Registration Dossier

Administrative data

Description of key information

2 -hydroxyethyl acrylate itself is comprehensively tested in respect to subacute (rat inhalation), subchronic (rat oral, dog oral) and chronic toxicity (rat inhalation). The data are supported by test performed with the structural analogue 2 hydroxypropyl acrylate which was tested in subacute study in rat, mouse, dog and rabbit by inhalation exposure.

In the 2 years inhalation study with male/female Sprague-Dawley rats (DowChemCo, 1979) the lowest observed adverse effect concentration (LOAEC), based on severe local irritation effects was 5 ppm (equivalent to approx. 0.024 mg/L).

No toxicity was observed in rats exposed to 0.5 ppm HEA (corresponding to 0.0024 mg/L), thus NOAEC in this study was determined to be 0.0024 mg/L. Gross and histopathologic examination of rats exposed to 5.0 ppm HEA revealed a characteristic yellow staining of the haircoat, as well as an increased incidence, increased severity and earlier onset of the lesions associated with chronic murine pneumonia. These exposure-related effects were not observed in rats exposed to 0.5 ppm HEA.

In the subchronic oral feed studies in rat and dogs no systemic toxicity were described up to the highest dose tested (rat: males 191 mg/kg; females 305 mg/kg bw) (dog: males 125 mg/kg bw; females 131 mg/kg bw)

Key value for chemical safety assessment

Repeated dose toxicity: via oral route - systemic effects

Link to relevant study records

Referenceopen allclose all

Endpoint:
sub-chronic toxicity: oral
Type of information:
experimental study
Adequacy of study:
weight of evidence
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
study well documented, meets generally accepted scientific principles, acceptable for assessment
Remarks:
Study was conducted prior to the advent of GLP regulations (1982)
Principles of method if other than guideline:
Groups of male and female Beagle dogs (2/sex/group) were maintained for 97 days on a diet containing 0.06, 0.2, or 0.4 % HEA in diet (equivalent to doses of 21, 60 and 125 and 22, 63 and 131 mg/kg body weight/day for males and females respectively).
GLP compliance:
no
Remarks:
(Study was conducted prior to the advent of GLP regulations)
Limit test:
no
Specific details on test material used for the study:
- Name of test material (as cited in study report): 2-hydroxyethyl acrylate
- Analytical purity: 97 %
- Source: Texas Division
- Physical state: pale yellow liquid
- Density: ca. 1.07
Species:
dog
Strain:
Beagle
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Age at study initiation: 6-7 months
- Weight at study initiation: no data
- Housing: 2 dogs/cage
- Diet (ad libitum): Purina Laboratory Chow mixed with 1 % peanut oil
- Water: ad libitum
- Acclimation period:

ENVIRONMENTAL CONDITIONS
no details
Route of administration:
oral: feed
Vehicle:
unchanged (no vehicle)
Analytical verification of doses or concentrations:
not specified
Duration of treatment / exposure:
97 days
Frequency of treatment:
daily
Dose / conc.:
21 mg/kg bw/day (nominal)
Remarks:
administered in males
Dose / conc.:
60 mg/kg bw/day (nominal)
Remarks:
administered in males
Dose / conc.:
125 mg/kg bw/day (nominal)
Remarks:
administered in males
Dose / conc.:
22 mg/kg bw/day (nominal)
Remarks:
administered in females
Dose / conc.:
63 mg/kg bw/day (nominal)
Remarks:
administered in females
Dose / conc.:
131 mg/kg bw/day (nominal)
Remarks:
administered in females
No. of animals per sex per dose:
2
Control animals:
yes, plain diet
Details on study design:
Post-exposure period: no
Positive control:
no
Observations and examinations performed and frequency:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: frequently

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: frequently

BODY WEIGHT: Yes
- Time schedule for examinations: weekly

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study):
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: Yes
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: Yes
- Food consumption records were kept weekly throughout the experimental period

HAEMATOLOGY: Yes
- Time schedule for collection of blood: before test start and after 83 days on the diet
- Anaesthetic used for blood collection: No data
- Animals fasted: No data
- How many animals: all
- Parameters examined: serum urea nitrogen, alkaline phosphatase, bromsulfophthalein (B.S.P.), serum glutamic oxalacetic transaminase (S.G.O.T.), and serum glutamic pyruvic transaminase (S.G.P.T.) values

CLINICAL CHEMISTRY: No

URINALYSIS: No
Sacrifice and pathology:
GROSS PATHOLOGY: Yes
HISTOPATHOLOGY: Yes

All animals were fasted overnight and weighed before examination at autopsy. Bone marrow smears were taken from the rib of the male and female dogs on the control and 0.4 percent levels of 2-hydroxyethyl acrylate and from the female dogs on the control. The lungs, heart, liver, kidneys, spleen, brain, and testes were removed and weighed.
Portions of each organ, as well as lymph node, esophagus, aorta, pancreas, uterus, ovary, urinary bladder, gall bladder, stomach, skeletal muscle, large intestine, small intestine, spinal cord, pituitary gland, adrenal gland, thyroid, parathyroid, and peripheral nerve were preserved. Hematoxylin-eosin stained sections of the tissues were prepared for microscopic examination.
Statistics:
no data
Clinical signs:
no effects observed
Description (incidence and severity):
No compound-related effects
Mortality:
no mortality observed
Description (incidence):
No compound-related effects
Body weight and weight changes:
no effects observed
Food consumption and compound intake (if feeding study):
no effects observed
Description (incidence and severity):
No compound-related effects
Food efficiency:
not examined
Water consumption and compound intake (if drinking water study):
not examined
Ophthalmological findings:
not examined
Haematological findings:
no effects observed
Description (incidence and severity):
No compound-related effects
Clinical biochemistry findings:
not examined
Urinalysis findings:
not examined
Behaviour (functional findings):
not examined
Immunological findings:
not examined
Organ weight findings including organ / body weight ratios:
no effects observed
Description (incidence and severity):
No compound-related effects
Gross pathological findings:
no effects observed
Description (incidence and severity):
No compound-related effects
Neuropathological findings:
not examined
Histopathological findings: non-neoplastic:
no effects observed
Description (incidence and severity):
No compound-related effects
Histopathological findings: neoplastic:
no effects observed
Description (incidence and severity):
No compound-related effects
Dose descriptor:
NOAEL
Effect level:
125 mg/kg bw/day (nominal)
Based on:
test mat.
Sex:
male
Basis for effect level:
other: high dose
Dose descriptor:
NOAEL
Effect level:
131 mg/kg bw/day (nominal)
Based on:
test mat.
Sex:
female
Basis for effect level:
other: high dose
Critical effects observed:
no

One female dog on the 0.4 percent level of 2 -hydroxyethyl acrylate was relatively small at the beginning of the experimental period and showed a slight weight loss during this period. This dog was found to have an enlarged spleen. However, upon microscopic examination of the tissues from this animal, no evidence of adverse changes was noted. Thus, the dog's condition was not attributed to the experimental compound.

 

Thus, there was no evidence of adverse effects as judged by general appearance and behavior, weight gain, food consumption, hematological values, examination of bone marrow, urea nitrogen content and alkaline phosphatase activity in the serum, serum bromsulfophthalein, serum glutamic oxalacetic transaminase and serum glutamic pyruvic transaminase tests, final average body and organ weights, and gross and microscopic examination of tissues.

Details on hematology, clinical chemistry, body weight, organ weights and pathological/microscopic examinations are given in the attachment.

Endpoint:
sub-chronic toxicity: oral
Type of information:
experimental study
Adequacy of study:
weight of evidence
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
study well documented, meets generally accepted scientific principles, acceptable for assessment
Remarks:
Study was conducted prior to the advent of GLP regulations (1982).
Principles of method if other than guideline:
Groups of male and female Sherman strain rats (10/sex/group) were maintained for 100 days on a diet containing 0, 0.03. 0.1 or 0.3 % HEA (equivalent to doses of approx. 0, 20, 65, and 196 mg/kg body weight/day for males and 0, 30, 102, and 305 mg/kg body weight/day for females).
GLP compliance:
no
Remarks:
(Study was conducted prior to the advent of GLP regulations)
Limit test:
no
Specific details on test material used for the study:
- Name of test material (as cited in study report): 2-hydroxyethyl acrylate
- Analytical purity: 97 %
- Source: Texas Division
- Physical state: pale yellow liquid
- Density: ca. 1.07
Species:
rat
Strain:
Sherman
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Age at study initiation: 64 days
- Weight at study initiation: no data
- Housing: 2 rats/cage
- Diet (ad libitum): Purina Lboratory Chow
- Water: ad libitum
- Acclimation period: since weaning at the age of 21 days

ENVIRONMENTAL CONDITIONS
no details
Route of administration:
oral: feed
Vehicle:
unchanged (no vehicle)
Analytical verification of doses or concentrations:
not specified
Duration of treatment / exposure:
100 days
Frequency of treatment:
daily
Dose / conc.:
0.03 other: % nominal in diet
Remarks:
equivalent to doses of approx. 20 and 30 mg/kg bw /day for males and females, respectively
Dose / conc.:
0.1 other: % nominal in diet
Remarks:
equivalent to doses of approx. 65 and 102 mg/kg bw /day for males and females, respectively
Dose / conc.:
0.3 other: % nominal in diet
Remarks:
equivalent to doses of approx. 196 and 305 mg/kg bw /day for males and females, respectively
No. of animals per sex per dose:
10
Control animals:
yes, plain diet
Details on study design:
Post-exposure period: no

Animals were weighed twice weekly for the first 28 days, and once a week thereafter. They were observed frequently for gross changes in appearance or behavior. Records were kept of mortality and food consumption was recorded for the first month. Terminal hematological values were obtained from 5 male and 5 female rats for the control group. Samples of blood serum were obtained for the determination of urea nitrogen content and alkaline phosphatase activity.

At autopsy animals were fasted overnight, weighed and killed by decapitation. The lungs, heart, liver, kidneys, spleen, testes and brain were removed examined and weighed. Portions of these organs, as well as pituitary, thyroid, parathyroid, adrenal, pancreas, lymph nodes, peripheral nerve, urinary bladder, esophagus, stomach, small intestine, large intestine, ovary and uterus were preserved in 10% neutral formalin and hematoxylin-eosin stained sections were prepared for histological examinations.
Positive control:
no
Observations and examinations performed and frequency:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: frequently

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: frequently

BODY WEIGHT: Yes
- Time schedule for examinations: during the first 28 days of the study twice weekly, then once a week thereafter

FOOD CONSUMPTION AND COMPOUND INTAKE:
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: No
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: No
- Time schedule for food consumption: recorded during the first 30 days

HAEMATOLOGY: no

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: before sacrifice
- Animals fasted: Yes
- Parameters: urea nitrogen content and alkaline phosphatase activity

URINALYSIS: No
Sacrifice and pathology:
GROSS PATHOLOGY: Yes
HISTOPATHOLOGY: Yes

At autopsy the animals were fasted overnight, weighed, and sacrificed by decapitation. The lungs, heart, liver, kidneys, spleen, testes, and brain were removed, examined, and weighed. Portions of these organs, as well as pituitary, thyroid, parathyroid, adrenal, pancreas, lymph node, peripheral nerve, urinary bladder, esophagus, stomach, small intestine, large intestine, ovary, and uterus were preserved in 10 % neutral formalin and hematoxylin-eosin stained sections were prepared for histological examination.
Statistics:
When appropriate, the Fisher "t"-test was used in comparing the mean values obtained on the experiment groups with those of the controls; in general, probability values (P) of less than 0.05 were interpreted as indicating a significant difference.
Clinical signs:
no effects observed
Description (incidence and severity):
No substance-related effects.
Mortality:
no mortality observed
Description (incidence):
No substance-related effects.
Body weight and weight changes:
no effects observed
Description (incidence and severity):
No substance-related effects.
Food consumption and compound intake (if feeding study):
no effects observed
Description (incidence and severity):
No substance-related effects.
Food efficiency:
not examined
Water consumption and compound intake (if drinking water study):
not examined
Ophthalmological findings:
not examined
Haematological findings:
not examined
Clinical biochemistry findings:
no effects observed
Description (incidence and severity):
No substance-related effects.
Urinalysis findings:
not examined
Behaviour (functional findings):
not examined
Immunological findings:
not examined
Organ weight findings including organ / body weight ratios:
no effects observed
Description (incidence and severity):
No substance-related effects.
Gross pathological findings:
no effects observed
Description (incidence and severity):
No substance-related effects.
Neuropathological findings:
not examined
Histopathological findings: non-neoplastic:
no effects observed
Description (incidence and severity):
No substance-related effects.
Histopathological findings: neoplastic:
no effects observed
Description (incidence and severity):
No substance-related effects.
Other effects:
no effects observed
Key result
Dose descriptor:
NOAEL
Effect level:
>= 196 mg/kg bw/day (nominal)
Based on:
test mat.
Sex:
male
Basis for effect level:
other: high dose
Dose descriptor:
NOAEL
Effect level:
>= 305 mg/kg bw/day (nominal)
Based on:
test mat.
Sex:
female
Basis for effect level:
other: high dose
Key result
Critical effects observed:
no

The rats were maintained for 100 days on diets containing HEA without evidence of adverse effect as judged by general appearance and behaviour, growth, food consumption, serum, urea, nitrogen and alkaline phosphatase determinations, final average body and organ weights, organ/body weight ratios, and gross and microscopic examination of tissues. Gross examination of all tissues was made at autopsy and microscopic examination of hematoxylin and eosin stained sections was made of brain, pituitary, thyroid, parathyroid, adrenals, pancreas, spleen, lymph node, lung, heart, liver, kidney urinary bladder, esophagus, stomach, small intestine, large intestin, and gonads.

See attachment for body weights, organ weights and pathological observation.

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed
Dose descriptor:
NOAEL
196 mg/kg bw/day
Study duration:
subchronic
Species:
rat
Quality of whole database:
The feeding studies were performed pre-OECD TG and pre-GLP, but the studies are well reported using an adequate number of animals (comparable to current OECD TG) pathological and histopathological examinations were performed and the results reported. Therefore the studies have to be regarded to be reliable.

Repeated dose toxicity: inhalation - systemic effects

Link to relevant study records
Reference
Endpoint:
chronic toxicity: inhalation
Remarks:
combined repeated dose and carcinogenicity
Type of information:
experimental study
Adequacy of study:
key study
Study period:
10 May 1974 to 07 May 1976
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
study well documented, meets generally accepted scientific principles, acceptable for assessment
Remarks:
Study was conducted prior to the advent of GLP regulations (1982).
Reason / purpose:
reference to same study
Reason / purpose:
reference to same study
Principles of method if other than guideline:
Groups of 99-100 male and female rats were exposed to atmospheres containing 0 ppm (controls), 5.0 ppm (24 mg/m3) or 0.5 ppm (2.4 mg/m3) 2-hydroxyethyl acrylate (HEA) for 6 hours/day, 5 days/week over an 18 month period, and subsequently held for a post-exposure period of 5 months (males) and 6 months (females). The study included 12-month interim sacrifices for pathologic and cytogenetic examinations.
GLP compliance:
no
Remarks:
(Study was conducted prior to the advent of GLP regulations)
Limit test:
no
Specific details on test material used for the study:
- Name of test material (as cited in study report): 2-Hydroxyethyl acrylate
- Analytical purity: 94 %
Species:
rat
Strain:
Sprague-Dawley
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Strain: Spartan substrain
- Source: Spartan Research Animals, Michigan
- Housing: 3-4 animals/cage
- Diet: ad libitum
- Water: ad libitum

ENVIRONMENTAL CONDITIONS
- Temperature: ambient
- Humidity: ambient
Route of administration:
inhalation: vapour
Type of inhalation exposure:
whole body
Vehicle:
air
Details on inhalation exposure:
GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: 3.7 cubic meters stainless steel chambers under dynamic airflov- conditions
- System of generating vapours: The exposure atmosphere in each chamber was generated by metering liquid HEA at a calculated rate into the top of
a 15 inch glass column ( 2" diameter) that was heated to a temperature (ca. 80°C) hot enough to vaporize the HEA. Dry compressed air was introduced at the bottom of the glass column to sweep the vapours into the chamber where they were diluted with room air at a rate calculated to provide the desired HEA Concentration.

TEST ATMOSPHERE
- The nominal concentration of HEA in the chamber was calculated from the ratio of the amount of liquid HEA used to the rate of total chamber airflow.
- Brief description of analytical method used:
The concentration of HEA in each chamber was determined three or more times daily.
Analytical concentrations for the first 6 1/2 months of exposure were obtained by drawing 10 liters of air from the chamber at a rate of 1 liter/min through a charcoal tube. The HEA absorbed on the charcoal was extracted into 2 mL of carbon disulfide. The quantity of HEA in a 2 µL sample of carbon disulfide extract was analysed by gas chromatography (detector: FID).
For the last 11 1/2 months of the study HEA samples were collected by bubbling chamber air through water instead of charcoal. Improved reproducibility of sample analysis and convenience were the primary reasons for using water instead of charcoal. Fifty liters of air from the chamber were drawn through 20 mL of distilled water in a fritted glass bubbler at a rate of 1 liter/min. The quantity of HEA in a 2 µL sample of the trapping solution was analyzed by gas chromatography using the same conditions as before.
- Samples taken from breathing zone: no
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
Sixty per cent of the total exposure days for the low exposure level and 73 % of the total exposure days of the high exposure level were within 50 % of the an analytical concentrations. The high nominal concentration values and variability in analytical concentrations reflect the fact that HEA, having a relatively low vapour pressure, was difficult to vaporize. Much of the HEA dispensed into the vaporization apparatus was not vaporized, but that not vaporized was not subtracted from the amount dispensed in calculation of the nominal concentration. Although the analytical concentrations were not identical to the target concentrations, especially for the higher exposure level, the target concentrations of 0.5 and 5.0 ppm were referred to throughout the study report.
Duration of treatment / exposure:
18 months
Frequency of treatment:
6 hours per day, 5 days per week
Dose / conc.:
0.024 mg/L air (nominal)
Remarks:
corresponding to 5 ppm
Dose / conc.:
0.002 mg/L air (nominal)
Remarks:
corresponding to 0.5 ppm
No. of animals per sex per dose:
99 - 100
Control animals:
yes, concurrent vehicle
Details on study design:
- Post-exposure recovery period: Males: 5 months; females: 6 months
Positive control:
none
Observations and examinations performed and frequency:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: no details given

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: no details given

BODY WEIGHT: Yes
- Time schedule for examinations: no details given

HAEMATOLOGY: Yes
- Time schedule for collection of blood: prior to the scheduled 12-month interim sacrifice, and again after 5 months of the post-exposure observation period
- Anaesthetic used for blood collection: No data
- Animals fasted: No data
- How many animals: 10 rats/sex/exposure group
- Parameters were examined: packed cell volume (PVC), red blood cell count (RBC), hemoglobin concentration (Hgb), total white blood cell count (WBC) and differential white blood cell count.

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of serum: prior to the scheduled 12-month interim sacrifice, and again after 5 months of the post-exposure observation period
- Anaesthetic used for blood collection: No data
- Animals fasted: No data
- How many animals: 5 and 9 or 10 rats/sex/exposure group, respectively
- Parameters were examined: blood urea nitrogen (DUN) concentration, serum alkaline phosphatase (AP) activity, and serum glutamic pyruvic transaminase (SGPT) activity

URINALYSIS: Yes
- Time schedule for collection of blood: prior to the scheduled 12-month interim sacrifice, and again after 5 months of the post-exposure observation period
- Anaesthetic used for blood collection: No data
- Animals fasted: No data
- How many animals: 5 and 10 rats/sex/exposure group, respectively
- Parameters were examined: Urinary specific gravity, pH, and the presence or absence of glucose, protein, ketones, bilirubin and occult blood were evaluated at both time intervals. Urinary urobilinogen was evaluated at the preterminal sampling interval only.



Sacrifice and pathology:
GROSS PATHOLOGY: Yes
HISTOPATHOLOGY: Yes

An interim necropsy of 5 rats/sex/exposure group was conducted after 12 months exposure. Terminal necropsy was conducted after completion of
23 months (18 months exposure + 5 months post-exposure) for male rats, and after completion of 24 months (18 months exposure + 6 months post-exposure) for female rats.

The eyes of 5 rats/sex/exposure group were placed in Zenker's fixative. The trachea and lungs were removed as a unit and distended with formalin
fixative. The weights of the brain, heart, liver, kidneys and testes (males) were recorded for 5 rats/sex/group sacrificed after 12 months and also for 9-19 rats/sex/exposure group sacrificed at termination.

Gross examination:
Representative portions of the major organs and tissues, including brain, heart, liver, kidneys, testes, lungs, thoracic and/or mesenteric lymph nodes, salivary glands, pancreas, adrenals, spleen, thymus, aorta, skeletal muscle, small intestine, large intestine, thyroid gland, parathyroid glands, eyes (those not fixed in Zenker's fixative), esophagus, trachea, spinal cord, peripheral nerve, pituitary gland, epididymides, urinary bladder, accessory sex glands, adipose tissue, ovaries, uterus, nasal turbinates, and any gross lesion suggestive of an unexpected pathologic process or with a tumour formation was preserved in buffered 10 % formalin fixative. The eyes were examined with a glass slide technique and the data were entered with the gross data.

Microscopic examination:
- Control and High (5.0 ppm) Exposure Group: All available tissues from all rats were examined.
- Low (0.5 ppm) Exposure Group: In the absence of any discernible exposure-related lesions in the tissues from rats exposed to 5.0 ppm, the 12-month interim examination of rats of the 0.5 ppm exposure group was limited to grossly visible lesions suggestive of tumour formation. From the terminal necropsy, all available lungs, livers, kidneys, lymph nodes, tracheas, plus grossly visible lesions suggestive of an unexpected pathologic process
or tumour formation were examined from all rats.
Statistics:
Significance of differences between control and test values for hematology, clinical chemistry, body weights, organ weights, and organ/body weight ratio data was statistically determined by an analysis of variance and Dunnett's Test (Steel and Torrie, 1960). A significance level of p<0.05 was used. Cumulative mortality data were analysed using Fisher's Exact Probability Test, p<0.05 (Siegel, 1956). The pathologic data were statistically analysed using Fisher's Exact Probability Test and the Mantel-Haenzel Test (Siegel, 1956). A significance level of p<0.05 was used.
Clinical signs:
no effects observed
Description (incidence and severity):
Overall, the cumulative mortality data did not suggest any unequivocal exposure-related effects with the possible exception of initial increased mortality associated with the onset of chronic murine pneumonia in rats exposed to 5.0 ppm HEA.
Mortality:
no mortality observed
Description (incidence):
The cumulative mortality for male rats exposed to 5.0 ppm HEA was statistically increased from equivalent data on control males in the 16th month of the study. This correlated with the onset of chronic murine pneumonia which initially affected this group and subsequently spread to the other exposure and control groups. During months 20-22, the males exposed to 5.0 ppm HEA had decreased cumulative mortality when compared to the male control group. The mortality of male rats exposed to 0.5 ppm HEA was comparable to the mortality of control males, except for a statistical increase in the 10th mouth and a statistical decrease in the 17th month of the study. The mortality of exposed female rats was comparable to mortality of control females except for a statistical increase in the 17th month for females exposed to 5.0 ppm HEA and a statistical increase In the 15th month for females exposed to 0.5 ppm HEA.
Body weight and weight changes:
effects observed, non-treatment-related
Description (incidence and severity):
Body weight data are presented in the table below, please see section "Any other information on results incl. tables". Male rats assigned to groups exposed to 5.0 or 0.5 ppm HEA had statistically lower body weights than the controls prior to initiation of the exposure period. These lower body weights were also noted during the exposure period, but the rate of body weight gain was comparable for all groups of male rats. Body weights of female rats in the HEA exposure groups were also slightly lower than control rats at the onset of the study. These differences disappeared by the fifth day of the study. In female rats, sporadic differences in body weight between HEA exposed and control rats occurred throughout the study. Overall, there were no alterations of body weights at either sex that could be attributed to the exposure to either level of HEA.
Food consumption and compound intake (if feeding study):
not examined
Food efficiency:
not examined
Water consumption and compound intake (if drinking water study):
not examined
Ophthalmological findings:
not examined
Haematological findings:
effects observed, treatment-related
Description (incidence and severity):
- 12-months interim examination:
The haematological values for the male rats exposed to HEA showed no differences from the values of control males. Haematologic data for female rats exposed to 5.0 ppm HEA were statistically higher in haemoglobin concentration and statistically lower in total white blood cell count than the similar values for control females. These statistical differences, which were not noted in females exposed to 0.5 ppm HEA, may or may not have been related to exposure to 5.0 ppm HEA.

- 5-months post-exposure examination:
There were no differences from controls, except for a statistical increase in red blood cell count for the male rats which had been exposed to 5.0 ppm HEA. These data indicate that if the statistically significant haematologic changes noted at the 12 -month examination were related to exposure to 5.0 ppm HEA, these changes were transient in nature and did not persist into the terminal phases of the study.
Clinical biochemistry findings:
no effects observed
Description (incidence and severity):
There were no significant differences between control and exposed groups.
Urinalysis findings:
no effects observed
Description (incidence and severity):
- 12-months interim examination:
Examination of the data on the male rats 4 days prior to the 12-month interim kill suggested a possible increase in occult blood from one rat in each exposed group. Subsequently the urinalysis was repeated at the time of the interim kill and showed no evidence of occult blood in any of the rats tested. All other parameters measured on urine of male rats showed no difference from the control group. The urine of female rats tested 4 days prior to the interim kill showed a slight decrease in specific gravity when compared to that of the control group. Repetition of the urinanalysis at the time of the interim kill showed no apparent decrease of specific gravity when compared to control. All other parameters measured on urine of male rats showed no difference when compared to the control group.

- 5-months post-exposure examination:
None of the parameters measured showed differences between exposed and control groups for either sex.
Behaviour (functional findings):
not examined
Immunological findings:
not examined
Organ weight findings including organ / body weight ratios:
effects observed, non-treatment-related
Description (incidence and severity):
- 12-months interim examination:
There were no significant differences in weights of heart, liver, or kidneys for male rats exposed to HEA. However, there were significantly decreased terminal body weights for male rats exposed to 5 ppm or 0.5 ppm HEA. In addition, there was a significant increase in the brain/body weight ratio and in the testes/body weight ratio for male rats exposed to 0.5 ppm. These relative weight changes are considered secondary to the difference in total body weights. There were no significant differences in body weight or weights of brain, heart, liver or kidney for female rats exposed to HEA.

- Terminal sacrifice:
There were no statistically significant differences in body weights or weights of heart, liver, kidneys, or testes for either group of male rats. The male rats exposed to 0.5 ppm HEA had a borderline statistically lower mean brain weight than the control group. This borderline decrease was considered of no toxicologic significance. There were no statistically significant differences in body weights, or weights of brain, liver, or kidney for either group of HEA- exposed female rats. The female rats exposed to 5.0 ppm HEA did show a statistical decrease in the absolute weight of the heart compared to the control group. This observation was considered of no toxicologic significance in view of (1) lack of change in the relative weight of these hearts, and (2) the inclusion of one heart weight that was inordinately low in weight due to a lower total body weight.
Gross pathological findings:
effects observed, treatment-related
Description (incidence and severity):
Gross and histopathologic examination of rats exposed to 5.0 ppm HEA revealed a characteristic yellow staining of the haircoat, as well as an increased incidence, increased severity and earlier onset of the lesions associated with chronic murine pneumonia. These exposure-related effects were not observed in rats exposed to 0.5 ppm HEA. (see Histopathological findings: non-neoplastic).
Neuropathological findings:
not specified
Histopathological findings: non-neoplastic:
effects observed, treatment-related
Description (incidence and severity):
- Gross and histopathologic examination of rats exposed to 5.0 ppm HEA revealed a characteristic yellow staining of the haircoat, as well as an increased incidence, increased severity and earlier onset of the lesions associated with chronic murine pneumonia. These exposure-related effects were not observed in rats exposed to 0.5 ppm HEA.


- Integument:
A statistically significant number of male and female rats exposed to 5.0 ppm HEA had a distinctive grossly-visible yellow staining of the haircoat that persisted into the post-exposure period of the study. This was considered to be the result of the contact of HEA with the haircoat. The yellow staining was not observed grossly on rats from the lower exposure level of HEA (0.5 ppm). Microscopic examination of sections of the stained haircoat revealed no histologic alterations.
 
- Respiratory System:
Chronic murine pneumonia occurred in the groups of rats used in this study. This was indicated by pulmonary consolidation, atelectasis, bronchiectasis or tenacious mucopurulent inflammation along the tracheobronchial system. Historically, the organism Mycoplasma has been cultured from lung-lesions of this type occurring in the testing laboratory. These cases of chronic murine pneumonia sometimes included abscess formation, pleuritis, pericarditis, rhinitis and/or tracheitis. In addition to the lesions of chronic murine pneumonia, all groups had rats with varying degrees of pulmonary inflammatory reactions or aggregates of alveolar macrophages, hematogenous pigment, cholesterol clefts or red blood cells.
Statistical evaluation:
An increase in the incidence of numerous gross or microscopically visible lesions occurring as part of or secondary to the chronic murine pneumonia in male and/or female rats exposed to 5.0 ppm HEA. This included pulmonary consolidation, congestion, bronchiectasis, peribronchiolar lymphoid hyperplasia, peribronchiolar fibrosis, focal purulent inflammation and epithelial hyperplasia of bronchi/bronchioles, diffuse epithelial hyperplasia of the trachea, pulmonary aggregates of haematogenous pigment, focal pulmonary atelectasis, and focal hypercellularity of alveolar walls secondary to aggregates of red blood cells within alveoli.
An increase in the incidence of pulmonary aggregates of haematogenous pigment and focal hypercellularity of alveolar walls secondary to aggregates of red blood cells within alveoli in lungs of female rats exposed to 0.5 ppm HEA.
An increase in the incidence of diffuse pulmonary congestion of female rats exposed to 0.5 ppm HEA.
Overall assessment of these data suggests exposure to 5.0 ppm HEA increased the severity of lesions occurring as part of chronic murine pneumonia. However, this appeared not to be the case with exposure of rats to 0.5 ppm HEA.
 
- Lvmphoreticular System:
Inflammatory or hyperplastic changes occurred in some lymph nodes of some rats for all groups. Some lymph nodes contained increased amounts of haematogenous pigment, oedema, abscess formation or pooling of red blood cells. There were inflammatory reactions in thoracic lymph nodes secondary to chronic murine pneumonia.
Statistical evaluation:
Increases in the incidence of oedema, inflammation and reactive lymphoid hyperplasia of the thoracic lymph nodes of female rats exposed to 5.0 ppm HEA. Female rats exposed to 0.5 ppm HEA also had increased incidence of oedema and reactive lymphoid hyperplasia of thoracic lymph nodes. These inflammatory responses were considered to be associated with chronic murine pneumonia that occurred in these rats.
An increase in the incidence of oedema of mesenteric lymph nodes of female rats exposed to 5.0 ppm
 
- Spleen:
Increased hemopoietic activity and haematogenous pigment was commonly observed in the spleen of some rats from both control and exposed groups. Reticuloendothelial hyperplasia and also splenic atrophy were noted in the spleens of some control and exposed rats.
 
- Liver:
All groups, exposed and control, had rats with variable degrees of focal inflammation, necrosis, fatty metamorphosis, cytoplasmic vacuolization, swollen hepatocytes, bile duct hyperplasia, pericholangiolar inflammation, sinusoidal distention, aggregates of reticuloendothelial cells adjacent to degenerate hepatocytes, biliary cyst formation, and foci or areas of atypical hepatocytes. Extramedullary hematopoiesis or vascular distention also occurred in livers of rats from all groups.
Statistical analysis:
Decreased incidence of mottling and also congestion of the liver in male rats exposed to 5.0 ppm HEA.
Increased incidence of focal areas of swollen hepatocytes and focal aggregates of mononuclear cells in liver of male rats exposed to 5.0 ppm HEA.
An increase in the incidence of focal bile duct proliferation in livers of female rats exposed to 5.0 ppm HEA.
 
- Thyroid and parathvroid glands:
Thyroid hyperplasia or adenoma formation was observed in rats of all control and exposed groups. This usually involved the interfollicular cells of the thyroid. The most frequent alteration in the parathyroid glands was hyperplasia occurring secondary to the age-related progressive chronic nephropathy.
 
- Pancreas:
Focal atrophy of pancreatic acinar tissue and focal fibrosis was noted in both control and exposed groups of rats. Hyperplastic nodules and neoplasms of the pancreatic acini were also noted in both control and exposed groups. Some control and exposed rats had pancreatic islets that were enlarged, or neoplastic. A few rats had pancreatic islets showing slight cytoplasmic vacuolation.
 
- Female Reproductive Svstem:
An age-related occurrence of uterine endometrial hyperplasia, polyp formation and ovarian cyst formation was observed. Various forms of uterine inflammation also occurred in rats of all groups. A few cases of uterine abscessation or cyst formation were noted. Neoplasm occurred in a few cases.
Statistical analysis:
An increase in the incidence of inflammation of the uterus in female rats exposed to 5.0 ppm HEA.
 
- Male Reproductive System:
An age-related decrease in testicular spermatogenic activity was noted in rats of both control and exposed groups. This was sometimes accompanied by decreased content of spermatogenic cells in the epididymis. Also, the accessory sex glands were sometimes found to have a decreased content of secretory material.
Other infrequent observations included inflammation of the accessory sex glands, abscessation of preputial glands, or neoplasia.
Statistical evaluation:
An increased incidence of vascular fibrinoid degeneration in testes of male rats exposed to 5.0 ppm HEA.
 
- Stomach:
All exposed and control groups had some rats with focal gastric erosions/ulcers, gastric hemorrhage or hyperemia. Dilatation of gastric pits was also noted upon microscopic examination of some rats from each of the exposed and control groups. Gastric mucosal hyperplasia or hyperkeratosis also occurred in a few control and exposed rats. Mineralization of the gastric wall was noted in some rats from each control and exposed group. These rats usually had chronic progressive nephropathy and uremia.
Statistical evaluation:
Increase in the incidence of microscopically visible dilatation of gastric pits in male rats exposed to 5.0 ppm HEA.
 
- Small and large intestines:
Various inflammatory processes were noted in segments of the intestinal tract of some rats from all control and exposed groups. Isolated cases of diverticulum formation, focal ulceration, reactive lymphoid hyperplasia and neoplasia were also noted. Intestinal nematodiasis was also noted in some rats from all groups. Focal inflammation and/or necrosis of the mesenteric fat was noted in a few rats scattered amongst all exposed and control groups of rats.
 
- Eyes:
All groups had rats with various inflammatory changes of the cornea or other components of the eye. Some rats had eyes with focal hyperplasia of the cornea epithelium.
 
- Nervous System:
The most common lesions were hyperplastic or neoplastic proliferations of the pituitary gland; some of these were associated with haematogenous pigment aggregates, hemangiectasis, or compression of the adjacent portion of the brain. Some rats had vacuolar degeneration of the peripheral nerves, and other rats had neoplasms originating from the Schwann cells of the peripheral nerves.
 
- Adrenal Glands:
Hyperplastic or neoplastic changes were observed in the adrenal cortex or medulla of rats from all groups. Hematocyst formation and vascular sinusoidal distention and cytoplasmic vacuolization of the adrenal cortical cells also occurred in all groups.
 
- Cardiovascular System:
All groups, exposed and control, had rats with age-related myocardial degenerative changes, aortic and thoracic vessel mineralization, periarteritis of the mesenteric and other vessels (testes, liver, etc.). Thrombosis and hematoma formation were occasional complications of the mesenteric periarteritis. Thrombosis of the left atrium caused the death of some rats.
Statistical evaluation:
An increase in the incidence of a grossly-visible flaccidity of the myocardium of males exposed to 0.5 ppm HEA.
An increase in the incidence of a microscopically-visible degeneration of myocardial blood vessels in female rats exposed to 5.0 ppm HEA.
 
- Urinary System:
An age-related progressive chronic nephropathy occurred in rats (especially males) from all groups of rats. This was sometimes accompanied by secondary parathyroid hyperplasia and mineralization of certain tissues, such as the gastric wall. Other incidental lesions in kidneys included inflammation or hyperplasia of renal pelvic epithelium, mineralized deposits, focal purulent inflammation, focal fibrosis, cyst formation, calculus formation or neoplasia. A few rats had diffuse or focal urocystitis, inflammation or hyperplasia of the urinary bladder mucosa.
 
- Subcutaneous Tissues and Mammary Glands:
A substantial number of control and exposed females had evidence of mammary gland hyperplasia, neoplasia and/or galactocele formation. Epidermal inclusion cysts or subcutaneous or integumentary neoplasms were also noted in a few control and exposed rats.
Statistical evaluation:
Increase in the incidence of female rats having a total of 3 grossly-visible subcutaneous masses (suggestive of mammary tissue origin) in the groups exposed to 5.0 or 0.5 ppm HEA. However, this was not the case with female rats of either exposure group that had 1, 2, 4 or 5 subcutaneous masses suggestive of mammary tissue origin.
Histopathological findings: neoplastic:
effects observed, non-treatment-related
Description (incidence and severity):
A variety of neoplasms considered spontaneous in origin occurred in a number of tissues or organs of control and exposed groups of rats. As expected, mammary fibroadenomas and pituitary adenomas were the most frequently occurring neoplasms in female rats of all groups. Adrenal pheochromocytomas, pancreatic acinar adenomas, pituitary adenomas and subcutaneous fibromas were the most common neoplasms in the male rats of all groups.
Neoplasms, all of which were considered spontaneous in origin, occurred in the following organs and tissues: liver, lung, pancreas, kidney, testes, preputial gland, stomach, small and large intestine, spinal cord and peripheral nerves, pituitary gland, subcutaneous tissue, mammary tissue, integument, ear canal, oral cavity, adrenal gland, lymph nodes, spleen, brain, adipose tissue, thyroid, ovary, uterus, clitoral gland and vagina.
Statistical analyses revealed no exposure-related increases in the incidence of any of these neoplasms in HEA exposed rats compared to control rats. Statistical analyses also revealed no differences between the temporal or total incidence of HEA-exposed rats bearing benign neoplasms, malignant neoplasms, or all types of neoplasms combined compared to control rats.
Dose descriptor:
NOAEC
Remarks:
local effects
Effect level:
0.002 mg/L air (nominal)
Based on:
test mat.
Sex:
male/female
Basis for effect level:
gross pathology
histopathology: non-neoplastic
Key result
Dose descriptor:
NOAEC
Remarks:
systemic effects
Effect level:
0.024 mg/L air (nominal)
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: high dose
Key result
Critical effects observed:
no

Table 1a-b: Mean body weights of male and female rats exposed to vapors of 2 -Hydroxyethyl acrylate for up to 23 months (males) and 24 months (females)

 

1a: Days 0 -251

Days on Test

0

5

7

12

19

26

33

40

54

68

96

131

159

194

223

251

Males

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

0.0

ppm

299.8

(100)

314.4

(100)

322.2

(100)

343.4

(100)

375.3

(100)

393.3

(100)

416.1

(100)

437.6

(100)

466.9

(100)

488.0

(99)

522.6

(99)

548.3

(99)

569.0

(99)

594.6

(98)

557.3

(98)

608.2

(98)

5.0

ppm

*290.3

(99)

*308.7

(99)

320.4

(99)

*334.6

(99)

*364.1

(99)

392.5

(99)

*406.8

(99)

*422.4

(99)

*453.3

(99)

*473.4

(99)

*501.0

(99)

*528.0

(99)

*532.8

(99)

*546.4

(99)

555.6

(99)

*553.5

(99)

0.5

ppm

*287.0

(100)

*301.7

(100)

*309.3

(100)

*334.2

(100)

*357.0

(100)

379.7*

(100)

*391.9

(100)

*410.2

(100)

*437.6

(99)

*455.4

(99)

*495.3

(99)

*514.4

(97)

*519.9

(96)

*536.8

(95)

*541.5

(95)

*546.7

(94)

Females

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

0.0

ppm

224.1

(100)

221.0

(100)

222.7

(100)

232.8

(100)

241.8

(100)

247.3

(100)

259.3

(100)

266.7

(100)

277.6

(100)

287.2

(100)

302.6

(100)

293.7

(99)

309.3

(99)

331.2

(99)

337.0

(98)

336.9

(97)

5.0

ppm

*216.9

(100)

224.2

(100)

*230.6

(100)

235.0

(100)

243.7

(100)

*260.7

(100)

265.8

(100)

266.3

(100)

*287.0

(100)

*299.7

(100)

*312.1

(99)

*318.8

(99)

325.2

(99)

327.6

(98)

336.8

(98)

337.0

(98)

0.5

ppm

*219.2

(99)

222.2

(99)

220.0

(99)

230.3

(99)

241.7

(99)

*255.1

(98)

258.4

(98)

266.0

(98)

281.3

(98)

290.4

(98)

307.8

(98)

*320.7

(98)

309.5

(98)

327.4

(98)

332.2

(98)

336.4

(98)

1b: Days 286- 723

Days on Test

286

314

342

377

405

433

468

496

532

552

585

620

648

675

702

723

Males

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

0.0

ppm

632.7

(98)

642.8

(98)

648.9

(97)

654.3

(86)

658.0

(85)

661.4

(83)

664.1

(83)

628.3

(83)

593.0

(43)

604.0

(38)

577.2

(31)

587.1

(24)

558.3

(20)

521.8

(16)

518.8

(14)

 

5.0

ppm

*578.8

(99)

*583.4

(99)

*607.7

(98)

*615.2

(87)

*621.0

(86)

*621.0

(84)

*602.0

(78)

*543.4

(60)

589.2

(48)

589.3

(47)

599.0

(43)

587.0

(40)

557.7

(34)

507.2

(29)

535.3

(19)

 

0.5

ppm

*570.6

(93)

*575.5

(93)

*589.2

(93)

*596.0

(84)

637.8

(83)

*625.1

(84)

*627.7

(81)

611.4

(77)

587.3

(60)

573.9

(47)

558.7

(36)

559.4

(24)

520.5

(17)

549.1

(10)

518.9

(09)

 

Females

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

0.0

ppm

349.8

(97)

348.8

(95)

356.3

(96)

363.5

(86)

372.2

(86)

387.6

(85)

395.2

(85)

395.8

(85)

393.6

(73)

401.4

(67)

401.2

(61)

410.7

(52)

430.9

(48)

437.3

(38)

456.5

(29)

442.2

(20)

5.0

ppm

349.4

(95)

350.9

(95)

369.7

(93)

376.1

(83)

373.3

(83)

385.9

(82)

395.4

(81)

*359.7

(74)

387.6

(63)

395.8

(57)

417.7

(52)

413.3

(46)

421.9

(41)

404.3

(35)

406.9

(30)

411.0

(27)

0.5

ppm

351.9

(96)

351.6

(94)

351.6

(92)

367.2

(81)

*400.2

(81)

389.2

(78)

400.9

(76)

397.1

(73)

396.8

(73)

409.6

(63)

405.6

(55)

405.8

(47)

412.0

(41)

418.3

(31)

425.0

(23)

422.9

(20)

*: Significant difference from control data using analysis of variance and Dunnett's test p < 0.05.

( ) : Indicates numbers of rats weighed.

Day 0: Pre-exposure data

Table 2a-b: Body weights, and organ/body weight ratios for male (a) and female (b) rats exposed to vapors of 2 -Hydroxyethyl acrylate 5 days / week for 12 months

(a) males:

Exposure level (ppm)

Sex

Body weight g

Organ Weights (g and g/100 g Body Weight)

Brain

Heart

Liver

Kidneys

Testes

g

g/100g

g

g/100g

g

g/100g

g

g/100g

g

g/100g

0

M

633

1.94

0.31

1.60

0.25

17.83

2.82

4.40

0.70

4.35

0.69

M

584

2.02

0.35

1.54

0.26

12.76

2.18

3.48

0.60

4.36

0.75

M

670

1.97

0.29

1.68

0.25

17.46

2.61

4.60

0.69

4.18

0.62

M

635

1.96

0.31

1.73

0.27

15.89

2.50

4.12

0.65

3.88

0.61

M

583

1.95

0.33

1.66

0.28

11.75

2.02

3.13

0.54

2.55

0.44

Mean

± S.D.

621 ± 37

1.97 ± 0.03

0.32 ± 0.02

1.64 ± 0.07

0.26 ± 0.01

15.14 ± 2.75

2.42 ± 0.32

3.95 ± 0.62

0.63 ± 0.07

3.87 ± 0.76

0.62 ± 0.12

5.0

M

582

1.97

0.34

1.58

0.27

15.29

2.63

3.72

0.64

4.27

0.73

M

550

1.87

0.34

1.60

0.29

13.41

2.44

3.24

0.59

3.98

0.72

M

566

1.84

0.33

1.50

0.26

13.34

2.36

3.54

0.63

4.19

0.74

M

533

1.90

0.36

1.49

0.28

12.51

2.35

3.20

0.60

3.81

0.72

M

592

2.04

0.34

1.79

0.30

20.34

3.44

5.13

0.87

4.14

0.70

Mean

± S.D.

565*

±24

1.93 ± 0.08

0.34 ± 0.01

1.59 ± 0.12

0.28 ± 0.02

14.98 ± 3.17

2.64 ± 0.46

3.77 ± 0.79

0.66 ± 0.12

4.08 ± 0.18

0.72 ± 0.02

0.5

M

596

1.98

0.33

1.66

0.28

13.45

2.26

3.10

0.52

4.73

0.79

M

542

1.93

0.36

1.55

0.29

12.72

2.35

3.38

0.62

4.36

0.81

M

581

1.98

0.34

1.75

0.30

14.92

2.57

3.38

0.58

4.36

0.75

M

498

1.92

0.39

1.29

0.26

11.79

2.37

3.18

0.64

4.06

0.81

M

526

2.08

0.40

1.50

0.29

11.74

2.23

3.47

0.66

4.37

0.83

Mean

± S.D.

549*

±40

1.98 ± 0.06

0.36* ± 0.03

1.55 ± 0.17

0.28 ± 0.02

12.92 ± 1.32

2.35 ± 0.13

3.30 ± 0.15

0.60 ± 0.06

4.38 ± 0.24

0.80* ± 0.03

*: Statistically significant difference from control mean by analysis of variance and Dunnett's test p < 0.05.

(b) females:

Exposure level (ppm)

Sex

Body Body

weight g

Organ Weights (g and g/100 g Body Weight)

Brain

Heart

Liver

Kidneys

g

g/100g

g

g/100g

g

g/100g

g

g/100g

0

F

300

1.83

0.61

1.03

0.34

7.30

2.43

1.91

0.64

F

328

1.82

0.56

1.03

0.31

7.72

2.35

2.06

0.63

F

309

1.91

0.62

1.05

0.34

6.89

2.23

2.35

0.76

F

310

1.89

0.61

1.09

0.35

7.83

2.53

2.41

0.78

F

339

1.81

0.53

1.03

0.30

7.04

2.08

2.08

0.61

Mean

± S.D.

317 ± 16

1.85 ± 0.05

0.59 ± 0.04

1.05 ± 0.02

0.33 ± 0.02

7.36 ± 0.41

2.32 ± 0.18

2.16 ± 0.21

0.68 ± 0.08

5.0

F

359

1.83

0.51

1.17

0.33

7.50

2.09

2.47

0.69

F

332

1.83

0.55

0.12

0.34

7.69

2.32

2.43

0.73

F

337

1.69

0.50

1.04

0.31

7.98

2.37

2.27

0.67

F

376

1.85

0.49

1.22

0.32

8.90

2.37

2.53

0.67

F

307

1.83

0.60

1.09

0.36

7.29

2.38

1.87

0.61

Mean

± S.D.

342 ± 26

1.80 ± 0.07

0.53 ± 0.04

1.13 ± 0.07

0.33 ± 0.02

7.87 ± 0.63

2.30 ± 0.12

2.31 ± 0.27

0.68 ± 0.04

0.5

F

340

1.90

0.56

0.92

0.27

7.76

2.28

2.05

0.60

F

336

1.81

0.54

1.07

0.32

7.98

2.38

2.21

0.66

F

373

1.89

0.51

1.27

0.34

12.77

3.42

2.38

0.64

F

338

1.90

0.56

1.11

0.33

8.88

2.63

2.03

0.60

F

347

1.86

0.54

1.17

0.34

8.52

2.46

2.21

0.64

Mean

± S.D.

347 ± 15

1.87 ± 0.04

0.54 ± 0.02

1.11 ± 0.13

0.32 ± 0.03

9.18 ± 2.05

2.63 ± 0.46

2.17 ± 0.14

0.63 ± 0.02

for more details see attachment: Carcinogenicity study - tables

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed
Dose descriptor:
NOAEC
24 mg/m³
Study duration:
chronic
Species:
rat
Quality of whole database:
Well performed and reported study.

Repeated dose toxicity: inhalation - local effects

Link to relevant study records
Reference
Endpoint:
short-term repeated dose toxicity: inhalation
Type of information:
experimental study
Adequacy of study:
supporting study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
study well documented, meets generally accepted scientific principles, acceptable for assessment
Remarks:
Study with restrictions: no data on test substance purity. Study was conducted prior to the advent of GLP regulations (1982).
Principles of method if other than guideline:
Three groups of animals, each consisting of 25 male Sherman rats, were exposed to 5, 10, and 25 ppm of HEA vapours, respectively. The duration of exposures was seven hours per day, five days per week for a total of twenty exposures. Interim sacrifices were performed on the 5 and 10 ppm groups after two weeks and on the 25 ppm animals after one week of exposures.
GLP compliance:
no
Remarks:
(Study was conducted prior to the advent of GLP regulations)
Limit test:
no
Specific details on test material used for the study:
- Name of test material (as cited in study report): 2-Hydroxyethyl acrylate
- Analytical purity: no data
Species:
rat
Strain:
Sherman
Sex:
male
Details on test animals and environmental conditions:
no details given
Route of administration:
inhalation: vapour
Type of inhalation exposure:
whole body
Vehicle:
air
Details on inhalation exposure:
GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: glass, dynamic exposure chambers of 160 liter volume
- Source and rate of air: Constant chamber airflow in each chamber was maintained by a rotary pump connected to the exhaust side of the chamber. The vapour was introduced into the air inlet located at the top of the chamber.
- Method of conditioning air: Vapour generation of HEA was achieved by aerosolizing the liquid with nitrogen, at calculated rates, in a temperature controlled vaporization flask. The aerosols were rapidly vaporized and then diluted with filtered room air to ambient temperature prior to its being drawn into the exposure chamber.
- Temperature, humidity, pressure in air chamber: ambient

TEST ATMOSPHERE
- Nominal concentration: The nominal concentration of HEA in a chamber was determined from the ratios of the rate of liquid compound being aerosolized (mg/minute) and the rate of total chamber airflow (L/minute; rate of nitrogen ejected from the aerosolizer plus that of the make-up air drawn from the room).
- Brief description of analytical method used: The analytical concentrations were obtained by absorbing the HEA with distilled water from known volumes of chamber atmospheres and analyzing the solution for HEA content with a gas-liquid chromatographic technique. The chamber concentrations were analyzed twice daily.
- Samples taken from breathing zone: no
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
The analytical concentrations were, in general, 20 to 40 % lower than the calculated concentrations being set up for the experiments indicating the recovery of HEA from the experimental atmospheres ranged from 60 to 80 % only. This poor recovery was partly due to the very low vapour pressure of HEA and, perhaps, its reactivity with the animal furs. Gas-liquid chromatographic analyses indicated that HEA vapours generated from the heated flask system at 80°C were identical to the liquid HEA in composition.
Mean analytical concentrations: 4.5 ± 1.1 ppm, 10.6 ± 1.4 ppm, and 22.5 ± 3.9 ppm
Duration of treatment / exposure:
20 exposures
Frequency of treatment:
7 hours/ day, 5 days/ week
Dose / conc.:
5 ppm (nominal)
Remarks:
corresponding to approx. 0.024 mg/L
Dose / conc.:
10 ppm (nominal)
Remarks:
corresponding to approx. 0.048 mg/L
Dose / conc.:
25 ppm (nominal)
Remarks:
corresponding to approx. 0.120 mg/L
No. of animals per sex per dose:
25 male rats per dose group
Control animals:
yes, concurrent vehicle
Details on study design:
- Post-exposure recovery period in satellite groups: 1 and 14 days post-exposure, respectively
Positive control:
no
Observations and examinations performed and frequency:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: During the exposures, the animals were observed closely for signs of irritation and toxicity.

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: no data

BODY WEIGHT: Yes

Sacrifice and pathology:
GROSS PATHOLOGY: Yes
HISTOPATHOLOGY: Yes

Interim sacrifices were performed on the 5 and 10 ppm groups after two weeks and on the 25 ppm animals after one week of exposures. Gross and microscopic examinations were carried out on all animals which succumbed during the experimental period. At termination of the exposure studies, all animals were sacrificed and examined likewise. The organ to body weight ratios for lung, liver, spleen, kidney and testes were ádetermined for the 5 and 10 ppm groups.
Statistics:
Statistical analyses were applied to all appropriate physical and biological data (t-test for significance).
Clinical signs:
effects observed, treatment-related
Description (incidence and severity):
- 5 ppm: During and after the exposures, the animals in the 5 ppm group did not show any adverse effects.
- 10 ppm: The animals in this group exhibited mild nasal irritation and discharge. After seven exposures, some animals also acquired lung rattles.
- 25 ppm: The responses of the animals to 25 ppm of HEA were eye and nasal irritation followed by dyspnoea and a bloated stomach (According to the authours these signs indicate that HEA is an upper respiratory tract irritant.). These conditions became more severe as the exposures prolonged. After one exposure, the animals began to lose body weight drastically and died probably of respiratory failure
Mortality:
mortality observed, treatment-related
Description (incidence):
- 5 ppm: No mortality observed
- 10 ppm: One animal died after 15 exposures
- 25 ppm: A total of eight animals died during the 10 exposure days and an addition of nine animals died after the termination of the exposures. Only three animals survived and recovered from the exposures.
Body weight and weight changes:
effects observed, treatment-related
Description (incidence and severity):
- 5 ppm: The growth and the body weight gain of the low-dose animals were similar to those observed in the control animals.
- 10 ppm: The mean body weights of the animals of the 10 ppm group showed, in general, a trend of loss during the five exposure days of the week, but a rapid recovery or a gain during the two no-exposure weekend days. Similar trends of loss and gain of mean body weights were observed repeatedly throughout the four week studies. It was noted that the mean terminal body weight of rats exposed to 10 ppm of HEA for twenty days was significantly lower than that of the control animals.
- 25 ppm: After one exposure, the animals began to lose body weight drastically.
Food consumption and compound intake (if feeding study):
not examined
Food efficiency:
not examined
Water consumption and compound intake (if drinking water study):
not examined
Ophthalmological findings:
not examined
Haematological findings:
not examined
Clinical biochemistry findings:
not examined
Urinalysis findings:
not examined
Behaviour (functional findings):
not examined
Immunological findings:
not examined
Organ weight findings including organ / body weight ratios:
effects observed, treatment-related
Description (incidence and severity):
The organ to body weight ratios of liver and kidneys were significantly higher in exposed animals of the 10 ppm group. Similar elevation of liver to body weight ratio was also seen in the 5 ppm HEA groups. On the contrary, the heart to body weight ratio for the animals in the 5 ppm group was significantly lower.
Gross pathological findings:
effects observed, treatment-related
Description (incidence and severity):
See description "Histopahtological findings: non-neoplastic".
Neuropathological findings:
not examined
Histopathological findings: non-neoplastic:
effects observed, treatment-related
Description (incidence and severity):
- Sacrificed animals:
Ulcerative keratitis appeared to be an HEA dose-related lesion with lesions in 14, 6, and 3 animals at levels of 25 ppm, 10 ppm and 5 ppm, respectively. Twenty exposures produced a higher incidence of corneal ulcers than 8 or 9 exposures at the 10 ppm and 5 ppm level. With 14 days recovery, there was a lower incidence of corneal ulceration at the 10 ppm and 5 ppm level. One control rat had an ulcerative corneal lesion of unknown etiology.
Focal ulcerative rhinitis was present in 7 and 4 rats at 25 ppm and 10 ppm, respectively. This lesion was not present in the 14 days recovery rats on the above doses or in any 5 ppm and control rats.
Most HEA exposed rats and control rats had chronic inflammatory cells in the lamina propria of the trachea and larynx. In addition, 6, 4, and 6 rats at 25 ppm, 10 ppm, and 5 ppm, respectively, had superimposed acute reactions involving the mucosa of the trachea. Chronic-active tracheitis was not present in the control and was interpreted as resulting from HEA exposure. Chronic-active laryngitis was present in 7, 6, and 3 animals at 25 ppm, 10 ppm, and control levels, respectively. The lesion was not evident at the 5 ppm level.

- Deceased animals:
There were 17 spontaneous deaths in the group of 25 rats at the 25 ppm level, there was a high incidence of focal acute bronchopneumonia in these rats. Evaluation of the respiratory system was most difficult due to the high incidence of chronic murine pneumonia in the control and HEA exposed rats. Therefore, it was impossible to evaluate subtle pulmonary lesions with regard to HEA exposure.

The myocardial and testicular lesions observed were considered spontaneous and not related to HEA exposure.
Histopathological findings: neoplastic:
no effects observed
Dose descriptor:
NOAEC
Remarks:
systemic effects
Effect level:
ca. 0.12 mg/L air (nominal)
Based on:
test mat.
Sex:
male
Basis for effect level:
other: high dose
Key result
Dose descriptor:
LOAEC
Remarks:
local effects
Effect level:
ca. 0.024 mg/L air (nominal)
Based on:
test mat.
Sex:
male
Basis for effect level:
histopathology: non-neoplastic
Critical effects observed:
no

Conclusions:

- HEA produced ulcerative keratitis at levels of 25 ppm, 10 ppm, and 5 ppm.

- Focal ulcerative rhinitis resulted from HEA exposure at 25 ppm and 10 ppm.

- The higher incidence of chronic-active laryngitis in the HEA-exposed rats was interpreted as being compound-related at the 25 ppm and 10 ppm levels.

- Chronic-active tracheitis in the HEA-exposed rats was interpreted as being compound-related at the 25 ppm, 10 ppm, and 5 ppm levels.

- Lesions at the 25 ppm level were more severe than those at the 10 ppm and 5 ppm levels.

- Bronchopneumonia and severe upper respiratory lesions were responsible for the spontaneous deaths at the 25 ppm HEA exposure level.

- Fourteen days recovery did not significantly reduce the number of lesions observed, except for the absence of ulcerative rhinitis.

Endpoint conclusion
Endpoint conclusion:
adverse effect observed
Dose descriptor:
LOAEC
24 mg/m³
Study duration:
subacute
Species:
rat

Repeated dose toxicity: dermal - systemic effects

Endpoint conclusion
Endpoint conclusion:
no study available

Repeated dose toxicity: dermal - local effects

Endpoint conclusion
Endpoint conclusion:
no study available

Additional information

Repeated dose toxicity: Inhalation route

In the key chronic inhalation study (Dow Chemical Co., 1979), male and female Sprague-Dawley rats (99 or 100 animals/sex/dose group) were exposed to atmospheres containing 0 ppm (controls), 5.0 ppm (0.024 mg/L) or 0.5 ppm (0.0024 mg/L) of test substance for 6 hours/day, 5 days/week over an 18 month period, and subsequently held for a post-exposure period of 5 months (males) and 6 months (females). The study included 12-month interim sacrifices for pathologic and cytogenetic examinations. Haematology, blood chemistry and urine analysis were measured prior to the scheduled 12-month interim sacrifice, and again after 5 months of the post-exposure observation period. Histopathological examination was carried out for the all available tissues of the control and 5 ppm groups at interim and terminal sacrifice, and at 0.5 ppm terminal sacrifice limited evaluations were performed.

Body weights, terminal organ weights and cumulative mortality, urinalysis, clinical chemistry and haematology did not appear to be altered by chronic HEA exposure. Overall treatment was not associated with adverse effects except that the rats in the 5 ppm treatment group developed yellow staining of the fur and a marginal increase in Mycoplasma-induced chronic murine pneumonia which was interpreted as being treatment-related. No treatment-related effects were seen in the 0.5 ppm group.

Overall chronic inhalation exposure to HEA at a dose of 5 ppm caused only a minimal toxicological effect while no toxicity was seen at 0.5 ppm. Gross and histopathological examination of tissues showed no indication of significant chronic toxicity or a carcinogenic effect in either the 5 or 0.5 ppm treatment groups. The NOAEC was set at 0.0024 mg/L (nominal) based on an increased incidence, increased severity, and earlier onset of the lesions associated with the chronic murine pneumonia observed at the high dose level.

In a 4-week inhalation study 15 to 20 male Sherman rats per group were exposed for 7 hours/day, 5 days/week to HEA vapours at concentrations of 0, 5, 10 or 25 ppm (corresponding to approx. 0.024, 0.048, and 0.120 mg/L) (Dow Chem. Co., 1970).Mean analytical concentrations: 4.5 ± 1.1 ppm, 10.6 ± 1.4 ppm, and 22.5 ± 3.9 ppm. The duration of exposures was seven hours per day, five days per week for a total of twenty exposures. Interim sacrifices were performed on the 5 and 10 ppm groups after 2 weeks of exposure and on the 25 ppm animals after one week of exposure. All animals were subjected to a gross and microscopic examination irrespective of whether they died during treatment or were sacrificed at termination of treatment. Clinical signs of mild nasal irritation were observed at 10 ppm; concentrations of 25 ppm produced dyspnoea and abdominal bloating which became more severe as the number of exposures increased.

Histopathological examination found ulcerative keratitis (superficial loss of cornea with inflammation) in all groups exposed to HEA. Ulcerative keratitis appeared to be an HEA dose-related lesion with lesions in 14, 6, and 3 animals at levels of 25 ppm, 10 ppm and 5 ppm, respectively. Twenty exposures produced a higher incidence of corneal ulcers than 8 or 9 exposures at the 10 ppm and 5 ppm level. Focal ulcerative rhinitis (superficial loss of nasal epithelial tissue with inflammation) was observed in 7 and 4 rats in the 25 and 10 ppm exposure groups, respectively. This lesion was not present in the 14 days recovery rats on the above doses or in any 5 ppm and control rats.The higher incidence of chronic-active laryngitis in the HEA-exposed rats was interpreted as being compound-related at the 25 ppm and 10 ppm levels as was the chronic-active tracheitis at the 25 ppm, 10 ppm, and 5 ppm levels.There were 17 spontaneous deaths in the 25 ppm treatment group. Unfortunately due to the high incidence of chronic murine pneumonia in all groups (not treatment-related) it was impossible to characterize any lung pathology which might have been caused by exposure to HEA. At termination, mean body weights of rats exposed to 10 ppm for 20 days were significantly lower than controls. Relative weights of livers were higher for rats that were exposed to 10 and 5 ppm, relative kidney weight was increased at 10 ppm only. Testicular atrophy was observed histopathologically in one of 9 rats exposed to 10 ppm HEA for 20 exposures but was judged not to be treatment-related. No testicular atrophy was found in the highest exposure group. The lowest observed adverse effect concentration (LOAEC), based on severe local irritation effects (ulcerative keratitis and chronic-active tracheitis), was 5 ppm. No NOAEC was derived in this study.

The test result from the sub-acute study is supported by data from a structural analogue:

An inhalation study with rats, mice, rabbits and dogs was conducted with hydroxypropyl acrylate (Dow Chemical Company 1983). Three groups of animals per species, consisting of 10 male Sprague-Dawley rats, 20 male Swiss-Webster mice, 4 male white rabbits, or 2 male beagle dogs, were used in the study. The animals were exposed (whole body) to hydroxypropyl acrylate vapours at 0 (unexposed control), 5 ppm (0.027 mg/L) or 10 ppm (0.053 mg/L). Exposures were 6 hours/day, 5 days/week for a total of 21 exposures for the rats and mice and 20 exposures for rabbits and dogs.

In the rat study, no mortality was observed. Five of 10 rats exposed to 10 ppm developed slight cloudiness of the cornea. No treatment-related decreases in mean body weights were found, and the absolute and relative organ weights were not affected. No treatment-related effects on the haematological measurements, the clinical chemistry measurements, or the urinalysis parameters were identified. At necropsy, focal corneal cloudiness was noted in 8 of 10 rats from the high exposure group suggesting an irritant effect. Histologically, a small increase in the number of animals with changes in the lungs at 10 ppm (subacute pneumonitis) and the nasal mucosa (both concentrations) was observed. No other treatment-related effects in the examined tissues were observed and no systemic toxicity was identified. The LOAEC was 5 ppm (0.027 mg/L) based on the effects in the nasal mucosa.

In the mouse study, no mortality was observed. Three of 20 mice exposed to 10 ppm, but none exposed to 5 ppm showed signs of eye irritation. No compound-related, statistically significant effects on mean body weights were found. However, the high dose mice showed slightly lower body weights during weeks 1, 3 and 4 of exposure (up to 4.5 % lower in week 1) which recovered during the weekend without treatment. No gross or histopathological changes related to exposure were observed. The NOAEC was 5 ppm (0.027 mg/L).

In the rabbit study, no mortality was observed. All rabbits exposed to 10 ppm and 2 of 4 animals exposed to 5 ppm developed slight rhinitis and eye irritation (moderate conjunctivitis). No treatment-related effects on mean body weight were observed and all groups gained a similar amount of weight during the study. The absolute and relative organ weights were not affected. No treatment-related effects on the haematological measurements, or the clinical chemistry measurements were identified. Gross and histopathological changes related to exposure were found in the upper respiratory system (rhinitis, squamous metaplasia, and ulcerations), trachea and lungs (bronchitis, focal pneumonitis) of both hydroxypropyl acrylate exposure groups. The tracheal changes varied from no effect in some low dose animals to focal ulceration, squamous metaplasia and tracheitis in the high dose group. The most marked effects were seen in the upper respiratory system of all rabbits, especially those in the 10 ppm group that were characterized by mucopurulent rhinitis with squamous metaplasia and ulceration of the nasal turbinate mucosa. The LOAEC was 5 ppm (0.027 mg/L) based on effects on the upper respiratory system.

In the dog study, no mortality was observed. During the exposures, both dogs exposed to 10 ppm lost body weight (from 2 to 10 %) and exhibited nasal irritation (exudative rhinitis) and eye irritation (bilateral corneal cloudiness, slight corneal edema, and bilateral suppurative conjunctivitis). The body weights showed some recovery during the weekends when no exposures occurred. One dog exposed to 5 ppm exhibited exudative rhinitis approximately half way through the study. At necropsy, exudative rhinitis, tracheitis, and suppurative bronchopneumonia were observed in all hydroxypropyl acrylate-exposed dogs. Microscopic lesions included suppurative rhinitis, squamous metaplasia and hyperplasia of the lining epithelium and focal area of ulceration in the mucosa of the nasal turbinates. These lesions extended to the trachea and lungs of the high exposure group resulting in bronchopneumonia. The LOAEC was 5 ppm (0.027 mg/L) based on effects on the upper respiratory system.

Repeated dose toxicity: Oral route

Groups of male and female Sherman strain rats (10/sex/group) were maintained for 100 days on a diet containing 0, 0.03. 0.1 or 0.3 % HEA (equivalent to doses of 0, 20, 65, and 196 mg/kg body weight/day for males and 0, 30, 102, and 305 mg/kg body weight/day for females). Treatment did not cause any adverse effects as judged by general appearance and behaviour, growth, food consumption, serum, urea, nitrogen and alkaline phosphatase determinations, final average body and organ weights, organ/body weight ratios, and gross and microscopic examination of tissues. The NOAEL for male and female rats was approx. 196 – 305 mg/kg bw/d (Dow Chemical Co., 1967).

Groups of male and female Beagle dogs (2/sex/group) were maintained for 97 days on a diet containing 0.06, 0.2, or 0.4 % HEA in diet (equivalent to doses of 21, 60 and 125 and 22, 63 and 131 mg/kg body weight/day for males and females respectively). There was no evidence of adverse effects as judged by general appearance and behavior, weight gain, food consumption, hematological values, examination of bone marrow, urea nitrogen content and alkaline phosphatase activity in the serum, serum bromsulfophthalein, serum glutamic oxalacetic transaminase and serum glutamic pyruvic transaminase tests, final average body and organ weights, and gross and microscopic examination of tissues. The NOAEL was approx. 125 -131 mg/kg bw/d (Dow Chemical Co., 1967).

Repeated dose toxicity: Dermal route

There are no experimental data available on subchronic and chronic toxicity of 2-hydroxyethyl acrylate by the dermal route of exposure. But due to animal welfare reasons and since the substance is corrosive and a skin sensitizer, no long-term testing by the dermal route is planned.

Justification for classification or non-classification

Based on the available data, classification for repeated dose toxicity is not warranted according to EU Classification, Labelling and Packaging of Substances and Mixtures (CLP) Regulation (EC) No. 1272/2008.