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Description of key information

Key study: In a recently performed subchronic oral toxicity study in rats (OECD TG 408)  with additional neurotoxicity screening  in rats, the NOAEL for  systemic toxicity was determined to the highest dose administered, 500 mg/kg/d. There was no evidence for the induction of damage of the nerve system which was indicated in a former study (OECD TG 422) at a dose of 1000 mg/kg/d. The NOAEL for the repeated dose toxicity by oral gavage in the OECD TG 422 study was determined to be 200 mg/kg/day.
A repeated inhalation study in rats for 3 weeks revealed a NOEL of 100 ppm. Nose and eye irritation was observed at 250 ppm (LOEL).

Key value for chemical safety assessment

Repeated dose toxicity: via oral route - systemic effects

Link to relevant study records
Reference
Endpoint:
sub-chronic toxicity: oral
Type of information:
experimental study
Adequacy of study:
key study
Study period:
20 Febuary 2014 - 02 July 2014
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to
Guideline:
OECD Guideline 408 (Repeated Dose 90-Day Oral Toxicity in Rodents)
Version / remarks:
adopted on 21 September 1998
Qualifier:
according to
Guideline:
OECD Guideline 424 (Neurotoxicity Study in Rodents)
Version / remarks:
adopted on 21 July 1997
GLP compliance:
yes (incl. certificate)
Limit test:
no
Species:
rat
Strain:
Sprague-Dawley
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Harlan Italy S.r.l., San Pietro al Natisone (UD), Italy
- Age at study initiation: (P) Males/females: approximately 47-49 days old
- Weight at study acclimatisation: (P) 86 - 103 g (male and female)
- Fasting period before study:
- Housing: No more than 5 per cage of one sex in clear polysulphone soilid bottomed cages measuring 59.5X38X20 cm (Code 1354 G, suppied by Techniplast Gazzada S.a.r.l., Buguggiate, Varese, Italy). Each cage tray held absorbent material inside suitable bedding bags which were changed at least twice a week.
- Diet: ad libitum, commercially available laboratory rodent diet (4 RF 21, Mucedola S.r.l., Via G. Galilei, 4, 20019, Settimo Milanese (MI), Italy) throughout the sudy, except as indicated during week 13 of treatment, samples of blood were taken under conditions of food deprivation.
- Water: ad libitum, supplied via water bottles
- Acclimation period: approximately 3 weeks


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ±2 °C
- Humidity (%): 55 ±15 %
- Air changes (per hr): 15 - 20 air changes per hour
- Photoperiod (hrs dark / hrs light): 12 hrs dark/ 12 hrs light
Route of administration:
oral: gavage
Vehicle:
corn oil
Details on oral exposure:
PREPARATION OF DOSING SOLUTIONS: The test item was suspended in corn oil to give the required concentrations of 20, 40 and 100 mg/mL. The test-substance preparations were produced daily.
The test substance was administered as an suspension. It was administered orally by gavage at a dose volume of 5 mL/kg body weight.
Control animals received the vehicle alone at the same dose volume. The dose was administered to each animal on the basis of the most recently recorded body weight and the volume administered was recorded for each animal.
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
Prior to commencement of treatment the proposed formulation procedure was checked by chemical analysis to confirm that the method was
acceptable. Stability over a 24 hour period at room temperature was assessed for content check prior to the start of treatment. Samples of the
formulations prepared at weeks 1 and 13 were analysed to check the concentration and homogeneity. Results of all the analyses were within the limits of acceptance (85-115% for concentration and CV < 10% for homogeneity).
Duration of treatment / exposure:
For a minimum of 13 consecutive weeks followed by a recovery period of 4 weeks (for 5 males and 5 females of groups 1, 4, 5 and 8.
Animals of the main phase were dosed up until the day before necropsy.
Frequency of treatment:
daily, 7 days a week
Dose / conc.:
100 mg/kg bw/day (nominal)
Dose / conc.:
200 mg/kg bw/day (nominal)
Dose / conc.:
500 mg/kg bw/day (nominal)
No. of animals per sex per dose:
Main groups
Group Treatment (mg/kg/day) number of animals
--------------------------------------------------------------
1 0 15 males and 15 females
2 100 10 males and 10 females
3 200 10 males and 10 females
4 500 15 males and 15 females
----------------------------------------------------------------
Neuropathology groups
----------------------------------------------------------------
5 0 10 males and 10 females
6 100 5 males and 5 females
7 200 5 males and 5 females
8 500 10 males and 10 females
-----------------------------------------------------------------
Control animals:
yes, concurrent vehicle
Details on study design:
- Dose selection rationale: The dose levels of 100, 200 and 500 mg/kg/day were defined based on information from previous studies (see chapter 7.8).
Observations and examinations performed and frequency:
CAGE SIDE OBSERVATIONS: Yes (Mortality (all groups))
- Time schedule: daily
All observations were recorded for individual animals. Examination of individual animals for signs of reaction to treatment was carried out twice daily
once early in each working day and again in the afternoon. At weekends and on public holiday similar procedure was used except that the final check was carried out at ca. mid-day.

DETAILED CLINICAL OBSERVATIONS AND NEUROTOXICITY: Yes (main groups)
- Time schedule: All clinical signs were recorded for individual animals. Once before commencement of treatment and once daily during the study, each animal was subjected to a detailed clinical examination. Observations were performed at the same time interval each day, the interval was selected taking into consideration the presence of post-dose reactions. The signs “breathing difficulties” was not tabulated due to technical problems.

Once before commencement of treatment and once weekly thereafter during treatment period, the first 10 animals of each sex were given a detailed clinical examination. The same examination was carried out once during Week 4 of the recovery period in the recovery animals.. Animals were examined in an open arena for a minimum of three minutes.
Observed parameters, described by an evaluation scale, are indicated below:

Removal (from cage): Easy, Difficult, Very difficult
Handling reactivity: Normal, Slow, Moderate, Marked
Lachrymation: Absent, Slight, Marked
Palpebral closure: Absent, Slight, Moderate, Marked
Salivation: Absent, Slight, Marked
Piloerection: Absent, Present
Rearing: Absent, Intervals of number of times (i.e. 1-3, 4-7, 8-10)
Spasms: Absent, Tonic spasms, Clonic spasms, Tonic-clonic spasms
Myoclonia: Absent, Present
Mobility impairment: Absent, Slight, Moderate, Marked
Arousal (animal activity): Very slow, Slow, Normal, Moderate, Marked
Vocalisation: Absent, Present
Stereotypies: Absent, Present
Unusual respiratory pattern: Absent, Present
Bizarre behaviour: Absent, Present
Urination: Absent, Intervals of number of times (i.e. 1-3, 4-6)
Defecation: Absent, Intervals of number of times (i.e. 1-3, 4-6)
Tremors: Absent, Present
Gait (one of the following options): Normal
Ataxia (Slight, Moderate, Marked)
Hunched (Slightly, Moderately, Severely)
Pronation
Forelimbs drag (Slight, Moderate, Marked)
Hindlimbs drag (Slight, Moderate, Marked)

The test included observation of changes in gait and posture, reactivity to handling, presence of clonic or tonic movements, stereotypies or bizarre behaviour and effects on the autonomic nervous system (e.g. lachrymation, piloerection, unusual respiratory pattern). Changes in fur, skin, eyes, mucous membranes, occurrences of secretions and excretions were also recorded.
An evaluation of sensory reactivity to stimuli of different modalities (e.g.auditory, visual and proprioceptive stimuli), an assessment of grip strength
and motor activity were also performed in the same animals once before commencement of treatment and once during Weeks 1, 4, and 12 of treatment and Week 4 of recovery.

Motor activity assessment (MA)
The motor activity (MA) was measured by an automated activity recording over a period of 5 minutes.

BODY WEIGHT: Yes (all animals)
- Time schedule for examinations:
Each animal was weighed on the day of allocation to treatment group, on the day that treatment commenced, weekly thereafter and just prior to
necropsy.

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): Yes (all animals)
The weight of food consumed by each cage of rats was recorded at weekly intervals following allocation. The group mean daily intake per rat was
calculated. Food consumption of Groups 5, 6, 7 and 8 was inadvertently recorded on Day 72 (and not on Day 71 as for weekly schedule). Therefore,
in the report the food consumed on Day 71 was calculated over a period of 8 days and that for the subsequent week (78) over a 6 day period.
FOOD EFFICIENCY:
- Body weight gain in kg/food consumption in kg per unit time X 100 calculated as time-weighted averages from the consumption and body
weight gain data: No data

OPHTHALMOSCOPIC EXAMINATION: Yes
- Time schedule for examinations:Both eyes of all animals assigned to the study were examined just prior to the commencement of treatment by means of an ophthalmoscope, and by a slitlamp microscope, after the instillation of 0.5% Tropicamide (Visumidriatic®, Visufarma, Rome, Italy). The eyes of all animals from the high dose and control groups (Main groups) were re-examined during Week 13 of treatment.
- Dose groups that were examined: all animals

Both eyes of all animals assigned to the study were examined just prior to the commencement of treatment by means of an ophthalmoscope, and by
a slit-lamp microscope, after the instillation of 0.5% Tropicamide (Visumidriatic®, Visufarma, Rome, Italy). One animal with non-resolving lesions (No. 27580066) was replaced with a spare animal showing no ocular abnormality, from the batch initially ordered for the study. The eyes of all animals
from high dose and control groups were re-examined during week 13 of treatment.

HAEMATOLOGY: Yes (main groups)
- Time schedule for collection of blood: during week 13 of treatment prior to necropsy
- Anaesthetic used for blood collection: Yes (identity): isofluorane (identity: no data)
- Animals fasted: Yes
- How many animals: 10 male and 10 female animals from each group (main phase groups)
At the end of Week 4 of the recovery period, blood samples were also taken from all surviving animals under identical conditions in order to reevaluate haematology (except coagulation) and clinical chemistry parameters, since potential treatment-related changes were observed at measurements
performed during the treatment period.
- Parameters checked: The blood samples collected were divided into tubes as follows:
EDTA anticoagulant for haematological investigations
Heparin anticoagulant for biochemical tests
Citrate anticoagulant for coagulation tests

The measurements performed on blood samples are listed below:
-Haematology
Haematocrit
Haemoglobin
Red blood cell count
Reticulocyte count
Mean red blood cell volume
Mean corpuscular haemoglobin
Mean corpuscular haemoglobin concentration
White blood cell count
Differential leucocyte count - Neutrophils
- Lymphocytes
- Eosinophils
- Basophils
- Monocytes
- Large unstained cells
Abnormalities of the blood film
Platelets
Prothrombin time

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: during week 13 of treatment
- Animals fasted: Yes
- How many animals: all surviving animals
- Parameters checked: Clinical chemistry
Alkaline phosphatase
Alanine aminotransferase
Aspartate aminotransferase
Gamma-glutamyltransferase
Urea
Creatinine
Glucose
Triglycerides
Phosphorus
Total bilirubin
Total cholesterol
Total protein
Albumin
Globulin
A/G Ratio
Sodium
Potassium
Calcium
Chloride



Necropsy (main groups)
The clinical history of the animal was studied and a detailed post mortem examination was conducted (including examination of the external surface
and orifices). Changes were noted, the requisite organs weighed and the required tissue samples preserved in fixative and processed for
histopathological examination (see sections organ weights to Histopathological examination).

Organ weights (main groups)
From all animals of the main groups (main phase and recovery phase) completing the scheduled test period, the organs indicated in the table1 below were dissected free of fat and weighed. The ratios of organ weight to body weight were calculated for each animal.

Intravascular Perfusion in situ fixation - Neuropathology (Neuropathology groups)
Tissues from all animals of the neuropathology groups (main phase and recovery phase) were fixed in situ using an intravascular perfusion fixation
followed by an additional period of immersion post-fixation. Animals were anesthetised by intraperitoneal injection of penthotal sodium and perfused
using 10% neutral buffered formalin. Central and peripheral nervous system (CNS and PNS) organs/tissues, listed in Annex 2 of Study Protocol - Neuropathology continued the fixation in 10% neutral buffered formalin in order to allow the complete fixation. After fixation sampling of CNS and PNS
organs/tissues was performed and the brain was weighed (data not reported).

Tissues fixed and preserved
Samples of all the tissues listed in table 1 below were fixed and preserved in 10% neutral buffered formalin (except eyes, testes and epididymides which were fixed in Modified Davidson’s fluid and preserved in 70% ethyl alcohol).

Histopathological examination
The tissues required for the histopathological examination are listed in table 1 below. After dehydration and embedding in paraffin wax, sections of
the tissues were cut at 5 micrometre thickness and stained with haematoxylin and eosin.
The examination was as detailed below:
a) Tissues specified in table 1 below from 10 animals/sex in the control and high dose groups killed at the end of the 13 weeks of treatment.
b) All abnormalities in all groups.

The examination was then extended to include, from all other animals killed after 13 weeks of treatment and 4 weeks of recovery, liver and stomach in
which treatment-related changes were observed at the high dose level.

Histopathological examination - Neuropathology (Neuropathology groups)

Preparation of samples of CNS e PNS was performed following the indication reported in “Current Pathology Techniques” Symposium Review: Advances and Issues in Neuropathology – Toxicologic Pathology, 36: 871-889 2008. CNS and PNS samples were embedded in paraffin wax, sectioned at 4 mm and stained with haematoxylin and eosin and with special stain such as Cresyl violet, specific for neurons, and Luxol Fast Blue, specific for myelin.
The examination was as detailed below:
i Tissues specified in Table 2 of Study Protocol - Neuropathology (see below) from 5 animals/sex in the control and high dose groups killed
at the end of the 13 weeks of treatment (Neuropathology animals).

Table1: of study protocol (main groups)
---------------------------

Organs / Tissues Weight Fixation Microscopic
Preservation Examination
------------------------------------------------------------------------------------------------------
Abnormalities x x
Adrenal glands x x x
Aorta x x
Bone marrow (from sternum) x x
Brain (7 sections) x x x
Caecum x x
Colon x x
Duodenum x x
Epididymides x x x
Eyes x *
Femur with joint x *
Heart x x x
Ileum x x
Jejunum (including Peyer’s patches) x x
Kidneys x x x
Liver x x x
Lungs (including mainstem bronchi) x x
Lymph nodes - cervical x x
Lymph nodes - mesenteric x x
Mammary area x x
Oesophagus x x
Ovaries x x x
Oviducts (a) x
Pancreas x x
Parathyroid glands (b) x x
Pituitary gland x x
Prostate gland x x
Rectum x x
Salivary glands x x
Sciatic nerve x x
Seminal vesicles x *
Skeletal muscle x *
Skin x x
Spinal column x
Spinal cord (cervical, thoracic, lumbar) x x
Spleen x x x
Stomach x x
Testes x x x
Thymus (where present) x x x
Thyroid x x
Trachea x x
Urinary bladder x x
Uterus - cervix x x x
-----------------------------------------------------------------------------------------------------------
*: not examined as no signs of toxicity or target organ involvement were observed
a: weighed and preserved with ovaries
b: preserved with thyroid gland

Table 2 of Study Protocol
(Neuropathology Groups)

Organs / Tissues Weight Fixation Preservation Microscopic Examination
----------------------------------------------------------------------------------------------------------------
Brain (Cerebellum, Frontal Lobe,
Hippocampus, Midbrain, Medulla x x x
Oblongata, Parietal Lobe, Pons)

Diaphragm (transversal and longitudinal) x x Cervical ganglia (Ganglion Dorsal
Root Cervical and Ganglion x x Dorsal Root Lumbar)
Eyes with optic nerves x x
Gasserian ganglia (Ganglion
Gasserian) x x
Skeletal muscle x x
Lumbar ganglia (Nerve Root Dorsal
Cervical,
Nerve Root Dorsal Lumbar, x x
Nerve Root Ventral Lumbar,
Nerve Root Ventral Cervical)
Spinal cord (cervical, thoracic, lumbar)
Sciatic nerve (proximal, transversal
and longitudinal) x x
Tibial nerve (Tibial Nerve Distal,
Tibial Nerve Proximal) x x
-----------------------------------------------------------------------------------------------------------------
Sacrifice and pathology:
GROSS PATHOLOGY: Yes (see table 1 section Observation and examinations performed and frequency)
HISTOPATHOLOGY: Yes (see table 1 section Observation and examinations performed and frequency)
Statistics:
For continuous variables the significance of the differences amongst groups was assessed by analysis of variance. Differences between each treated group and the control group were assessed by Dunnett's test using a pooled error variance. The homogeneity of the data was verified by Bartlett's
test before Dunnett's test. If data were found to be inhomogeneous a Modified t test (Cochran and Cox) was applied. The mean values, standard
deviations and statistical analysis were calculated from the actual values in the computer without rounding off. Statistical analysis of histopathology
findings were carried out by means of the non-parametric Kolmogorov-Smirnov test.
Clinical signs:
effects observed, treatment-related
Description (incidence and severity):
no mortality, no systemic toxicity
Mortality:
mortality observed, treatment-related
Description (incidence):
no mortality, no systemic toxicity
Body weight and weight changes:
no effects observed
Food consumption and compound intake (if feeding study):
no effects observed
Food efficiency:
not specified
Ophthalmological findings:
no effects observed
Haematological findings:
effects observed, treatment-related
Clinical biochemistry findings:
effects observed, treatment-related
Description (incidence and severity):
Increase of phosphorous in a number of animals (not dose-dependent) Increse in urea in animals of the high dose group
Behaviour (functional findings):
no effects observed
Organ weight findings including organ / body weight ratios:
effects observed, treatment-related
Description (incidence and severity):
Slight increases in kidney and liver weights in mid- and high dose females
Gross pathological findings:
effects observed, treatment-related
Description (incidence and severity):
effects of inflammation in the stomach of a single high-dose male
Histopathological findings: non-neoplastic:
no effects observed
Histopathological findings: neoplastic:
not examined
Details on results:
CLINICAL SIGNS AND MORTALITY
No mortality occurred during the study.

Convulsions were occasionally observed during the treatment period in individual animals from the mid- and low dose groups, in the high dose males
(2/15 from Group 4, 1/10 from Group 8) and high dose females (8/15 from Group 4, 4/10 from Group 8). Convulsions were occasionally associated
with salivation in some of the animals. Single episodes of ataxia, breathing difficulties or red discharge from mouth were also observed.
No clinical signs were observed during the 4 week recovery period.

Weekly detailed clinical signs (Removal from cage and Open field measurements)
No changes of note were found at the weekly clinical examination which included an evaluation of neurotoxicity during treatment and recovery periods.

Neurotoxicity assessment (Functional Tests and Motor activity)
No differences between treated animals and controls which could be considered treatment-related were observed at functional tests (sensory reactivity, landing footsplay, grip strength) and motor activity measurements performed during treatment and recovery periods.

BODY WEIGHT AND WEIGHT GAIN
No treatment-related changes were observed in body weights during treatment and recovery periods.
Body weight gain was comparable between treatment and control groups..

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study)
No significant changes were observed in food consumption.

FOOD EFFICIENCY
No data

OPHTHALMOSCOPIC EXAMINATION
No findings were seen at the ophthalmic examination.

HAEMATOLOGY
Treatment Phase
Lymphocytosis and monocytosis were recorded at the end of treatment in many animals treated with 200 and 500 mg/kg/day.
Recovery Phase
Lymphocytosis and monocytosis were still observed in the females and in one male at the end of recovery.
Coagulation
No changes of toxicological relevance were observed during the treatment period of the study.

CLINICAL CHEMISTRY
Treatment Phase
Increase of phosphorus was recorded in a number of males from all treated groups (with no dose-relation) and in females dosed with 200 and 500
mg/kg/day. In addition, urea was increased in animals of both sexes dosed with 500 mg/kg/day.
No other changes of toxicological significance were observed.
Recovery Phase
Phosphorus was still higher than controls in treated animals.
No other relevant changes were recorded.

MACROSCOPIC OBSERVATION
Thickening and oedematous consistency of the non-glandular region of the stomach was observed in a single high dose male. No changes were observed at necropsy at the end of recovery.

MICROSCOPIC OBSERVATION
The exposure to the test item resulted in different size and tissue distribution of hepatocytic vacuolation in treated males and females when compared to the corresponding controls.
However such liver changes were considered functional and not adverse.
Several males and females showed changes in the stomach such as squamous hyperplasia or ulceration in the non-glandular region of the stomach, or erosion in the glandular region of the stomach, which could be attributed to gavage procedure.

Microscopic examination (Neuropathology groups)
The exposure to the test item at the high dose level did not produce any neuropathological changes. Therefore, under the conditions of this experiment the test item was devoid of pathologic neurotoxic effects.
Dose descriptor:
NOAEL
Remarks:
systemic
Effect level:
500 mg/kg bw/day (nominal)
Based on:
test mat.
Remarks:
suspended in corn oil
Sex:
male/female
Basis for effect level:
other: no effects observed
Critical effects observed:
no
Conclusions:
On the basis of the above results, minor signs of possible treatment-related effects of the test item, Dimethylaminoethyl methacrylate, were observed at in vivo and at post mortem in male and female rats only at the dose levels of 200 and 500 mg/kg/day, when administered by oral gavage for 13 consecutive weeks at the dosages of 100, 200 and 500 mg/kg/day. None of them was considered to be systemically adverse.
No changes indicating a neuropathological effect of the treatment with the test item were observed at any of the dose levels tested.
No significant changes or relevant signs of systemic toxicity were observed in the animals dosed up to 500 mg/kg/day.
Therefore, the high dose of 500 mg/kg/day, when administered daily for 13 consecutive weeks, was considered the No Observed Adverse
Effect Level (NOAEL) of systemic long-term toxicity.
Level (NOAEL).
Executive summary:

The oral toxicity of Dimethylaminoethyl methacrylate (CAS 2867 -47 -2, Purity: 99.79%) when given by daily administration to rats, has been investigated over a period of 13 consecutive weeks and recovery from any treatment-related effects during a treatment-free period of 4 weeks. Three groups, each of 10 male and 10 female Sprague Dawley rats, received the test item by gavage at dosages of 100, 200 and 500 mg/kg/day for 13 consecutive weeks. A fourth similarly constituted group received the vehicle alone (corn oil) and acted as a control. Additional five male and 5 female animals were included in separate groups for neuropathology investigations. Control and high dose main and neuropathology groups included each 5 additional animals per sex to be sacrificed after 4 weeks of recovery.

Minor signs of possible treatment-related effects of the test item, Dimethylaminoethyl methacrylate, were observed at in vivo and at post mortem in male and female rats only at the dose levels of 200 and 500 mg/kg/day, when administered by oral gavage for 13 consecutive weeks at the dosages of 100, 200 and 500 mg/kg/day. None of them were considered to be systemically adverse.

No changes indicating a neuropathological effect of the treatment with the test item were observed at any of the dose levels tested.

No significant changes were observed in the animals dosed at 100 mg/kg/day.

Therefore, the high dose of 500 mg/kg/day, when administered daily for 13 consecutive weeks, was considered the No Observed Adverse Effect Level (NOAEL) for systemic long-term toxicity.

This study is acceptable and satisfies the guideline requirement for a 13 week oral toxicity study (OECD 408) in rats.

(NOTE: Any of the data in this dataset are disseminated by the European Union on a right-to-know basis and this is not a publication in the sense of a book or an article in a journal. The right of ownership in any part of this information is reserved by the data owner(s). The use of this information for any other, e.g. commercial purpose is strictly reserved to the data owners and those persons or legal entities, who have paid the respective access fee for the intended purpose.)

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed
Dose descriptor:
NOAEL
500 mg/kg bw/day
Study duration:
subchronic
Species:
rat
Quality of whole database:
Guideline study, performed in 2014; valid without restriction (Klimisch 1)

Additional information

Four studies of varied validity have been evaluated. In these studies the test substance was administrated by the oral, dermal or inhalation route, respectively. The oral study by the Ministry of Health and Welfare, Japan, was identified as reliable because it was conducted according to OECD guideline 422 in compliance with GLP (MHW Japan, 1998).

The key study is a recently performed 90 d oral toxicity study in rats according to OECD TG 408, the NOEAL for systemic toxicity was determined to 500 mg/kg/d, the highest dose administered.

The reliability of the dermal study (Manabe, 1990) is not assignable because no sufficiently detailed data were available for assessment. Therefore, this study was omitted from assessment. The results of the inhalation study were estimated to be reliable, and this study was identified as a key study (Gage, 1970).

Oral exposure:

In the key study, only minor signs of possible treatment-related effects of the test item, Dimethylaminoethyl methacrylate, were observed at in vivo and at post mortem in male and female rats only at the dose levels of 200 and 500 mg/kg/day, when administered by oral gavage for 13 consecutive weeks at the dosages of 100, 200 and 500 mg/kg/day. None of them was considered to be systemically adverse.

No changes indicating a neuropathological effect of the treatment with the test item were observed at any of the dose levels tested.

No significant changes or relevant signs of systemic toxicity were observed in the animals dosed up to 500 mg/kg/day.

Therefore, the high dose of 500 mg/kg/day, when administered daily for 13 consecutive weeks, was considered the No Observed Adverse Effect Level (NOAEL) of systemic long-term toxicity.

In a second study which was performed according to OECD guideline 422, rats were administrated with gavage doses of 0 40, 200, and 1000 mg/kg/day. The dosing periods were 43 days for males and 41 to 52 days (from 14 days before mating to day 3 of lactation) for females, respectively. The NOAEL for the repeated oral dose toxicity is considered to be 200 mg/kg/day for both sexes.

Inhalation exposure:

The subacute vapour inhalation toxicity of the test substance was studied in rats with a constant flow pump for 3 weeks, 5 days/week, 6 hours/day (Gage, 1970). At 250 ppm (1606 mg/m³), nose and eye irritation and labored breathing were observed. The body weight gain was slow. No changes in haematological parameters were observed. No pathological (macroscopical and microscopical) effects on organs were observed. At 100 ppm (643 mg/m³), no toxic effects were observed. The NOAEL for repeated inhalation toxicity is considered to be 100 ppm (643 mg/m³).

Justification for classification or non-classification

EU classification according to Annex VI of the Directive 67/548/EEC:

- No classification required.

GHS classification according to Annex I 1272/2008 CLP (EU GHS):

- No classification required.