U.S. Environmental Protection Agency
Hazard Characterization Document
September, 2014
SCREENING-LEVEL HAZARD CHARACTERIZATION
SPONSORED CHEMICAL
2-Pyrrolidone (CASRN 616-45-5)
SUPPORTING CHEMICAL
l-Methyl-2-pyrrolidone (CASRN 872-50-4)
The High Production Volume (HPV) Challenge Program1 was conceived as a voluntary initiative
aimed at developing and making publicly available screening-level health and environmental
effects information on chemicals manufactured in or imported into the United States in quantities
greater than one million pounds per year. In the Challenge Program, producers and importers of
HPV chemicals voluntarily sponsored chemicals; sponsorship entailed the identification and
initial assessment of the adequacy of existing toxicity data/information, conducting new testing if
adequate data did not exist, and making both new and existing data and information available to
the public. Each complete data submission contains data on 18 internationally agreed to "SIDS"
(Screening Information Data 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
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
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.
4European Chemicals Agency, http://echa.europa.eu

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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.
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Chemical Abstract
Service Registry Number
(CASRN)
Sponsored Chemical
616-45-5
Supporting Chemical
872-50-4
Chemical Abstract Index
Name
Sponsored Chemical
2-Pyrrolidone
Supporting Chemical
l-methyl-2-pyrrolidone
Structural Formula
Sponsored Chemical
NH
SMILES: 0=C(NCC1)C1
Supporting Chemical
CH,
/
SMILES: OC1CCCN1C
Summary
2-Pyrrolidone is a clear liquid with moderate vapor pressure and high water solubility. It is
expected to have high mobility in soil. Volatilization of 2-pyrrolidone is considered low based
on its Henry's Law constant. The rate of hydrolysis is considered negligible under
environmental conditions. The rate of atmospheric photooxidation is considered moderate.
Based on data for the supporting chemical 1-methyl-2-pyrolidone, 2-pyrrolidone is expected to
be readily biodegradable. 2-Pyrrolidone is expected to have low persistence (PI) and low
bioaccumulation potential (Bl).
The acute oral and dermal toxicity of 2-pyrrolidone in rats and rabbits, respectively, is low. In
a three-month repeated-dose toxicity study, male rats given 2-pyrrolidone via drinking water
exhibited increased urinary specific gravity, reduced urinary volume and increased mean
relative kidney weights at > 529 mg/kg-bw/day, with a NOAEL of 184 mg/kg-bw/day.
Females exhibited histopathological changes in thymocytes at all doses, with a LOAEL of ~
42 mg/kg-bw/day. In another three-month repeated-dose study, female rats administered 2-
pyrrolidone via drinking water exhibited decreased body weight gains of 16% at 1339 mg/kg-
bw/day and 8% at 5 mg/kg-bw/day. No specific reproductive toxicity studies are available for
2-pyrrolidone. However, in the three-month drinking water study with female rats only,
decreased relative and absolute uterine weights and increased absolute pituitary weights were
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observed. No histopathological changes in the reproductive organs were observed in the other
three month drinking water study in either sex. In an oral gavage prenatal developmental
toxicity study in rats, dams exhibited decreased body weights at > 600 mg/kg-day (with
decreased gravid uterine weights at 1900 mg/kg-day); the NOAEL for maternal toxicity is 190
mg/kg-day. In this study, fetuses exhibited increased incidences of malformations, visceral
and skeletal anomalies and decreased fetal weights at 1900 mg/kg-day, resulting in a
developmental NOAEL of 600 mg/kg-day. In another prenatal oral gavage developmental
toxicity study in rats, the developmental NOAEL was 1875 mg/kg-day (only dose tested); data
were inadequate to establish a maternal NOAEL. 2-Pyrrolidone induced gene mutations in
yeast in vitro, but did not induce gene mutations in bacteria in vitro or chromosomal
aberrations in mammalian cells in vitro. 2-Pyrrolidone did not induce micronuclei in mice in
vivo. 2-Pyrrolidone is irritating to rabbit skin and eyes.
For 2-Pyrrolidone, the 96-h LCso for fish is 580 mg/L, the 48-h EC so for aquatic invertebrates
is 13.21 mg/L. For the toxicity to aquatic plants, the 96-h ECso values are 84 mg/L for
biomass and 353 mg/L for growth rate.
No data gaps were identified under the HPV Challenge Program.	
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The sponsor, BPPB Consortium, submitted a Test Plan and Robust Summaries to EPA for 2-
pyrrolidone (CASRN 616-45-5; CA Index name: 2-pyrrolidone) on January 2, 2003. EPA
posted the submission on the ChemRTK HPV Challenge website on January 31, 2003
(http://www.epa.gov/chemrtk/pubs/summaries/2pvrroli/cl4223tc.htm). EPA comments on the
original submission were posted to the website on June 19, 2003. Public comments were also
received and posted to the website. The sponsor submitted updated/revised documents on
August 13, 2003, which were posted to the ChemRTK website on October 22, 2003.
Supporting Chemical Justification
The sponsor provided data from a ready biodegradation test for a supporting chemical, 1-m ethyl -
2-pyrrolidone (CASRN 872-50-4). These data were used to support the inherent biodegradation
data for the sponsored compound based on structural similarities between the two compounds.
In addition to data provided by the industry sponsor for 1-methyl-2-pyrrolidone, an assessment
of this compound is available through the OECD Cooperative Chemicals Assessment Program
(http ://www. oecd. org / env/hazard/data).
1. Chemical Identity
1.1	Identification and Purity
2-Pyrrolidone, a cyclic amide, is a clear liquid with unpleasant ammonia-like odor. A discussion
of purity was not included in the submitted test plan. However, purity was stated for several
individual studies (in robust summaries); values ranged from > 97% to 99.9% in all cases except
one, which noted use of 'crude' 2-pyrrolidone with no further description.
1.2	Physical-Chemical Properties
The physical-chemical properties and are summarized in Table 1. 2-Pyrrolidone is a clear liquid
with moderate vapor pressure and high water solubility.
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Table 1. Physical-Chemical Properties of 2-Pyrrolidone1
Property
Value
CASRN
616-45-5
Molecular Weight
85.11
Physical State
Clear liquid
Melting Point
25 °C (measured)
Boiling Point
245 °C (measured)
Vapor Pressure
0.0095 mm Hg at 25°C (measured)
Dissociation Constant (pKa)
Not applicable
Henry's Law Constant
1.0xlO-9 atm-m3/mole (estimated)2
Water Solubility
Miscible; 1 x 106 mg/L at 20 °C (measured)3
Log K0„
-0.71 at 25°C (measured)
'BPPB Consortium. 2003. Revised Test Plan and Robust Summary for 2-Pyrrolidone. Available online at
http://www.epa.gov/chemrtk/pubs/summaries/2pvrroli/cl4223tc.htm as of December 8, 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 8, 2011.
3SRC. 2011. The Physical Properties Database (PHYSPROP). Syracuse, NY: SRC Inc. Available online at
http://www.svrres.com/esc/phvsprop.htm as of December 8, 2011.
2. General Information on Exposure
2.1 Production Volume and Use Pattern
2-Pyrrolidone had an aggregated production and/or import volume in the United States between
50 to 100 million pounds during calendar year 2005.
Non-confidential information in the IUR indicated that the chemical is processed and used in the
following industrial categories and in the following ways: (1) in other basic organic chemical
manufacturing, both as intermediates but also as uses for which information was not readily
obtainable (NRO); and (2) in printing ink manufacturing, as solvents that become part of product
formulation or mixture.
Non-confidential commercial and consumer uses of this chemical were reported as "Other" and
"NRO."
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2.2 Environmental Exposure and Fate
2-Pyrrolidone is expected to have high mobility in soil. It was degraded approximately 99%
over 9 days using non-adapted activated sludge in a Zahn-Wellens test (OECD 302B), which
means that it was inherently biodegradable. A structural analog, 1-methyl-2-pyrrolidone
(CASRN 872-50-4), achieved 73% of its theoretical biochemical oxygen demand (BOD) in 28
days using the modified MITI (OECD 301C) test. Therefore, it is concluded that 2-pyrrolidone
is likely to be readily biodegradable. Volatilization of 2-pyrrolidone is considered low based on
its Henry's Law constant. The rate of atmospheric photooxidation is considered moderate. 2-
Pyrrolidone is expected to have low persistence (PI) and low bioaccumulation potential (Bl).
The environmental fate properties are summarized in Table 2.
Table 2. Environmental Fate Properties of 2-Pyrrolidone1
Property
Value
Photodegradation Half-life
10.8 hours (estimated)2
Hydrolysis Half-life
>1 year
Biodegradation
99% after 9 days (inherently biodegradable);
73% after 28 days (readily biodegradable)4
Bioaccumulation Factor
BAF = 0.9 (estimated)2
Log Koc
0.9 (estimated)2
Fugacity
(Level III Model)2
Air (%)
Water (%)
Soil (%)
Sediment (%)
<0.1
32.2
67.7
0.1
Persistence3
PI (low)
Bioaccumulation3
Bl (low)
'BPPB Consortium. 2003. Revised Test Plan and Robust Summary for 2-Pyrrolidone. Available online at
http://www.epa.gov/chemrtk/pubs/summaries/2pyrroli/cl4223tc.htm as of December 8, 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 8, 2011.
3Federal Register. 1999. Category for Persistent, Bioaccumulative, and Toxic New Chemical Substances. Federal
Register 64, Number 213 (November 4, 1999) pp. 60194-60204.
4Datafor l-Methyl-2-pyrrolidone CASRN 872-50-4
Conclusion: 2-Pyrrolidone is a clear liquid with moderate vapor pressure and high water
solubility. It is expected to have high mobility in soil. Volatilization of 2-pyrrolidone is
considered low based on its Henry's Law constant. The rate of hydrolysis is considered
negligible under environmental conditions. The rate of atmospheric photooxidation is
considered moderate. Based on data for the supporting chemical l-methyl-2-pyrolidone, 2-
pyrrolidone is expected to be readily biodegradable. 2-Pyrrolidone is expected to have low
persistence (PI) and low bioaccumulation potential (Bl).
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3. Human Health Hazard
A summary of the human health toxicity data for SIDS and other endpoints is provided in Table
3.
Acute Oral Toxicity
Sprague-Dawley rats (5/sex) were administered a 50% solution of 2-pyrrolidone via gavage at
5000 mg/kg in distilled water and observed for 14 days following dosing. No mortalities were
observed.
LDso > 5000 mg/kg
Acute Dermal Toxicity
New Zealand White rabbits (5/sex) were administered 2-pyrrolidone via the dermal route at 2000
mg/kg under occluded conditions for 24 hours and observed for 14 days following dosing. No
mortalities were observed.
LD50 > 2000 mg/kg
Repeated-Dose Toxicity
(l)Wistar rats (10/sex/dose) were administered 2-pyrrolidone (99.7% pure) via drinking water at
0, 600, 2400, 7200 or 15,000 ppm (~ 33, 184, 529 and 1062 mg/kg-bw for males and 42, 230,
643 and 1189 mg/kg-bw for females) for 3 months. No mortalities were observed. Effects
included decreased food consumption in both sexes at 15,000 ppm and females at 7200 ppm,
decreased water consumption in both sexes atl 5,000 and 7200 ppm and decreased body weight
gain in both sexes at 15,000 (~8 and 9% in females and males, respectively) and 7200 ppm (~
16%) and 7% in females and males, respectively). Hematological effects included prolonged
prothrombin time in both sexes at 15,000 ppm. Clinical chemistry effects included decreased
total protein, globulins, triglycerides and creatinine in both sexes at 15,000 ppm. Decreased
creatinine and total protein were also observed at the 7200 ppm dose level in both sexes and
females, respectively. Urinalysis revealed increased urinary specific gravity, reduced urinary
volume and dark yellow discoloration in 15,000 and 7200 ppm males. Increased mean relative
kidney weights were observed in both sexes at 15,000 ppm and in males at 7200 ppm. Females
exhibited altered thymocytes of irregular size and shape with increased numbers of large, pale
blast-like lymphocytic thymocytes among smaller, dark-staining cells. A clear dose-response
was not obvious and no changes in the cortex/medulla ratio, thymic medulla, or T-cell areas of
other organs were seen. Although the sponsor's submission notes that other studies show these
thymocyte changes occur in controls, the lack of such an effect in controls in the current study
indicates a possible effect of the test substance (robust summary from HPV submission;
TSCATS OTS0521310-3).
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LOAEL (males) ~ 529 mg/kg-bw/day (based on effects on clinical chemistry, urinalysis and
increased kidney weights)
NOAEL (males) ~ 184 mg/kg-bw/day
LOAEL (females) ~ 42 mg/kg-bw/day (based on histopathological changes in thymocytes)
NOAEL (females) ~ Not established
(2) Female Wistar rats (5/dose) were administered 0, 50 and 15,000 ppm (~0, 5 and 1339 mg/kg-
bw/day) 2-pyrrolidone (99.7% pure) via drinking water for 3 months. Additional rats at 0 and
15,000 ppm were followed without dosing for an additional 4 weeks. The purpose of the study
was to further evaluate the thymic effects seen in females in the repeated-dose study (#1). Food
and water consumption and body weight were measured each week and rats were observed for
signs of toxicity each day. Hematological examinations were conducted at the end of the dosing
period. All rats were subjected to gross and histological pathology examinations, although the
organs examined were not listed. Estrous cycle determination was prepared in three intervals
(start, mid and end of study). At 15,000 ppm, food and water consumption were impaired up to
21.5 and 33.1% lower than controls, respectively. At 50 ppm, the changes were 17.6 and 15%
lower than controls, respectively. Body weight gain was 8 and 16% lower than controls at 50
and 15,000 ppm, respectively. At the highest dose, relative and absolute uterine weights were
significantly decreased at 4 weeks and absolute pituitary gland weight was significantly
increased. After 3 months, altered cellular composition was seen in the thymic cortex in both
controls and treated rats, due to the incidences observed, the authors concluded that there was no
treatment-related effect. A NOAEL and LOAEL were not established (ECHA database).
Reproductive Toxicity
No reproductive toxicity studies are available.
In the three-month drinking water repeated-dose toxicity study in male and female Wistar rats,
described above, no gross lesions or microscopic findings were detected in male or female
reproductive organs, which included all genital tract organs (except oviducts) as well as pituitary
and adrenal glands. Some reproductive and related organs (uterus, epididymides, seminal
vesicles, prostate, pituitary gland and spleen) were not weighed in this study.
In the three-month drinking water repeated-dose toxicity study with female Wistar rats,
described above, relative and absolute uterine weights were significantly decreased at 4 weeks
and absolute pituitary gland weight was significantly increased at the highest dose tested. No
effects on the estrous cycle were observed (ECHA database).
Developmental Toxicity
(1) Pregnant Sprague-Dawley rats (25/group) were administered 2-pyrrolidone via gavage at 0,
190, 600 or 1900 mg/kg in distilled water from days 6 to 15 of gestation. No mortalities or
treatment-related clinical signs of toxicity were observed. Maternal effects included reduced
body weight gain and food consumption in mid- and high-dose animals and reduced gravid
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uterine weight at the highest dose. Developmental effects in high-dose pups included reduced
fetal weight, malformations (acaudia, microcaudia, anal atresia, missing vertebrae and missing
ribs), increased incidence of visceral anomalies as well as skeletal anomalies (reduced
ossification of frontal bones, irregular ossification of supraoccipital bones, reduced pre-sacral
vertebrae and ossification centers on the seventh cervical vertebra). The submitted robust
summary notes that statistically significant differences in incidence of reduced ossification (of
the interparietal bone, first lumbar vertebra, pubic bones, ischial bones) or absent ribs were
observed at 190 and 600 mg/kg, but the submitters attributed these effects to intergroup
variation. The accuracy of this claim could not be verified due to limited information in the
robust summary.
LOAEL (maternal toxicity) = 600 mg/kg-day (based on decreased body weights)
NOAEL (maternal toxicity) = 190 mg/kg-day
LOAEL (developmental toxicity) = 1900 mg/kg-day (based on increased incidence of
malformations, visceral and skeletal anomalies and decreased fetal weights)
NOAEL (developmental toxicity) = 600 mg/kg-day
(2)	Pregnant Sprague-Dawley rats (25/group) were administered 2-pyrrolidone via gavage at
1700 |iL/kg (approximately 1875 mg/kg) in distilled water from days 6 to 15 of gestation. One
death was observed on day 17 post-coitum, presumably in a dosed dam (although this is not clear
in the summary of this study). There were no data on maternal body weight gain and therefore,
maternal toxicity could not be fully evaluated. No treatment-related maternal effects were
observed in the mean number of implantations, percentage of resorptions or following
macroscopic examination. No treatment-related fetal effects were observed for mean weight and
length of fetuses, mean placental weight, percentage of malformed live fetuses or skeletal
malformations.
NOAEL (developmental toxicity) ~ 1875 mg/kg-day (based on no effects at the highest dose
tested)
(3)	Pregnant female NMRI mice (12/dose; 14/control) were administered 2-pyrrolidone
(unknown purity) at 0, 1279 and 3199 mg/kg-day via gavage from gestation days 11 through 15.
Implantation and fetal resorption sites were recorded and the number of live and dead fetuses and
body length, weight and sex were determined. Fetuses were examined macroscopically for any
malformations. At 3199 mg/kg-day, the mean weight and length of fetuses were somewhat
lower than 'comparative values' (without further elaboration other than noting only 2 runts were
seen at the highest dose). A total of 4 malformations were seen at 3199 mg/kg-day (3 in a single
fetus, with 2 dams effected), which matched the number of malformations in the control group
(again, with 3 seen in a single fetus, with two dams affected). At 1279 mg/kg-day, mean litter
size (along with mean number of implantations) were decreased but the effect was considered
not to be treatment-related due to the timing (i.e., nidation takes place on the gestation day 5-6).
The malformation rate at 1279 mg/kg-day was somewhat increased vs. controls; 4 of 6
malformations at this dose were cleft palates. The slightly increased incidence of malformations
was considered in the 'range of physiological fluctuations' (ECHA database).
NOAEL (maternal toxicity) = 3199 mg/kg-day (highest dose tested)
NOAEL (developmental toxicity) = 3199 mg/kg-day (highest dose tested)
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Genetic Toxicity - Gene Mutations
In vitro
Salmonella typhimurium strains TA1535, TA1538, TA100, TA1537 and TA98 were exposed to
2-pyrrolidone (99.9% purity) in distilled water up to 150 |iL/plate with and without metabolic
activation. The positive control produced appropriate responses. The cytotoxic concentration
was 150 |iL/plate. 2-Pyrrolidone did not exhibit genetic activity with or without metabolic
activation.
2-Pyrrolidone was not mutagenic in this assay.
Genetic Toxicity — Chromosomal Aberrations
In vitro
(1)	Human lymphocytes were exposed to 2-pyrrolidone (99.9% purity) in distilled water at 1250,
2500 or 3500 |ig/mL without metabolic activation or 2500, 5000 or 6000 |ig/mL with metabolic
activation. Positive and negative controls produced appropriate responses. High doses were
considered minimally cytotoxic.
2-Pyrrolidone did not induce chromosomal aberrations in this assay.
(2)	Saccharomyces cerevisiae strain D61.M was exposed to 2-pyrrolidone up to 445.0 mM
without metabolic activation. Negative controls produced appropriate responses. Information on
the use and response of positive controls was not provided. The cytotoxic concentration was 321
mM. The frequency of aneuploidy increased with dose.
2-Pyrrolidone induced aneuploidy in this assay.
In vivo
NMRI mice (5/sex/dose) were administered 2-pyrrolidone (>99.5% purity) in distilled water via
intraperitoneal injection at 500, 1000 or 2000 mg/kg and were sacrificed at 24 hours post-
administration (and at 16 and 48 hours at 2000 mg/kg) and bone marrow was collected for
analysis. Negative and positive controls produced appropriate responses. Clinical signs of
toxicity included irregular respiration, piloerection, abdominal position, apathy and squatting
posture. The ratio of polychromatic to normochromatic erythrocytes containing micronuclei did
not differ from negative controls or in the various dose groups at any sacrifice interval.
2-Pyrrolidone did not induce micronuclei in mice in this assay.
Additional Information
Skin Irritation
(1) Six male Vienna white rabbits were administered 0.5 mL undiluted 2-pyrrolidone (crude) for
24 hours under occlusive cover to intact and 'scarified' skin and observed for 8 days. Skin
reddening and edema were seen on both intact and scarified skin and were both more severe on
the scarified skin. Necrosis was seen in one rabbit. The overall primary irritation value was 2.5
(between mild (2) and severe (3) values) (TSCATS OTS0522884; additional details from ECHA
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database). There were several deviations from OECD test guidelines, including use of a 24 hour
exposure period.
2-Pyrrolidone was irritating to rabbit skin.
(2) Three New Zealand white rabbits were exposed to 0.5 g of the undiluted test substance under
semiocclusive conditions on the shaved dorsal area for 4 hours and observed up to 72 hours. The
test site was washed after exposure. One rabbit exhibited slight erythema, which resolved after
24 hours. No corrosion was observed (ECHA database).
2-Pyrrolidone was not irritating to rabbit skin.
Eye Irritation
Vienna white rabbits (1 male; 5 females) were administered 0.1 mL undiluted 2-pyrrolidone
(crude) in the eye and observed for 15 days. Effects were seen in the cornea, iris and
conjunctivae and were severe in some rabbits. By day 15, not all effects were reversed and
severe effects were still seen in one rabbit. The overall primary irritation value was 42
(TSCATS OTS0522884).
2-Pyrrolidone was irritating to rabbit eyes.
(2) Two Vienna white rabbits were administered 0.05 mL of the undiluted test substance to the
conjunctival sac of one eye and not washed; the eyes were observed up to 8 days after
instillation. At 24-72 hours, the mean corneal opacity score was 2 (out of 2 as a maximum
score). The iris score for the same time period was zero. The mean conjunctivae score for
redness was 1 (out of 2 as a maximum) but no conjunctival swelling occurred. Complete
reversal was seen by day 7 (ECHA database).
2-Pyrrolidone was irritating to rabbit eyes.
Conclusion: The acute oral and dermal toxicity of 2-pyrrolidone in rats and rabbits, respectively,
is low. In a three-month repeated-dose toxicity study, male rats given 2-pyrrolidone via drinking
water exhibited increased urinary specific gravity, reduced urinary volume and increased mean
relative kidney weights at > 529 mg/kg-bw/day, with a NOAEL of 184 mg/kg-bw/day. Females
exhibited histopathological changes in thymocytes at all doses, with a LOAEL of ~ 42 mg/kg-
bw/day. In another three-month repeated-dose study, female rats administered 2-pyrrolidone via
drinking water exhibited decreased body weight gains of 16% at 1339 mg/kg-bw/day and 8% at
5 mg/kg-bw/day. No specific reproductive toxicity studies are available for 2-pyrrolidone.
However, in the three-month drinking water study with female rats only, decreased relative and
absolute uterine weights and increased absolute pituitary weights were observed. No
histopathological changes in the reproductive organs were observed in the other three month
drinking water study in either sex. In an oral gavage prenatal developmental toxicity study in
rats, dams exhibited decreased body weights at > 600 mg/kg-day (with decreased gravid uterine
weights at 1900 mg/kg-day); the NOAEL for maternal toxicity is 190 mg/kg-day. In this study,
fetuses exhibited increased incidences of malformations, visceral and skeletal anomalies and
decreased fetal weights at 1900 mg/kg-day, resulting in a developmental NOAEL of 600 mg/kg-
day. In another prenatal oral gavage developmental toxicity study in rats, the developmental
NOAEL was 1875 mg/kg-day (only dose tested); data were inadequate to establish a maternal
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NOAEL. 2-Pyrrolidone induced gene mutations in yeast in vitro, but did not induce gene
mutations in bacteria in vitro or chromosomal aberrations in mammalian cells in vitro. 2-
Pyrrolidone did not induce micronuclei in mice in vivo. 2-Pyrrolidone is irritating to rabbit skin
and eyes.
Table 3. Summary Table of the Screening Information Data Set under the U.S. HPV
Challenge Program - Human Health Data
Endpoint
2-Pyrrolidone
(616-45-5)
Acute Oral Toxicity
LDso (mg/kg)
>5000
Acute Dermal Toxicity
LD50 (mg/kg)
>2000
Repeated-Dose Toxicity
Oral (mg/kg-bw/day)
(rat; 3-m)
NOAELmales ~ 184
LOAELmales ~ 529
NOAELfemaies = Not Established
LOAELfemales ~ 42
Reproductive Toxicity
Oral
In the 3-month repeated-dose toxicity study in female
rats, decreased absolute uterine weight and increased
pituitary weights were observed. No histopathological
changes in male and female reproductive organs were
observed in the other 3-month study.
Developmental Toxicity
Oral (mg/kg-day)
Maternal
NOAEL = 190
LOAEL = 600
Developmental
NOAEL = 600
LOAEL = 1900
Genetic Toxicity -
Gene Mutations In vitro
Negative
Genetic Toxicity -
Chromosomal Aberrations
In vitro
In vivo
Positive
[Aneuploidy in yeast]
Negative
Additional Information
Skin Irritation
Eye Irritation
Irritating
Irritating
Measured data in bold
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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 4.
Acute Toxicity to Fish
Zebra fish (Brachydanio rerio) were exposed to 2-pyrrolidone (purity 99.7%) at nominal
concentrations of 0, 50, 100, 1000, 2150, 4640 or 10,000 mg/L under static conditions for 96
hours. Measured concentrations were 0, 38, 98, 947, 2084, 4600 and 9935 mg/L at 96 hours. At
10,000 mg/L, 100% mortality was observed at 96 hours. Clinical signs included apathy and
tumbling.
96-h LCso = 6783 mg/L
Acute Toxicity to Aquatic Invertebrates
(1)	Daphnia magna were exposed to 2-pyrrolidone (purity > 99.5%) at nominal concentrations of
0, 31.25, 62.5, 125, 250 or 500 mg/L under static conditions for 48 hours. Measured
concentrations were not provided. No daphnids were found immobilized by treatment and no
adverse effects were noted at any concentration.
48-h ECso > 500 mg/L
(2)	Daphnia magna were exposed to 2-pyrrolidone at nominal concentrations of 10, 100 or 1000
mg/L under static conditions for 96 hours. Daphnia were observed for 21 days. Measured
concentrations were not provided. No mortality occurred in the first 96 hours of exposure in any
group. At the end of the 3-week exposure period the numbers of surviving daphnids were 17/20,
18/20 and 12/20 for the 10, 100 and 1000 mg/L groups, respectively.
96-h EC50 > 1000 mg/L
(3)	Daphniapulex were exposed to 2-pyrrolidone (purity > 97%) at unspecified concentrations
under static conditions for 48 hours. Measured concentrations were not provided. The mean
effective concentration was taken from three valid tests.
48-h ECso = 13.21 mg/L
Toxicity to Aquatic Plants
Green algae (Desmodesmus subspicatus) were exposed to 2-pyrrolidone (purity > 99.5%) at
nominal concentrations of 0, 25, 50, 100, 250 or 500 mg/L for 96 hours. Measured
concentrations were not provided.
96-h ECso (biomass) = 84 mg/L
96-h ECso (growth rate) = 353 mg/L
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U.S. Environmental Protection Agency
Hazard Characterization Document
September, 2014
Conclusion: For 2-pyrrolidone, the 96-h LC50 for fish is 580 mg/L, the 48-h EC50 for aquatic
invertebrates is 13.21 mg/L. For the toxicity to aquatic plants, the 96-h EC50 values are 84 mg/L
for biomass and 353 mg/L for growth rate.
Table 4. Summary of the Screening Information Data Set as Submitted under the U.S.
HPV Challenge Program - Aquatic Toxicity Data
Endpoint
2-Pyrrolidone
(616-45-5)
Fish
96-h LCso (mg/L)
6783
Aquatic Invertebrates
48-h ECso (mg/L)
13.21
Aquatic Plants
96-h ECso (mg/L)
(Growth rate)
(Biomass)
353
84
Bold = measured data (i.e., derived from testing)
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