U.S. Environmental Protection Agency
September, 2014
Hazard Characterization Document
SCREENING-LEVEL HAZARD CHARACTERIZATION
Chlorinated Pyridines Category
SPONSORED CHEMICALS
2,3,4,5,6-Pentachloropyridine
3,6-Dichloro-2-trichloromethylpyridine
2-Chloro-5-trichloromethylpyridine
3,4,5,6-Tetrachlo-2-pyridine carbonitrile
Chloropyridine derivatives
Methyl chloropyridine derivatives
CASRN 2176-62-7
CASRN 1817-13-6
CASRN 69045-78-9
CASRN 17824-83-8
CASRN 68412-40-8
CASRN 70024-85-0
SUPPORTING CHEMICAL
2,3,5,6-Tetrachloropyridine
CASRN 2402-79-1
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 Set2)
endpoints that are screening-level indicators of potential hazards (toxicity) for humans or the
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
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.
environment.

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U.S. Environmental Protection Agency
Hazard Characterization Document
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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, ATSDR, IARC,
EXTOXNET, EPA SRS, etc.), STN/CAS online databases (Registry file for locators, ChemAbs for
toxicology data, RTECS, Merck, etc.), Science Direct and ECHA4. OPPT's focus on these specific
sources is based on their being of high quality, highly relevant to hazard characterization, and publicly
available.
OPPT may not develop HCs for those HPV chemicals which have recently been assessed and published
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. HCs may be created if new data suggest a need to update the case
work where the OECD document will be used as key support documentation.
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.
4European Chemicals Agency, http://echa.europa.eu
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Chemical Abstract
Service Registry Number
(CASRN)
2176-62-7
2402-79-1
1817-13-6
69045-78-9
17824-83-8
68412-40-8
70024-85-0
Chemical Abstract
Index Name
Pyridine, pentachloro-
Pyridine, 2,3,5,6-tetrachloro-
Pyridine, 3,6-dichloro-2-(trichloromethyl)-
Pyridine, 2-chloro-5-(trichloromethyl)-
2-Pyridinecarbonitrile, 3,4,5,6-tetrachloro-
Pyridine, chloro derivs.
Pyridine, methyl-, chloro derivs.	
Structural Formulae
See Appendix
Summary
The chlorinated pyridines category consists of seven chemicals. Chlorinated pyridines are solids
at room temperature, and have high boiling points. These substances tend to possess low to
moderate vapor pressure and are moderately soluble in water. Volatilization is slight to moderate
based on estimated Henry's Law constants. The sponsor did not provide hydrolysis data for these
chemicals, except for the supporting chemical tetrachloropyridine, which is hydrolytically stable
at pHs 4, 7 or 9. Except for the supporting chemical tetrachloropyridine, all sponsored chemicals
have a negligible rate of atmospheric oxidation. These chemicals have moderate mobility in soil.
These chemicals are not readily biodegradable based on estimated biodegradation data for the
sponsored chemicals and measured data for the supporting chemical tetrachloropyridine. These
chemicals are expected to possess low bioconcentration potential (Bl) and moderate persistence
(P2) under environmental conditions.
Human Health Hazard
Subcategory I: Pentachloropyridine
The acute oral toxicity of 2,3,4,5,6-pentachloropyridine in rats is moderate. The acute inhalation
toxicity of 2,3,5,6-tetrachloropyridine (supporting chemical) is low in rats. In the 90-day
repeated-dose dietary toxicity study of 2,3,4,5,6,-pentachloropyridine the LOAEL for male rats is
30 mg/kg-bw/day based on increased liver and kidney weights and hyaline droplet degeneration
of renal tubules. The NOAEL for males is 10 mg/kg-bw/day. No systemic toxicity was seen in
females; the NOAEL for females is 30 mg/kg-bw/day, the highest dose tested. A 91-day dietary
repeated-dose toxicity study of 2,3,5,6-tetrachloropyridine (supporting chemical) showed
degenerative changes in the kidney of male rats at 10 mg/kg-bw/day. The NOAEL for males is 3-
mg/kg-bw/day. In females, the NOAEL is 100 mg/kg-bw/day (highest dose tested). In a
combined repeated-dose/reproductive/developmental toxicity study of 2,3,5,6-tetrachloropyridine
(supporting chemical) in rats via gavage, the LOAEL in males is 25 mg/kg-day based on hyaline
protein nephropathy with a NOAEL of 5 mg/kg-day. In females, the LOAEL of 150 mg/kg-day
is based on effects on liver and kidney; the NOAEL is 25 mg/kg-day. No reproductive toxicity
3

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Hazard Characterization Document
September, 2014
study is available for 2,3,4,5,6,-pentachloropyridine. A combined repeated-dose
reproductive/developmental toxicity study in rats via gavage with a supporting chemical 2,3,5,6-
tetrachloropyridine showed no treatment-related effects on reproductive organs. The NOAEL for
reproductive toxicity is 150 mg/kg-day, the highest dose tested. In a prenatal developmental
toxicity study of 2,3,4,5,6,-pentachloropyridine in rats via gavage, maternal toxicity was seen at
50 mg/kg-day (increased liver and kidney weights) with a NOAEL of 10 mg/kg-day. The
LOAEL for developmental toxicity is 200 mg/kg-day based on decreased fetal weights; the
NOAEL is 50 mg/kg-day. 2,3,4,5,6,-Pentachloropyridine and 2,3,5,6,-tetrachloropyridine
(supporting chemical) did not induce gene mutations in bacteria and did not induce chromosomal
aberrations in rat lymphocytes in vitro or in mouse bone marrow cells in vivo. The subcategory
members are irritating to rabbit skin, but not to rabbit eyes. 2,3,5,6-Tetrachloropyridine
(supporting chemical) is not a dermal sensitizer in guinea pigs.
No data gaps were identified for subcategory I under the HPV Challenge program.
Subcategory II: Chlorinated Trichloromethylpyridines
The acute oral toxicity for members of the chlorinated trichloromethylpyridine subcategory in rats
is low. The acute toxicity in rats via inhalation is inconclusive (LCso > 0.108 mg/L) because the
concentration tested was not high enough to establish the potential hazard. In a 3-week dermal
toxicity study of 2-chloro, 5 trichloromethylpyridine in rats, the LOAEL was 500 mg/kg-day
based on mortality and effects on clinical chemistry parameters, organ weight changes and
histopathology of liver (vacuolation and necrosis of centrilobular hepatocytes), kidney
(vacuolation of renal tubular epithelium) and testes (atrophy of the seminiferous tubular
epithelium). The NOAEL is 100 mg/kg-day. There are no data for reproductive or
developmental toxicity. 2-Chloro-5-trichloromethylpyridine induced gene mutations in bacteria
and mouse lymphoma cells in vitro and induced chromosomal aberrations in a human lymphocyte
assay in vitro. Subcategory members are irritating to rabbit skin and eyes, while 2-chloro-
5-trichloromethylpyridine is a dermal sensitizer in guinea pigs.
Data gaps for the reproductive and developmental toxicity endpoints were identified for
subcategory II under the HPV Challenge Program.
Additional Sponsored Chemicals
3,4,5,6,-Tetrachloro-2-pyridine carbonitrile (CASRN17824-83-8)
Acute toxicity of 3,4,5,6,-Tetrachloro-2-pyridine carbonitrile to rats is low. 3,4,5,6,-Tetrachloro-
2-pyridine carbonitrile was corrosive to rabbit skin and irritating to rabbit eyes. No data are
available for repeated-dose, reproductive, developmental toxicity and gene mutation and
chromosomal aberrations endpoints.
Data gaps for acute, repeated-dose, reproductive, developmental toxicity and gene mutation and
chromosomal aberrations endpoints were identified under the HPV Challenge Program.
Chloropyridine derivatives (CASRN 68412-400-8)
No data are available for acute, repeated-dose, reproductive, developmental toxicity and gene
mutation and chromosomal aberrations endpoints.	
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Data gaps for acute, repeated-dose, reproductive, developmental toxicity and gene mutation and
chromosomal aberrations endpoints were identified under the HPV Challenge Program.
Methyl chloropyridine derivatives (CASRN 70024-85-0)
No data are available for acute, repeated-dose, reproductive, developmental toxicity and gene
mutation and chromosomal aberrations endpoints.
Data gaps for acute, repeated-dose, reproductive, developmental toxicity and gene mutation and
chromosomal aberrations endpoints were identified under the HPV Challenge Program.
Hazard to the Environment
Subcategory I: Tetra- and Pentachloropyridines
For subcategory I, the 96-h LC50 for fish is 0.47 mg/L. Based on the supporting chemical,
2,3,5,6-tetrachloropyridine, the 48-h EC50 for aquatic invertebrates is 2.05 mg/L. The 72-h EC50
for algae is 1.66 mg/L for biomass, and, based on the supporting chemical, 2,3,5,6-
tetrachloropyridine, the 72-h EC50 for algae is 9.7 mg/L for growth rate.
No data gaps were identified for the tetra- and penta-chloropyridines under the HPV Challenge
Program.
Subcategory II: Chlorinated Trichloromethylpyridines
There are no adequate data available for the evaluation of the ecological toxicity of the
chlorinated trichloromethylpyridines.
The acute fish and aquatic invertebrate toxicity and aquatic plant toxicity endpoints were
identified as a data gaps for the chlorinated trichloromethylpyridines under the HPV Challenge
Program.
Additional Sponsored Chemicals
Chloropyridine derivatives
There are no available data for the evaluation of ecological toxicity of the chloropyridine
derivatives.
The acute fish and aquatic invertebrate toxicity and aquatic plant toxicity endpoints were
identified as a data gaps for the chloropyridine derivatives under the HPV Challenge Program.
Methyl chloropyridine derivatives
There are no available data for the evaluation of ecological toxicity of the methyl chloropyridine
derivatives.
The acute fish and aquatic invertebrate toxicity and aquatic plant toxicity endpoints were
identified as a data gaps for the methyl chloropyridine derivatives under the HPV Challenge
Program.	
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The sponsor, Dow Agro Sciences LLC, submitted a Test Plan and Robust Summaries to EPA for
the chlorinated pyridines category on December 27, 2005. Test Plan and Robust Summaries for the
individual category members were received by EPA, previously. EPA posted the individuals and
category submissions on the ChemRTK HPV Challenge website on January 26, 2006
(http://www.epa.gov/hpv/pubs/summaries/chlrpycat/cl6113tc.htm).
EPA comments on the submissions were posted to the website on September 27, 2006. Public
comments were also received and posted to the website.
Category Justification
The sponsor originally submitted the category members as individual submissions. EPA then
received a category document combining these chemicals into one category, in which the sponsor
proposed a category of seven structurally-related chlorinated pyridines. EPA has modified this
approach for the purposes of this Hazard Characterization as follows.
For human health effects, the chlorinated pyridine category now consists of two subcategories, (I)
Pentachlorinated Pyridines and (II) Chlorinated Trichloromethylpyridines, and three individually
evaluated chlorinated pyridine substances. The chemicals in the subcategories have a pyridine
nucleus bearing at least one chlorine atom. Subcategory I consists of 2,3,4,5,6-pentachloropyridine.
Subcategory II contains 3,6-dichloro-2-trichloromethylpyridine and 2-chloro-5-
trichloromethylpyridine. These two chemicals share a trichloromethylated pyridine nucleus and
differ only by the presence of one vs. two chlorine atoms and the positions of the substituents. All
three chemicals in Subcategories I and II have good leaving groups in the 2-position that can
undergo displacement by biological nucleophiles such as --SH. In addition, the toxicity of
subcategory II members may differ significantly from the other chlorinated pyridines owing to the
presence of the potentially reactive trichloromethyl group.
As to the remaining three proposed category members, 3,4,5,6-tetrachloro-2-pyridinecarbonitrile
contains an additional functional group, the nitrile group, that is not shared by any of the other
proposed single-chemical category members and that may confer additional toxicological
properties. The chloropyridine derivatives and methyl chloropyridine derivatives are both complex
mixtures that consist mainly of chemicals that are roughly similar in structure to the proposed
category members; however, many of the constituents are significantly different or more complex
(such as chlorinated bipyridines), and therefore their grouping with the other proposed category
members (or with each other) is inappropriate. As such, the nitrile and two mixtures will be
evaluated individually for health effects in this hazard characterization.
The sponsor proposed reduced health effects testing on the basis that the chlorinated pyridines,
except for 2,3,4,5,6-pentachloropyridine, are closed-system intermediates (CSIs). EPA's evaluation
of the submitted information indicated that the chemicals do not meet the criteria to adequately
support the CSI status. Therefore, EPA has determined that the chemicals do not qualify for
reduced testing and data for the repeated-dose and reproductive toxicity endpoints are needed for
the purposes of the HPV Challenge Program.
For environmental toxicity, EPA is employing two subcategories based on chemical properties and
structural similarity. Subcategory I, Tetra- and Pentachloropyridines, consists of 2,3,4,5,6-
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pentachloropyridine and 3,4,5,6-tetrachloro-2-pyridinecarbonitrile. Subcategory II, Chlorinated
Trichloromethylpyridines, consists of 3,6-dichloro-2-trichloromethylpyridine and 2-chloro-5-
trichloromethylpyridine. As with human health, the single-chemical members can undergo
nucleophilic substitution of the 2-chlorine by biological nucleophiles, possibly inducing toxicity
beyond the typical narcosis/baseline toxicity (see Supporting Chemical Justification below). The
two complex mixtures, chloropyridines and chlorinated bipyridines, do not clearly overlap with one
another and contain various structure types, some not clearly identified, and therefore their grouping
with the other proposed category members or with each other is inappropriate. These two
sponsored chemicals will be evaluated individually for ecological effects in this hazard
characterization.
Toxicity and environmental fate endpoints will only be read across within subcategories and not
between subcategories.
Justification for Supporting Chemical
For ecological toxicity the supporting chemical 2,3,5,6-tetrachloropyridine, is structurally similar to
the sponsored chemicals 2,3,4,5,6-pentachloropyridine and 3,4,5,6-tetrachloro-2-pyridine carbo-
nitrile, because it has a pyridine nucleus with more than three chlorine substituents. Furthermore, in
biological systems, a 2-substituted pyridine can undergo displacement of a good leaving group in
that position, such as chloride, by biological nucleophiles such as -SH (Hermens, J. 1985). Similar
reactivity is associated with toxicity to aquatic organisms that is 22 to nearly 2000 times greater
than narcosis type toxicity (Lipnick, R.L. 1989, Lipnick, R.L. 1991, Newsome, L.D., et al. 1984).
Therefore, EPA considers the test data for supporting chemical 2,3,5,6-tetrachloropyridine adequate
for reading across to the sponsored chemicals in Subcategory I for the purposes of this hazard
characterization.
1. Chemical Identity
1.1	Identification and Purity
The following information was taken from the 2005 Test Plan: All the sponsored members of the
chlorinated pyridines category, except 2,3,4,5,6-pentachloropyridine, are chemicals or process
streams used in other manufacturing processes or concerted to feedstock for chlorine production.
2,3,4,5,6-Pentachloropyridine is a production chemical. The purity of the sponsored chemicals in
subcategories I and II is high (90-100%), where indicated.
1.2	Physical-Chemical Properties
The physical-chemical properties for members of the chlorinated pyridines category are provided in
Table 1.
Chlorinated pyridines are solids at room temperature, and have high boiling points. These
substances tend to possess low to moderate vapor pressure and are moderately soluble in water.
Volatilization is slight to moderate based on estimated Henry's Law constants.
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2. General Information on Exposure
2.1 Production Volume and Use Pattern
The Chlorinated Pyridine Category chemicals had an aggregated production and/or import volume
in the United States between 14 million and 90 million pounds during calendar year 2005.
CASRN 1817-13-6, 17824-83-8 and 2176-62-7:
Non-confidential information in the IUR indicated that the industrial processing and uses of the
chemicals include pesticide and other agricultural chemical manufacturing as intermediates.
No commercial and consumer uses were reported for the chemicals.
CASRN 69045-78-9 was not reported in the 2006 IUR.
CASRN 68412-40-8:
No industrial processing and uses, and commercial and consumer uses were reported for the
chemical.
CASRN 70024-85-0:
Non-confidential information in the IUR indicated that the industrial processing and uses of the
chemical include other basic organic chemical manufacturing as intermediates. No commercial and
consumer uses were reported for the chemical.
2.2 Environmental Exposure and Fate
Except for the supporting chemical tetrachloropyridine, all sponsored chemicals have a negligible
rate of atmospheric oxidation. These chemicals have moderate mobility in soil. These chemicals are
not readily biodegradable, based on estimated biodegradation data for the sponsored chemicals and
measured data for the supporting chemical tetratchloropyridine. These chemicals are expected to
possess low bioconcentration potential (Bl) and moderate persistence (P2) under environmental
conditions.
The environmental fate properties of the chlorinated pyridines category members are summarized in
•	CASRN 2176-62-7:
•	CASRN 1817-13-6:
•	CASRN 17824-83-8
•	CASRN 68412-40-8
•	CASRN 70024-85-0
10 million to < 50 million pounds;
1 million to < 10 million pounds;
1 million to < 10 million pounds;
1 million to < 10 million pounds;
1 million to < 10 million pounds;
Table 2.
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Table 1. Physical-Chemical Properties of Chlorinated Pyridines Category1

Subcategory I
Subcategory II
Additional Sponsored Chemicals
Property
SPONSORED
CHEMICAL
2,3,4,5,6-
Pcntachloro-
pyridinc
SUPPORTING
CHEMICAL
2,3,5,6-
Tctrachloro-
pyridinc
SPONSORED
CHEMICAL
3,6-Dichloro-2-
trichlomcthyl-
pyridinc
SPONSORED
CHEMICAL
2-Chloro-5-
trichloromcthyl-
pyridinc
SPONSORED
CHEMICAL
3,4,5,6-
Tetrachloro-2-
pyridinc
carbonitrilc
SPONSORED
CHEMICAL
Chloropyridinc
Derivatives
(mixture of
several
ehemieals)
SPONSORED
CHEMICAL
Chloropyridinc
Derivatives
(mixture of
several
chemicals)
CASRN
2176-62-7
2402-79-1
1817-13-6
69045-78-9
17824-83-8
68412-40-8
70024-85-0
Melting Point
125-126 °C
(m)
90.5 °C
(m)
47-48°C
(m)
52-54°C
(m)
150.5-151.5 °C
(m)
No data
No data
Boiling Point
273 °C (e)
251.6 °C (m)
272°C (e)
245°C (e)
310.1 °C (e)
No data
No data
Vapor Pressure
0.014 mmHg
(0.018 hPa)
at 25 °C
(m)
0.02 mmHg
(0.0267 hPa)
at 25 °C
(e)
0.0052 mmHg
(0.0069 hPa)
at 25 °C
(e)
0.11 mmHg
(0.14 hPa) at 25°C
(e)
0.000033 mmHg
(0.000044475
hPa) at 25 °C
(e)
No data
No data
Log Kow
3.53 at 25°C
(m)
3.32 at 25 °C
(m)
4 at 25 °C
(e)
3.35 at25°C
(e)
2.93 at 25 °C
(e)
No data
No data
Henry's Law
Constant2
1.154 xlO"5
atm-m3/mole
(e)
3.31xl0"5
atm-m3/mole
(e)
1.341xl0"4
atm-m3/mole
(e)
1.457xl0"4
atm-m3/mole
(e)
1.341xl0"6
atm-m3/mole
(e)
No data
No data
Water solubility
8.5 mg/L at 25 °C
(m)
29.8-30.2 mg/L at
23 °C
(m)
7.5 mg/L at 25 °C
(e)
99 mg/L at 25°C
(e)
45 mg/L at 25
°C
(e)
No data
No data
1 HPV Challenge Group Revised Test Plan and Robust Summary for Chlorinated Pyridines Category. Available at:
http://www.epa.gov/oppt/chemrtk/pubs/summaries/chlrpycat/cl6113tc.htm
as of July 29, 2011
2Estimated values were obtained from EPIWIN (v 3.20)
(m) = measured data (i.e., derived from testing); (e) = estimated data

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Table 2. Environmental Fate Properties of Chlorinated Pyridines1

Subcategory I
Subcategory II
Additional Sponsored Chemicals
Property
SPONSORED
CHEMICAL
2,3,4,5,6-
Pcntachloro-
pyridinc
SUPPORTING
CHEMICAL
2,3,5,6-
Tctrachloro-
pyridinc
SPONSORED
CHEMICAL
3,6-Dichloro-2-
trichlomcthyl-
pvridinc
SPONSORED
CHEMICAL
2-Ch!oro-5-
trichloromcthyl-
pyridinc
SPONSORED
CHEMICAL
3,4,5,6-
Tctrachloro-2-
pyridinc
carbonitrilc
SPONSORED
CHEMICAL
Chloropvridinc
Derivatives
(mixture of
several
chemicals)
SPONSORED
CHEMICAL
Chloropvridinc
Derivatives
(mixture of
several
chemicals)
CASRN
2176-62-7
2402-79-1
1817-13-6
69045-78-9
17824-83-8
68412-40-8
70024-85-0
Photodegradation
50 % after 974
days
50 % after 7 days
50% after 768
days
50 % after 224
days
50% after 3881
days
No data
No data
Stability in water
No rate constants
could be
calculated
Hydrolytically
stable at pHs of
4,7, or 9,
up to 70 °C
(m)
No data
No data
No data
No data
No data
Transport between
environmental
compartments
Air (%)
Water (%)
Soil (%)
73.55
6.5
19.5
86
< 10
<2
32.9
6.7
59.1
17.9
27.1
53.8
1.5
55.6
41.9
No data
No data
Biodegradation2
Not Readily
biodegradable
No biodegradation
observed
(m)
Not Readily
Biodegradable
Not Readily
Biodegradable
Not Readily
Biodegradable
No data
No data
Bioaccumulation
No data
No data
BCF = 238.4
BCF= 153
BCF = 35.95
No data
No data
1 All data, except estimated biodegradation data, obtained from HPV Challenge Group Revised Test Plan and Robust Summary for Chlorinated Pyridines Category. Available at:
http://www.epa.gov/oppt/chemrtk/pubs/summaries/chlrpvcat/cl6113tc.htm as of July 29, 2011.
2Estimated biodegradation data obtained from BIOWIN (v 4.10)
(m) = measured data (i.e., derived from testing).

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Conclusion: Chlorinated pyridines are solids at room temperature, and have high boiling points.
These substances tend to possess low to moderate vapor pressure and are moderately soluble in
water. Volatilization is slight to moderate based on estimated Henry's Law constants. The
sponsor did not provide hydrolysis data for these chemicals, except for the supporting chemical
tetrachloropyridine, which is hydrolytically stable at pHs 4, 7 or 9. Except for the supporting
chemical tetrachloropyridine, all sponsored chemicals have a negligible rate of atmospheric
oxidation. These chemicals have moderate mobility in soil. These chemicals are not readily
biodegradable, based on estimated biodegradation data for the sponsored chemicals and
measured data for the supporting chemical 2,3,5,6-tetrachloropyridine. These chemicals are
expected to possess low bioconcentration potential (Bl) and moderate persistence (P2) under
environmental conditions.
3. Human Health Hazard
A summary of health effects data submitted for SIDS endpoints is provided in Table 3. The table
also indicates where data for tested category members are read-across (RA) to untested members
of the category as appropriate.
Acute Oral Toxicity
Subcategory I: Pentachloropyridine
2,3,4,5,6-Pentachloropyridine (CASRN2176-62-7)
(1)	Fischer 344 rats (3 males/dose) were administered 2,3,4,5,6-pentachloropyridine (> 99% w/w
purity) in corn oil via gavage at 100, 250, 500 or 750 mg/kg and observed for 14 days following
dosing. Mortalities were observed at 500 (2/3) and 750 (3/3) mg/kg. Additional details from
TSCATS (OTS0536503).
LDso = 435 mg/kg
(2)	2,3,4,5,6-pentachloropyridine was administered to 3 female rats via the diet. The study
summary is missing critical study information, including dose levels, duration of observation, rat
strain, number of animals/dose and mortality at each dose. The reported LD50 value of 126
mg/kg > LD50 <1000 mg/kg is provided for general information purposes.
2,3,5,6-Tetrachloropyridine (CASRN2402-79-1, supporting chemical)
(1)	Rats (strain not specified, 5/sex/dose) were administered 2,3,5,6-tetrachloropyridine (purity
not indicated) via an unspecified oral route at 500, 1000 or 2000 mg/kg. Details on mortalities
and length of observation period were not specified. The reported LD50 values of 1182 mg/kg
for males and 1414 mg/kg for females are provided for general information purposes.
(2)	Female rats (strain not specified, 2/dose) were administered 2,3,5,6-tetrachloropyridine
(purity not indicated) via gavage at 126, 252, 500, 1000 or 2000 mg/kg in corn oil. Mortalities
were observed at 1000 (1/2) and 2000 (2/2) mg/kg. No information was provided on the length
of observation period. The reported LD50 value of - 1000 mg/kg is provided for general
information purposes.
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Subcategory II: Chlorinated Trichloromethylpyridines
3,6-Dichloro-2-trichloromethylpyridine (CASRN1817-13-6)
Rats (3 males/dose, strain not stated) were administered 3,6-dichloro-2-trichloromethylpyridine
(purity not indicated) in corn oil via gavage at 130, 250, 500, 1000 or 2000 mg/kg and observed
for 14 days following dosing. Mortality occurred at 2000 mg/kg (3/3).
1000 mg/kg < LDso < 2000 mg/kg
2-Chloro-5-trichloromethylpyridine (CASRN 69045-78-9)
Sprague-Dawley rats (3 males/dose) were administered 2-chloro-5-trichloromethylpyridine (90-
100% w/w purity) in corn oil via gavage at 130, 250, 500, 1000 or 2000 mg/kg and observed for
14 days following dosing. Mortalities occurred at 1000 (2/3) and 2000 (2/3) mg/kg.
500 mg/kg < LD50 < 1000 mg/kg
Additional Sponsored Chemicals
3,4,5,6,-tetrachloro-2-pyridine carbonitrile (CASRN 17824-83-8)
Female rats (strain not specified, 2/dose) were administered 3,4,5,6-tetrachloro-2-pyridine
carbonitrile via gavage as a 20% suspension in corn oil at 252, 500, 1000, 2000 or 3980 mg/kg
and observed for two weeks. Mortality was seen at 2000 (1/2) and 3980 (2/2) mg/kg.
LD50 = 1000 - 2000 mg/kg
Chloropyridine derivatives (CASRN 68412-400-8)
No data
Methyl chloropyridine derivatives (CASRN 70024-85-0)
No data
Acute Inhalation Toxicity
Subcategory I: Pentachloropyridine
2,3,5,6-Tetrachloropyridine (CASRN2402-79-1, supporting chemical)
Sprague-Dawley rats (6 males) were exposed whole-body to 2,3,5,6-tetrachloropyridine (purity
not indicated) at 6300 ppm (56 mg/L) for 7 hours and observed for 14 days. No mortality was
observed.
LC50 > 56 mg/L
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Subcategory II: Chlorinated Trichloromethylpyridines
2-Chloro-5-trichloromethylpyridine (CASRN 69045-78-9)
Fischer 344 rats (6 males) were exposed whole-body to 2-chloro-5-trichloromethylpyridine (90-
100% w/w purity) as vapor at 11.4 ppm (~0.108 mg/L) for 6 hours and observed for 14 days
following dosing. No mortality was observed.
LCso > 0.108 mg/L
Repeated-Dose Toxicity
Subcategory I: Pentachloropyridine
2,3,4,5,6-Pentachloropyridine (CASRN2176-62-7)
Rats (strain not specified, 10 - 15/sex/dose) were administered 2,3,4,5,6-pentachloropyridine
(> 99% w/w purity) via the diet at 0, 0.3, 1, 3, 10 or 30 mg/kg-bw/day for 90 days. Animals
were examined frequently for clinical signs of toxicity. Body weight and food consumption
were measured weekly. Hematological parameters were examined during weeks 3 and 12 and at
termination of the exposure. Serum glutamic pyruvic transaminase was measured on days 1, 3,
7, 14, 30 and 90. Blood urea nitrogen was measured on day 90. At the termination of exposure,
complete necropsies were performed, including gross pathological and histopathological
examinations. No mortalities or clinical signs of toxicity were observed. There were no
treatment-related effects observed in females. Effects in males included increased relative liver
and kidney weights and mild focal hyaline droplet degeneration of the convoluted tubules of the
renal cortex4 at 30 mg/kg-bw/day. Testicular tubal atrophy of varying degrees was observed in
all dose groups, including controls. In an effort to clarify testicular findings among dosed rats,
additional groups were administered 2,3,4,5,6-pentachloropyridine via gavage or the diet. In the
follow-up gavage study, male rats (10/dose) were administered 2,3,4,5,6-pentachloropyridine
(vehicle not indicated) at 0, 62.5, 125 or 250 mg/kg-bw/day for 5 days/week for 2 weeks. In the
follow-up dietary study, male rats (30/dose) were administered 2,3,4,5,6-pentachloropyridine at
0, 62.5, 125 or 250 mg/kg-bw/day for 242 days. No treatment-related testicular effects were
observed in the two follow-up studies.
LOAEL (males) = 30 mg/kg-bw/day (based on increased liver and kidney weights and
degeneration of renal tubules)
NOAEL (males) = 10 mg/kg-bw/day
NOAEL (females) = 30 mg/kg-bw/day (highest dose tested)
2,3,5,6-Tetrachloropyridine (CASRN2402-79-1, supporting chemical)
(1) Sherman rats (10/sex/dose) were administered 2,3,5,6-tetrachloropyridine (purity not
indicated) in the diet at 0, 1, 3, 10, 30 or 100 mg/kg-bw/day for 91 days. Changes in organ
weight included increased kidney weight in males at 30 and 100 mg/kg-bw/day, slightly
increased liver weight in males at 100 mg/kg-bw/day and slightly increased liver and spleen
weights in females at 30 and 100 mg/kg-bw/day. Macroscopic evaluation revealed pale kidneys
in males at 30 and 100 mg/kg-bw/day. Histopathological evaluation identified mild, reversible
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degenerative changes (hyaline droplets) in male kidneys at 10, 30 and 100 mg/kg-bw/day5. No
mortalities, clinical signs of toxicity or changes in body weight, food consumption, hematology
and clinical chemistry parameters were observed.
LOAEL (males) = 10 mg/kg-bw/day (based on degenerative changes in the kidneys)
NOAEL (males) = 3 mg/kg-bw/day
NOAEL (females) = 100 mg/kg-bw/day (highest dose tested)
(2) In a combined repeated-dose/reproductive/developmental toxicity screening test, Sprague-
Dawley rats (15/sex/dose) were administered 2,3,5,6-tetrachloropyridine (purity not indicated)
via gavage at 0 (vehicle), 5, 25 or 150 mg/kg-day for approximately 52 days. After 2 weeks of
dosing, the parental rats were mated for 2 weeks to produce F1 litters. (The vehicle identity was
not indicated in the robust summary.) Dosing of both sexes continued through the gestation and
lactation periods. All parental animals and litters were euthanized following lactation day 4. No
mortalities were observed. Increased liver and kidney weights were observed in males and
females at 150 mg/kg-day. Effects in the liver at this dose were limited to centrilobular
hypertrophy of hepatocytes. Renal effects at 150 mg/kg-day included pale kidney coloration in
males and females, hyaline protein droplet nephropathy4 in males and slight to severe renal
tubule epithelial cell degeneration/regeneration, very slight to slight distention of renal tubules
and inflammation of renal papillae in females. Protein droplet nephropathy was also observed in
males at 25 mg/kg-day. Alterations in a number of clinical chemistry parameters (not specified)
were also observed in females given 150 mg/kg-day, but were considered secondary to renal and
hepatic effects. No significant treatment-related effects were observed on clinical signs, food
consumption, body weight or body weight gain.
LOAEL (males) = 25 mg/kg-day (based on hyaline protein droplet nephropathy in the kidneys)
NOAEL (males) = 5 mg/kg-day
LOAEL (females) = 150 mg/kg-day (based on increased liver and kidney weights, hypertrophy
of hepatocytes and renal histopathology)
NOAEL (females) = 25 mg/kg-day
Subcategory II: Chlorinated Trichloromethylpyridines
2-Chloro-5-trichloromethylpyridine (CASRN 69045-78-9)
In a 3-week dermal toxicity study, rats (10/sex/dose, strain not stated) were administered 2-
chloro-5-trichloromethylpyridine (crude, purity not indicated) in corn oil at 0 (corn oil), 20, 100
or 500 mg/kg-day under occluded conditions for 21 days. Due to mortality at 500 mg/kg-day,
treatment at this dose was suspended for 4 days after the fifth day of exposure and upon re-
initiation, dosing was reduced to once every 2 days. Parameters measured included clinical
observations, body weight, food consumption, hematology, clinical chemistry, urinalysis, organ
5 The presence of nephropathy in association with the hyaline droplet accumulation in male rats suggests that the
nephropathy in the males is occurring by an a 1 p ha - 2 |i - g 1 o b u 1 i n - mc d i a tc d mechanism, which appears to be unique to
male rats and the response is probably not relevant to humans for purposes of risk assessment. However, the key
events and data necessary to demonstrate this mode of action which is outlined in EPA's Risk Assessment Forum,
Alpha-2|i-Globulin: Association with Chemically Induced Renal Toxicity and Neoplasia in the Rat,
EPA/625/3-91/019F are not contained in the data set.
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weights and histopathology. Clinical observations at 500 mg/kg-day included lethargy, a
hunched appearance, ano-genital staining and bouts of continual shaking. At the application site,
moderate skin irritation was observed at 500 mg/kg-day, characterized by acute dermatitis and a
moderate to marked thickening of the epidermis. Depressed cholinesterase activity was observed
in the plasma of females and in the brain tissue of males at 500 mg/kg-day. Males exhibited
elevated alkaline phosphatase and glutamic pyruvic transaminase activity, higher plasma
potassium ion concentrations, higher triglyceride levels and lower cholesterol at 500 mg/kg-day.
Depressed total protein levels were observed in females at 500 mg/kg-bw/day. At 500 mg/kg-
day, males exhibited increased weights of the brain, heart, kidneys and lungs, while both sexes
had higher liver weights. The hepatic activity of aminopyrine-N-demethylase was elevated in
males at 500 mg/kg-day. Histopathological effects observed at 500 mg/kg-day included
vacuolation and necrosis of centrilobular hepatocytes, vacuolation of the renal tubular epithelium
and atrophy of the seminiferous tubular epithelium. The overall toxic effect observed at 500
mg/kg-day was characterized by liver necrosis and a disturbance of lipid metabolism. Details are
from TSCATS (OTS0545698).
LOAEL = 500 mg/kg-day (based on mortality, changes in clinical chemistry, changes in organ
weights and histopathological effects on the liver, kidneys and testes)
NOAEL = 100 mg/kg-day
Additional Sponsored Chemicals
3,4,5,6,-tetrachloro-2-pyridine carbonitrile (CASRN17824-83-8)
No data
Chloropyridine derivatives (CASRN 68412-400-8)
No data
Methyl chloropyridine derivatives (CASRN 70024-85-0)
No data
Reproductive Toxicity
Subcategory I: Pentachloropyridine
2,3,5,6-Tetrachloropyridine (CASRN2402-79-1, supporting chemical)
In the combined oral repeated-dose/reproductive/developmental toxicity screening test in
Sprague-Dawley rats (via gavage) described previously, no treatment-related reproductive effects
of 2,3,5,6-tetrachloropyridine were observed on fertility parameters of parental rats. Neonatal
parameters evaluated included clinical/morphological alterations, body weight and survival. No
adverse effects were reported for the fertility or neonatal parameters evaluated in the study.
LOAEL (systemic toxicity, males) = 25 mg/kg-day (based on hyaline protein droplet
nephropathy in the kidneys)
NOAEL (systemic toxicity, males) = 5 mg/kg-day
LOAEL (systemic toxicity, females) = 150 mg/kg-day (based on increased liver and kidney
weights, hypertrophy of hepatocytes and renal histopathology)
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NOAEL (systemic toxicity, females) = 25 mg/kg-day
NOAEL (reproductive toxicity) = 150 mg/kg-day (highest dose tested)
2,3,4,5,6-Pentachloropyridine (CASRN2176-62-7)
In the 91-day oral repeated-dose toxicity dietary study in rats described previously, no treatment-
related effects were observed in the reproductive organs of rats exposed up to 30 mg/kg-bw/day
(highest dose tested)
Subcategory II: Chlorinated Trichloromethylpyridines
No data
Additional Sponsored Chemicals
3,4,5,6,-tetrachloro-2-pyridine carbonitrile (CASRN 17824-83-8)
No data
Chloropyridine derivatives (CASRN 68412-400-8)
No data
Methyl chloropyridine derivatives (CASRN 70024-85-0)
No data
Developmental Toxicity
Subcategory I: Pentachloropyridine
2,3,4,5,6-Pentachloropyridine (CASRN2176-62-7)
In a prenatal-development toxicity study, pregnant female Sprague-Dawley rats (25/dose) were
administered 2,3,4,5,6-pentachloropyridine in corn oil via gavage at 0 (corn oil), 10, 50 or 200
mg/kg-day from days 6 to 20 of gestation. Mean measured concentrations were 94-101% of
the targeted concentrations. Animals were examined daily for clinical signs and body weight.
Food consumption was measured in 3-day intervals. On day 21 of gestation, complete
necropsies were performed and kidney, liver and gravid uterus weights were taken.
Reproductive parameters included numbers of corpora lutea, implantation sites, viable fetuses
and resorptions. Fetal observations included sex, body weight and external, visceral, craniofacial
and skeletal examinations. No treatment-related mortality was observed. Clinical signs of
toxicity included perioral soiling (salivation) at 50 and 200 mg/kg-day and urine soiling at 200
mg/kg-day. Decreased body weight, body weight gain and food consumption were observed at
200 mg/kg-day. Increased absolute and relative kidney weights and increased relative liver
weight were observed at 50 and 200 mg/kg-day. Increased absolute liver weight was observed at
200 mg/kg-day. Histopathological effects included increased size of the kidneys in one animal at
200 mg/kg-day and each had a pale cortex. Developmental effects were limited to decreased
fetal body weight at 200 mg/kg-day, which was correlated with decreased maternal body weight.
There were no treatment-related effects on pregnancy rates, resorption rates, litter size, numbers
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of corpora lutea or implantations, percent pre-implantation loss, percent post-implantation loss,
fetal sex ratios or gravid uterine weights at any dose level.
LOAEL (maternal toxicity) = 50 mg/kg-day (based on increased liver and kidney weights)
NOAEL (maternal toxicity) = 10 mg/kg-day
LOAEL (developmental toxicity) = 200 mg/kg-day (based on decreased fetal body weight)
NOAEL (developmental toxicity) = 50 mg/kg-day
2,3,5,6-Tetrachloropyridine (CASRN2402-79-1, supporting chemical)
In the combined repeated-dose/reproductive/developmental toxicity screening test in Sprague-
Dawley rats (via gavage) described previously, developmental effects measured included
clinical/morphological alterations, body weight and survival of pups. No developmental effects
of 2,3,5,6-tetrachloropyridine were observed at the highest dose of 150 mg/kg-day.
LOAEL (maternal toxicity) = 150 mg/kg-day (based on increased liver and kidney weights,
hypertrophy of hepatocytes and renal histopathology)
NOAEL (maternal toxicity) = 25 mg/kg-day
NOAEL (developmental toxicity) = 150 mg/kg-day (highest dose tested)
Subcategory II: Chlorinated Trichloromethylpyridines
No data
Additional Sponsored Chemicals
3,4,5,6,-tetrachloro-2-pyridine carbonitrile (CASRN 17824-83-8)
No data
Chloropyridine derivatives (CASRN 68412-400-8)
No data
Methyl chloropyridine derivatives (CASRN 70024-85-0)
No data
Genetic Toxicity - Gene Mutation
In vitro
Subcategory I: Pentachloropyridine
2,3,4,5,6-Pentachloropyridine (CASRN2176-62-7)
In a bacterial reverse point mutation assay, Salmonella typhimurium strains TA98, TA100,
TA1535, TA1537 and Escherichia coli strain WP2uvrA were exposed to 2,3,4,5,6-
pentachloropyridine ( > 99% w/w purity) at 0.33 - 3333 |ig/plate with metabolic activation and
3.3 - 3333 |ig/plate without metabolic activation. Positive and negative controls were used and
yielded the expected results. 2,3,4,5,6-Pentachloropyridine did not induce an increase in
revertants/plate over the negative control in any tester strain either in the presence or absence of
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metabolic activation. In a preliminary mutagenic assay, which used concentrations up to 5000
|ig/plate, cytotoxicity was observed at 1000 |ig/plate in strains TA98, TA100 and TA1537
without activation.
2,3,4,5,6-Pentachloropyridine was not mutagenic in this assay.
2,3,5,6-Tetrachloropyridine (CASRN2402-79-1, supporting chemical)
In an Ames test, Salmonella typhimurium strains TA98, TA100, TA1535 and TA1537 were
exposed to 2,3,5,6-tetrachloropyridine at 0.5 - 50 |ig/plate without metabolic activation and 1.67
- 166.7 |ig/plate with metabolic activation. Cytotoxicity was seen at 50 |ig/plate without
activation and at 166.7 |ig/plate with activation. No information on the use or response of
positive and negative controls was provided. 2,3,5,6-tetrachloropyridine did not induce a
mutagenic response in any of the bacterial strains.
2,3,5,6-tetrachloropyridine was not mutagenic in this assay.
Subcategory II: Chlorinated Trichloromethylpyridines
2-Chloro-5-trichloromethylpyridine (CASRN 69045-78-9)
(1)	Salmonella typhimurium strains TA1535, TA1537, TA1538, TA98 and TA100 were exposed
to 2-chloro-5-trichloromethylpyridine (purity not indicated) in DMSO up to 5000 |ig/plate with
and without metabolic activation. Positive and negative controls were used and yielded the
expected results. Increased mutation frequency was observed in strains TA98 and TA100
without activation at > 200 |ig/plate. Cytotoxicity was observed at > 1000 |ig/plate. Details are
from TSCATS (OTS0509740, Doc. # 88-8500713).
2-Chloro-5-trichloromethylpyridine was mutagenic in this assay.
(2)	Mouse lymphoma cells (L5178Y) were exposed to 2-chloro-5-trichloromethylpyridine
(purity not indicated) in DMSO at 8 - 512 |ig/mL with or without metabolic activation. Positive
and negative controls were used and yielded the expected results. Cytotoxicity was observed at
512 |ig/mL, Increased mutation frequency was observed under trifluorothymidine selection
without activation and under ouabain selection with or without activation. Details are from
TSCATS (OTS0509740, Doc. # 88-8500704).
2-Chloro-5-trichloromethylpyridine was mutagenic in this assay.
Additional Sponsored Chemicals
3,4,5,6,-tetrachloro-2-pyridine carbonitrile (CASRN 17824-83-8)
No data
Chloropyridine derivatives (CASRN 68412-400-8)
No data
Methyl chloropyridine derivatives (CASRN 70024-85-0)
No data
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Genetic Toxicity - Chromosomal Aberrations
In vitro
Subcategory I: Pentachloropyridine
2,3,4,5,6-Pentachloropyridine (CASRN2176-62-7)
In an in vitro cytogenicity assay, rat lymphocytes were exposed to 2,3,4,5,6-pentachloropyridine
(> 99% w/w purity) in DMSO at 3.8, 15 or 30 |ag/mL for 4 or 24 hours without metabolic
activation and 7.5, 30 or 60 |ag/mL for 4 hours with metabolic activation. The cytotoxic
concentration was 60 |ig/mL without activation (regardless of exposure duration) or 120 |ig/mL
with activation. Negative and positive controls were used and yielded the expected results. No
increase in the frequency of cells with chromosomal abnormalities was observed.
2,3,4,5,6-Pentachloropyridine did not induce chromosomal aberrations in this assay.
Subcategory II: Chlorinated Trichloromethylpyridines
2-Chloro-5-trichloromethylpyridine (CASRN 69045-78-9)
In an in vitro cytogenicity assay, human lymphocytes were exposed to 2-chloro-5-
trichloromethylpyridine (purity not indicated) in DMSO at 2.5 - 167 |ag/m L with or without
metabolic activation. Positive and negative controls were used and yielded the expected results.
Chromosomal aberrations were observed at an increased frequency at 100 - 167 |ag/m L with or
without activation. Details are from TSCATS (OTS0509740, Doc. # 88-8500713).
2-Chloro-5-trichloromethylpyridine induced chromosomal aberrations in this assay.
Additional Sponsored Chemicals
3,4,5,6,-tetrachloro-2-pyridine carbonitrile (CASRN 17824-83-8)
No data
Chloropyridine derivatives (CASRN 68412-400-8)
No data
Methyl chloropyridine derivatives (CASRN 70024-85-0)
No data
In vivo
Subcategory I: Pentachloropyridine
2,3,4,5,6-Pentachloropyridine (CASRN2176-62-7)
In a cytogenetic assay, CFLP male mice were administered 2,3,4,5,6-pentachloropyridine (>
99% w/w purity) via gavage 11.75 or 100 mg/kg in sunflower oil. Bone marrow preparation
was carried out 24 or 48 hours after treatment. Positive (cyclophosphamide) and negative
(sunflower oil) controls were used and yielded the expected results. No significant increase in
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the number of cells showing alterations or in the frequency of numerical and structural
chromosomal aberrations was observed.
2,3,4,5,6-Pentachloropyridine did not induce chromosomal aberrations in this assay.
2,3,5,6-Tetrachloropyridine (CASRN2402-79-1, supporting chemical)
In a bone marrow micronucleus assay, CD-I mice were administered single doses of 2,3,5,6-
tetrachloropyridine (purity not indicated) via gavage at 22.5, 75 or 225 mg/kg in males or 93,
310 or 930 mg/kg in females. Animals were sacrificed 24, 48 or 72 hours after treatment and
polychromatic erythrocytes (PCEs) were evaluated for micronuclei. Negative and positive
(cyclophosphamide) controls produced appropriate responses. There were no increases in the
frequencies of micronucleated PCEs in mice treated with 2,3,5,6-tetrachloropyridine.
2,3,5,6-Tetrachloropyridine did not induce micronuclei in this assay.
Subcategory II: Chlorinated Trichloromethylpyridines
No data
Additional Information
Skin Irritation
Subcategory I: Pentachloropyridine
2,3,4,5,6-Pentachloropyridine (CASRN2176-62-7)
A male rabbit (strain not specified) was administered either a undiluted
2,3,4,5,6- pentachloropyridine ( > 99% w/w purity) or 10% dilution in Dowanol DPM to intact
or abraded abdominal skin under semi-occlusive conditions. Ten applications were administered
to the intact abdominal site over a period of 14 days, while three consecutive daily applications
were made to the abraded site. Additionally, 10 applications of the 10% dilution were made to
the ear under open conditions over a period of 14 days. Undiluted applications to the abdomen
resulted in slight to moderate hyperemia, slight edema and slight necrosis. Diluted applications
to the abdomen produced slight to moderate hyperemia and edema. Results were similar on
intact and abraded skin. No irritation was observed on the treated ear.
2,3,4,5,6-Pentachloropyridine was irritating to rabbit skin in this study.
2,3,5,6-Tetrachloropyridine (CASRN2402-79-1, supporting chemical)
(1)	Rabbits (strain, number/dose not specified) were administered 3-10 applications of solid
2,3,5,6-tetrachloropyridine (purity not indicated, amount not specified) to intact or abraded skin
(abdomen) over a 14-day period. Effects included slight hyperemia, which was resolved after a
few days.
2,3,5,6-Tetrachloropyridine was irritating to rabbit skin in this study.
(2)	Rabbits (strain, number/dose not specified) were administered 3 to 10 applications of 20%
2,3,5,6-tetrachloropyridine (purity not indicated, amount not specified) in perchloroethylene for
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24 hours to intact and abraded abdominal skin or the intact ear over a 14-day period. Effects on
the ear included slight hyperemia and slight necrosis. Effects on the intact belly skin included
moderate hyperemia, slight necrosis, slight edema and moderate exfoliation. Effects on the
abraded belly skin included slight hyperemia, moderate edema and moderate necrosis. All
effects were resolved by the end of the study period.
2,3,5,6-Tetrachloropyridine was irritating to rabbit skin in this study.
Subcategory II: Chlorinated Trichloromethylpyridines
3,6-Dichloro-2-trichloromethylpyridine (CASRN1817-13-6)
Rabbits (two males, strain not stated) were administered 0.5 g of 3,6-dichloro-2-
trichloromethylpyridine (purity not indicated) dermally under semi-occluded conditions for 14
days (a total of 10 applications) to intact skin or 3 days to abraded skin. The tests were
conducted using the dry, undiluted test substance and also moistened with water. Effects
observed included redness, swelling, exfoliation and burns at the site of application. Effects
were more severe on moistened skin.
3,6-Dichloro-2-trichloromethylpyridine was irritating to rabbit skin in this study.
2-Chloro-5-trichloromethylpyridine (CASRN 69045-78-9)
Rabbits (two males, strain not stated) were administered 0.5 g of 2-chloro-5-
trichloromethylpyridine (90-100% w/w purity) dermally under semi-occluded conditions for 14
days (a total of 10 applications) to intact skin or 3 consecutive daily applications to abraded skin.
Effects observed included redness, edema, exfoliation and/or burns at the site of application.
2-Chloro-5-trichloromethylpyridine was irritating to the rabbit skin in this study.
Additional Sponsored Chemicals
3,4,5,6,-Tetrachloro-2-pyridine carbonitrile (CASRN 17824-83-8)
Two white rabbits (strain and sex not specified) were administered undiluted 3,4,5,6,-tetrachloro-
2-pyridine carbonitrile dermally onto intact and abraded sites on the abdomen under occluded
conditions. Applications were repeated for up to 10 days. Another rabbit was treated in a
similar fashion with a 10% solution of the test material in dipropylene glycol monomethyl ether.
After two applications of the undiluted test substance to rabbits, dosing was discontinued since
moderate burns occurred. The burn sites appeared to heal normally within the 8 days of
observation period. The rabbit treated with a 10% solution of the test substance died overnight.
3,4,5,6,-Tetrachloro-2-pyridine carbonitrile was corrosive to rabbit skin in this study.
Chloropyridine derivatives (CASRN 68412-400-8)
No data
Methyl chloropyridine derivatives (CASRN 70024-85-0)
No data
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Eye Irritation
Subcategory I: Pentachloropyridine
2,3,4,5,6-Pentachloropyridine (CASRN2176-62-7)
One rabbit (strain and sex not specified) was administered 0.1 mL undiluted 2,3,4,5,6-
pentachloropyridine ( > 99% w/w purity) to both eyes and observed for up to 8 days post-
treatment. The right eye was washed within 30 seconds of exposure for 2 minutes in a flowing
stream of water while the left eye remained unwashed. In both washed and unwashed eyes, the
material caused very slight discomfort and conjunctival irritation, which resolved within 1 hour.
2,3,4,5,6-Pentachloropyridine was not irritating to rabbit eyes in this study.
2,3,5,6-Tetrachloropyridine (CASRN2402-79-1, supporting chemical)
Rabbits (strain and number not correctly specified) were administered undiluted 2,3,5,6-
tetrachloropyridine (purity not indicated) to the eyes. One eye was rinsed following application
and the other was left unrinsed. Effects included very slight pain and prominence of conjunctival
capillaries. Effects were nearly resolved within 1 hour.
2,3,5,6-Tetrachloropyridine was not irritating to rabbit eyes in this study.
Subcategory II: Chlorinated Trichloromethylpyridines
3,6-Dichloro-2-trichloromethylpyridine (CASRN 1817-13-6)
A New Zealand White rabbit was administered 0.1 g of 3,6-dichloro-2-trichloromethylpyridine
(purity not indicated) in each eye. One eye was then rinsed for 2 minutes, while the other was
left unrinsed. Effects observed included slight discomfort, moderate conjunctival redness and
swelling, moderate reddening of the iris and transient corneal injury. Similar results were
obtained regardless of rinsing.
3,6-Dichloro-2-trichloromethylpyridine was irritating to rabbit eyes in this study.
2-Chloro-5-trichloromethylpyridine (CASRN 69045-78-9)
A New Zealand White rabbit was administered 0.1 g of 2-chloro-5-trichloromethylpyridine (90-
100% w/w purity) in each eye. The right eye was then rinsed within 30 seconds for 2 minutes,
while the left eye remained unrinsed. Effects observed included severe discomfort, slight
conjunctival redness, very slight reddening of the iris and very slight corneal haziness. Similar
results were obtained regardless of rinsing.
2-Chloro-5-trichloromethylpyridine was irritating to the rabbit eyes in this study.
Additional Sponsored Chemicals
3,4,5,6,-Tetrachloro-2-pyridine carbonitrile (CASRN 17824-83-8)
One white rabbit (strain and sex not specified) was administered 0.1 mg undiluted 3,4,5,6,-
tetrachloro-2-pyridine carbonitrile in both eyes. On eye was left unwashed and the other eye was
rinsed under running water within 1 hour of test substance instillation. The rabbit was observed
for 7 days. The test substance produced slight to moderate conjunctival redness, with no
evidence of corneal or iridial effects. The irritation resolved within 7 days.
22

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U.S. Environmental Protection Agency	September, 2014
Hazard Characterization Document
3,4,5,6,-Tetrachloro-2-pyridine carbonitrile was irritating to rabbit eyes in this study.
Chloropyridine derivatives (CASRN 68412-400-8)
No data
Methyl chloropyridine derivatives (CASRN 70024-85-0)
No data
Sensitization
Subcategory I: Pentachloropyridine
2,3,4,5,6-Pentachloropyridine (CASRN2176-62-7)
In a split adjuvant test eight guinea pigs were administered 2,3,4,5,6-pentachloropyridine (> 99%
w/w purity) in Dowanol DPM/Tween 80,9/1 during induction and challenge phases. The test
material was reported to be sensitizing, but the study summary is missing critical study details,
including method of exposure, doses tested and detailed results. These data are provided for
general information purposes.
2,3,5,6-Tetrachloropyridine (CASRN2402-79-1, supporting chemical)
Hartley guinea pigs (5/sex/dose) were administered six topical 0.5 mL applications of 2,3,5,6-
tetrachloropyridine (purity not indicated) as a 5% solution in a 9:1 dipropylene glycol
monomethyl ether: Tween 80 mixture during a 2-week induction phase to clipped abdominal
skin. After a 2-week rest period, the guinea pigs were challenged with 0.3 mL of
2,3,5,6-tetrachloropyridine or vehicle and observed for up to 48 hours. No evidence of erythema
or edema was observed.
2,3,5,6-Tetrachloropyridine was not sensitizing to guinea pig skin in this assay.
Subcategory II: Chlorinated Trichloromethylpyridines
2-Chloro-5-trichloromethylpyridine (CASRN 69045-78-9)
Hartley albino guinea pigs (10 males) were administered 0.1 mL of a 10% solution of 2-chloro-
5-trichloromethylpyridine (90-100% w/w purity) in dipropylene glycol monomethyl ether/Tween
80 dermally under semi-occluded conditions, receiving four applications over 7 days. After
resting for 14 days, the guinea pig skin was challenged with the same test solution. A positive
sensitization response was observed in 8 of 10 animals.
2-Chloro-5-trichloromethylpyridine was sensitizing to guinea pig skin in this assay.
Additional Sponsored Chemicals
3,4,5,6,-Tetrachloro-2-pyridine carbonitrile (CASRN 17824-83-8)
No data
23

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Chloropyridine derivatives (CASRN 68412-400-8)
No data
Methyl chloropyridine derivatives (CASRN 70024-85-0)
No data
Conclusion:
Subcategory I: Pentachloropyridine
The acute oral toxicity of 2,3,4,5,6-pentachloropyridine in rats is moderate. The acute inhalation
toxicity of 2,3,5,6-tetrachloropyridine (supporting chemical) is low in rats. In the 90-day
repeated-dose dietary toxicity study of 2,3,4,5,6,-pentachloropyridine the LOAEL for male rats is
30 mg/kg-bw/day based on increased liver and kidney weights and hyaline droplets degeneration
of renal tubules. The NOAEL for males is 10 mg/kg-bw/day. No systemic toxicity was seen in
females; the NOAEL for females is 30 mg/kg-bw/day, the highest dose tested. The 91-day
dietary repeated-dose toxicity study of 2,3,5,6-tetrachloropyridine (supporting chemical) showed
degenerative changes in the kidney of male rats at 10-mg/kg-bw/day. The NOAEL for males is
3-mg/kg-bw/day. In females, the NOAEL is 100 mg/kg-bw/day (the highest dose tested). In a
combined repeated-dose/reproductive/developmental toxicity study of 2,3,5,6-
tetrachloropyridine (supporting chemical) in rats via gavage, the LOAEL in males is 25 mg/kg-
day based on hyaline protein nephropathy with a NOAEL of 5 mg/kg-day. In females, the
LOAEL of 150 mg/kg-day is based on the effects on liver and kidney; the NOAEL is 25 mg/kg-
day. No reproductive toxicity study is available for 2,3,4,5,6,-pentachloropyridine. The 90-day
repeated-dose dietary study showed no treatment-related effects on reproductive organs for
2,3,4,5,6,-pentachloropyridine. A combined repeated-dose/reproductive/developmental toxicity
study in rats via gavage with 2,3,5,6-tetrachloropyridine showed no treatment-related effects on
reproductive organs. The NOAEL for reproductive toxicity is 150 mg/kg-day, the highest dose
tested. In a prenatal developmental toxicity study of 2,3,4,5,6,-pentachloropyridine in rats via
gavage, maternal toxicity was seen at 50 mg/kg-day (increased liver and kidney weights) with a
NOAEL of 10 mg/kg-day. The LOAEL for developmental toxicity is 200 mg/kg-day based on
decreased fetal weights. The NOAEL is 50 mg/kg-day. 2,3,4,5,6,-Pentachloropyridine and
2,3,5,6,-tetrachloropyridine (supporting chemical) did not induce gene mutation in bacteria and
did not induce chromosomal aberrations in rat lymphocytes in vitro or in mouse bone marrow
cells in vivo. The subcategory members are irritating to rabbit skin, but not to rabbit eyes.
2,3,5,6-Tetrachloropyridine (supporting chemical) is not a dermal sensitizer in guinea pigs.
Subcategory II: Chlorinated Trichloromethylpyridines
The acute oral toxicity for members of the chlorinated trichloromethylpyridine subcategory in
rats is low. The acute toxicity in rats via inhalation is inconclusive (LCso > 0.108 mg/L) because
the concentration tested was not high enough to establish the potential hazard In a 3-week
dermal toxicity study of 2-chloro, 5 trichloromethylpyridine in rats, the LOAEL is 500 mg/kg-
day based on mortality and effects on clinical chemistry parameters, organ weight changes and
histopathology of liver (vacuolation and necrosis of centrilobular hepatocytes), kidney
(vacuolation of renal tubular epithelium) and testes (atrophy of the seminiferous tubular
epithelium). The NOAEL is 100 mg/kg-day. There are no data for reproductive or
developmental toxicity. 2-Chloro-5-trichloromethylpyridine induced gene mutation in bacteria
24

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September, 2014
and mouse lymphoma cells in vitro and induced chromosomal aberrations in a human
lymphocyte assay in vitro. Subcategory members are irritating to rabbit skin and eyes, while 2-
chloro-5-trichloromethylpyridine is a dermal sensitizer in guinea pigs.
Additional Sponsored Chemicals
3,4,5,6,-Tetrachloro-2-pyridine carbonitrile (CASRN17824-83-8)
No data are available for acute, repeated-dose, reproductive, developmental toxicity and gene
mutation and chromosomal aberrations endpoints. 3,4,5,6,-Tetrachloro-2-pyridine carbonitrile
was corrosive to rabbit skin and irritating to rabbit eyes.
Chloropyridine derivatives (CASRN 68412-400-8)
No data are available for acute, repeated-dose, reproductive, developmental toxicity and gene
mutation and chromosomal aberrations endpoints.
Methyl chloropyridine derivatives (CASRN 70024-85-0)
No data are available for acute, repeated-dose, reproductive, developmental toxicity and gene
mutation and chromosomal aberrations endpoints.
4. Hazard to the Environment
A summary of aquatic toxicity data submitted for SIDS endpoints is provided in Tables 4a and
4b. The tables also indicate where data are read-across (RA) to untested members of the
category.
Acute Toxicity to Fish
Subcategory I: Tetra- and Pentachloropyridines
2,3,4,5,6-Pentachloropyridine (CASRN2176-62-7)
Fathead minnows (Pimephalespromelas) were exposed to 2,3,4,5,6-pentachloropyridine at
nominal concentrations of 0, 0.28, 0.43, 0.66, 1.02 or 1.57 mg/L under flow-through conditions
for 96 hours. Measured concentrations were not provided. Affected fish lost schooling behavior
and swam near the tank surface. They were hypoactive and under-reactive to external stimuli,
had increased respiration, were hemorrhagic and deformed, had rigid musculature and lost
equilibrium prior to death.
96-h LCso = 0.47 mg/L
2,3,5,6-Tetrachloropyridine (CASRN2402-79-1, supporting chemical)
(1) Rainbow trout (iOncorhynchus mykiss) were exposed to 2,3,5,6-tetrachloropyridine at
unspecified measured concentrations under flow-through conditions for 96 hours. No other
information was provided.
96-h LCso = 1.5 mg/L
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Table 3. Summary of Screening Information Data Set under the U.S. HPV Challenge Program - Human Health Data

Subcategory I
Subcategory II
Additional Sponsored Chemicals
Endpoints
SPONSORED
CHEMICAL
2,3,4,5,6-
Pentachloro-pyridine
2176-62-7
SUPPORTING
CHEMICAL
2,3,5,6-Tetrachlo ni-
pv rid ine
2402-79-1
SPONSORED
CHEMICAL
3,6-Dichloro-
2-trichloromethvl-
pv rid ine
1817-13-6
SPONSORED
CHEMICAL
2-Chloro-
5-trichloromethyl-
pvridine
69045-78-9
SPONSORED
CHEMICAL
3,4,5,6-Tetrachloro-2-
p> riiline carbonitrile
17824-83-8
SPONSORED
CHEMICAL
Chloropyridine
Derivatives
68412-40-8
SPONSORED
CHEMICAL
Chloropyridine
Derivatives
70024-85-0
Acute Oral Toxicity
LDso (mg/kg)
435
-
1000 < LDso < 2000
500 < LDso <1000
1000 < LDso < 2000
No Data
No Data
Acute Inhalation Toxicity
LC50 (mg/L)
No Data
>56
(RA)
>56
No Data
>0.108a
(RA)
> 0.108"
No Data
No Data
No Data
Repeated-Dose Toxicity
NOAEL/LOAEL
Oral (mg/kg-bw/day)
(rat; 90-d, dietary)
NOAELmales = 10
LOAELmales = 30
NOAELfemales = 30
(highest dose tested)
(rat; 90-d, dietary)
NOAEL (males) = 3
LOAEL (males) = 10
NOAEL (females) = 100
(highest dose tested)
(rat; 28-d, dietary)
NOAELm„ies = 5
LOAELmaies — 25
NOAELfema]es = 25
LOAELfemales 150
-
-
No Data
No Data
No Data
Repeated-Dose Toxicity
NOAEL/LOAEL
Dermal (mg/kg-day)
-
-
No Data
NOAEL = 100
LOAEL = 500
(RA)
NOAEL = 100
LOAEL = 500
-
-
-
Reproductive Toxicity
NOAEL/LOAEL
(mg/kg-day)
No effects on
reproductive organs in
the 90-day repeated-dose
toxicity study
No Data
NOAEL = 150
(RA)
NOAEL = 150
(highest dose tested)
No Data
No Data
No Data
No Data
No Data
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Table 3. Summary of Screening Information Data Set under the U.S. HPV Challenge Program - Human Health Data

Subcategory I
Subcategory II
Additional Sponsored Chemicals
Endpoints
SPONSORED
CHEMICAL
2,3,4,5,6-
Pentachloro-pyridine
2176-62-7
SUPPORTING
CHEMICAL
2,3,5,6-Tetrachlo ni-
pv rid ine
2402-79-1
SPONSORED
CHEMICAL
3,6-Dichloro-
2-trichloromethvl-
pv rid ine
1817-13-6
SPONSORED
CHEMICAL
2-Chloro-
5-trichloromethyl-
pvridine
69045-78-9
SPONSORED
CHEMICAL
3,4,5,6-Tetrachloro-2-
p> riiline carbonitrile
17824-83-8
SPONSORED
CHEMICAL
Chloropyridine
Derivatives
68412-40-8
SPONSORED
CHEMICAL
Chloropyridine
Derivatives
70024-85-0
Developmental Toxicity
NOAEL/LOAEL
Oral (mg/kg-/day)
Maternal Toxicity
Developmental Toxicity
NOAEL = 10
LOAEL = 50
NOAEL = 50
LOAEL = 200
NOAEL=25
LOAEL = 150
NOAEL = 150
(highest dose tested)
No Data
No Data
No Data
No Data
No Data
Genetic Toxicity - Gene
Mutation
In vitro
Negative
Negative
No Data
Positive
(RA)
Positive
No data
No data
No Data
Genetic Toxicity -
Chromosomal Aberrations
In vitro
Negative
-
No Data
Positive
(RA)
Positive
No Data
No Data
No Data
Genetic Toxicity-
Chromosomal Aberrations
In vivo
Negative
Negative
-
-
No Data
No Data
No Data
Additional Information
Skin Irritation
Eye Irritation
Sensitization
Irritating
Not irritating
Irritating
Not irritating
Not sensitizing
Irritating
Irritating
Irritating
Slightly irritating
Sensitizing
Corrosive
Irritating
-
-
Measured data in bold text; (RA) = Read Across; (-) indicates that endpoint was not addressed for this chemical; (a) = concentration tested is not high enough
to establish the potential hazard.
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(2) Fathead minnows (Pimephalespromelas) were exposed to 2,3,5,6-tetrachloropyridine at
unspecified nominal concentrations under static conditions for 96 hours. 2,3,5,6-
Tetrachloropyridine was lethal to all fish at 2 mg/L. No mortality occurred at 1 mg/L.
96-h LCso > 1 < 2 mg/L
Subcategory II: Chlorinated Trichloromethylpyridines
No adequate fish toxicity data are available.
Additional Sponsored Chemicals
Chloropyridine derivatives (CASRN 68412-40-8)
No fish toxicity data are available.
Methyl chloropyridine derivatives (CASRN 70024-85-0)
No fish toxicity data are available.
Acute Toxicity to Aquatic Invertebrates
Subcategory I: Tetra and Pentachloropyridines
2,3,5,6-Tetrachloropyridine (CASRN2402-79-1; supporting chemical)
Daphnia magna were exposed to 2,3,5,6-tetrachloropyridine at unspecified measured
concentrations and conditions for 48 hours. No other information was provided.
48-h EC50 = 2.05 mg/L (filtered samples)
48-h EC50 = 2.14 mg/L (unfiltered samples)
Subcategory II: Chlorinated Trichloromethylpyridines
No adequate aquatic invertebrate toxicity data are available.
Additional Sponsored Chemicals
Chloropyridine derivatives (CASRN 68412-40-8)
No aquatic invertebrate toxicity data are available.
Methyl chloropyridine derivatives (CASRN 70024-85-0)
No aquatic invertebrate toxicity data are available.
Toxicity to Aquatic Plants
Subcategory I: Tetra- and Pentachloropyridines
2,3,4,5,6-Pentachloropyridine (CASRN2176-62-7)
Green algae (Pseudokirchneriella subcapitata) were exposed to 2,3,4,5,6-pentachloropyridine at
nominal concentrations of 0, 0.125, 0.250, 0.500, 1.00, 2.00 or 4.00 mg/L under static conditions
for 96 hours. Acetone was used as a carrier solvent at 0.01%. Mean measured concentrations
ranged from 16.0 to 60.4% of target dose levels. EC50 values were calculated using nominal
concentrations.
72-h EC50 (biomass) = 1.66 mg/L
72-h EC50 (growth) > 4 mg/L
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2,3,5,6-Tetrachloropyridine (CASRN2402-79-1; supporting chemical)
Algae (Pseudokirchneriella subcapitata) were exposed to 2,3,5,6-tetrachloropyridine at
unspecified measured concentrations and conditions for 120 hours. No other information was
provided.
72-h ECso (biomass) = 14.3 mg/L
72-h EC50 (growth rate) = 9.7 mg/L
Subcategory II: Chlorinated Trichloromethylpyridines
No aquatic plant toxicity data are available.
Additional Sponsored Chemicals
Chloropyridine derivatives (CASRN 68412-40-8)
No aquatic plant toxicity data are available.
Methyl chloropyridine derivatives (CASRN 70024-85-0)
No aquatic plant toxicity data are available.
Chronic Toxicity to Aquatic Invertebrates
Subcategory I: Tetra- and Pentachloropyridine
2,3,5,6-Tetrachloropyridine (CASNo. 2402-79-1; supporting chemical)
Daphnia magna were exposed to 2,3,5,6-tetrachloropyridine at measured concentrations of 0.25
- 2.67 mg/L under flow-through conditions for 21 days. Mortality was observed at > 0.61 mg/L,
growth was affected at 2.67 mg/L and reproduction was affected at > 1.78 mg/L.
21-d EC50 (mortality) = 1.94 mg/L
Conclusion:
Subcategory I: Tetra- and Pentachloropyridines
For subcategory I, the 96-h LC50 for fish is 0.47 mg/L. Based on the supporting chemical,
2,3,5,6-tetrachloropyridine, the 48-h EC50 for aquatic invertebrates is 2.05 mg/L. The 72-h EC50
for algae is 1.66 mg/L for biomass, and, based on the supporting chemical, 2,3,5,6-
tetrachloropyridine, the 72-h EC50 for algae is 9.7 mg/L for growth rate.
Subcategory II: Chlorinated Trichloromethylpyridines
There are no adequate data available for the evaluation of the ecological toxicity of the
chlorinated trichloromethylpyridines.
Additional Sponsored Chemicals
Chloropyridine derivatives
There are no available data for the evaluation of ecological toxicity of the chloropyridine
derivatives.
Methyl chloropyridine derivatives (CASRN 70024-85-0)
There are no available data for the evaluation of ecological toxicity of the methyl chloropyridine
derivatives.
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Table 4a. Summary of Screening Information Data Set under the U.S. HPV Challenge
Program - Aquatic Toxicity Data
Subcategory
I: Tetra- and Pentachloropyridines
II: Chlorinated
Trichloromethylpyridines
Endpoints
SUPPORTING
CHEMICAL
2,3,5,6-
Tetrachloro-
pyridine
(supporting
chemical)
(2402-79-1)
SPONSORED
CHEMICAL
2,3,4,5,6-
Pentachloro-
pyridine
(2176-62-7)
SPONSORED
CHEMICAL
3,4,5,6-
Tetrachloro-2-
pyridine
carbonitrile
(17824-83-8)
SPONSORED
CHEMICAL
3,6-Dichloro-
2-trichlorometh
yl-pyridine
(1817-13-6)
SPONSORED
CHEMICAL
2-Chloro-
5-trichloromethy
1-pyridine
(69045-78-9)
Fish
96-h LCso (mg/L)
1.5
0.47
No Data
0.47
(RA)
No Data
No Adequate Data
Aquatic
Invertebrates
48-h ECso (mg/L)
2.05
No Adequate Data
2.05
(RA)
No Data
2.05
(RA)
No Data
No Adequate Data
Aquatic Plants
72-h ECso (mg/L)
biomass
growth rate
14.3
9.7
1.66
> 4
No Data
1.66
9.7
(RA)
No Data
No Data
Bold = experimental data (i.e., derived from testing); (RA) = Read Across
Table 4b. Summary of Screening Information Data Set under the U.S.
HPV Challenge Program - Aquatic Toxicity Data
Subcategory
Additional Sponsored Chemicals
Endpoints
SPONSORED
CHEMICAL
Chloropyridine
derivatives
(1817-13-6)
SPONSORED
CHEMICAL
Methyl chloropyridine
derivatives
(70024-85-0)
Fish
96-h LCso (mg/L)
No Data
No Data
Aquatic Invertebrates
48-h ECso (mg/L)
No Data
No Data
Aquatic Plants
72-h ECso (mg/L)
biomass
growth rate
No Data
No Data
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5. References
Hermens, J. 1985. Quantitative correlation studies between the acute lethal toxicity of 15
organic halides to the guppy (Poecilia reticulate) and chemical reactivity towards 4-
nitrobenzylpyridine, Toxicol. Environ. Chem. 9:219-236.
Lipnick, R.L., et al. 1987. A QSAR Study of the Acute Toxicity of Some Industrial Organic
Chemicals to Goldfish. Narcotic, Electrophile, and Proelectrophile, Xenobiotica, 17, pp 1011-
1025.
Lipnick, R.L. 1989. SYMPOSIUM, Structure-Activity Relationships in Environmental
Toxicology and Chemistry, Narcosis, Electrophile and Proelectrophile Toxicity Mechanism:
Application of SAR and QSAR, Environmental Toxicology and Chemistry, 8, pp 1-12.
Lipnick, R.L. 1991. Outliers: their origin and use in the classification of molecular mechanisms
of toxicity, The Science of the Total Environment, 109/110, pp 131-153.
Newsome, L.D., et al. 1984. Validation of Fish Toxicity QSARs for Certain Non-Reactive Non-
Electrolyte Organic Compounds, K. L. E. Kaiser (ed.) QSAR in Environmental Toxicology, pp
279-299.
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APPENDIX
The following pages show:
Table 1. Chemical Structures of the Chlorinated Pyridine Category Members.
Table 2. Chemical Composition of the Process Streams in the Chlorinated Pyridine Category.
Table 1. Chemical Structures of the Chlorinated Pyridine Category Members
Chemical Name
CASRN
Structure
Sponsored Chemicals
2,3,4,5,6 -Pentachloro -pyridine
2176-62-7
CL ,0!
3,6-Dichloro-2-trichloromethyl-pyridine
1817-13-6
01
2-Chloro-5-trichloromethyl-pyridine
69045-78-9
,N ,CI
"y"
Yu
3,4,5,6-Tetrachloro-2-pyridine carbonitrile
17824-83-8
V	•; N
Chloropyridine
Derivatives
68412-40-8
No structure is included for this
chemical, since it is a process stream
Methyl Chloropyridine
Derivatives
70024-85-0
No structure is included for this
chemical, since it is a process stream
Supporting Chemical
2,3,5,6-Tetrachloro-pyridine
2402-79-1

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Table 2. Chemical Composition of the Process Streams in the Chlorinated Pyridine
Category Members
Chemical
Name
CASRN
Composition*
Chloropyridine
Derivatives
68412-40-8
Pentachloropyridine, 3.3%
2,3,4,6-Tetrachloro-5-pyridinecarbonitrile, 0.1%
Hexachlorobenzene, 16.2%
Pentachloroethynylpyridine,28.1%
3,4,5,6-Tetrachloro-l,2-benzenedicarbonitrile ,0.8%
2,4,5,6-Tetrachloro-l,3-benzenedicarbonitrile,1.4%
Trichloroethylenetetrachloropyridine isomers (3 isomers), 9.5%
Pentachloro(trichloroethenyl)-benzene, 1.0%
l,2,4-Trichloro-5-[(chloropheny)thio]benzene,0.2%
Tetrachlorodihydromethylbenzo(A)carbazole isomers ( 3 isomers), 0.9%
Hexachlorobipyridylene Isomers/Derivatives (3 isomers/derivatives),
0.5%
Perchlorovinylcyanopyridine isomers (2 isomers), 0.7%
4-[p-bis(2-hydroxyethylamino]phenyl-l-bromoisoquinoline, 2.0%
Heptachlorobipyridylene Isomers/Derivatives (2 isomers/derivatives),
1.1%
Octachlorobipyridylene Isomers/Derivatives (5 isomers/derivatives),
6.7% Trichlorovinyltetrachloroethynylpyridine, 9.8%
Hexachlorobipyridylene Isomers/Derivatives(9), 16.5%
Nonachlorophenylpyridine, 0.2%
Octachloronaphthalene, 0.7%
Heptachlorobipyridylene Isomer or Derivative, 0.3%
Irieol, 0.4%


Methyl
Chloropyridine
Derivatives
70024-85-0
1,2,3,4,1 l-Pentachloro-8-(trichloromethyl) dipyrioimidazolium
tetrachloroferrate and process contaminants, 46%
Chlorinated pyridines, 31%
Ferric chloride, 15%
Chlorinated bipyridines, 6%
Chlorohydrocarbons, 2%
*The percentages represent data gathered at one point in time, and vary with the time of process stream sampling..
33

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