2-isopropyl-N-hydroxyethyl 1,3-oxazolidine;methyl carbonato-N-ethyl-2-isopropyl-1,3-oxazolidine;reaction mass of: carbonato-bis-N-ethyl-2-isopropyl-1,3-oxazolidine

Endpoint summary

Description of key information

A 28d repeated dose oral toxicity study was performed in rats. Most of the reactions of the rat to Incozol L.V. were of an adaptive rather than toxicological nature. The body weight, spinal cord vacuolation and forestomach gastritis in the intermediate and high dose levels are the only toxicological findings. Since the test article is known to degrade in a number of liquid vehicles, the poor stability means that the actual dosed amount cannot be determined. Therefore, the no observable adverse effect limit (NOAEL) may need to be based on target concentration, 150 mg/kg bw/day.

Key value for chemical safety assessment

Toxic effect type:

dose-dependent

Repeated dose toxicity: via oral route - systemic effects

Link to relevant study records

Reference

Endpoint:

short-term repeated dose toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

from 1998-06-24 to 1999-02-17

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 407 (Repeated Dose 28-Day Oral Toxicity Study in Rodents)

Version / remarks:

adopted: 1995

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.7 (Repeated Dose (28 Days) Toxicity (Oral))

Version / remarks:

cited as: Directive 92/69/EEC

Deviations:

no

GLP compliance:

yes

Limit test:

no

Species:

rat

Strain:

other: Hsd:Brl:WH

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Harlan UK Ltd., Bicester
- Age at study initiation: 7 weeks old
- Weight at study initiation: their body weight was within ±20 % of the overall mean for each sex
- Fasting period before study: yes
- Housing: stainless steel mesh cages of size 30 x 28 x 24cm, floor area 840 cm2
- Diet: ad libitum to SQC Rat and Mouse Maintenance Diet No 1, Expanded (Special Diets Services Ltd. Witharn).
- Water: ad libitum, tab water
- Acclimation period: about 2 weeks

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19 to 25 °C
- Humidity (%): 40 to 70 %
- Air changes: 15 air changes/hour
- Photoperiod: 12 hours light (06:00 to 18:00) and 12 hours dark.

Route of administration:

oral: gavage

Vehicle:

corn oil

Details on oral exposure:

- Method of administration: Gavage

Analytical verification of doses or concentrations:

yes

Duration of treatment / exposure:

28 days

Frequency of treatment:

Dosing regime: 7 days/week

Dose / conc.:

0 mg/kg bw/day (actual dose received)

Dose / conc.:

150 mg/kg bw/day (actual dose received)

Dose / conc.:

500 mg/kg bw/day (actual dose received)

Dose / conc.:

1 000 mg/kg bw/day (actual dose received)

No. of animals per sex per dose:

5 male and 5 female animlas per dose

Control animals:

yes, concurrent vehicle

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: Observations (Weekly)
Before being removed from the home cage, the animal was observed and evaluated for the following: Posture, Convulsion, Arousal, Excessive vocalisation, Gait, Arousal upon opening cage, Tremor
Each animal was removed from its cage, and observed for the following: Ease of removal, Ease of Handling, Excessive vocalisation, Tremor, Convulsion, Palpebral, closure, Exophthalmus, Lacrimation, Lacrimation type, Salivation, Respiration, Piloerection, Appearance of fur
Motor activity (Week 4 only):
Motor activity of each animal was assessed in an automated photocell activity recorder for 30 min. Activity counts were recorded at 2 min intervals


DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: All animals were observed daily for signs of ill health or overt toxicity. In addition, each animal was given a detailed physical examination at weekly intervals. An individual record was maintained of the clinical condition of each animal.

BODY WEIGHT: Yes
- Time schedule for examinations: Individual body weights were recorded before treatment on the first day of dosing, at weekly intervals and before necropsy.

FOOD CONSUMPTION AND COMPOUND INTAKE:
The amount of food consumed by each animal was determined weekly. Consumption was calculated as g/animal/week.

FOOD EFFICIENCY: No

HAEMATOLOGY: Yes
- Time schedule for collection of blood: Blood samples (3 x 0.5 mL nominal) were withdrawn from all animals during Week 4
- Anaesthetic used for blood collection: No
- How many animals: all
- Parameters checked:
The following parameters were determined on blood taken into EDTA anticoagulant: haemoglobin concentration, packed cell volume, red blood cell count, mean cell volume, mean cell haemoglobin, reticulocytes, platelet count, mean cell haemoglobin concentration, total and differential white cell count
Bone Marrow
Bone marrow smears were prepared at necropsy. They were fixed in methanol and examined by a haematologist.

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: Blood samples (3 x 0.5 mL nominal) were withdrawn from all animals during Week 4
- How many animals: all animals
The following parameters were determined on plasma derived from whole blood collected into lithium heparin anticoagulant:
aspartate, aminotransferase, alkaline phosphatase potassium, inorganic phosphorus, total protein, globulin, total cholesterol, urea, creatinine, alanine aminot, ransferase, Sodium, Calcium, Chloride ,,Albumin ,albumin/globulin ratio ,Glucose, total bilirubin

URINALYSIS: No

NEUROBEHAVIOURAL EXAMINATION: Yes
- Time schedule for examinations: before initiation of treatment, and once weekly thereafter
- Dose groups that were examined: all dose groups
- Battery of functions tested: sensory activity / grip strength and motor activity

Sacrifice and pathology:

GROSS PATHOLOGY: Yes
-Parameters: external surfaces of the body and all viscera
- Fresh organ weights: liver, kidneys, adrenal glands, testes with epididymides, ovaries, spleen, thymus, thyroids, brain and heart of all animals. Paired organs were weighed together.
- Preserved from all animals: Adrenals, Animal identification, Blood sample, Bone marrow smear (femur), Brain ,Bronchial, lymnh nodes, Caecum, Colon, Sciatic nerves, Eyes, Femur with bone marrow and articular surface, Gross lesions, Harderian glands, Head, Heart, Ileum, Jejunum, Kidney, Lacrimal glands, Larynx, Liver, Lungs, Mammary, Mandibular Iymoh nodes, Mesenteric lymoh nodes, Muscle (quadriceps), Nasal Turbinates, Nasopharynx , Oesophagus, Optic nerves , Ovaries, Pancreas, Pevers patches, Pituitary, Prostate, Rtectum, Salivary glands, Seminal vesicles, Skin , Spinal cord cervica, Spinal cord lumbar, Spinal cord thoracic, Spleen, Sternum with bone marrow, Stomach, Testes + epididymicisa, Thymus , Thyroids + parathyroids Tongue , Trachea , Trachea bifurcation , Urinary bladder , Uterus , Vagina , Zymbal glands

HISTOPATHOLOGY: Yes
Investigated: All tissues and organs collected at necropsy from all animals

Statistics:

Body weight gains, necropsy body weight, haematology, myelograms, clinical chemistry, locomotor activity and FOB data were analysed using two-way analysis of variance (ANOVA). Pair wise comparisons, for each sex separately, were made using Dunnett's test. For each sex separately, a regression test was performed to determine whether there was a linear relationship between increasing dose and response. Where it showed a significant result (P<0.05) and any of the pair wise comparisons were also significant, the regression result was not reported. Levene's test for equality of variances across groups, between sexes and for any interaction was also performed. Where these tests showed evidence of a sex effect only (P<0.01), the data were re-analysed using one-way ANOVA, separately for each sex. One-way ANOVA was also used where data for only one sex were suitable for analysis. For the one-way ANOVAs, pair wise comparisons with control were made using Dunnett's test. A regression test was performed to determine whether there was a linear relationship between increasing dose and response. Where it showed a significant result (P<0.05) and any of the pair wise comparisons were also significant, the regression result was not reported. Levene's test for equality of variances among the groups was also performed and in all cases this showed no evidence of heterogeneity (P>0.01). Organ weights were analysed using Analysis of Covariance (ANCOVA) and Dunnett's test, using the necropsy body weight as covariate. This analysis depends on the assumption that the relationship between the organ weights and the covariate is the same for all groups, and the validity of this assumption was tested. Levene's test for equality of variances among the groups was also performed for all organ weights and in all cases this showed no evidence of heterogeneity (P>0.01).

Clinical signs:

no effects observed

Description (incidence and severity):

There were no clinical signs of toxicity, including no effect during the functional observation battery of tests..

Mortality:

no mortality observed

Description (incidence):

No mortality occurred.

Body weight and weight changes:

no effects observed

Description (incidence and severity):

Top dose animals showed small (16 %) decreases in weight gain.

Food consumption and compound intake (if feeding study):

no effects observed

Description (incidence and severity):

There was no effect on food consumption for either sex.

Food efficiency:

not examined

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

not examined

Ophthalmological findings:

not examined

Haematological findings:

effects observed, treatment-related

Description (incidence and severity):

Decrease in haemoglobin concentration, red blood cell count and packed cell volume. The most marked effect was seen in females.
There was a decrease in haemoglobin concentration (P<0.001), red blood cell count (P<0.001) and packed cell volume (P<0.001) parameters in the high dose of both sexes, the most marked effect was seen in females. The male and female intermediate dose haemoglobin concentration (P<0.001) and packed cell volume (P<0.001) and the female intermediate dose red blood cell count (P<0.001) were also decreased. Other minor statistically significant changes were considered not to be of toxicological importance. There were decreases in high dose male (P<0.05) and intermediate dose male (P<0.01) absolute neutrophil counts and decreases in high (P<0.001) and intermediate (P<0.001) dose monocytes. Additionally, there was a slight decrease in high dose female total white blood cell count. Other minor statistically significant changes were considered not to be of toxicological importance.

Clinical biochemistry findings:

effects observed, treatment-related

Description (incidence and severity):

Increase of alkaline phosphatase in high dose group, a dose-related increase in aspartate aminotransferase.
When compared to control animals, there was an increase of alkaline phosphatase in high (P<0.01) and intermediate (P<0.01) dose males. Additionally, there was a dose-related increase in aspartate aminotransferase in the high and intermediate dose males. The aspartate aminotransferase of the high dose females also increased (P<0.01). Urea levels for high dose males were observed to have increased but this effect was not as clearly demonstrated in high dose females. Total cholesterol levels of high (P<0.001) and intermediate (P<0.01) dose males and high dose females (P<0.001) had decreased.

Urinalysis findings:

not examined

Behaviour (functional findings):

no effects observed

Description (incidence and severity):

There were no findings in the functional observational battery that could be related to test article administration.

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Description (incidence and severity):

The weights of liver and kidneys of high and intermediate dose animals had increased with varying statistical significances which are presented in the table. Other minor statistically significant changes were considered not to be of toxicological importance.

Gross pathological findings:

effects observed, treatment-related

Description (incidence and severity):

Dose-related changes were found in the stomach and liver. Yellow appearance, thickening and raised or irregular surface were found in the stomach of two low, five intermediate and six high dose animals. Pallor of the liver was noted in two intermediate and three high dose animals and large liver in one intermediate and one high dose animal. These macroscopic findings correlated with those seen microscopically. The majority of the other organs and tissues examined were generally unremarkable. Findings which occurred were generally minor and consistent with the expected spectrum of gross findings in rats of this strain and age.

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Description (incidence and severity):

The main dose-related changes in most treated animals were in the stomach, liver, kidney, thyroid and spinal nerve roots. Dose-related forestomach gastritis was seen in intermediate and high dose animals. The gastritis was characterised by diffuse squamous cell hyperplasia and slight oedema/inflammation of the submucosa, with erosion/ulcer in one high dose female. Liver changes consisted of periportal vacuolation and centrilobular hypertrophy. Periportal vacuolation was characterised by vacuoles of varying size within the hepatocyte cytoplasm. Vacuolation was seen in all the high dose males and to a lesser extent in the low and intermediate dose males. No clear cut dose-related effect was seen in females. Centrilobular hypertrophy was characterised by increased hepatocyte cell size with an eosinophilic staining cytoplasm. Hypertrophy was evident in intermediate and high dose animals, notably females. These findings correlated with the increase in liver weight in high and intermediate dose animals and with the pallor noted macroscopically.
Kidney changes in males consisted of cortical tubular vacuolation of the proximal convoluted tubules of the pars recta in some low and all intermediate and high dose males. Additionally, hyaline droplets, which appear as eosinophilic cytoplasmic inclusions in the proximal tubular epithelial cells, were present in all control and some low dose males, but were absent in the high and intermediate dose males. Vacuolation was also found in most treated females, but cortical tubular basophilia of this region also occurred in all high and intermediate dose females. Single cell necrosis was occasionally found in these basophilic tubules of female rat kidneys. Thyroid follicular cell hypertrophy was apparent to a minor extent in all high dose animals and two intermediate dose males, and was characterised by an increase in the height of follicular epithelial cells and a relative decrease in the amount of colloid. Spinal nerve root vacuolation was apparent in all high dose and two intermediate dose animals, and was characterised by vacuoles in the spinal nerve roots, which appeared to arise from separation or splitting of the myelin sheath. No changes were found in the sciatic nerve.

Histopathological findings: neoplastic:

no effects observed

Key result

Dose descriptor:

NOAEL

Effect level:

150 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: body weight, spinelcord vacuolation and forestomach gastritis in intermediate and high dose level.

Dose descriptor:

NOEL

Effect level:

< 150 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: body weight, spinelcord vacuolation and forestomach gastritis in intermediate and high dose level.body weight, spinelcord vacuolation and forestomach gastritis in intermediate and high dose level.

Key result

Critical effects observed:

not specified

The liver changes appear to be adaptive, and no histological alterations were found to reflect the changes in haematology and clinical chemistry. The thyroid changes may possibly relate to the liver changes. The gastritis was due to local irritation. Although other findings were noted in kidney and spinal root, these were absent or less frequently found at 150 mg/kg/day, and therefore classification is not justified.

Conclusions:

Most of the reactions of the rat to Incozol L.V. were of an adaptive rather than toxicological nature. The body weight, spinal cord vacuolation and forestomach gastritis in the intermediate and high dose levels are the only toxicological findings. Since the test article is known to degrade in a number of liquid vehicles, the poor stability means that the actual dosed amount cannot be determined. Therefore, the no observable adverse effect limit (NOAEL) may need to be based on target concentration, 150 mg/kg/day.

Executive summary:

A study was conducted according to OECD TG 407 and Directive 92/69/EEC method B.7 to assess the repeated dose toxicity of Incozol LV to the rat. Therefore 4 groups of 5 male and 5 female animals were administrated to 0, 150, 500 and 1000 mg/kg bw/day doses of Incozol LV.

The animals tolerated the administered doses of Incozol L.V. for 4 weeks and showed no adverse clinical signs. Although, the formulations were found to be homogenous they were not stable and achieved concentration analysis results were generally below the acceptable range for this laboratory (90 to 110 % of nominal). However, due to known reactivity of the test article i.e. moisture scavenger and its reactivity with a number of liquid vehicles and solvent systems (reactions with hydroxyl groups) it is highly likely that the test article rapidly degraded. The analytical procedure used in this study was not designed to specifically determine any degradation products from the parent compound. Therefore, it cannot be determined whether the animals received the intended doses described above.

Administration of the test article did not have an effect on body weight gain in the low and intermediate dose animals. However, the high dose males gained less weight than controls particularly in the second two weeks of the study. Overall, there was a dose related decrease in body weight gains in the females, with the largest decrease in weight gain occurring in the second two weeks of the study.

There was no effect on food consumption and there were no findings in the functional observational battery that could be related to test article administration.

 

 

Haemoglobin concentration, red blood cell count and packed cell volume parameters had decreased in the high dose of both sexes; the most marked effect was seen in females. The male and female intermediate dose haemoglobin concentration and packed cell volume and the female intermediate dose red blood cell count were also decreased. However, there was no change in the myelograms.

There were decreases in high dose male and intermediate dose male absolute neutrophil counts and decreases in high and intermediate dose monocytes. Additionally, there was a slight decrease in high dose female total white blood cell count.

When compared to control animals, there was an increase of alkaline phosphatase in high and intermediate dose males. Additionally, there was a dose-related increase in aspartate aminotransferase in the high and intermediate dose males. The aspartate aminotransferase of the high dose females also increased. Total cholesterol levels of high and intermediate dose males and high dose females had decreased. These changes correlate with adaptive changes in the liver, i.e. enzyme induction and lipid metabolism.

The weights of liver and kidneys of high and intermediate dose animals had increased.

At necropsy, yellow appearance, thickening and raised or irregular surface were found in the stomach of two low dose, five intermediate dose and six high dose animals. Pallor of the liver was noted in two intermediate dose and three high dose animals and large liver in one intermediate and one high dose animal.

Microscopically, the main dose-related changes in most treated animals were in the stomach, liver, kidney, thyroid and spinal nerve roots.

Dose-related forestomach gastritis was seen in intermediate and high dose animals. This is considered to represent a local irritant effect of the test article.

 

Liver changes consisted of periportal vacuolation and centrilobular hypertrophy. Periportal vacuolation was seen in all the high dose males and to a lesser extent in the low and intermediate dose males. No clear cut dose-related effect was seen in females. Hepatic centrilobular hypertrophy was evident in intermediate and high dose animals, notably females. These findings correlated with the increase in liver weight in high and intermediate dose animals and with the pallor noted macroscopically. Hepatic centriiobular hypertrophy is commonly associated with metabolising enzyme induction in response to increased metabolism of a xenobiotic. These liver changes can be regarded as adaptive changes rather than toxicity.

Kidney changes in some low and all intermediate and high dose males consisted of cortical tubular vacuolation of the proximal convoluted tubules of the pars recta. Additionally, hyaline droplets, were present in all control and some low dose males, but were absent in the high and intermediate dose males. Vacuolation was also found in most treated females, but cortical tubular basophilia of this region also occurred in all high and intermediate dose females. Single cell necrosis was occasionally found in these basophilic tubules of female rat kidneys.

Thyroid follicular cell hypertrophy was apparent to a minor extent in all high dose animals and two intermediate dose males. Follicular cell hypertrophy is commonly associated with liver cell hypertrophy and is generally considered to be an adaptive change due to increased thyroid hormone metabolism in the liver.

Spinal nerve root vacuolation was apparent in all high dose and two intermediate dose animals, and was characterised by vacuoles in the spinal nerve roots, which appeared to arise from separation or splitting of the myelin sheath. No changes were found in the sciatic nerve. The significance of the spinal nerve root vacuolation was uncertain. Despite the occasional behavioural observation during the functional observation battery, such as tiptoe gait, the number of instances of clinical signs does not correlate with the number of animals with spinal cord vacuolation.

In conclusion, most of the reactions of the rat to Incozol L.V. were of an adaptive rather than toxicological nature. The body weight, spinal cord vacuolation and forestomach gastritis in the intermediate and high dose levels are the only toxicological findings. Since the test article is known to degrade in a number of liquid vehicles, the poor stability means that the actual dosed amount cannot be determined. Therefore, the no observable adverse effect limit (NOAEL) may need to be based on target concentration, i.e. 150 mg/kg/day.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

NOAEL

150 mg/kg bw/day

Study duration:

subacute

Species:

rat

Quality of whole database:

GLP and guideline compliant study.

Repeated dose toxicity: inhalation - systemic effects

Endpoint conclusion

Endpoint conclusion:

no study available

Repeated dose toxicity: inhalation - local effects

Endpoint conclusion

Endpoint conclusion:

no study available

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

Oral

A study was conducted according to OECD TG 407 and Directive 92/69/EEC method B.7 to assess the repeated dose toxicity of Incozol LV to the rat. Therefore 4 groups of 5 male and 5 female animals were administrated to 0, 150, 500 and 1000 mg/kg bw/day doses of Incozol LV.

The animals tolerated the administered doses of Incozol L.V. for 4 weeks and showed no adverse clinical signs. Although, the formulations were found to be homogenous they were not stable and achieved concentration analysis results were generally below the acceptable range for this laboratory (90 to 110% of nominal). However, due to known reactivity of the test article i.e. moisture scavenger and its reactivity with a number of liquid vehicles and solvent systems (reactions with hydroxyl groups) it is highly likely that the test article rapidly degraded. The analytical procedure used in this study was not designed to specifically determine any degradation products from the parent compound. Therefore, it cannot be determined whether the animals received the intended doses described above. Administration of the test article did not have an effect on body weight gain in the low and intermediate dose animals. However, the high dose males gained less weight than controls particularly in the second two weeks of the study. Overall, there was a dose related decrease in body weight gains in the females, with the largest decrease in weight gain occurring in the second two weeks of the study. There was no effect on food consumption and there were no findings in the functional observational battery that could be related to test article administration.  

Haemoglobin concentration, red blood cell count and packed cell volume parameters had decreased in the high dose of both sexes; the most marked effect was seen in females. The male and female intermediate dose haemoglobin concentration and packed cell volume and the female intermediate dose red blood cell count were also decreased. However, there was no change in the myelograms. There were decreases in high dose male and intermediate dose male absolute neutrophil counts and decreases in high and intermediate dose monocytes. Additionally, there was a slight decrease in high dose female total white blood cell count. When compared to control animals, there was an increase of alkaline phosphatase in high and intermediate dose males. Additionally, there was a dose-related increase in aspartate aminotransferase in the high and intermediate dose males. The aspartate aminotransferase of the high dose females also increased. Total cholesterol levels of high and intermediate dose males and high dose females had decreased. These changes correlate with adaptive changes in the liver, i.e. enzyme induction and lipid metabolism. The weights of liver and kidneys of high and intermediate dose animals had increased. At necropsy, yellow appearance, thickening and raised or irregular surface were found in the stomach of two low dose, five intermediate dose and six high dose animals. Pallor of the liver was noted in two intermediate dose and three high dose animals and large liver in one intermediate and one high dose animal. Microscopically, the main dose-related changes in most treated animals were in the stomach, liver, kidney, thyroid and spinal nerve roots.

Dose-related forestomach gastritis was seen in intermediate and high dose animals. This is considered to represent a local irritant effect of the test article.   Liver changes consisted of periportal vacuolation and centrilobular hypertrophy. Periportal vacuolation was seen in all the high dose males and to a lesser extent in the low and intermediate dose males. No clear cut dose-related effect was seen in females. Hepatic centrilobular hypertrophy was evident in intermediate and high dose animals, notably females. These findings correlated with the increase in liver weight in high and intermediate dose animals and with the pallor noted macroscopically. Hepatic centriiobular hypertrophy is commonly associated with metabolising enzyme induction in response to increased metabolism of a xenobiotic. These liver changes can be regarded as adaptive changes rather than toxicity. Kidney changes in some low and all intermediate and high dose males consisted of cortical tubular vacuolation of the proximal convoluted tubules of the pars recta. Additionally, hyaline droplets, were present in all control and some low dose males, but were absent in the high and intermediate dose males. Vacuolation was also found in most treated females, but cortical tubular basophilia of this region also occurred in all high and intermediate dose females. Single cell necrosis was occasionally found in these basophilic tubules of female rat kidneys. Thyroid follicular cell hypertrophy was apparent to a minor extent in all high dose animals and two intermediate dose males. Follicular cell hypertrophy is commonly associated with liver cell hypertrophy and is generally considered to be an adaptive change due to increased thyroid hormone metabolism in the liver. Spinal nerve root vacuolation was apparent in all high dose and two intermediate dose animals, and was characterised by vacuoles in the spinal nerve roots, which appeared to arise from separation or splitting of the myelin sheath. No changes were found in the sciatic nerve. The significance of the spinal nerve root vacuolation was uncertain. Despite the occasional behavioural observation during the functional observation battery, such as tiptoe gait, the number of instances of clinical signs does not correlate with the number of animals with spinal cord vacuolation.

In conclusion, most of the reactions of the rat to Incozol L.V. were of an adaptive rather than toxicological nature. The body weight, spinal cord vacuolation and forestomach gastritis in the intermediate and high dose levels are the only toxicological findings. Since the test article is known to degrade in a number of liquid vehicles, the poor stability means that the actual dosed amount cannot be determined. Therefore, the no observable adverse effect limit (NOAEL) may need to be based on target concentration, i.e. 150 mg/kg bw/day.

Justification for classification or non-classification

Based on the results of the 28 d repeated dose toxicity study (oral) according to Regulation (EC) No 1272/2008 (CLP), as amended for the tenth time in Regulation (EC) 2017/776, the test item is not classified for repeated dose toxicity (oral).