Isodecyl acrylate

Endpoint summary

Description of key information

No repeated study was available on isodecyl acrylate. 
A read-across with 2-ethylhexyl acrylate (2-EHA) for inhalation study and with C12C14 lauryl acrylate for oral study is proposed and is justified in the section 13 of IUCLID. 
In a subacute repeated toxicity study on Lauryl acrylate, no adverse effect was observed at the highest tests dose ( 1000 mg/kg/d).
In a subchronic repeated dose study on 2-EHA by the inhalation route a NOAEC of 0.075 mg/l (10 ppm) was determined in rats for local effects (degeneration of the olfactory epithelial layer in the cranial part of the nasal cavity). The respective NOAEC for systemic effects was 0.226 mg/l (30 ppm) based on clinical chemistry (elevated activities of transaminase and alkaline phosphatase).

Key value for chemical safety assessment

Repeated dose toxicity: via oral route - systemic effects

Link to relevant study records

Reference

Endpoint:

short-term repeated dose toxicity: oral

Remarks:

combined repeated dose and reproduction / developmental screening

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2012

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

OECD Guideline 422 (Combined Repeated Dose Toxicity Study with the Reproduction / Developmental Toxicity Screening Test)

Version / remarks:

no

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Limit test:

no

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Laboratories, Research Models and Services, Germany GmbH
- Age at study initiation: 10-11 weeks (males/females)
- Fasting period before study: no

- Housing:
During the study period, the rats were housed individually in Makrolon type M III cages supplied by Becker & Co., Castrop-Rauxel, Germany (floor area of about 800 cm²), with the following exceptions:
• During overnight matings, male and female mating partners were housed together in Makrolon type M III cages.
• Pregnant animals and their litters were housed together until PND 4 (end of lactation).
• For motor activity (MA) measurements the animals were housed individually in polycarbonate cages supplied by TECNIPLAST, Hohenpeißenberg, Germany with wire covers from Ehret, Emmendingen, Germany (floor area of about 800 cm2) and small amounts of bedding material (the present supplier is documented in the raw data).

Pregnant females were provided with nesting material (cellulose wadding) toward the end of gestation.
Dust-free wooden bedding was used in this study. Wooden gnawing blocks (Type NGM E-022) supplied by Abed® Lab. and Vet. Service GmbH, Vienna, Austria, were added for environmental enrichment. The cages with the test animals were arranged on the racks in such a way that uniform experimental conditions (ventilation and light) were ensured.

- Diet (ad libitum): ground Kliba maintenance diet mouse-rat “GLP”
- Water (ad libitum): from water bottles

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20-24
- Humidity (%): 30-70
- Air changes (per hr): 15
- Photoperiod: 12 hours light from 06.00-18.00h, 12 hours dark from 18.00-06.00h
- Acclimation period: 5-6 days before the beginning of the treatment period

Route of administration:

oral: gavage

Vehicle:

corn oil

Details on oral exposure:

PREPARATION OF DOSING SOLUTIONS:

The test substance was applied as a solution. To prepare this solution, the appropriate amount of test substance was weighed out depending on the desired concentration. Then, corn oil was filled up to the desired weight, subsequently released with a magnetic stirrer. The test substance preparations were produced at least once a week.

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

The analyses of the test substance preparations were carried out at the Analytical Chemistry Laboratory of Experimental Toxicology and Ecology of BASF SE, Ludwigshafen, Germany. The study was carried out in compliance with the Principles of Good Laboratory Practice.
The stability of the test substance in corn oil for a period of 7 days at room temperature was confirmed.
Concentration control Analysis of the test substance preparations were performed in samples of all concentrations at the start of the administration period.

Duration of treatment / exposure:

After the acclimatization period, the test substance was administered orally via gavage to the F0 generation parental animals, daily. The treatment lasted up to one day prior to sacrifice.

Frequency of treatment:

daily in the morning

Remarks:

Doses / Concentrations:
0 (vehicle alone), 100, 300 and 1000 mg/kg
Basis:
other: nominal conc.

No. of animals per sex per dose:

10 male and 10 female rats per dose group

Control animals:

yes, concurrent vehicle

Details on study design:

no

Positive control:

No positive control.

Observations and examinations performed and frequency:

Parental animals

- Mortality
A check for moribund and dead animals was made twice daily on working days and once daily on Saturdays, Sundays and public holidays. If animals were in a moribund state, they were sacrificed and necropsied.
- Clinical observations
A cageside examination was conducted at least once daily for any signs of morbidity, pertinent behavioral changes and signs of overt toxicity. Abnormalities and changes were documented daily for each affected animal.
The littering and lactation behavior of the dams was generally evaluated in the mornings in combination with the daily clinical inspection of the dams. Only particular findings (e.g. inability to deliver) were documented on an individual dam basis. On weekdays (except public holidays) the parturition behavior of the dams was inspected in the afternoons in addition to the evaluations in the mornings. The day of littering was considered the 24-hour period from about 15.00 h of one day until about 15.00 h of the following day.
- Detailed clinical observations
Detailed clinical observations (DCO) were performed in all animals prior to the administration period and thereafter at weekly intervals. The findings were ranked according to the degree of severity, if applicable. The animals were transferred to a standard arena (50 × 37.5 cm with sides of 25 cm high). The following parameters were examined:
1. abnormal behavior during “handling”
2. fur
3. skin
4. posture
5. salivation
6. respiration
7. activity/arousal level
8. tremors
9. convulsions
10. abnormal movements
11. impairment of gait
12. lacrimation
13. palpebral closure
14. exophthalmus
15. feces (appearance/consistency)
16. urine
17. pupil size

- Food consumption
Generally, food consumption was determined once a week for male and female parental animals, with the following exceptions:
• Food consumption was not determined during the mating period (male and female F0 animals).
• Food consumption of the F0 females with evidence of sperm was determined on GD 0, 7, 14 and 20.
• Food consumption of F0 females, which gave birth to a litter was determined for PND 4.
Food consumption was not determined in females without positive evidence of sperm (during the mating period of dams used in parallel) and females without litter (during the lactation period of dams used in parallel) and in males after the premating period.

- Body weight data
Body weight was determined before the start of the administration period in order to randomize the animals. During the administration period body weight was determined on study day 0 (start of the administration period) and thereafter once a week at the same time of the day (in the morning). The body weight change of the animals was calculated from these results.
The following exceptions are notable for the female animals:
• During the mating period the parental females were weighed on the day of positive evidence of sperm (GD 0) and on GD 7, 14 and 20.
• Females with litter were weighed on the day of parturition (PND 1) and on PND 4.
• Females without a litter and without positive evidence of sperm in the vaginal smear were weighed weekly. These body weight data were solely used for the calculations of the dose volume.

- Functional observational battery
A functional observational battery was performed in the first five male animals per test group, the first 5 female animals with litter of all test groups at the end of the administration period starting at about 10.00 h. The FOB started with passive observations without disturbing the animals, followed by removal from the home cage, open field observations
in a standard arena and sensorimotor tests as well as reflex tests. The findings were ranked according to the degree of severity, if applicable. The observations were performed at random.

- Home cage observations:
The animals were observed in their closed home cages; during this period any disturbing activities (touching the cage or rack, noise) were avoided during these examinations in order not to influence the behavior of the animals. Attention was paid to:
1. Posture
2. Tremors
3. Convulsions
4. Abnormal movements
5. Impairment of gait
Open field observations:

The animals were transferred to a standard arena (50 × 50 cm with sides of 25 cm height) and observed for at least 2 minutes. The following parameters were examined:
1. Behavior when removed from cage
2. Fur
3. Skin
4. Salivation
5. Nose discharge
6. Lacrimation
7. Eyes/ pupilsize
8. Posture
9. Palpebral closure
10. Respiration
11. Tremors
12. Convulsions
13. Abnormal movements/ stereotypes
14. Impairment of gait
15. Activity/ arousal level
16. Feces excreted within 2 minutes (number/ appearance/ consistency)
17. Urine excreted within 2 minutes (amount/ color)
18. Rearing within 2 minutes

- Sensory motor tests/ reflexes:
The animals were then removed from the open field and subjected to following sensory motor or reflex tests:
1. Reaction to an object being moved towards the face (Approach response)
2. Touch sensitivity (Touch response)
3. Vision (Visual placing response)
4. Pupillary reflex
5. Pinna reflex
6. Audition (Auditory startle response)
7. Coordination of movements (Righting response)
8. Behavior during handling
9. Vocalization
10. Pain perception (Tail pinch)
11. Grip strength of forelimbs
12. Grip strength of hindlimbs
13. Landing foot-splay test
14. Other findings

- Motor activity assessment
Motor activity (MA) was also measured from 14:00 h onwards on the same day as the FOB was performed in the first five parental males and females (with litter) per group. Motor activity was measured on the same day as FOB was performed. The examinations were performed using the TSE Labmaster System supplied by TSE Systems GmbH, Bad Homburg, Germany. For this purpose, the animals were placed in new clean polycarbonate cages with a small amount of bedding for the duration of the measurement. Eighteen beams were allocated per cage. The numbers of beam interrupts was counted over 12 intervals of 5 minutes per interval. The sequence in which the animals were placed in the cages was selected at random. On account of the time needed to place the rats in the cages, the starting time was "staggered" for each animal. The measurement period began when the 1st beam was interrupted and finished exactly 1 hour later. No food or water was offered to the animals during these measurements and the measurement room was darkened after the transfer of the last animal.


Clinical pathology

In the morning blood was taken from the retrobulbar venous plexus from fasted animals.
The animals were anaesthetized using isoflurane (Isoba®, Essex GmbH Munich, Germany). The blood sampling procedure and subsequent analysis of blood and serum samples were carried out in a randomized sequence. For urinalysis the individual animals were transferred to metabolism cages (withdrawal of food and water) and urine was collected overnight. Urine samples were evaluated in a randomized sequence. The following examinations were carried out in the first 5 surviving parental males and the first 5 surviving females with litter (in order of delivery) per group:

- Hematology
The following parameters were determined in blood with EDTA-K3 as anticoagulant using a particle counter (Advia 120 model; Bayer, Fernwald, Germany): Furthermore, blood smears were prepared and stained according to WRIGHT without being evaluated, because of non-ambiguous results of the differential blood cell counts measured by the automated instrument. (reference: Hematology: Principles and
Procedures, 6th Edition, Brown AB, Lea & Febiger, Philadelphia, 1993, page 101).

Parameters: Leukocyte count, Erythrocyte count, Hemoglobin, Hematocrit, Mean corpuscular volume, Mean corpuscular
hemoglobin, Mean corpuscular hemoglobin concentration, Platelet count, Differential blood count, Reticulocytes, Prothrombin time

- Clinical chemistry
Parameters: Alanine aminotransferase (ALT) (L-alanine: 2-oxoglutarate aminotransferase; Aspartate aminotransferase (AST) (L-aspartate: 2-oxoglutarate aminotransferase; Alkaline phosphatase (ALP) (orthophosphoric acid monoester phosphohydrolase; ¿-Glutamyltransferase
(GGT) (¿ -glutamyl) peptide: aminoacid-¿- glutamyl-transferase; Sodium (Na+), Potassium, Chloride, Calcium, Inorganic phosphorus, Glucose, Urea, Creatinine, Total bilirubin, Total proteins, Albumin,Total cholesterol, Triglycerides , Biles acids

- Urinalysis (parameters)
pH, Protein, Glucose, Ketones, Urobilinogen, Bilirubin, Blood, Specific gravity, Sediment Color, turbidity, Volume



Litter observations

-. Pup number and status at delivery
All pups delivered from the F0 parents were examined as soon as possible on the day of birth to determine the total number of pups and the number of liveborn and stillborn pups in each litter. Pups, which died before the first determination of their status on the day of birth, were defined as stillborn pups.

- Pup viability/mortality
In general, a check was made for any dead or moribund pups twice daily on workdays (once in the morning and once in the afternoon) or as a rule, only in the morning on Saturdays, Sundays or public holidays. The number and percentage of dead pups on the day of birth (PND 0) and of pups dying between PND 1 - 4 (lactation period) were determined. Pups which died accidentally or were sacrificed due to maternal death were not included in these calculations. The number of live pups/litter was calculated on the day after birth, and on lactation day 4. The viability index was calculated.

- Sex ratio
On the day of birth (PND 0) the sex of the pups was determined by observing the distance between the anus and the base of the genital tubercle; normally, the anogenital distance is considerably greater in male than in female pups. The sex of the pups was finally
confirmed at necropsy. The sex ratio was calculated at day 0 and day 4 after birth.

- Pup clinical observations
The live pups were examined daily for clinical symptoms (including gross-morphological findings) during the clinical inspection of the dams.

- Pup body weight data
The pups were weighed on the day after birth (PND 1) and on PND 4. Pups' body weight change was calculated from these results.
The individual weights were always determined at about the same time of the day (in the morning). “Runts” were defined on the basis of the body weights on PND 1. "Runts" are pups that weigh less than 75% of the mean weight of the respective control pups.

Sacrifice and pathology:

Parental animals

Necropsy
All parental animals were sacrificed by decapitation under isoflurane anesthesia. The exsanguinated animals were necropsied and assessed by gross pathology; special attention was given to the reproductive organs.

Weight parameters
The following weights were determined in all animals sacrificed on schedule:
1. Anesthetized animals
2. Epididymides
3. Testes
The following weights were determined in 5 animals per sex/test group sacrificed on schedule (females with litters only, same animals as used for clinical pathological examinations):
1. Adrenal glands
2. Brain
3. Heart
4. Kidneys
5. Liver
6. Spleen
7. Thymus

Organ/tissue fixation
The following organs or tissues of all parental animals were fixed in 4% buffered formaldehyde solution or modified Davidson’s solution:
1. All gross lesions
2. Adrenal glands
3. Aorta
4. Bone marrow (femur)
5. Brain
6. Cecum
7. Cervix
8. Coagulating gland
9. Colon
10. Duodenum
11. Eyes with optic nerve
12. Esophagus
13. Extraorbital lacrimal glands
14. Epididymides (modified Davidson’s solution)
15. Femur with knee joint
16. Heart
17. Ileum
18. Jejunum (with Peyer’s patches)
19. Kidneys
20. Larynx
21. Liver
22. Lungs
23. Lymph nodes (axillary and mesenteric)
24. Mammary gland (male and female)
25. Nose (nasal cavity)
26. Ovaries (modified Davidson’s solution)
27. Oviducts
28. Pancreas
29. Parathyroid glands
30. Pharynx
31. Pituitary gland
32. Prostate gland
33. Rectum
34. Salivary glands (mandibular and sublingual)
35. Sciatic nerve
36. Seminal vesicles
37. Skeletal muscle
38. Spinal cord (cervical, thoracic and lumbar cord)
39. Spleen
40. Sternum with marrow
41. Stomach (forestomach and glandular stomach)
42. Testes (modified Davidson’s solution)
43. Thymus
44. Thyroid glands
45. Trachea
46. Urinary bladder
47. Uterus
48. Vagina

- Histopathology
Fixation was followed by histotechnical processing, examination by light microscopy and assessment of findings from the following organs of all animals/test group, all animals affected/test group or 5 animals per sex/test group, females with litters only, same animals as used for
clinical pathological examinations.
Special attention was given to stages of spermatogenesis in the male gonads.
A correlation between gross lesions and histopathological findings was attempted.

Organs:
Adrenal glands, All gross lesions, Bone marrow (femur) , Brain, Cecum, Cervix, Coagulating glands, Colon, Duodenum, Epididymides, Heart,
Ileum, Jejunum, Kidneys, Live, Lungs, Lymph nodes (axillary and mesenteric, Ovaries , Oviducts, Prostate gland, Peyer’s patches , Rectum,
Sciatic nerve , Seminal vesicles, Spinal cord (cervical, thoracic, lumbar) , Spleen, Stomach (forestomach and glandular stomach), Testes , Thymus , Thyroid glands , Trachea , Urinary bladder , Uterus , Vagina



Offsprings

- Pup necropsy observations
All pups with scheduled sacrifice on PND 4 were sacrificed under isoflurane anesthesia with CO2. All pups were examined externally and eviscerated; their organs were assessed macroscopically.
All stillborn pups and all pups that died before PND 4 were examined externally, eviscerated and their organs were assessed macroscopically. All pups without notable findings or abnormalities were discarded after their macroscopic evaluation. Animals with notable findings or abnormalities were evaluated on a case-bycase basis, depending on the type of finding noted.

Other examinations:

Reproductive indices
The following indeces were determined: mating and fertility index for both males and females, gestation index, live birth index

Offspring viability index
The following indices were determined: sex ratio and viability index

Statistics:

For parameters with bidirectional changes:
Non-parametric one-way analysis using KRUSKAL-WALLIS test. If the resulting p-value was equal or less than 0.05, a pairwise comparison of each dose group with the control group was performed using WILCOXON-test (twosided) for the hypothesis of equal medians.
For parameters with unidirectional changes:
Pairwise comparison of each dose group with the control group using the WILCOXON-test (one-sided) for the hypothesis of equal medians.

Clinical signs:

effects observed, non-treatment-related

Description (incidence and severity):

One female animal of test group 3 (No.138) showed a swelling of the left mouth region on study days 21 and 28.
No other abnormal clinical signs in all test groups were observed.

Summary clinical observations for males and females
Slight to moderate salivation in 3 male animals of test groups 2 and all male animals of test group 3 was observed after treatment in the pre-mating period.
Slight to moderate salivation in 4 male animals of test groups 2 and all male animals of test group 3 was observed after treatment in the mating period.
Slight to moderate salivation in 5 male animals of test groups 2 and all male animals of test group 3 was observed after treatment in the post-mating period.
Slight to moderate salivation in 1 female animal of test groups 2 and in 7 female animals of test group 3 was observed after treatment in the pre-mating period.
Slight to moderate salivation in 1 female animal of test groups 2 and in 7 female animals of test group 3 was observed after treatment in the mating period.
Animal No. 126 (mated with Animal No. 26) did not show sperm in vaginal smear.


Summary clinical observations for females during gestation
Animal No. 138 of test group 3 showed a swelling of the left mouth region from gestation day 1 to 17. Because of a single incidence this finding was assessed as being incidental.
Animal Nos. 123, 125, 127 and 128 of test group 2 showed slight salivation after treatment. All animals of test group 3 showed slight to moderate salivation after treatment. These findings were substance-related because of the smelling of the test substance, but no adverse effects.
Animal Nos. 123 and 127 of test group 2 and animal No. 131 and 134 of test group 3 did not deliver any pups. These findings were assessed as being spontaneous in nature and without biological relevance.
Animal No. 109 of control group showed apathy and reduced nutritional condition on gestation day 23.

Clinical observations for females during lactation
Animal Nos. 125 and 128 of test group 2 showed slight salivation after treatment on different study days.
Animal Nos. 132, 135, 136, 137, 138, 139 and 140 of test group 3 showed slight to moderate salivation after treatment on different lactation days.
These findings were substance-related because of the smelling of the test substance, but no adverse effects.
Animal No. 109 of the control group showed a complete litter loss after insufficient after-birth and maternal care. Due to the reduced nutritional condition and the apathy, this animal was sacrificed in a moribund state on lactation day 1.

Mortality:

mortality observed, non-treatment-related

Description (incidence):

Animal No. 109 was sacrificed in a moribund state on lactation day 1.
No other animal died prematurely in the present study.

Body weight and weight changes:

effects observed, non-treatment-related

Description (incidence and severity):

Body weight of females of test group 2 (300 mg/kg bw/d) was significantly decreased on gestation day 20 (-5.4%).
Body weight change was significantly decreased in females of test group 3 (1000 mg/kg bw/d) when regarding the premating period from day 0 to day 13 (-6.1%).
Due to the lack of dose response relationship these findings were assessed as being incidental.

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

The food consumption was significantly increased (+10.7%) on day 7 in males of test group 3 (1000 mg/kg bw/d) during premating period.

Food efficiency:

not examined

Water consumption and compound intake (if drinking water study):

not examined

Ophthalmological findings:

not specified

Haematological findings:

effects observed, treatment-related

Description (incidence and severity):

No treatment-related, adverse changes among hematological parameters were observed.
In females of test group 3 (1000 mg/kg bw/d) relative eosinophil counts were lower compared to controls. This was the only altered hematology parameter among these animals and the decrease was marginal below the historical range (relative eosinophil counts 1.6-3.1 %). Therefore, this alteration was regarded as treatment-related, but not adverse (ECETOC, Technical Report No 85, 2002).

Clinical biochemistry findings:

effects observed, non-treatment-related

Description (incidence and severity):

No treatment-related changes among clinical chemistry parameters were observed.
In females of test group 3 (1000 mg/kg bw/d) albumin levels were lower and cholesterol levels were higher compared to controls. Additionally, in females of test group 2 (300 mg/kg bw/d) albumin levels were decreased. Albumin levels were marginally decreased (<4% compared to controls) and regarding mean values were not dose-dependently altered. They were marginally below the historical control range, whereas the higher cholesterol
levels were within the historical control range (albumin: 39.13-42.59 g/L, cholesterol: 1.06- 2.03 mmol/L). Therefore, both changes were regarded as incidental and not treatment-related.

Urinalysis findings:

no effects observed

Description (incidence and severity):

No treatment-related changes among urinalysis parameters were observed.

Behaviour (functional findings):

effects observed, non-treatment-related

Description (incidence and severity):

Functional observational battery
Deviations from "zero values" were obtained in several rats. However, as most findings were equally distributed between test-substance treated groups and controls, were without a dose-response relationship or occurred in single rats only, these observations were considered as incidental.
The following examinations were performed during FOB and are assessed individually:
Home cage observations:No test substance-related effects were observed.
Open field observations: No test substance-related effects were observed.
Sensorimotor tests/reflexes: No test substance-related effects were observed.
Quantitative Parameters: No test substance-related effects were observed.

Motor activity measurement
Comparing the single intervals with the control groups, no significant deviations were measured with the exception of slightly decreased values in all interval in males of test group 3 (1000 mg/kg bw/d). As a consequence, the overall motor activity measurement in male animals of test group 3 was significantly decreased. As no FOB parameter was changed and no findings occurred during DCO, the change was assessed as being spontaneous and not related to treatment.
No changes were noted for male animals of test groups 1 and 2 (100 and 300 mg/kg bw/d) as well as female animals of test groups 1-3 (100, 300 and 1000 mg/kg bw/d) when compared to the control group.

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Description (incidence and severity):

Absolute weights
When compared to the control group 0 (set to 100%), the mean absolute kidney and liver weights were significantly increased in male animals. All other mean absolute weight parameters in males and all weight parameters in females did not show significant differences when compared to the control group 0.

Relative weights
When compared to the control group 0 (set to 100%), the mean relative kidney and liver weights were significantly increased in male animals. All other mean relative weight parameters did not show significant differences when compared to the control group 0.
As there was no dose response or a histopathological correlate, the increased kidney weights were regarded as incidental.
The increase in absolute (test group 3, 1000 ppm) and relative liver weights in test group 2 and 3 (300 and 1000 mg/kg bw/day) in male animals was considered to be treatment - related, as they followed a dose response although a histopathological correlate was missing.

Gross pathological findings:

effects observed, non-treatment-related

Description (incidence and severity):

Female animal No. 109 that died showed light red foci on the kidney, and an effusion in the thoracic cavity, and a retained fetus in the uterus.
Two male animals (Animal Nos. 23 and 26) of dose group 2 (300 ppm) showed a focus on the liver.
All other findings occurred individually. They were considered to be incidental or spontaneous in origin and without any relation to treatment.

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

no effects observed

Description (incidence and severity):

Animal No. 109 showed multifocal necroses in the kidney correlating to red foci in the macroscopic diagnosis. The uterus was necrotic with inflammation, fetal tissue was no longer recognizable histologically. Both findings are likely to have contributed to the moribund state of this animal.
Male animal Nos.23 and 26 showed macroscopically a focus on the liver which correlated histologically with focal necrosis. This was not considered to be treatment – related as it was focal and not present in test group 3.
All other findings occurred either individually or were biologically equally distributed over control and treatment groups. They were considered to be incidental or spontaneous in origin and without any relation to treatment.

Histopathological findings: neoplastic:

not examined

Other effects:

not examined

Dose descriptor:

NOAEL

Remarks:

parental toxicity

Effect level:

1 000 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Remarks on result:

not determinable due to absence of adverse toxic effects

Critical effects observed:

not specified

Conclusions:

No test substance-related, adverse findings were noted on clinical examination and pathology. Indeed no adverse maternal toxicity was observed in this study. The NOAEL (no observed adverse effect level) for general systemic toxicity was 1000 mg/kg bw/d.

Executive summary:

The objective of the study was to detect possible effects of the test substance on the integrity and performance of male and female reproductive systems including gonadal function, mating behavior, conception, gestation and parturition. Furthermore, it was intended to obtain information about the general toxicological profile including target organs and the no observed adverse effect level (NOAEL) after repeated oral administration. The duration of treatment covered a 2-week pre-mating and mating period in both sexes, approximately 1 week post-mating in males, and the entire gestation period as well as 4 days of lactation and two weeks thereafter in females.

Lauryacrylate 1214 was administered orally via gavage to groups of 10 male and 10 female Wistar rats at dose levels of 0, 100, 300 and 1000 mg/kg bw/d (respectively test groups 0,1,2 and 3).

Regarding clinical examinations, no signs of general systemic toxicity were observed in male or female parental animals of test groups 1-3 during the entire study period. Regarding clinical pathology, no treatment-related, adverse effects were observed up to a dose of the compound of 1000 mg/kg bw/d. Regarding pathology, the liver of male animals of test group 2 and 3 (300 and 1000 mg/kg bw/day, respectively) showed an increase in absolute (group 3 only) and relative weights which was regarded to be adaptive and non-adverse in the absence of histological findings.

The NOAEL (no observed adverse effect level) for general systemic toxicity was 1000 mg/kg bw/d.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

1 000 mg/kg bw/day

Study duration:

subacute

Species:

rat

Quality of whole database:

This study is considered to be reliable with a klimisch score of 1 (reliable without restrictions)

Repeated dose toxicity: inhalation - systemic effects

Link to relevant study records

Reference

Endpoint:

sub-chronic toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

02 Apr 1985 - 19 July 1985

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

OECD Guideline 413 (Subchronic Inhalation Toxicity: 90-Day Study)

Deviations:

yes

Remarks:

see below

Principles of method if other than guideline:

The study was conducted according to OECD guideline 413 (1981). Compared to the actual version of the test guideline, validity is restricted in that food consumption was not recorded, lung tissues were not perfused, and laryngopharynx was not examined.

GLP compliance:

yes

Limit test:

no

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Dr. K. Thomae GmbH, D-7950 Biberach, Germany
- Age at study initiation: approximately 8-week old
- Weight at study initiation (mean): male rats: 223 g (213 - 234 g); female rats: 158 g (150 - 164 g)
- Housing: single
- Diet (ad libitum): Kliba Labordiaet Ratte/Maus A 343 10 mm Pellet, Klingentalmuehle AG, CH-4303 Kaiseraugst
- Water (ad libitum): tap water
- Acclimation period: 5 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 - 24 °C
- Humidity (%): 30 - 70 %
- Photoperiod (hrs dark / hrs light): 12 h dark / 12 h light

Route of administration:

inhalation: vapour

Type of inhalation exposure:

whole body

Vehicle:

other: unchanged (no vehicle)

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: Inhalation chambers (glass/steel inhalation chambers) with a capacity of approx. 1.3 m3
- Method of holding animals in test chamber: animals in wire cages
- Temperature, humidity in air chamber: 22.8-23.6 °C, 36-41 %


TEST ATMOSPHERE
- Brief description of analytical method used: The test substance concentrations were checked intermittently (10 and 30 ppm) or continuously (100 ppm) by total hydrocarbons analyzers (THCA)/GC/FID.
- Samples taken from breathing zone: yes

EXPOSURE SYSTEM
The test and control animals were exposed to the test substance vapors and control air in a whole-body exposure system, respectively. All air streams, supply air and exhaust air of all test groups were adjusted by air flow meters (rotameters), measured continuously and recorded approximately every 2 hours. The air temperatures in the exposure systems were measured continuously with multipurpose thermometers (Diehl GmbH & Co) and recorded approximately every 2 hours. The pressures in the exposure systems were measured continuously (slanting tube pressure gage) and recorded once a day.

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Measured test substance concentrations were within ± 5% of the nominal concentrations (see table below).

Duration of treatment / exposure:

90 days

Frequency of treatment:

6 h/day; 5 days/week

Remarks:

Doses / Concentrations:
10; 30; 100 ppm (corresponding to approx. 0.075; 0.226; 0.753 mg/L)
Basis:
nominal conc.

No. of animals per sex per dose:

Groups of 10 male and 10 female rats per test concentration were exposed to test substance vapors in a whole-body exposure system on 6 hours per day, 5 days per week at 10, 30, and 100 ppm (corresponding to approximately 0.075 mg/L, 0.226 mg/L or 0.753 mg/L).

Control animals:

yes, sham-exposed

Details on study design:

- Dose selection rationale:
In order to obtain preliminary information about the profile of action of 2-EHA vapor, the maximum concentration during the 90-day study was to be within the saturation range of the test substance (estimated by extrapolation of the vapor-pressure curve: T = 20°C; p= 0.13 mbar = 130 ppm). For technical reasons (e.g. condensation phenomena and hence poor reproducibility with slight temperature fluctuations), the maximum concentration which could be reliably maintained under the study conditions was chosen to be 100 ppm. The minimum concentration of 10 ppm was based on the applicable MAC value for methyl acrylate (1984). The intermediate concentration was established between these two concentrations as 30 ppm in order to obtain any concentration-response relationships.

- Post-exposure period: none

- Control: An air control with 10 male and 10 female rats was run in parallel.

Positive control:

no

Observations and examinations performed and frequency:

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: Mortality and clinical signs were checked each day.


BODY WEIGHT: Yes
- Time schedule for examinations: Body weight determinations were conducted once a week.


OPHTHALMOSCOPIC EXAMINATION: Yes
- Time schedule for examinations: The eyes of the animals in the control group and the high dose group were checked with a focusable hand-held slit lamp for changes in the refracting media at the beginning of the pre-flow period (day -8) and at the end of the study (day 83).
- Dose groups that were examined: high-dose, control


HAEMATOLOGY: Yes
- Time schedule for collection of blood: at the end of the exposure period
- Anaesthetic used for blood collection: No
- How many animals: 10
- Parameters were examined:
The following hematological examinations were carried out on 10 animals per test group and sex at the end of the exposure period: Hemoglobin, erythrocytes, hematocrit, mean hemoglobin content per erythrocyte, mean cell volume, mean corpuscular hemoglobin concentration, platelets, leukocytes.

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: at the end of the exposure period
- How many animals:
- Parameters were examined:
The following clinicochemical examinations were carried out on 10 animals per test group and sex at the end of the exposure period: Total bilirubin, creatinine, urea, sodium, potassium, total protein, glucose, inorganic phosphate, calcium, chloride, triglycerides, cholesterol, albumine, globulins.
The following enzyme activities were determined: - Glutamic-pyruvic transaminase - Alkaline phosphatase - Glutamic-oxalacetic transaminase. Clotting analyses were performed: Prothrombin timne (Hepato Quick's test).


URINALYSIS: No

Sacrifice and pathology:

GROSS PATHOLOGY: Yes
HISTOPATHOLOGY: Yes

The animals were sacrificed at the end of the 3-month inhalation period and each animal was completely necropsied. Histopathologic examination was carried out on 31 organs/tissues of high dose and control animals. The lungs, nasal cavity, thyroid and parathyroid glands, trachea and liver from all animals/all test groups were subjected to histopathology examination.

Statistics:

T-test according to Williams.

WILLIAMS DA (1971 ). A test for differences between treatment means when several dose levels are compared with a zero dose control. Biometrics 27: 103 - 117
WILLIAMS DA (1972 ). The comparisdn of several dose levels with a zero dose control. Biometrics 28: 519 - 531

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

- 100 ppm (0.753 mg/L): Mild lethargy, eyelid closure during exposure.
- 30 ppm (0.226 mg/L): Mild lethargy and eyelid closure during exposure.
- 10 ppm (0.075 mg/L): As compared to control animals, no toxic effects which could be interpreted as being related to the test substance.

Mortality:

no mortality observed

Description (incidence):

There were no deaths during the study.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

- 100 ppm (0.753 mg/L): Retarded body weight gain in both sexes on determination of the body weight change; retarded body weight gain in male animals only on determination of body weight.
- 30 ppm (0.226 mg/L): Slight retardation in body weight gain of the female animals.
- 10 ppm (0.075 mg/L): As compared to control animals, no toxic effects which could be interpreted as being related to the test substance.

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:

no effects observed

Description (incidence and severity):

No findings.

Haematological findings:

no effects observed

Description (incidence and severity):

No findings

Clinical biochemistry findings:

effects observed, treatment-related

Description (incidence and severity):

- 100 ppm (0.753 mg/L): Increase in glutamic-pyruvic transaminase activity and alkaline phosphatase activity of female rats; reduction of total proteins in female animals and very slightly in male rats; slightly reduced albumin concentrations in both sexes (not statistically significant); reduction of glucose level in female animals.
- 30 ppm (0.226 mg/L): Reduced total protein and albumin levels in both sexes; only a tendency to a reduction in albumin levels in female animals.
- 10 ppm (0.075 mg/L): As compared to control animals, no toxic effects which could be interpreted as being related to the test substance.

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 findings

Gross pathological findings:

effects observed, treatment-related

Description (incidence and severity):

- 100 ppm (0.753 mg/L): Reduction in body weight resulted in darker coloration of liver parenchyma with indistinct lobular marking (decrease in liver lipids).
- 30 ppm (0.226 mg/L): No findings.
- 10 ppm (0.075 mg/L): No findings.

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Description (incidence and severity):

Nasal cavity:
Degeneration of olfactory mucosa was diagnosed. This degeneration was characterized by a reduction of cellular layers, reduction or loss of
apical cytoplasmic structures such as olfactory knobs and microvilli, and by necrosis. Identification of the remaining olfactory mucosa cells
was not possible. Occasional mitoses were present.
Level I: Degeneration of olfactory mucosa was diagnosed in all rats of 100 ppm group and in 4 males and 4 females each of 30 ppm group. In 100 ppm group, the degeneration affected the olfactory mucosa diffusely in the dorsal and dorsolateral area, and the severity was mainly moderate. In 30 ppm group, the degeneration affected only small areas of the dorsolateral olfactory mucosa and was minimal in severity.
LeveL II: Degeneration of olfactory mucosa was diagnosed in all rats of 100 ppm group, 1 male of group 2, 2 males and 1 femaLe of 10 ppm group 1, and 1 male of control group. In 100 ppm group, the degeneration was diffuse (dorsal, dorsolateral), whereas in the other groups, the degeneration was focal. The severity was minimal to marked in 100 ppm group, and mainly minimal in the other groups.
LeveL III: Degeneration of oLfactory mucosa was only diagnosed in one male and one female each of the 100 ppmgroup. The severity was slight.
Level IV: No degeneration of the olfactory mucosa was noted.

Liver
Fatty change, characterized by micro- to macrovesicular hepatocellular fat deposits was diagnosed in rats of all groups including controls.
The fatty change was mainly localized in zones 1 (periportal zone) and 2 (intermediate zone). In 5 males of 30 ppm group and in one male of 100 ppm group, fatty change was noted also in zone 3 (zone surrounding terminal hepatic venule). Generally, the severity of fatty change was higher in males than in females. In females, the severity of fatty change was similar in all groups. In males, the severity of fatty change was less in 100 ppmgroup when compared with the rats of the other groups.

Histopathological findings: neoplastic:

no effects observed

Key result

Dose descriptor:

NOAEC

Effect level:

0.075 mg/L air (nominal)

Sex:

male/female

Basis for effect level:

other: Local effects: degeneration of the olfactory epithelial layer in the cranial part of the nasal cavity

Dose descriptor:

LOAEC

Effect level:

0.226 mg/L air (nominal)

Sex:

male/female

Basis for effect level:

other: Local effects: degeneration of the olfactory epithelial layer in the cranial part of the nasal cavity

Dose descriptor:

NOAEC

Effect level:

0.226 mg/L air (nominal)

Sex:

male/female

Basis for effect level:

other: Systemic effects: Clinical chemistry: elevated activities of transaminase and alkaline phosphatase

Dose descriptor:

LOAEC

Effect level:

0.753 mg/L air (nominal)

Sex:

male/female

Basis for effect level:

other: Systemic effects: Clinical chemistry: elevated activities of transaminase and alkaline phosphatase

Critical effects observed:

not specified

Concentrations in the inhalation chambers:

A study mean with standard deviation was calculated from the daily means of the individual chamber concentrations of the test groups:
		Concentration
     Nominal		       Measured
 [ppm]	[mg/L]		[ppm]    	[mg/L]
----------------------------------------------
  10	0.075		9.9 ± 0.47	0.0745
  30    0.226		30 ± 1.7	0.226
 100    0.753		100 ± 4.6	0.753
----------------------------------------------

Conclusions:

In this subchronic repeated dose study by the inhalation route a NOAEC of 0.075 mg/l (10 ppm) was determined in rats for local effects (degeneration of the olfactory epithelial layer in the cranial part of the nasal cavity). The respective NOAEC for systemic effects was 0.226 mg/l (30 ppm) based on clinical chemistry (elevated activities of transaminase and alkaline phosphatase).

Executive summary:

In a valid 90-day inhalation study, Wistar rats were administered in a whole-body exposition on 6 hours per day, 5 days per week, to 2-EHA vapour at concentrations of 0 ppm, 10 ppm, 30 ppm or 100 ppm (approximately 0.075 mg/l, 0.226 mg/l or 0.753 mg/l for the treatment groups) (2-EHA purity 99.7 %). The study design was conducted according to OECD 413 (1981).

Clinical observations:

There were no treatment-related premature deaths. Repeated exposure to 10 ppm was tolerated without signs by male and female Wistar rats. At 30 ppm and 100 ppm the clinical signs (eyelid closure, lethargy) were not very pronounced and possibly point to the irritant effect of the 2-EHA vapors.. Body weight gain was lower in both sexes of the high dose during and at the end of the study. A transiently reduced body weight gain was observed in mid dose females. From day 21 onwards mean body weight (absolute) was lower in high dose males compared to the control group. This parameter was not significantly altered in any other group at any time point during the study.

Clinical-chemical changes:

In the 100 ppm dose group an increase in the glutamic-pyruvic transaminase and alkaline phosphatase activities of the female rats as well as in some cases a reduction of total protein values and albumin concentrations were described. These effects were considered to be the only systemic ones of toxicological significance.

Gross Pathology:

The only effect of the test substance found on gross pathological assessment of the male animals in the 100 ppm group was a dark coloration of the liver parenchyma associated with indistinct lobular marking This finding is attributable to the decrease in the liver lipid content and is a consequence of the reduction in body weight.

Histopathology:

The inhalation of 2-EHA in rats was associated with degeneration of the olfactory mucosa in the dorsal and dorsolateral areas of the anterior parts of the nasal cavity. In 100 ppm group, the degenenation is considered to be treatment-related. In 30 ppm group , the degeneration was mainly minimal and similar to the histopathologic changes diagnosed in affected rats of the 10 ppm group and 0 ppm group (control). However, the incidence of degeneration was higher in mid group.

Slight to moderate hepatic fatty change in males and minimal to slight hepatic fatty change in females was a common finding in rats of all dose groups. In the males of 100 ppm group, the severity of the fatty change was less than in the rats of the other dose groups. This finding was compatible with the macroscopic findings in the liver of the rats of 100 ppm group (darker than normal, less distinct lobular pattern). This effect in the males of 100 ppm group is also considered to be related to the inhalation of the test article. However, this effect is presumed not to be a direct toxic effect of the test article, but rather reflect the poor body condition of the rats. A specific target organ could not be identified, electron microscopical examinations revealed no indication for peroxisome proliferation.

The other lesions noted in this study are not considered to be related to treatment.

NOAEC local effects: 0.075 mg/l (10 ppm)

NOAEC systemic 0.226 mg/l (30 ppm)

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

NOAEC

226 mg/m³

Study duration:

subchronic

Species:

rat

Quality of whole database:

It is a reliable study with a klimisch score of 2.

Repeated dose toxicity: inhalation - local effects

Link to relevant study records

Reference

Endpoint:

sub-chronic toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

02 Apr 1985 - 19 July 1985

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

OECD Guideline 413 (Subchronic Inhalation Toxicity: 90-Day Study)

Deviations:

yes

Remarks:

see below

Principles of method if other than guideline:

The study was conducted according to OECD guideline 413 (1981). Compared to the actual version of the test guideline, validity is restricted in that food consumption was not recorded, lung tissues were not perfused, and laryngopharynx was not examined.

GLP compliance:

yes

Limit test:

no

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Dr. K. Thomae GmbH, D-7950 Biberach, Germany
- Age at study initiation: approximately 8-week old
- Weight at study initiation (mean): male rats: 223 g (213 - 234 g); female rats: 158 g (150 - 164 g)
- Housing: single
- Diet (ad libitum): Kliba Labordiaet Ratte/Maus A 343 10 mm Pellet, Klingentalmuehle AG, CH-4303 Kaiseraugst
- Water (ad libitum): tap water
- Acclimation period: 5 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 - 24 °C
- Humidity (%): 30 - 70 %
- Photoperiod (hrs dark / hrs light): 12 h dark / 12 h light

Route of administration:

inhalation: vapour

Type of inhalation exposure:

whole body

Vehicle:

other: unchanged (no vehicle)

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: Inhalation chambers (glass/steel inhalation chambers) with a capacity of approx. 1.3 m3
- Method of holding animals in test chamber: animals in wire cages
- Temperature, humidity in air chamber: 22.8-23.6 °C, 36-41 %


TEST ATMOSPHERE
- Brief description of analytical method used: The test substance concentrations were checked intermittently (10 and 30 ppm) or continuously (100 ppm) by total hydrocarbons analyzers (THCA)/GC/FID.
- Samples taken from breathing zone: yes

EXPOSURE SYSTEM
The test and control animals were exposed to the test substance vapors and control air in a whole-body exposure system, respectively. All air streams, supply air and exhaust air of all test groups were adjusted by air flow meters (rotameters), measured continuously and recorded approximately every 2 hours. The air temperatures in the exposure systems were measured continuously with multipurpose thermometers (Diehl GmbH & Co) and recorded approximately every 2 hours. The pressures in the exposure systems were measured continuously (slanting tube pressure gage) and recorded once a day.

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Measured test substance concentrations were within ± 5% of the nominal concentrations (see table below).

Duration of treatment / exposure:

90 days

Frequency of treatment:

6 h/day; 5 days/week

Remarks:

Doses / Concentrations:
10; 30; 100 ppm (corresponding to approx. 0.075; 0.226; 0.753 mg/L)
Basis:
nominal conc.

No. of animals per sex per dose:

Groups of 10 male and 10 female rats per test concentration were exposed to test substance vapors in a whole-body exposure system on 6 hours per day, 5 days per week at 10, 30, and 100 ppm (corresponding to approximately 0.075 mg/L, 0.226 mg/L or 0.753 mg/L).

Control animals:

yes, sham-exposed

Details on study design:

- Dose selection rationale:
In order to obtain preliminary information about the profile of action of 2-EHA vapor, the maximum concentration during the 90-day study was to be within the saturation range of the test substance (estimated by extrapolation of the vapor-pressure curve: T = 20°C; p= 0.13 mbar = 130 ppm). For technical reasons (e.g. condensation phenomena and hence poor reproducibility with slight temperature fluctuations), the maximum concentration which could be reliably maintained under the study conditions was chosen to be 100 ppm. The minimum concentration of 10 ppm was based on the applicable MAC value for methyl acrylate (1984). The intermediate concentration was established between these two concentrations as 30 ppm in order to obtain any concentration-response relationships.

- Post-exposure period: none

- Control: An air control with 10 male and 10 female rats was run in parallel.

Positive control:

no

Observations and examinations performed and frequency:

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: Mortality and clinical signs were checked each day.


BODY WEIGHT: Yes
- Time schedule for examinations: Body weight determinations were conducted once a week.


OPHTHALMOSCOPIC EXAMINATION: Yes
- Time schedule for examinations: The eyes of the animals in the control group and the high dose group were checked with a focusable hand-held slit lamp for changes in the refracting media at the beginning of the pre-flow period (day -8) and at the end of the study (day 83).
- Dose groups that were examined: high-dose, control


HAEMATOLOGY: Yes
- Time schedule for collection of blood: at the end of the exposure period
- Anaesthetic used for blood collection: No
- How many animals: 10
- Parameters were examined:
The following hematological examinations were carried out on 10 animals per test group and sex at the end of the exposure period: Hemoglobin, erythrocytes, hematocrit, mean hemoglobin content per erythrocyte, mean cell volume, mean corpuscular hemoglobin concentration, platelets, leukocytes.

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: at the end of the exposure period
- How many animals:
- Parameters were examined:
The following clinicochemical examinations were carried out on 10 animals per test group and sex at the end of the exposure period: Total bilirubin, creatinine, urea, sodium, potassium, total protein, glucose, inorganic phosphate, calcium, chloride, triglycerides, cholesterol, albumine, globulins.
The following enzyme activities were determined: - Glutamic-pyruvic transaminase - Alkaline phosphatase - Glutamic-oxalacetic transaminase. Clotting analyses were performed: Prothrombin timne (Hepato Quick's test).


URINALYSIS: No

Sacrifice and pathology:

GROSS PATHOLOGY: Yes
HISTOPATHOLOGY: Yes

The animals were sacrificed at the end of the 3-month inhalation period and each animal was completely necropsied. Histopathologic examination was carried out on 31 organs/tissues of high dose and control animals. The lungs, nasal cavity, thyroid and parathyroid glands, trachea and liver from all animals/all test groups were subjected to histopathology examination.

Statistics:

T-test according to Williams.

WILLIAMS DA (1971 ). A test for differences between treatment means when several dose levels are compared with a zero dose control. Biometrics 27: 103 - 117
WILLIAMS DA (1972 ). The comparisdn of several dose levels with a zero dose control. Biometrics 28: 519 - 531

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

- 100 ppm (0.753 mg/L): Mild lethargy, eyelid closure during exposure.
- 30 ppm (0.226 mg/L): Mild lethargy and eyelid closure during exposure.
- 10 ppm (0.075 mg/L): As compared to control animals, no toxic effects which could be interpreted as being related to the test substance.

Mortality:

no mortality observed

Description (incidence):

There were no deaths during the study.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

- 100 ppm (0.753 mg/L): Retarded body weight gain in both sexes on determination of the body weight change; retarded body weight gain in male animals only on determination of body weight.
- 30 ppm (0.226 mg/L): Slight retardation in body weight gain of the female animals.
- 10 ppm (0.075 mg/L): As compared to control animals, no toxic effects which could be interpreted as being related to the test substance.

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:

no effects observed

Description (incidence and severity):

No findings.

Haematological findings:

no effects observed

Description (incidence and severity):

No findings

Clinical biochemistry findings:

effects observed, treatment-related

Description (incidence and severity):

- 100 ppm (0.753 mg/L): Increase in glutamic-pyruvic transaminase activity and alkaline phosphatase activity of female rats; reduction of total proteins in female animals and very slightly in male rats; slightly reduced albumin concentrations in both sexes (not statistically significant); reduction of glucose level in female animals.
- 30 ppm (0.226 mg/L): Reduced total protein and albumin levels in both sexes; only a tendency to a reduction in albumin levels in female animals.
- 10 ppm (0.075 mg/L): As compared to control animals, no toxic effects which could be interpreted as being related to the test substance.

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 findings

Gross pathological findings:

effects observed, treatment-related

Description (incidence and severity):

- 100 ppm (0.753 mg/L): Reduction in body weight resulted in darker coloration of liver parenchyma with indistinct lobular marking (decrease in liver lipids).
- 30 ppm (0.226 mg/L): No findings.
- 10 ppm (0.075 mg/L): No findings.

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Description (incidence and severity):

Nasal cavity:
Degeneration of olfactory mucosa was diagnosed. This degeneration was characterized by a reduction of cellular layers, reduction or loss of
apical cytoplasmic structures such as olfactory knobs and microvilli, and by necrosis. Identification of the remaining olfactory mucosa cells
was not possible. Occasional mitoses were present.
Level I: Degeneration of olfactory mucosa was diagnosed in all rats of 100 ppm group and in 4 males and 4 females each of 30 ppm group. In 100 ppm group, the degeneration affected the olfactory mucosa diffusely in the dorsal and dorsolateral area, and the severity was mainly moderate. In 30 ppm group, the degeneration affected only small areas of the dorsolateral olfactory mucosa and was minimal in severity.
LeveL II: Degeneration of olfactory mucosa was diagnosed in all rats of 100 ppm group, 1 male of group 2, 2 males and 1 femaLe of 10 ppm group 1, and 1 male of control group. In 100 ppm group, the degeneration was diffuse (dorsal, dorsolateral), whereas in the other groups, the degeneration was focal. The severity was minimal to marked in 100 ppm group, and mainly minimal in the other groups.
LeveL III: Degeneration of oLfactory mucosa was only diagnosed in one male and one female each of the 100 ppmgroup. The severity was slight.
Level IV: No degeneration of the olfactory mucosa was noted.

Liver
Fatty change, characterized by micro- to macrovesicular hepatocellular fat deposits was diagnosed in rats of all groups including controls.
The fatty change was mainly localized in zones 1 (periportal zone) and 2 (intermediate zone). In 5 males of 30 ppm group and in one male of 100 ppm group, fatty change was noted also in zone 3 (zone surrounding terminal hepatic venule). Generally, the severity of fatty change was higher in males than in females. In females, the severity of fatty change was similar in all groups. In males, the severity of fatty change was less in 100 ppmgroup when compared with the rats of the other groups.

Histopathological findings: neoplastic:

no effects observed

Key result

Dose descriptor:

NOAEC

Effect level:

0.075 mg/L air (nominal)

Sex:

male/female

Basis for effect level:

other: Local effects: degeneration of the olfactory epithelial layer in the cranial part of the nasal cavity

Dose descriptor:

LOAEC

Effect level:

0.226 mg/L air (nominal)

Sex:

male/female

Basis for effect level:

other: Local effects: degeneration of the olfactory epithelial layer in the cranial part of the nasal cavity

Dose descriptor:

NOAEC

Effect level:

0.226 mg/L air (nominal)

Sex:

male/female

Basis for effect level:

other: Systemic effects: Clinical chemistry: elevated activities of transaminase and alkaline phosphatase

Dose descriptor:

LOAEC

Effect level:

0.753 mg/L air (nominal)

Sex:

male/female

Basis for effect level:

other: Systemic effects: Clinical chemistry: elevated activities of transaminase and alkaline phosphatase

Critical effects observed:

not specified

Concentrations in the inhalation chambers:

A study mean with standard deviation was calculated from the daily means of the individual chamber concentrations of the test groups:
		Concentration
     Nominal		       Measured
 [ppm]	[mg/L]		[ppm]    	[mg/L]
----------------------------------------------
  10	0.075		9.9 ± 0.47	0.0745
  30    0.226		30 ± 1.7	0.226
 100    0.753		100 ± 4.6	0.753
----------------------------------------------

Conclusions:

In this subchronic repeated dose study by the inhalation route a NOAEC of 0.075 mg/l (10 ppm) was determined in rats for local effects (degeneration of the olfactory epithelial layer in the cranial part of the nasal cavity). The respective NOAEC for systemic effects was 0.226 mg/l (30 ppm) based on clinical chemistry (elevated activities of transaminase and alkaline phosphatase).

Executive summary:

In a valid 90-day inhalation study, Wistar rats were administered in a whole-body exposition on 6 hours per day, 5 days per week, to 2-EHA vapour at concentrations of 0 ppm, 10 ppm, 30 ppm or 100 ppm (approximately 0.075 mg/l, 0.226 mg/l or 0.753 mg/l for the treatment groups) (2-EHA purity 99.7 %). The study design was conducted according to OECD 413 (1981).

Clinical observations:

There were no treatment-related premature deaths. Repeated exposure to 10 ppm was tolerated without signs by male and female Wistar rats. At 30 ppm and 100 ppm the clinical signs (eyelid closure, lethargy) were not very pronounced and possibly point to the irritant effect of the 2-EHA vapors.. Body weight gain was lower in both sexes of the high dose during and at the end of the study. A transiently reduced body weight gain was observed in mid dose females. From day 21 onwards mean body weight (absolute) was lower in high dose males compared to the control group. This parameter was not significantly altered in any other group at any time point during the study.

Clinical-chemical changes:

In the 100 ppm dose group an increase in the glutamic-pyruvic transaminase and alkaline phosphatase activities of the female rats as well as in some cases a reduction of total protein values and albumin concentrations were described. These effects were considered to be the only systemic ones of toxicological significance.

Gross Pathology:

The only effect of the test substance found on gross pathological assessment of the male animals in the 100 ppm group was a dark coloration of the liver parenchyma associated with indistinct lobular marking This finding is attributable to the decrease in the liver lipid content and is a consequence of the reduction in body weight.

Histopathology:

The inhalation of 2-EHA in rats was associated with degeneration of the olfactory mucosa in the dorsal and dorsolateral areas of the anterior parts of the nasal cavity. In 100 ppm group, the degenenation is considered to be treatment-related. In 30 ppm group , the degeneration was mainly minimal and similar to the histopathologic changes diagnosed in affected rats of the 10 ppm group and 0 ppm group (control). However, the incidence of degeneration was higher in mid group.

Slight to moderate hepatic fatty change in males and minimal to slight hepatic fatty change in females was a common finding in rats of all dose groups. In the males of 100 ppm group, the severity of the fatty change was less than in the rats of the other dose groups. This finding was compatible with the macroscopic findings in the liver of the rats of 100 ppm group (darker than normal, less distinct lobular pattern). This effect in the males of 100 ppm group is also considered to be related to the inhalation of the test article. However, this effect is presumed not to be a direct toxic effect of the test article, but rather reflect the poor body condition of the rats. A specific target organ could not be identified, electron microscopical examinations revealed no indication for peroxisome proliferation.

The other lesions noted in this study are not considered to be related to treatment.

NOAEC local effects: 0.075 mg/l (10 ppm)

NOAEC systemic 0.226 mg/l (30 ppm)

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

NOAEC

75 mg/m³

Study duration:

subchronic

Species:

rat

Quality of whole database:

It is a reliable study with a klimisch score of 2.

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

Combined Repeated Dose Toxicity Study with the Reproduction / Developmental Toxicity Screening Test, OECD 422 (read-across with Lauryacrylate 1214)

The objective of the study was to detect possible effects of the test substance on the integrity and performance of male and female reproductive systems including gonadal function, mating behavior, conception, gestation and parturition. Furthermore, it was intended to obtain information about the general toxicological profile including target organs and the no observed adverse effect level (NOAEL) after repeated oral administration. The duration of treatment covered a 2-week pre-mating and mating period in both sexes, approximately 1 week post-mating in males, and the entire gestation period as well as 4 days of lactation and two weeks thereafter in females.

Lauryacrylate 1214 was administered orally via gavage to groups of 10 male and 10 female Wistar rats at dose levels of 0, 100, 300 and 1000 mg/kg bw/d (respectively test groups 0,1,2 and 3).

Regarding clinical examinations, no signs of general systemic toxicity were observed in male or female parental animals of test groups 1-3 during the entire study period. Regarding clinical pathology, no treatment-related, adverse effects were observed up to a dose of the compound of 1000 mg/kg bw/d. Regarding pathology, the liver of male animals of test group 2 and 3 (300 and 1000 mg/kg bw/day, respectively) showed an increase in absolute (group 3 only) and relative weights which was regarded to be adaptive and non-adverse in the absence of histological findings.

The NOAEL (no observed adverse effect level) for general systemic toxicity was 1000 mg/kg bw/d.

90 -day repeated dose toxicity: Inhalation (read-across with 2 -ethylhexyl acrylate)

In a valid 90-day inhalation study (BASF, 1989) Wistar rats were administered in a whole-body exposition on 6 hours per day, 5 days per week, to 2-EHA vapour at concentrations of 0 ppm, 10 ppm, 30 ppm or 100 ppm (approximately 0.075 mg/l, 0.226 mg/l or 0.753 mg/l for the treatment groups) (2-EHA purity 99.7 %). The study design was conducted according to OECD 413 (1981).

Clinical observations:

There were no treatment-related premature deaths. Repeated exposure to 10 ppm was tolerated without signs by male and female Wistar rats. At 30 ppm and 100 ppm the clinical signs (eyelid closure, lethargy) were not very pronounced and possibly point to the irritant effect of the 2-EHA vapors.. Body weight gain was lower in both sexes of the high dose during and at the end of the study. A transiently reduced body weight gain was observed in mid dose females. From day 21 onwards mean body weight (absolute) was lower in high dose males compared to the control group. This parameter was not significantly altered in any other group at any time point during the study.

Clinical-chemical changes:

In the 100 ppm dose group an increase in the glutamic-pyruvic transaminase and alkaline phosphatase activities of the female rats as well as in some cases a reduction of total protein values and albumin concentrations were described. These effects were considered to be the only systemic ones of toxicological significance.

Gross Pathology:

The only effect of the test substance found on gross pathological assessment of the male animals in the 100 ppm group was a dark coloration of the liver parenchyma associated with indistinct lobular marking This finding is attributable to the decrease in the liver lipid content and is a consequence of the reduction in body weight.

Histopathology:

The inhalation of 2-EHA in rats was associated with degeneration of the olfactory mucosa in the dorsal and dorsolateral areas of the anterior parts of the nasal cavity. In 100 ppm group, the degenenation is considered to be treatment-related. In 30 ppm group , the degeneration was mainly minimal and similar to the histopathologic changes diagnosed in affected rats of the 10 ppm group and 0 ppm group (control). However, the incidence of degeneration was higher in mid group.

Slight to moderate hepatic fatty change in males and minimal to slight hepatic fatty change in females was a common finding in rats of all dose groups. In the males of 100 ppm group, the severity of the fatty change was less than in the rats of the other dose groups. This finding was compatible with the macroscopic findings in the liver of the rats of 100 ppm group (darker than normal, less distinct lobular pattern). This effect in the males of 100 ppm group is also considered to be related to the inhalation of the test article. However, this effect is presumed not to be a direct toxic effect of the test article, but rather reflect the poor body condition of the rats. A specific target organ could not be identified, electron microscopical examinations revealed no indication for peroxisome proliferation.

The other lesions noted in this study are not considered to be related to treatment.

NOAEC local effects: 0.075 mg/l (10 ppm) / NOAEC systemic effects: 0.226 mg/l (30 ppm)

Justification for classification or non-classification

Based on the results, no classification for isodecyl acrylate is required for repeated toxicity according to the Regulation EC n°1272/2008.