~ 0.077



NOAEL = NE



(mouse; 79-104 weeks)



NOAEL ~ 0.38



(highest dose tested)



(rabbit; 84 days)



LOAEL ~ 0.19



NOAEL = NE



(guinea pig; 205 days)



LOAEL ~ 0.38



NOAEL ~ 0.19



(monkey; 70 days)

Repeated-Dose Toxicity



NOAEL/LOAEL



Oral (mg/kg-bw/day)

LOAEL = 38



NOAEL = NE



(rat; 48-61 weeks)



LOAEL = 62



NOAEL = NE



(mouse; 53-78 weeks)

Reproductive Toxicity



NOAEL/LOAEL



Inhalation (mg/L)

LOAEL ~ 0.61 mg/L



NOAEL ~ 0.30 mg/L

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Table 3. Summary Table of the Screening Information Data Set

Endpoints

SPONSORED CHEMICAL
1,2-Dibromoethane
(CASRN 106-93-4)

Developmental Toxicity
NOAEL/LOAEL
Inhalation (mg/L)

Maternal Toxicity

LOAEL ~ 0.29 mg/L
NOAEL ~ 0.15 mg/L

Developmental Toxicity

LOAEL ~ 0.29 mg/L
NOAEL ~ 0.15 mg/L
(rats)

Maternal Toxicity

LOAEL ~ 0.29 mg/L
NOAEL ~ 0.15 mg/L

Developmental Toxicity

LOAEL ~ 0.15 mg/L
NOAEL = NE
(mice)

Genetic Toxicity - Gene Mutations
In vitro

Positive

Genetic Toxicity - Gene Mutations

In vivo

Negative

Genetic Toxicity - Chromosomal Aberrations
In vitro

Positive

Genetic Toxicity - Chromosomal Aberrations

In vivo

Positive

Genetic Toxicity - Other
In vitro

Unscheduled DNA Synthesis in Mammalian Cells
Sister Chromatid Exchanges
Mouse Lymphoma Assay

Positive
Positive
Positive

Genetic Toxicity - Other
In vivo

Unscheduled DNA Synthesis

Positive

Carcinogenicity
Inhalation (rats/mice)
Oral (rats/mice)

Positive
Positive

Skin irritation

Irritating

Eye irritation

Irritating

Summary of Environmental Effects - Aquatic Toxicity Data

Fish

96-h LC50 (mg/L)

136 - 991

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Table 3. Summary Table of the Screening Information Data Set

Endpoints

SPONSORED CHEMICAL
1,2-Dibromoethane
(CASRN 106-93-4)

Aquatic Invertebrates
48-h EC50 (mg/L)

82 (e)

Aquatic Plants
72-h EC50 (mg/L)

35.4(e)

Bold = measured data; (e) = estimated data (i.e., derived

rom modeling); NE = Not established

14


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