U.S. Environmental Protection Agency
Hazard Characterization Document
September, 2014
SCREENING-LEVEL HAZARD CHARACTERIZATION
Nitroalcohol Category
2-Methyl-2-nitro-l-propanol (MNP)	CASRN 76-39-1
2-(Hydroxymethyl)-2-nitro-l,3-propanediol (TN) CASRN 126-11-4
2-Ethyl-2-nitro-l,3-propanediol (NEPD)	CASRN 597-09-1
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 Setl1'2) 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.), 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 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
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.
4	European Chemicals Agency, http://echa.europa.eu.

-------
U.S. Environmental Protection Agency
Hazard Characterization Document
September, 2014
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.
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.
2

-------
U.S. Environmental Protection Agency
Hazard Characterization Document
September, 2014
Chemical Abstract Service
Registry Number
(CASRN)
76-39-1
126-11-4
597-09-1
Chemical Abstract
Index Name
1-Propanol, 2-methyl-2-nitro-
1,3-Propanediol, 2-(hydroxymethyl)-2-nitro-
1,3-Propanediol, 2-ethyl-2-nitro-
Structural Formula
CH3
°2N~>\/0H
h3c
SMILES: N(=0)(=0)C(C0)(C)C
	OH
°2N>^OH
OH
SMILES: N(=0)(=0)C(C0)(C0)C0
^ch3
°2N~7\/oh
OH
SMILES: N(=0)(=0)C(CC)(C0)C0
Summary
The nitroalcohol category consists of three structurally similar substances: 2-methyl-2-nitro-l-
propanol (MNP); 2-(hydroxymethyl)-2-nitro-1,3-propanediol (TN); and 2-ethyl-2-nitro-l,3-
propanediol (NEPD). All three compounds are crystalline solids with moderate to low vapor
pressure and high water solubility. The substances in the nitroalcohol category are expected to
possess high mobility in soil. Volatilization is considered low based on the Henry's Law
constants for these substances. The rate of hydrolysis is considered negligible under acidic
conditions and moderate to rapid under neutral and alkaline conditions. The rate of atmospheric
photooxidation is considered slow. 2-(Hydroxymethyl)-2-nitro-l,3-propanediol is not readily
biodegradable. No data were available for the other members of this category; however, similar
results are expected for these substances. The nitroalcohols are expected to have low persistence
(PI) and low bioaccumulation potential (Bl).
Human Health Hazard
Subcategory I, 2-(Hyilroxymethyl)-2-nitro-l,3-propanediol (TN), CASRN 126-11-4:
2-(Hydroxymethyl)-2-nitro-l,3-propanediol (TN) has low acute oral (rat) and dermal (rat and
rabbit) toxicity and moderate acute inhalation (rat) toxicity. In a 13-week dermal repeated-dose
3

-------
U.S. Environmental Protection Agency
Hazard Characterization Document
September, 2014
toxicity study, TN caused yellow discoloration at the application site, but no adverse effects were
observed on any parameters evaluated; the NOAEL for repeat-dose toxicity is 1000 mg/kg-
bw/day, the highest dose tested. No specific reproductive toxicity studies are available; however,
in the 13-week repeated-dose study, no adverse effects on the reproductive organs were observed.
In an oral gavage prenatal developmental toxicity study in rats, mortality, reduced body weight
gain and clinical signs were observed in dams at the highest dose tested (750 mg/kg-day); the
NOAEL for maternal toxicity is 750 mg/kg-day. A treatment-related increase in the number of
resorptions per dam was observed at 375 mg/kg-day; the NOAEL for developmental toxicity is
50 mg/kg-day. In a dermal prenatal developmental toxicity study in rabbits, decreased body
weight gain and food consumption were noted at 75 mg/kg-bw/day; the NOAEL for maternal
toxicity is 30 mg/kg-bw/day. No adverse effects on developmental parameters were observed; the
NOAEL for developmental toxicity is 75 mg/kg-bw/day (highest dose tested). TN showed no
mutagenic potential in bacteria in vitro but was mutagenic in mammalian cells in vitro. TN did
not induce chromosomal aberrations in Chinese hamster ovary cells, micronuclei in mice or
unscheduled DNA synthesis in vitro or in vivo. TN is not irritating to rabbit eyes or rabbit skin
and is not sensitizing to guinea pigs.
No data gaps were identified under the HPV Challenge Program.
Subcategory II, 2-Methyl-2-nitro-l-propanol (MNP), CASRN 76-39-1:
The acute oral and dermal toxicity for MNP is low in rats and rabbits, respectively. No data are
available for the repeated-dose/reproductive/developmental toxicity endpoints. MNP was not
mutagenic in bacteria in vitro. No data are available for the chromosomal aberrations endpoint.
MNP is irritating to rabbit eyes. MNP is not irritating to rabbit skin or sensitizing to guinea pigs.
Data gaps for repeated-dose, reproductive, developmental and genetic toxicity (chromosomal
aberrations) endpoints were identified for subcategory II under the HPV Challenge Program.
Subcategory III, 2-Ethyl-2-nitro-l,3-propanediol (NEPD), CASRN 597-09-1:
The acute oral and dermal toxicity for NEPD is low for rats and rabbits, respectively. No data are
available for the repeated-dose/reproductive/developmental toxicity endpoints. No data are
available for the genetic toxicity (gene mutation and chromosomal aberrations) endpoints. (NEPD
is irritating to rabbit eyes. NEPD is not irritating to rabbit skin or sensitizing to guinea pigs.
Data gaps for repeated-dose, reproductive, developmental and genetic (gene mutation and
chromosomal aberrations) toxicity endpoints for subcategory III were identified under the HPV
Challenge Program.
Hazard to the Environment
For 2-(hydroxymethyl)-2-nitro-l,3-propanediol (TN), the 96-h LCso ranges from 280 to 501 for
fish, the 48-h EC so is 80 mg/L for aquatic invertebrates and the 72-h EC so is > 4.5 (growth rate)
and 0.479 (biomass) for aquatic plants.
No data gaps were identified under the HPV Challenge Program.	
4

-------
U.S. Environmental Protection Agency
Hazard Characterization Document
September, 2014
The sponsor, The Dow Chemical Company, submitted a Test Plan and Robust Summaries to
EPA for the nitroalcohol category on December 16, 2002. EPA posted the submission on the
ChemRTK HPV Challenge website on April 3, 2003
(http://www.epa.gov/chemrtk/pubs/summaries/nitroalc/cl4355tc.htm). EPA comments on the
original submission were posted to the website on August 14, 2003. Public comments were also
received and posted to the website. The sponsor submitted updated/revised documents on
February 12, 2004, which were posted to the ChemRTK website on May 17, 2004. The
proposed nitroalcohol category originally consisted of the following two chemicals: 2-Methyl-2-
nitro-l-propanol (MNP), CASRN 76-39-1 and 2-(Hydroxymethyl)-2-nitro-l,3-propanediol (TN),
CASRN 126-11-4. On July 6, 2010, the sponsor submitted a revised test plan with a third
member for the nitroalcohol category, 2-Nitro-2-ethyl-1,3-propanediol (NEPD) CASRN
597-09-1.
A Reregi strati on Eligibility Decision (RED) for 2-(Hydroxymethyl)-2-nitro-1,3 -propanediol
(TN, tris nitro) was issued by EPA Office of Pesticide Programs in September 1993. The RED is
located at: http://www.epa.gov/pesticides/reregistration/status.htm.
Category Justification
For human health effects, the nitroalcohol category consists of three subcategories, (I) 2-Methyl-
2-nitro-l-propanol (MNP), (II) 2-(Hydroxymethyl)-2-nitro-1,3-propanediol (TN) and (III) 2-
Nitro-2-ethyl-l,3-propanediol (NEPD). The chemicals in the subcategories are 2-nitro
derivatives of branched, four carbon alcohols that differ in the number of alcohol functions. The
basis for a nitroalcohol category is similarities in the structure, production and decomposition
chemistry of the three category members. However, there is not sufficient information to support
using data for TN to satisfy the repeated-dose, reproductive and developmental toxicity
endpoints for MNP and NEPD at this time.
For aquatic toxicity, EPA agrees the category members (TN, MNP, and NEPD) are acceptable
given the similarities in chemical functions, decomposition products, log Kow values, water
solubility's, and predicted acute toxic effects.
The sponsor proposed reduced health effects testing on the basis that the nitroalcohols 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 for the purposes of the HPV
Challenge Program.
1. Chemical Identity
1.1 Identification and Purity
Nitroalcohols are non-volatile crystalline solids. All nitroalcohol production except that of TN is
consumed (site-limited) during the production of amino alcohols. The major use of TN is as an
antimicrobial agent for the control of bacteria in industrial processes registered under the Federal
Insecticide and Rodenticide Act (FIFRA). A minor use of TN is cross-linking in industrial
5

-------
U.S. Environmental Protection Agency
Hazard Characterization Document
September, 2014
processes such as the manufacturing of plywood (as part of the adhesive system). MPN is also
used in the production of 2-amino-2methyl-l-propanol (AMP).
As indicated in the Robust Summaries, the purity of TN ranges from 40 to >99.96%, the purity
of MNP ranges from 61.1 to 99.6% MNP, and the purity of NEPD is 98.9-99.3%, unless
otherwise indicated.
1.2 Physical-Chemical Properties
The substances contained in the nitroalcohol category are crystalline solids with moderate to low
vapor pressure and high water solubility. The physical-chemical properties of the nitroalcohol
category members are presented in Table 1.
Table 1. Physical-Chemical Properties of the Nitroalcohol Category1
Property
2-Methyl-2-nitro-l-
propanol
(MNP)
2-(Hydroxymethyl)-2-
nitro-1,3-propanediol
(TN)
2-Ethyl-2-nitro-1.3-
propanediol
(NEPD)
CASRN
76-39-1
126-11-4
597-09-1
Molecular Weight
119.12
151.12
149.15
Physical State
Crystalline solid
Crystalline solid
Crystalline solid
Melting Point
90°C
(measured)
175°C with decomposition
(measured)
57.5°C
(measured)
Boiling Point
94.5°C at 14.7 mm Hg
(measured)
Decomposes at 175°C
281.7°C
(estimated)2
Vapor Pressure
0.14 mm Hg at 25°C
(estimated)3
2.5 xlO-7 mmHg at 25°C
(estimated)2
1.24xl0 4 mmHg at 25°C
(estimated)2
Dissociation Constant (pKa)
Not applicable
Not applicable
Not applicable
Henry's Law Constant
3.6 x 109 atm-m3/mole
(estimated)2
< 1.0 x 1010 atm-m3/mole
(estimated)2
1.8 x 1010 atm-m3/mole
(estimated)2
Water Solubility
3.5xl06 mg/L at 25°C
(measured)
2.2x10s mg/L at 20°C
(measured)
1.0 x10s mg/L at 20°C
(measured)
Log Kow
-0.14 (estimated)2
1.06 at 25°C (measured)
-0.71 (estimated)2
'The Dow Chemical Company. 2010. Revised Test Plan and Robust Summary for the Nitroalcohol Category.
Available online at htto://www.epa. gov/chemrtk/pubs/summaries/nitroalc/c 14355tc.htm as of December 15, 2011.
2U.S. EPA. 2011. Estimation Programs Interface Suite™ for Microsoft® Windows, v4.10. U.S. Environmental
Protection Agency, Washington, DC, USA. Available online at
http://www.epa.gov/opptintr/exposure/pubs/episuitedl.htm as of December 15, 2011.
3N0M05. 1987. Programs to Enhance PC-Gems Estimates of Physical Properties for Organic Compounds. The
Mitre Corp.
2. General Information on Exposure
2.1 Production Volume and Use Pattern
The nitroalcohol category chemicals had an aggregated production and/or import volume in the
United States between 52 million and 120 million pounds during calendar year 2005.
• CASRN 126-11-4:	1 million to < 10 million pounds;
6

-------
U.S. Environmental Protection Agency
Hazard Characterization Document
September, 2014
•	CASRN 76-39-1:	50 million to < lOOmillion pounds;
•	CASRN 597-09-1:	1 million to < 10 million pounds;
Industrial processing and uses for the chemicals were claimed confidential. No commercial and
consumer uses were reported for these chemicals.
2.2 Environmental Exposure and Fate
The substances in the nitroalcohol category are expected to possess high mobility in soil. 2-
(Hydroxymethyl)-2-nitro-l,3-propanediol degraded 13.4% in 28 days using the manometric
respirometry (OECD 301F) test and was classified as not readily biodegradable. No data were
available for the other members of this category; however, similar results are expected for these
substances. The hydrolysis half-life of 2-(hydroxymethyl)-2-nitro-1,3-propanediol was 3.4 days
at pH 7 and 2.4 days at pH 9, while it was stable at pH 5. These results indicate that the
nitroalcohols have moderate to rapid hydrolysis at neutral and alkaline conditions, but are stable
under acidic conditions. Volatilization is considered low based on the Henry's Law constants for
these substances. The rate of atmospheric photooxidation is considered slow. Given the rate of
hydrolysis, the nitroalcohols are expected to have low persistence (PI) and low bioaccumulation
potential (Bl).
Table 2. Environmental Fate Properties of the Nitroalcohol Category1
Property
2-Methyl-2-nitro-l-
propanol
(MNP)
2-(Hydroxymethyl)-2-
nitro-1,3-propanediol
(TN)
2- Ethyl-2-nitro-1.3-
propanediol
(NEPD)
Photodegradation Half-life
13.7 days (estimated)2
5.6 days (estimated)2
6.6 days estimated)2
Hydrolysis Half-life
No data
Stable at pH 5;
3.4 days at pH 7 and 25°C;
2.4 days at pH 9 and 25°C
No data
Biodegradation
No data
13.4% after 28 days
(not readily biodegradable)
No data
Bioaccumulation Factor
BAF = 0.9 (estimated)2
BAF =1.2 (estimated)2
BAF = 0.9 (estimated)2
Log Koc
0.6 (estimated)2
1.0 (estimated)2
1.0 (estimated)2
Fugacity
(Level III Model)2
Air (%)
Water (%)
Soil (%)
Sediment (%)
0.1
34.6
65.2
0.1
<0.1
30.6
69.4
<0.1
<0.1
30.6
69.4
<0.1
Persistence3
PI (low)
PI (low)
PI (low)
Bioaccumulation3
Bl (low)
Bl (low)
Bl (low)
'The Dow Chemical Company. 2010. Revised Test Plan and Robust Summary for the Nitroalcohol Category.
Available online at http://www.epa. gov/chemrtk/pubs/summaries/nitroalc/c 14355tc.htm as of December 15, 2011.
2U.S. EPA. 2011. Estimation Programs Interface Suite™ for Microsoft® Windows, v4.10. U.S. Environmental
Protection Agency, Washington, DC, USA. Available online at
http://www.epa.gov/opptintr/exposure/pubs/episuitedl.htm as of December 15, 2011.
3Federal Register. 1999. Category for Persistent, Bioaccumulative, and Toxic New Chemical Substances. Federal
Register 64, Number 213 (November 4, 1999) pp. 60194-60204.
7

-------
U.S. Environmental Protection Agency
Hazard Characterization Document
September, 2014
Conclusion: The nitroalcohols category consists of three structurally similar substances: 2-
methyl-2-nitro-l-propanol, 2-(hydroxymethyl)-2-nitro-1,3-propanediol, 2-nitro-2-ethyl-l,3-
propanediol. All three compounds are crystalline solids with moderate to low vapor pressure and
high water solubility. The substances in the nitroalcohols category are expected to possess high
mobility in soil. Volatilization is considered low based on the Henry's Law constants for these
substances. The rate of hydrolysis is considered negligible under acidic conditions and moderate
to rapid under neutral and alkaline conditions. The rate of atmospheric photooxidation is
considered slow. 2-(Hydroxymethyl)-2-nitro-1,3-propanediol is not readily biodegradable. No
data were available for the other members of this category; however, similar results are expected
for these substances. The nitroalcohols are expected to have low persistence (PI) and low
bioaccumulation potential (Bl).
3. Human Health Hazard
A summary of health effects data submitted for SIDS endpoints is provided in Table 3.
Acute Oral Toxicity
Subcategory I: TN (CASRN126-11-4)
Cox Sprague-Dawley rats (10/sex/dose) were administered 53.1% TN (purity > 99%) in water
via gavage at 0, 700, 900, 1300, 1600 or 2200 mg/kg and observed for 14 days following dose
administration. Mortality occurred in males at > 900 mg/kg and in females at > 1600 mg/kg.
LDso = 990 - 1000 mg/kg
Subcategory II: MNP (CASRN 76-39-1)
Cox Sprague-Dawley rats (10/sex/dose) were administered MNP (purity 99.6%) in water via
gavage at 0, 402, 570, 800, 1100, 1600 or 2300 mg/kg-bw (males) and 0, 800, 1100, 1310, 1600
or 2300 mg/kg-bw (females) and observed for 14 days following dosing. Mortality occurred in
all dose groups within the first 3 days of dosing.
LD50 (males) = 845 mg/kg
LD50 (females) = 1480 mg/kg
Subcategory III: NEPD (CASRN 597-09-1)
Cox Sprague-Dawley rats (10/sex/dose) were administered NEPD (purity 98.9-99.3%) in water)
via gavage at 0, 500, 910, 1600, 3000 mg/kg and observed for 14 days following dosing.
Mortality occurred in four males and two females in the 1600 mg/kg group and in seven females
and eight females in the 3000 mg/kg group within the first day of dosing.
LD50 (males) = 2128 mg/kg
LD50 (females) = 2205 mg/kg
Acute Inhalation Toxicity
Subcategory I: TN (CASRN 126-11-4)
(1) Sprague-Dawley rats (5/sex/dose) were exposed (whole-body) to fine particle-sized dust of
TN (purity > 99.69%) at 2.12 mg/L for 4 hours. Animals were observed for 14 days following
8

-------
U.S. Environmental Protection Agency
Hazard Characterization Document
September, 2014
exposure. The mass median aerodynamic diameter was estimated to be 3.8 microns. Mortality
was noted within 4 days of exposure; one male and one female died.
LCso > 2.12 mg/L
(2) Sprague-Dawley rats (5/sex/dose) were exposed to aerosols of TN (54.82% in water; purity
not indicated) at measured concentrations of 0, 0.67, 1.8, 1.9, 2.7 or 4.7 mg/L for 4 hours.
Animals were observed for 14 days following exposure. The aerosol had an aerodynamic
diameter of 2.4 (± 2.0) |im. Mortality occurred at > 1.8mg/L within 6 days of treatment.
LC50 = 2.4 mg/L
Subcategory II: MNP (CASRN 76-39-1)
No Data
Subcategory III: NEPD (CASRN 597-09-1)
No Data
Acute Dermal Toxicity
Subcategory I: TN (CASRN 126-11-4)
(1)	Sprague-Dawley rats (5/sex) were administered TN (purity > 99.96%) in water dermally at
5000 mg/kg to the clipped, intact skin under semi-occlusive conditions for 24 hours. Animals
were observed for 14 days following dose administration. All animals survived.
LD50 > 5000 mg/kg
(2)	New Zealand White rabbits (5/sex) were administered TN (purity > 99%) in saline dermally
at 2000 mg/kg to the clipped, abraded skin under occlusive conditions for 24 hours. Animals
were observed for 14 days following dose administration. No deaths occurred.
LD50 > 2000 mg/kg
Subcategory II: MNP (CASRN 76-39-1)
New Zealand White rabbits (three males and two females) were administered MNP dermally at
2000 mg/kg to the clipped, intact skin of one group or the clipped, abraded skin of another group
under occlusive conditions for 24 hours. Animals were observed for 14 days following
exposure. No mortality occurred.
LD50 > 2000 mg/kg
Subcategory III: NEPD (CASRN 597-09-1)
New Zealand White rabbits (5/sex) were administered undiluted NEPD (purity 98.9-99.3%)
dermally at 2000 mg/kg to the clipped, intact abdomen skin of one group or the clipped, abraded
abdomen skin of another group under occlusive conditions for 24 hours. Animals were observed
for 14 days following exposure. In the first test, two male rabbits were found dead within 48
hours. The study author stated that the death of the animals did not appear treatment related. The
test was repeated with another set of animals. None of these animals died.
LD50 > 2000 mg/kg
9

-------
U.S. Environmental Protection Agency
Hazard Characterization Document
September, 2014
Repeated-Dose Toxicity
Subcategory I: TN (CASRN126-11-4)
In a dermal repeated-dose toxicity study, Crl: CD BR rats (15/sex/dose) were administered TN
(purity > 99.69%) dermally at 0, 250, 500 or 1000 mg/kg-bw/day applied to clipped, intact skin
under semi-occlusive conditions, 6 hours/day, 5 days/week for 13 weeks. No clinical signs of
toxicity were observed. Although application sites were discolored yellow throughout the study
duration, microscopic examination of skin samples from control and high-dose group animals
did not reveal any local effects on the skin. There were no treatment-related effects on body
weight gain, food consumption, hematology, serum chemistry parameters, urinalysis parameters,
absolute or relative organ weights (organs not specified), ophthalmoscopic findings or lesions at
gross necropsy.
NOAEL = 1000 mg/kg-bw/day (highest dose tested)
Subcategory II: MNP (CASRN 76-39-1)
No Data
Subcategory III: NEPD (CASRN 597-09-1)
No Data
Reproductive Toxicity
Subcategory I: TN (CASRN 126-11-4)
No specific reproductive toxicity studies are available.
In the 13-week dermal repeated-dose toxicity study, animals were subject to gross and
histopathological examination of the reproductive organs at the end of the study. A minimal cyst
was observed in the ovary of one high-dose female rat. No other effects on reproductive organs
(testes and ovaries) were noted.
Subcategory II: MNP (CASRN 76-39-1)
No Data
Subcategory III: NEPD (CASRN 597-09-1)
No Data
Developmental Toxicity
Subcategory I: TN (CASRN 126-11-4)
(1) Pregnant Sprague-Dawley rats (25/dose) were administered TN (purity > 99.69%) in water
via gavage at 0, 50, 375 or 750 mg/kg-day on days 6-15 of gestation. At the high-dose level, 7 of
25 dams died between days 9 and 11 of gestation, reduced body weight gain was noted and
clinical signs (including tremors and head bobbing) were observed. One low-dose and one high-
dose fetus had an umbilical herniation and two high-dose fetuses had omphalocele. Unascended
kidneys were noted in one fetus of the high-dose group and distended ureters and/or undeveloped
renal papillae were observed in three control fetuses and two mid-dose fetuses. At 375 mg/kg-
10

-------
U.S. Environmental Protection Agency
Hazard Characterization Document
September, 2014
day, a treatment-related increase in the number of resorptions/dam was noted. Decreased fetal
body weights were noted at the high-dose level. No skeletal malformations or variations or fetal
mortality were noted.
LOAEL (maternal toxicity) = 750 mg/kg-day (based on mortality, decreased body weight and
clinical signs)
NOAEL (maternal toxicity) = 375 mg/kg-day
LOAEL (developmental toxicity) = 375 mg/kg-day (based on increased number of resorptions
per dam)
NOAEL (developmental toxicity) = 50 mg/kg-day
(2) Pregnant New Zealand White rabbits (20/dose) were administered TN (purity > 99.69%) in
water via gavage at 10, 30 or 75 mg/kg-day on days 7-19 of gestation. No mortality was
observed. Clinical observations included hair loss, clear nasal discharge and decreased
defecation in all dose groups. At the high-dose level, mean body weight loss occurred during
gestation days 7-10. Food consumption and mean body weight gain were inhibited during the
overall treatment period. No treatment-related external, visceral or skeletal malformations were
observed in offspring.
LOAEL (maternal toxicity) = 75 mg/kg-day (based on decreased bodyweight and food
consumption)
NOAEL (maternal toxicity) = 30 mg/kg-day
NOAEL (developmental toxicity) = 75 mg/kg-day (highest dose tested)
Subcategory II: MNP (CASRN 76-39-1)
No Data
Subcategory III: NEPD (CASRN 597-09-1)
No Data
Genetic Toxicity - Gene Mutation
In vitro
Subcategory I: TN (CASRN 126-11-4)
(1)	In an Ames test, Salmonella typhimurium strains TA98, TA100, TA1535, TA1537 and
TA1538 were exposed to TN (purity > 99.69%) at concentrations of 0.1, 0.2, 0.3, 0.5 or 1
mg/plate in the presence and absence of metabolic activation. Positive and negative controls
were tested concurrently and responded appropriately. The cytotoxic concentration was 2
mg/plate. There were no increases in the number of revertants.
TN was not mutagenic in these assays.
(2)	Mouse lymphoma L5178Y cells were exposed to TN (purity > 99.69%) at concentrations
ranging of 5-80 |ig/mL in the absence of metabolic activation and 5-160 |ag/m L in the presence
of metabolic activation. The cytotoxic concentrations were 47.2 |ig/mL in the absence of
activation and 188.8 |ig/mL in the presence of activation. No details regarding the use or
response of positive controls were provided.
TN was mutagenic in this assay.
11

-------
U.S. Environmental Protection Agency
Hazard Characterization Document
September, 2014
Subcategory II: MNP (CASRN 76-39-1)
In an Ames test, Salmonella typhimurium strains TA98, TA100, TA1537 and TA1538 were
exposed to MNP (purity > 60.1% active) at concentrations of 0, 0.1, 0.5, 2.5, 5 or 10 |iL/plate in
the presence and absence of metabolic activation. Negative and positive controls were tested
concurrently and responded appropriately. There were no effects on viability of the bacteria and
no effects on the number of revertants were noted.
MNP was not mutagenic in these assays.
Subcategory III: NEPD (CASRN 597-09-1)
No Data
Genetic Toxicity - Chromosomal Aberrations
In vitro
Subcategory I: TN (CASRN 126-11-4)
Chinese hamster ovary (CHO) cells were exposed to TN (purity > 99.69%) at 0.125, 0.25, 0.5,
1.0 or 2.0 mg/mL in the presence and absence of metabolic activation. The cytotoxic
concentration was 10 mg/mL without activation and 1 mg/mL with activation. Positive controls
were tested concurrently and responded appropriately. There was no evidence of chromosomal
damage.
TN did not induce chromosomal aberrations in this assay.
Subcategory II: MNP (CASRN 76-39-1)
No Data
Subcategory III: NEPD (CASRN 597-09-1)
No Data
In vivo
Subcategory I: TN (CASRN 126-11-4)
In a micronucleus assay, CD-I mice were administered TN (purity > 99.69%) via gavage at 0,
500, 1000 or 2000 mg/kg-bw for males and 0, 500, 1000 or 1500 mg/kg-bw for females for 2
consecutive days. Animals were sacrificed 24 hours after the second dose. No further details
were provided.
TN did not induce micronuclei formation in this assay.
Subcategory II: MNP (CASRN 76-39-1)
No Data
Subcategory III: NEPD (CASRN 597-09-1)
No Data
12

-------
U.S. Environmental Protection Agency
Hazard Characterization Document
September, 2014
Genetic Toxicity - Other
In vitro
Subcategory I: TN (CASRN126-11-4)
In an unscheduled DNA synthesis assay, TN was tested (in an unspecified cell type/line) at
concentrations of 10, 50 100, 500, 1000 or 10,000 |ig/mL. There was no apparent cytotoxicity at
any dose level. No further details were provided.
TN did not induce unscheduled DNA synthesis in this assay.
Subcategory II: MNP (CASRN 76-39-1)
No Data
Subcategory III: NEPD (CASRN 597-09-1)
No Data
In vivo
Subcategory I: TN (CASRN 126-11-4)
In an unscheduled DNA synthesis assay, Fischer 344 rats were administered TN in water via
gavage at concentrations of 800-1200 mg/kg-bw and sacrificed 2-4 or 14-16 hours after dosing.
No further details were provided.
TN did not induce unscheduled DNA synthesis in this assay.
Subcategory II: MNP (CASRN 76-39-1)
No Data
Subcategory III: NEPD (CASRN 597-09-1)
No Data
Additional Information
Skin Irritation
Subcategory I: TN (CASRN 126-11-4)
Undiluted TN (0.5 g, purity > 99.96%) was applied to the clipped skin of three male and three
female rabbits for 4 hours under semi-occlusive conditions. Dermal irritation was evaluated up
to 72 hours after treatment. The Draize score at all observation times was 0.
TN was not irritating to rabbit skin in this study.
Subcategory II: MNP (CASRN 76-39-1)
Undiluted MNP (0.5g, purity 99.6%) was applied to clipped, intact and abraded skin sites on the
backs of six New Zealand White rabbits (3/sex) under occluded conditions for 24 hours.
Animals were observed up to 72 hours after exposure. Three rabbits, one at the abraded site,
exhibited minimal erythema at 24 hours. No irritation was observed at 72 hours. The primary
irritation index was 0.13.
MNP was not irritating to rabbit skin in this study.
13

-------
U.S. Environmental Protection Agency
Hazard Characterization Document
September, 2014
Subcategory III: NEPD (CASRN 597-09-1)
(1)	Undiluted NEPD (0.5 g, 98.9-99.3% purity) was applied to clipped, intact and abraded skin
sites on the backs of six New Zealand White rabbits (3/sex) under occluded conditions for 24
hours. Animals were observed at 24 and 72 hours after exposure. The Draize score at all
observation times was 0.
NEPD was not irritating to rabbit skin in this study.
(2)	Undiluted NEPD (0.5 g, 98.9-99.3% purity) was applied to clipped, intact and abraded skin
sites on the backs of six New Zealand White rabbits (3/sex) under occluded conditions for 4
hours. Animals were observed at 4, 24 and 72 hours after exposure. The Draize score at all
observation times was 0. There was no change in body weights of treated animals.
NEPD was not irritating to rabbit skin in this study.
Eye Irritation
Subcategory I: TN (CASRN 126-11-4)
Undiluted TN (0.1 g, purity > 95%) was instilled in the conjunctival sac of the left eye of 12
rabbits (sex not indicated). The eyes of six animals were left unwashed and the eyes of the other
six rabbits were irrigated with water 20 -30 seconds after instillation. No lesions were observed
following fluorescence treatment. Redness of the conjunctivae was observed in the unwashed
eye within 24 hours of treatment. The average scores for unwashed eyes were 2, 0.3 and 0 at 24,
48 and 72 hours, respectively. The average scores for washed eyes were 1.3 at 24 hours and 0
thereafter.
TN was not irritating to rabbit eyes in this assay.
Subcategory II: MNP (CASRN 76-39-1)
Undiluted MNP (0. lg, purity 99.6%) was instilled in the conjunctival sac of the right eye of six
New Zealand White rabbits (sex not indicated). The unwashed eyes were examined up to 7 days
post-treatment. Effects on the cornea, iris and conjunctiva were noted in all rabbits. All rabbits
exhibited corneal scarring at 72 hours with little recovery by 7 days. The average score ranged
from 36.5 to 37.7.
MNP was irritating to rabbit eyes in this assay.
Subcategory III: NEPD (CASRN 597-09-1)
Undiluted NEPD (0.1 g, purity 98.9-99.3%) purity) was instilled in the lower conjunctival sac of
the left eye of nine Albino rabbits (sex not indicated). The eyes of only 3 rabbits were irrigated
with 50 mL of lukewarm tap water after 20-30 seconds of exposure (washed group). The eyes
were examined at 24, 48 and 72 hrs on days 7, 9, 11 and 14 post-exposure. At 24 hrs and on day
14, eyes were examined under UV light for corneal lesions. At 24 hours, the eyes of the 6
animals from the unwashed group 2 of the animals from the washed group showed corneal
lesions. The conjunctivae of the unwashed group showed severe irritation. The irritation score
was 13 at 24 hours. At day 14, all eyes were normal with the exception of one rabbit in the
unwashed group.
NEPD was irritating to rabbit eyes in this assay.
14

-------
U.S. Environmental Protection Agency
Hazard Characterization Document
September, 2014
Sensitization
Subcategory I: TN (CASRN126-11-4)
(1)	In a guinea pig maximization test, guinea pigs (number and sex not indicated) were
intradermally administered 0.1 mL of 50% TN (purity 99.69%), 50% TN with Freund's
Complete Adjuvant (FCA) 1:1 or FCA with water 1:1 to the clipped, intact skin. Seven days
after intradermal administration, the induction phase continued with a topical application of 25%
TN to the clipped, intact skin under occlusive conditions for 48 hours. The challenge phase was
conducted on day 23 with a topical application of 25% TN to the clipped, intact skin under
occluded conditions for 24 hours. Observations were made up to 72 hours after the challenge
exposure. Positive and negative control groups were tested concurrently and responded
appropriately. There were no clinical signs of toxicity or changes in body weight. The scores
for all 10 animals exposed to TN were 0 for both erythema and edema.
TN was not a dermal sensitizer in guinea pigs in this assay.
(2)	Ten guinea pigs (sex not indicated) were intradermally administered 0.05 mL of a 0.5% TN
(purity 56.78%)) solution in water. After 48 hours, intradermal injection was repeated with 0.1
mL of 0.5% solution and continued 3 times/week until 10 injections were made. After a 2-week
rest period, animals were challenged in the same manner and observed for 48 hours. Positive
and negative control groups were tested concurrently and responded appropriately. None of the
test animals showed a dermal reaction.
TN was not a dermal sensitizer to guinea pigs in this assay.
Subcategory II: MNP (CASRN 76-39-1)
In a Buehler test, female guinea pigs (10/group) were topically administered 0.5 mL of 25%
MNP (purity 99.6%), 0.5 mL of 5% formaldehyde or 0.5 mL of 1% carboxymethylcellulose
(CMC) in water. All groups were exposed for 24 hours under occluded conditions. The test
sites were cleaned after the exposure period and the procedure was repeated once a week for 3
weeks. Two weeks after the last topical application, each group of animals was challenged
topically with 5, 10 and 25% MNP in the first group, 2% formaldehyde in the second group and
5, 10 and 25% MNP, 2% formaldehyde and 1% CMC in the third group. The positive and
negative control groups responded appropriately and no effects were observed in test animals.
MNP was not a dermal sensitizer to guinea pigs in this assay.
Subcategory III: NEPD (CASRN 597-09-1)
Ten male guinea pigs were intradermally administered 0.05 mL of a 1% NEPD (purity 98.9-
99.3%) in saline solution. After 48 hours, intradermal injection was repeated with 0.1 mL of 1%
solution and continued 2-3 times/week until 10 injections were made. After a 2-week rest
period, animals were challenged in the same manner with 0.1 ml of 1% NEPD and observed for
27 hours. Positive and negative control groups were tested concurrently and responded
appropriately. None of the test animals showed a dermal reaction.
NEPD was not a dermal sensitizer to guinea pigs in this assay.
Conclusion:
Subcategory I: 2-(Hydroxymethyl)-2-nitro-1,3-propanediol (TN) has low acute oral (rat) and
dermal (rat and rabbit) toxicity and moderate acute inhalation (rat) toxicity. In a 13-week dermal
repeated-dose toxicity study, TN caused yellow discoloration at the application site, but no
15

-------
U.S. Environmental Protection Agency
Hazard Characterization Document
September, 2014
adverse effects were observed on any parameters evaluated; the NOAEL for repeat-dose toxicity
is 1000 mg/kg-bw/day, the highest dose tested. No specific reproductive toxicity studies are
available; however, in the 13-week repeated-dose study, no adverse effects on the reproductive
organs were observed. In an oral gavage prenatal developmental toxicity study in rats, mortality,
reduced body weight gain and clinical signs were observed in dams at the highest dose tested
(750 mg/kg-day); the NOAEL for maternal toxicity is 750 mg/kg-day. A treatment-related
increase in the number of resorptions per dam was observed at 375 mg/kg-day; the NOAEL for
developmental toxicity is 50 mg/kg-day. In a dermal prenatal developmental toxicity study in
rabbits, decreased body weight gain and food consumption were noted at 75 mg/kg-bw/day; the
NOAEL for maternal toxicity is 30 mg/kg-bw/day. No adverse effects on developmental
parameters were observed; the NOAEL for developmental toxicity is 75 mg/kg-bw/day (highest
dose tested). TN showed no mutagenic potential in bacteria in vitro but was mutagenic in
mammalian cells in vitro. TN did not induce chromosomal aberrations in Chinese hamster ovary
cells, micronuclei in mice or unscheduled DNA synthesis in vitro or in vivo. TN is not irritating
to rabbit eyes or rabbit skin and is not sensitizing to guinea pigs.
Subcategory II: The acute oral and dermal toxicity for MNP is low in rats and rabbits,
respectively. MNP is irritating to rabbit eyes. MNP was not mutagenic in bacteria in vitro.
MNP is not irritating to rabbit skin or sensitizing to guinea pigs.
Subcategory III: The acute oral, dermal and intravenous toxicity for NEPD is low. NEPD is
irritating to rabbit eyes. NEPD is not irritating to rabbit skin or sensitizing to guinea pigs.
Table 3. Summary of Screening Information Data Set under the U.S. HPV Challenge
Program - Human Health Data

Subcategory I
Subcategory II
Subcategory II I
Endpoint
2-(Hydroxymethyl)-2-
nitro-1,3-propanediol
(TN: 126-11-4)
2-Methyl-2-nitro-
1-propanol
(MNP: 76-39-1)
2-Ethyl-2-nitro-
1,3-propanediol
(NEPD: 597-09-1)
Acute Oral Toxicity
LDso (mg/kg)
990 -1000
845 -1480
2128 (males);
2205 (females)
Acute Inhalation Toxicity
LCso (mg/L)
2.4
—
—
Acute Dermal Toxicity
LDso (mg/kg)
>2000
>2000
>2000
Acute Intravenous Toxicity
LDso (mg/kg)
-
-
1850
Repeated-Dose Toxicity
NOAEL/LOAEL
Dermal (mg/kg-bw/day)
(rat; 13-wk)
NOAEL = 1000
(highest dose tested)
No Data
No Data
Reproductive Toxicity
NOAEL/LOAEL
Dermal (mg/kg-bw/day)
No effects were seen
following evaluation of
reproductive organs in a 13-
wk dermal repeated-dose
toxicity study in rats
No Data
No Data
16

-------
U.S. Environmental Protection Agency
Hazard Characterization Document
September, 2014
Table 3. Summary of Screening Information Data Set under the U.S. HPV Challenge
Program - Human Health Data

Subcategory I
Subcategory II
Subcategory III
Endpoint
2-(Hydroxymethyl)-2-
nitro-1,3-propanediol
(TN: 126-11-4)
2-Methyl-2-nitro-
1-propanol
(MNP: 76-39-1)
2-Ethyl-2-nitro-
1,3-propanediol
(NEPD: 597-09-1)
Developmental Toxicity
NOAEL/LOAEL
Oral (mg/kg-day)
Maternal Toxicity
Developmental Toxicity
(rabbit)
NOAEL = 30
LOAEL = 75
NOAEL = 75
(highest dose tested)
No Data
No Data
Maternal Toxicity
(rat)
NOAEL = 375
LOAEL = 750


Developmental Toxicity
NOAEL = 50
LOAEL = 375


Genetic Toxicity - Gene
Mutation
In vitro
Positive
Negative
No Data
Genetic Toxicity -
Chromosomal Aberrations
In vitro
Negative
No Data
No Data
Genetic Toxicity-
Chromosomal Aberrations
In vivo
Negative
-
-
Genetic Toxicity - Other
Unscheduled DNA
Synthesis
In vitro
Negative
-
-
Genetic Toxicity -Other
Unscheduled DNA
Synthesis
In vivo
Negative
-
-
Additional Information
Skin Irritation
Eye Irritation
Sensitization
Not irritating
Not irritating
Not sensitizing
Not Irritating
Irritating
Not sensitizing
Not Irritating
Irritating
Not sensitizing
Measured data in bold text; (-) indicates that endpoint was not addressed for this chemical.
17

-------
U.S. Environmental Protection Agency
Hazard Characterization Document
September, 2014
4. Hazard to the Environment
A summary of aquatic toxicity data submitted for SIDS endpoints is provided in Table 1. The
table also indicates where data for tested category members are read-across (RA) to untested
members of the category.
Acute Toxicity to Fish
2-(Hydroxymethyl)-2-nitro- (CASRN126-11-4)
(1)	Sheepshead minnows (Cyprinodon variegatus) were exposed to 2-(hydroxymethyl)-2-nitro-
1,3-propanediol at measured concentrations of 64, 123, 190, 356 or 501 mg/L underflow-
through conditions for 96 hours. No mortality occurred.
96-h LCso > 501 mg/L
(2)	Fathead minnow (Pimephalespromelas) were exposed to 2-(hydroxymethyl)-2-nitro-
1,3-propanediol at nominal concentrations of 0, 100, 180, 320, 560 or 1,000 mg/L under static
conditions for 96 hours. Measured concentrations were not specified. All fish exposed to 560
and 1000 mg/L died within 24 hours. At 320 mg/L, 10 and 14 fish died within 24 and 96 hours,
respectively and only 2 surviving fish appeared normal.
96-h LCso = 280 mg/L
(3)	Rainbow trout (1Oncorhynchus mykiss) were exposed to 2-(hydroxymethyl)-2-nitro-
1,3-propanediol at unspecified concentrations under static conditions for 96 hours. No additional
details were provided.
96-h LCso = 410 mg/L
Acute Toxicity to Aquatic Invertebrates
2-(Hydroxymethyl)-2-nitro- (CASRN 126-11-4)
(l)Water fleas (Daphnia magna) were exposed to TN at nominal concentrations of 0, 10, 18, 32,
56, 100 or 180 mg/L under static conditions for 48 hours. Measured concentrations were not
specified. Immobility was observed only at 100 and 180 mg/L.
48-h LCso = 80 mg/L
Toxicity to Aquatic Plants
2-(Hydroxymethyl)-2-nitro- (CASRN 126-11-4)
(l)Green algae (Psuedokirchneriella subcapitata) were exposed to TN at measured
concentrations ofO, 0.017, 0.042, 0.11, 0.270, 0.66, 1.61 or 4.50 mg/L under static conditions for
96 hours.
72-h ECso (growth rate) > 4.50 mg/L
72-h ECso (biomass) = 0.479 mg/L
72-h ECso (cell density) = 0.460 mg/L
18

-------
U.S. Environmental Protection Agency
Hazard Characterization Document
September, 2014
Conclusion: For 2-(hydroxymethyl)-2-nitro-1,3-propanediol (TN), the 96-h LC50 ranges from
280 to 501 for fish, the 48-h EC50 is 80 mg/L for aquatic invertebrates and the 72-h EC50 is > 4.5
(growth rate) and 0.479 (biomass) for aquatic plants.
Table 4. Summary of the Screening Information Data Set as Submitted
under the U.S. HPV Challenge Program - Aquatic Toxicity Data
Endpoint
2-(Hydroxymethyl)-2-
2-Methyl-2-nitro-l-
2-Ethyl-2-nitro-1.3-

nitro-l,3-propanediol
propanol
propanediol

(TN: 126-11-4)
(MNP: 76-39-1)
(NEPD: 597-09-1)
Fish

No Data
No Data
96-h LCso (mg/L)
280- 501
280 -501
280 -501


(RA)
(RA)
Aquatic Invertebrates

No Data
No Data
48-h ECso (mg/L)
80
80
80


(RA)
(RA)
Aquatic Plants

No Data
No Data
72-h ECso (mg/L)
>4.5
>4.5
>4.5
(growth rate)
0.479
0.479
0.479
(biomass)

(RA)
(RA)
(Bold) = Experimental data (ie. derived from testing); (RA) = Read Across
19

-------