1-bromo-3,4,5-trifluorobenzene

Endpoint summary

Description of key information

In a GLP study performed according to OECD TG 407, groups of male and female Wistar rats were dosed orally via gavage at levels of 0, 100, 300 or 1000 mg/kg once daily on 7 days per week over 4 weeks. The test item was tolerated by the rats at 100 mg/kg bw/day without toxicologically relevant effects, while dosing with >= 300 mg/kg bw/day was not tolerated due to clinical, haematological, clinico-chemical, macroscopically, and histopathological changes (reference 7.5.1 -1).

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:

sub-chronic toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

August 18, 1998 - March 25, 1999

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)

Deviations:

no

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

1996

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Limit test:

no

Species:

rat

Strain:

Wistar

Remarks:

HsdCpb:WU

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Harlan Winkelmann GmbH, Germany
- Age at study initiation: 11 weeks
- Weight at study initiation: 175 - 288 g
- Housing: individually under conventional conditions in Type III Makrolon® cages.
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: 8 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21 - 22
- Humidity (%): 55 - 75
- Photoperiod (hrs dark / hrs light): 12 / 12

Route of administration:

oral: gavage

Vehicle:

other: Miglyol 812 neutral oil

Details on oral exposure:

Due to its low solubility in water and in 0.25% aqueous hydroxypropyl methylcellulose, the test item was solved in Miglyol. Fresh suspensions were prepared daily and stirred vigorously before use. The administration volume was 5 mL/kg body weight. The control rats received the vehicle (Miglyol 812 neutral oil) at the same frequency as the animals treated with the test item.

Analytical verification of doses or concentrations:

no

Remarks:

An analysis during the treatment period was not considered to be necessary because the suspensions were prepared daily.

Duration of treatment / exposure:

28 days

Frequency of treatment:

once daily on 7 days/week

Dose / conc.:

0 mg/kg bw/day (nominal)

Dose / conc.:

100 mg/kg bw/day (nominal)

Dose / conc.:

300 mg/kg bw/day (nominal)

Dose / conc.:

1 000 mg/kg bw/day (nominal)

No. of animals per sex per dose:

0 mg/kg bw/day : 10 m / 10 f
100 mg/kg bw/day : 5 m / 5 f
300 mg/kg bw/day : 5 m / 5 f
1000 mg/kg bw/day : 10 m / 10 f

Control animals:

yes, concurrent vehicle

Details on study design:

The dose selection was based on an acute oral toxicity study in rats. A dose level of 1000 mg/kg led to signs of lethargy and hunched posture, but no deaths were observed. At the highest dose level of 2000 mg/kg one of five male rats died and in addition effects such as lethargy, hunched posture, decrease in the respiration rate and red brown discolorations at the eyes and snout were observed.
Therefore, the high dose in this study was limited to 1000 mg/kg. The lower doses were set at 100 and 300 mg/kg. The dose of 1000 mg/kg was expected to be toxic after repeated administration and the dose of 100 mg/kg was expected to be tolerated by the rats.

Observations and examinations performed and frequency:

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: Mortality, behaviour, appearance and general condition of the rats were checked twice daily on working days and once daily on off days. Any deviations from normal were recorded with respect to their nature and severity, date of onset, duration and progress.

BODY WEIGHT: Yes
- Time schedule for examinations: Each rat was weighed weekly.

FOOD CONSUMPTION AND COMPOUND INTAKE: Yes
Food consumption was determined for each rat once a week by weighing the food which had not been consumed.

WATER CONSUMPTION AND COMPOUND INTAKE: Yes
- Time schedule for examinations: Water consumption was determined for each rat twice a week.

OPHTHALMOSCOPIC EXAMINATION: No

HAEMATOLOGY: Yes
- Time schedule for collection of blood: week 5 and week 7
- Anaesthetic used for blood collection: Yes, halothane
- Animals fasted: Yes
- How many animals: all
- Parameters checked: White blood cells, Red blood cells, Hemoglobin, Hematocrit %, Mean cell volume, Mean hemoglobin content, Mean hemoglobin concentration, Platelets, Reticulocytes %, Differential blood count %, Prothrombin time %, Partial thromboplastin time

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: week 5 and week 7
- Animals fasted: Yes
- How many animals: all
- Parameters checked: Sodium, Potassium, Calcium, Chloride, Phosphate, Glucose, Urea, Creatinine, Bilirubin, total, Cholesterol, Triglyceride, Alanine aminotransferase, Aspartate aminotransferase, Alkaline phosphatase, Protein, total, Albumin
Bile acid

URINALYSIS: Yes
- Time schedule for collection of urine: week 5 and week 7
- Metabolism cages used for collection of urine: Yes
- Animals fasted: Yes
- Parameters checked: pH, protein, glucose, Bilirubin, urobilinogen, Blood, Sediment, Specific gravity

NEUROBEHAVIOURAL EXAMINATION: Yes
- Time schedule for examinations: end of treatment period
- Dose groups that were examined: 5 m / 5 f per group
- Battery of functions tested: palpebral closure, ease of removal from cages, ease of handling, lacrimation, salivation, piloerection, fur appearance, mobility, arousal, gait, approach response, touch response, click response, tail pinch response, righting reflex, pupil response, vocalization, rearing, defecation and urination, landing foot splay, forelimb and hindlimb grip strengths. Additionally, one hour after administration, the rats were removed from their home cages and their motor activity was recorded over 90 minutes at 5 minute intervals in new cages. On each measuring day, measurements were conducted simultaneously in 10 rats.

IMMUNOLOGY: No

Sacrifice and pathology:

GROSS PATHOLOGY: Yes

HISTOPATHOLOGY: Yes

Statistics:

Standard methods (e.g. Dunnett-Test or Wilcoxon rank sum test) were used.

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

Most of the dosed rats had light white teeth. Other treatment related symptoms consisted of palpebral closure in rats dosed with >= 300 mg/kg, an increased incidence of salivation and burrowing in the litter in the female rats, and stretched position of body during movement, skin discoloration, soft feces, reduced spontaneous activity and lethargy in a few male rats dosed with 1000 mg/kg. At the end of the recovery period only the light white teeth were still visible.

Mortality:

mortality observed, treatment-related

Description (incidence):

Three male rats dosed with 1000 mg/kg died or were killed in moribund condition during the treatment period.

Body weight and weight changes:

effects observed, non-treatment-related

Description (incidence and severity):

The body weight gain in male rats dosed with 1000 mg/kg was significantly reduced and slightly lower in rats dosed with 300 mg/kg in comparison to the control group. In females, body weight gain was significantly increased in rats dosed with 1000 mg/kg and slightly increased in rats dosed with 100 or 300 mg/kg. The effects on body weight in high-dosed males and females were still present at the end of the recovery period but to a lower extent in the males.

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

In week 1, food consumption was significantly reduced in males dosed with >= 300 mg/kg and in females dosed with >= 100 mg/kg. While the reduction in males was still present in week 2 at a dose level of 1000 mg/kg, the food consumption in females dosed with 1000 mg/kg was significantly increased up to the end of the treatment period. At the end of the recovery period, there were no major differences in the food consumption of rats dosed with 0 or 1000 mg/kg.

Food efficiency:

not examined

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

effects observed, treatment-related

Description (incidence and severity):

With the exception of the significantly lower water intake on day 3, water consumption was significantly increased up to the end of the treatment period in males and females dosed with 1000 mg/kg. There were no major differences in the water consumption during the recovery period.

Ophthalmological findings:

not examined

Haematological findings:

effects observed, treatment-related

Description (incidence and severity):

In rats dosed with 1000 mg/kg, 3/7 males and 5/10 females showed a mild impairment of the parameters of the red blood count (erythrocytes, haemoglobin, haematocrit). The impairment was significant in the haemoglobin values of males and the erythrocyte and haemoglobin values of females. In addition, rats of both sexes showed a mild, but also significant increase in the number of reticulocytes, possible caused by the decrease in erythrocytes, haemoglobin, and haematocrit values.
In 2/7 males dosed with 1000 mg/kg the white blood count showed a considerable increase in the number of leucocytes with a simultaneous shift to left in the differential blood count. In one animal of this group the number of monocytes was severely increased.
Significant values of the eosinophilic granulocytes in the differential blood count of males dosed with 300 mg/kg and the partial thromboplastin time of males dosed with 1000 mg/kg were attributed to spontaneous reactions of one rat in each case. The deviations were still within the normal range of the laboratory and were therefore not to be regarded as toxicologically relevant.
These haematological findings were no longer observed at the end of the recovery period.

Clinical biochemistry findings:

effects observed, treatment-related

Description (incidence and severity):

Serum substrates and proteins (results at week 5): Males dosed with 1000 mg/kg showed slightly decreased serum glucose values. In addition, both males and females dosed with 1000 mg/kg showed a clear increase in total bilirubin, triglycerides and cholesterol. Cholesterol tended to be increased also at dose levels of >= 100 mg/kg. Creatinine was decreased in males dosed with 300 mg/kg and in females dosed with >= 100 mg/kg. Albumin and total protein values were increased at 300 mg/kg and total protein tended to be increased in females dosed with 100 and 1000 mg/kg.
Serum substrates and proteins (results at week 7): At the end of the recovery period males dosed with 1000 mg/kg did not show any toxicologically relevant deviation from the values of the control group. Slightly increased total bilirubin, cholesterol and triglyceride values were still present in high-dosed females.

Serum electrolytes (results at week 5): A mild, but dose-dependent increase in the serum calcium values was observed rats dosed with >= 100 mg/kg. The serum chloride values of males dosed with >= 300 mg/kg and of females dosed with 1000 mg/kg tended to be decreased. The serum phosphate values of males and females dosed with 1000 mg/kg were in some cases clearly increased. In females dosed with 300 mg/kg slightly increased serum phosphate values were observed.
Serum electrolytes (results at week 7): There were no toxicologically relevant deviations of the serum electrolyte values at the end of the recovery period. A very slightly increased serum phosphate value was seen only in one high-dosed female.

Serum enzymes (results at week 5): The values for aspartate aminotransferase, alanine aminotransferase and alkaline phosphatase of males dosed with 1000 mg/kg were statistically significant increased compared with controls. In females dosed with 1000 mg/kg a mild increase in alanine aminotransferase values was noted. In these rats, a tendency to increased alkaline phosphatase values was also observed, but this was not statistically significant.
Serum enzymes (results at week 7): The values of aspartate aminotransferase and alkaline phosphatase values in males dosed with 1000 mg/kg corresponded to those of the control. Only the alanine aminotransferase values of these rats were still slightly increased. The serum enzyme values of high-dosed females corresponded mostly to those of the control.

Serum bile acid (results at week 5): One male and one female from the control group displayed a non-physiologically high bile acid value. Almost all animals dosed with 1000 mg/kg displayed increased bile acid values and in in some cases the increase was considerable. In animals dosed with 100 or 300 mg/kg the values were mostly comparable with controls, which applies also to females of these groups with an exception for one male dosed with 100 mg/kg and one female dosed with 300 mg/kg showing slightly increased bile acid values.
Serum bile acid (results at week 7): Two males from the control group displayed non-physiologically high bile acid values. Apart from the values noted in two high-dose males, in the other rats of this dose group the values nearly normalized by the end of the recovery period. The bile acid values of high-dosed females corresponded mostly to those of the control.

Urinalysis findings:

effects observed, treatment-related

Description (incidence and severity):

Although the absolute values were within the normal range of this strain, the specific urine gravity in high-dosed females was significantly decreased at the end of the treatment period. In high-dosed males it was slightly increased at the end of the recovery period. Therefore, these changes were considered not to be toxicologically relevant. All other urine values corresponded essentially to the control. Except for the pH value, the urinalysis values of the treated animals corresponded mostly to those of the control. In males and females dosed with >= 300 mg/kg and in males dosed with 100 mg/kg the urine pH values were decreased as compared to the control, i.e. shifted to the acidic range. The pH values of females dosed with 100 mg/kg were comparable to the control. In two males of the low-dose group protein in their urine was noted. This finding has been known to occur in untreated rats of this strain and is seen as a spontaneous reaction. At the end of the recovery period the urine pH values of high-dosed rats corresponded to the control. None of the other values of the urinalysis displayed any toxicologically relevant deviations as compared to the control. Overall, urinalysis and urinary specific gravity did not reveal any relevant changes related to the test item.

Behaviour (functional findings):

effects observed, treatment-related

Description (incidence and severity):

None of the parameters tested (palpebral closure, ease of removal from cages, ease of handling, lacrimation, salivation, piloerection, fur appearance, mobility, arousal, gait, approach response, touch response, click response, tail pinch response, righting reflex, pupil response, vocalization, rearing, defecation and urination, landing foot splay, forelimb, and hindlimb grip strengths) were relevantly influenced by the treatment with the test item.
In females, the measurement of the motor activity did not reveal any statistically significant treatment related effects. In males, the motor activity in comparison to the control group was significantly decreased in the cumulation period 5-30 minutes in rats dosed with 1000 mg/kg and significantly increased in the cumulation period 35-60 minutes in rats dosed with 300 mg/kg.

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Description (incidence and severity):

Liver weights increased with increasing doses and were about twice as high at 1000 mg/kg as in the control group. Increased kidney weights, decreased spieen weights and reduced thymus weights were recorded in the high dose group.

Gross pathological findings:

effects observed, treatment-related

Description (incidence and severity):

Extreme white discoloration of the incisors in all rats treated with the test item.

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Description (incidence and severity):

The dosing with >= 300 mg/kg caused degenerative cell edema in the liver with nuclear enlargement. Additionally, 1000 mg/kg had led to nephroses of varying severity and to atrophy or depletion of the epididymides, accessory sexual glands, spieen and thymus. In high-dosed males which have died in the course of the study, degeneration of the germinal epithelium of the testes was seen. With the exception of the white discoloration of the teeth, the described alteration were not seen in the rats that were followed-up. Thus, these organ changes can be regarded as being reversible.

Histopathological findings: neoplastic:

not specified

Other effects:

not specified

Key result

Dose descriptor:

NOAEL

Effect level:

100 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

clinical biochemistry

haematology

histopathology: non-neoplastic

Key result

Critical effects observed:

yes

Lowest effective dose / conc.:

300 mg/kg bw/day (nominal)

System:

hepatobiliary

Organ:

liver

Treatment related:

yes

Dose response relationship:

yes

Relevant for humans:

not specified

Conclusions:

In a GLP study performed according to OECD TG 407, groups of male and female Wistar rats were dosed orally via gavage at levels of 0, 100, 300 or 1000 mg/kg bw/day once daily on 7 days per week over 4 weeks. The test item was tolerated by the rats at 100 mg/kg bw/day without toxicologically relevant effects, while the dosing with >= 300 mg/kg bw/day was not tolerated due to clinical, haematological, clinico-chemical, macroscopically, and histopathological changes.

Executive summary:

In a study according to OECD TG 407, the test item was administered once daily via gavage on 7 days per week over 4 weeks to groups of Wistar rats (5 m / 5 f) at dose levels of 0, 100, 300 or 1000 mg/kg bw/day. Five additional rats per sex of the control group and of the high-dose group were scheduled for a 2 week treatment-free recovery period. The total number of rats was 60 (30 m / 30 f). Mortality, appearance and behaviour were checked daily. Body weight and food consumption were recorded weekly and water consumption twice a week. Neurobehavioral tests (functional observation battery) and exanimation of the motor activity were performed at the end of the treatment period. Haematological, clinico-chemical examinations and urinalysis were carried out at the end of the treatment period and at the end of the recovery period. Post mortem exanimations were performed at the end of the treatment period and at the end of the follow-up period. All rats were subjected to macroscopic and histopathological examinations.

Three high-dosed males died or were killed in moribund condition during the treatment period. Light white teeth were noted in all treated rats. Palpebral closure occurred at dose levels of >= 300 mg/kg. Other symptoms such as stretched position of body during movement, skin discoloration, soft faeces, reduced spontaneous activity, and lethargy were seen exclusively in some high-dosed males. There were no behavioural signs of neurotoxicity and influences on the motor activity that could be attributed to treatment.

Whereas the body weight gain was significantly reduced in males dosed with 1000 mg/kg and slightly reduced in males dosed with 300 mg/kg, it was significantly increased in females dosed with 1000 mg/kg and to a lower extent in females dosed with 100 or 300 mg/kg.

Deviations in the food consumption were noted in males dosed with >= 300 mg/kg and in females of all dose group, especially in the first two weeks of the study.

The water consumption was significantly increased in high-dosed rats during the treatment period.

Haematological investigations in high-dosed rats revealed reversible significant decreases of haemoglobin in males and females and of erythrocytes in females, and a significant increase of reticulocytes in both sexes. All other haematological parameters were within the normal range.

Clinical chemistry revealed a number of serum values which were either lower or higher than those of the concurrent controls. The changes observed at 1000 mg/kg indicated damage to the liver and the biliary system. The aspartate aminotransferase, alanine aminotransferase and alkaline phosphatase values in high-dosed males were clearly higher than those of the control. In high-dosed females, a mild increase in alanine aminotransferase values and a tendency to increased alkaline phosphatase values was seen. Total bilirubin, triglycerides and cholesterol were clearly increased in both sexes at the highest dose level. Cholesterol tended to be increased also in the low- and mid-dose groups. Creatinine was decreased in mid-dosed males and the females of all dose groups, while albumin and total protein values were increased in mid-dose group. Total protein tended to be increased also in females dosed with 100 and 1000 mg/kg. Almost all high-dosed animals displayed increased bile acid values, in some the increase was considerable.

The liver weights increased with increasing doses and were about twice as high at 1000 mg/kg as in the control group. Increased kidney weights, decreased spleen weights and reduced thymus weights were recorded in the high dose group. Gross pathology revealed extreme white discoloration of the incisors in all dosed rats. The dosing with >= 300 mg/kg caused degenerative cell oedema in the liver with nuclear enlargement. Additionally, 1000 mg/kg had led to nephrosis of varying severity and to atrophy or depletion of the epididymides, accessory sexual glands, spleen and thymus. In high-dosed males that died in the course of the study, degeneration of the germinal epithelium of the testes was seen. With the exception of the white discoloration of the teeth, the described alteration were not seen in the rats that were followed-up. Thus, these organ changes can be regarded as being reversible.

The test item was tolerated by the rats at 100 mg/kg without toxicologically relevant effects, while the dosing with >= 300 mg/kg was not tolerated due to clinical, haematological, clinico-chemical, macroscopically, and histopathological changes.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

NOAEL

100 mg/kg bw/day

Study duration:

subacute

Species:

rat

Quality of whole database:

OECD TG 407

System:

hepatobiliary

Organ:

liver

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

In a study according to OECD TG 407, the test item was administered once daily via gavage on 7 days per week over 4 weeks to groups of Wistar rats (5 m / 5 f) at dose levels of 0, 100, 300 or 1000 mg/kg bw/day. Five additional rats per sex of the control group and of the high-dose group were scheduled for a 2 week treatment-free recovery period. The total number of rats was 60 (30 m / 30 f). Mortality, appearance and behaviour were checked daily. Body weight and food consumption were recorded weekly and water consumption twice a week. Neurobehavioral tests (functional observation battery) and exanimation of the motor activity were performed at the end of the treatment period. Haematological, clinico-chemical examinations and urinalysis were carried out at the end of the treatment period and at the end of the recovery period. Post mortem exanimations were performed at the end of the treatment period and at the end of the follow-up period. All rats were subjected to macroscopic and histopathological examinations.

Three high-dosed males died or were killed in moribund condition during the treatment period. Light white teeth were noted in all treated rats. Palpebral closure occurred at dose levels of >= 300 mg/kg. Other symptoms such as stretched position of body during movement, skin discoloration, soft faeces, reduced spontaneous activity, and lethargy were seen exclusively in some high-dosed males. There were no behavioural signs of neurotoxicity and influences on the motor activity that could be attributed to treatment.

Whereas the body weight gain was significantly reduced in males dosed with 1000 mg/kg and slightly reduced in males dosed with 300 mg/kg, it was significantly increased in females dosed with 1000 mg/kg and to a lower extent in females dosed with 100 or 300 mg/kg.

Deviations in the food consumption were noted in males dosed with >= 300 mg/kg and in females of all dose group, especially in the first two weeks of the study.

The water consumption was significantly increased in high-dosed rats during the treatment period.

Haematological investigations in high-dosed rats revealed reversible significant decreases of haemoglobin in males and females and of erythrocytes in females, and a significant increase of reticulocytes in both sexes. All other haematological parameters were within the normal range.

Clinical chemistry revealed a number of serum values which were either lower or higher than those of the concurrent controls. The changes observed at 1000 mg/kg indicated damage to the liver and the biliary system. The aspartate aminotransferase, alanine aminotransferase and alkaline phosphatase values in high-dosed males were clearly higher than those of the control. In high-dosed females, a mild increase in alanine aminotransferase values and a tendency to increased alkaline phosphatase values was seen. Total bilirubin, triglycerides and cholesterol were clearly increased in both sexes at the highest dose level. Cholesterol tended to be increased also in the low- and mid-dose groups. Creatinine was decreased in mid-dosed males and the females of all dose groups, while albumin and total protein values were increased in mid-dose group. Total protein tended to be increased also in females dosed with 100 and 1000 mg/kg. Almost all high-dosed animals displayed increased bile acid values, in some the increase was considerable.

The liver weights increased with increasing doses and were about twice as high at 1000 mg/kg as in the control group. Increased kidney weights, decreased spleen weights and reduced thymus weights were recorded in the high dose group. Gross pathology revealed extreme white discoloration of the incisors in all dosed rats. The dosing with >= 300 mg/kg caused degenerative cell oedema in the liver with nuclear enlargement. Additionally, 1000 mg/kg had led to nephrosis of varying severity and to atrophy or depletion of the epididymides, accessory sexual glands, spleen and thymus. In high-dosed males that died in the course of the study, degeneration of the germinal epithelium of the testes was seen. With the exception of the white discoloration of the teeth, the described alteration were not seen in the rats that were followed-up. Thus, these organ changes can be regarded as being reversible.

The test item was tolerated by the rats at 100 mg/kg without toxicologically relevant effects, while the dosing with >= 300 mg/kg was not tolerated due to clinical, haematological, clinico-chemical, macroscopically, and histopathological changes (reference 7.5.1 -1).

Justification for classification or non-classification

Classification, Labeling, and Packaging Regulation (EC) No. 1272/2008

The available experimental test data are reliable and suitable for classification purposes under Regulation 1272/2008. The substance is not considered to be classified for repeated dose toxicity according to Regulation (EC) No 1272/2008 (CLP), as amended for the twelfth time in Regulation (EU) 2019/521.