Registration Dossier

Administrative data

acute toxicity: oral
Type of information:
experimental study
Adequacy of study:
key study
Study period:
From 6th September to 19th November 1985
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Study is conducted by recognised test house, to experimental procedure in compliance with OECD Guideline 401. Full data set and rationale provided. GLP compliance not specified, although report is subject to Quality Assurance Procedure.

Data source

Reference Type:
study report
Report date:

Materials and methods

Test guideline
according to guideline
OECD Guideline 401 (Acute Oral Toxicity)
GLP compliance:
not specified
No mention of GLP is made within the report; however the report was subject to Quality Assurance at the laboratory where the testing was conducted. As such, it is assumed that the principles of GLP were followed
Test type:
standard acute method
Limit test:

Test material

Details on test material:
- Name of test material (as cited in study report): Bontron E-84
- Substance type: Solid
- Physical state: White powder
- Lot/batch No.: No batch number is specified within the report, but the test substance is deemed equivalent based on history of manufacture and use.
- Stability under test conditions: Not determined.
- Storage condition of test material: Ambient Conditions.
- Other:

Test animals

Details on test animals or test system and environmental conditions:
- Source: Interfauna UK Ltd, Huntingdon, Cambs, England
- Age at study initiation: 4 to 6 weeks
- Weight at study initiation: 95 to 156 g
- Fasting period before study: Overnight and 4 hours following dosing
- Housing: Housed in groups by sex in metal cages with wire mesh floors
- Diet (e.g. ad libitum): standard laboratory rodent diet (Labsure LAD 1) ad libitum. Batch diet used for the study is analysed for certain chemical and microbiological contaminants
- Water (e.g. ad libitum): Provided ad libitum. Results of routine chemical examination of water at source (Grafham Final Water) as conducted quarterly by the Anglian Water Authority are made available.
- Acclimation period: 5 days

- Temperature (°C): 20 – 24 °C
- Humidity (%): 63%
- Air changes (per hr): Approximately 15 air changes/hour
- Photoperiod (hrs dark / hrs light): Controlled by means of a time switch to 12 hours artificial light in each 24 hour period.

IN-LIFE DATES: From: 6th September 1985 To: 19th November 1985

Administration / exposure

Route of administration:
oral: gavage
other: 1% methyl cellulose
Details on oral exposure:
The appropriate dose volume of the test substance was administered to each rat using a syringe and plastic catheter.

- Concentration in vehicle: Test substance was prepared as various w/v concentrations in 1% methylcellulose and administered at a volume not exceeding 32 ml/kg
- Amount of vehicle (if gavage): Various
- Justification for choice of vehicle: Not specified
- Lot/batch no. (if required): Not specified
- Purity: Not specified



CLASS METHOD (if applicable)
- Rationale for the selection of the starting dose: N/A
Initial: 5000 mg/kg
Main study first phase: 2000 mg/kg, 3200 mg/kg, 5000 mg/kg, 8000 mg/kg
Main study second phase: 500 mg/kg, 1000 mg/kg, 2500 mg/kg
Final range: 500 mg/kg, 500 mg/kg, 1260 mg/kg, 2000 mg/kg
No. of animals per sex per dose:
Initial: 10 test (5 male, 5 female)
Main study first phase: 10 test (5 male, 5 female) per dose group
Main study second phase: 4 test (2 male, 2 female)
Final range: 10 test (5 male, 5 female)
Control animals:
Details on study design:
Sections of the study were conducted on the following dates:
Initial: 1985-09-06
Main study first phase: 1985-10-17, 1985-10-18
Main study second phase: 1985-10-28
Final range: 1985-11-05

A single group of rats (5 male, 5 female) were treated at 5000 mg/kg on 1985-09-06. Three of the ten rats died.

When further groups of ten rates were treated at 2000 mg/kg, 3200 mg/kg, 5000 mg/kg, 8000 mg/kg on 1985-10-17, 1985-10-18, thirty seven of the forty animals died.
In view of these mortalities, smaller groups of rats (two males and two females) were dosed at 500 mg/kg, 1000 mg/kg, 2500 mg/kg on 1985-10-28 in order to establish the expected region of toxicity. This was followed on 1985-11-05 by dosing further groups of ten rats (five males and five females) at 500 mg/kg, 500 mg/kg, 1260 mg/kg, 2000 mg/kg bodyweight.

Mortality data obtained from the groups of ten rats dosed on 1985-10-17, 1985-10-18 and 1985-11-05 were used for the LD50 determination.

- Duration of observation period following administration: 14 days (or other?): 15 days
- Frequency of observations and weighing:
Animals were observed soon after dosing and then at frequent intervals for the remainder of Day 1. On subsequent days, the animals were observed at least twice, once in the morning and once at the end of each experimental day. This latter observation was made at approximately 1130 hours on Saturday and Sunday. Clinical observations were recorded at each observation.
The animals on the study carried out on 1985-10-28 were observed for 5 days after dosing, and all other animals were observed for 14 days after dosing. In each instance, the following were recorded:
1) Approximate time of death of individual rats.
2) The nature, severity and approximate time of onset and duration of each toxic sign.
3) On main study, individual bodyweights of rats on Days 1 (day of dosing), 8 and 15 and at death.

- Necropsy of survivors performed: Yes

- Other examinations performed: clinical signs, body weight,organ weights, histopathology, other:
Surviving animals were killed on Days 6 or 15 by cervical dislocation. All animals that died during the study and those killed on Day 6 or 15 were subjected to a macroscopic post mortem examination which consisted of opening the abdominal and thoracic cavities. The macroscopic appearance of abnormal organs when present was recorded.
LD50 to male and female rats was calculated using mortality data obtained from rats doses on the dates of 1984-10-17, 1985-10-18 and 1985-11-05 according to the method of Finney (1971) Probit Analysis (3rd Edition) Cambridge University Press.
Seperate LD50 values of males and females were estimated by undertaking probit analysis on the mortality data by fitting two parallel lines on the data (males only and females only) using the technique described by Finney (1978, Statistical Method in Biological Assay, 3rd Edition, Charles Griffin, London). A chi-squared test was carried out to check that the data did not contain any evidence of non-parallelism.

Results and discussion

Effect levelsopen allclose all
Dose descriptor:
Effect level:
1 800 mg/kg bw
95% CL:
>= 1 300 - <= 2 400
Dose descriptor:
Effect level:
1 800 mg/kg bw
95% CL:
>= 1 400 - <= 2 200
Dose descriptor:
Effect level:
1 700 mg/kg bw
95% CL:
>= 1 200 - <= 2 400
Mortalities occured amongst the rats dosed at 1260 mg/kg and above within 1 and 47 hours of dosing. Please refer to Table 2 in the attached data below for details of times of death.
Clinical signs:
Signs of reaction to treatment observed shortly after doing in all rats were pilo-erection and lethargy. These were accompanied by:

a) Abnormal body carriage (hunched posture), abnormal gait (waddling) decreased respiratory rate and pallor of the extremities amongst rats from all groups.
b) Increased salivation in all female rats dosed at 5000 mg/kg and two female rats dosed at 8000 mg/kg.
c) A comatose-like condition amongst rats dosed at 2000 mg/kg and above
d) Gasping in one female rate dosed at 5000 mg/kg and one female rat dosed at 8000 mg/kg.
e) Noisy respiration in one female rat at 5000 mg/kg and two female rats dosed at 8000 mg/kg.

Recovery, as judged by external appearance and behaviour was apparently complete by Day 5

Please refer to Table 3 in the attached report for further information.
Body weight:
Bodyweight losses were recorded from the majority of rats that died during the study.

Bodyweight gains were recorded from days 8 to 15 for all surviving rats.

Please refer to Table 4 in the attached report for further information.
Gross pathology:
For rats that died during the study, autopsy revealed pallor of the kidneys in five rats and pallor of the spleen in four rats. Occasional incidences of haemorrhagic lungs, pallor and patchy livers and pale lngs were also observed.

In surviving rats, terminal autopsy results were normal.

Other findings:
Other observations:
One of the animals dosed at 8000 mg/kg bodyweight had a white suspension in the thoracic cavity at autopsy. Death was considered to be associated with an intubation error and this animal was excluded from the LD50 determination.

No treatment related differences in organ weights, histopathology or target organs were identified.

Any other information on results incl. tables

The LD50 and the associated 95% confidence limits for rats was estimated to be :

Males and females combined: 1800 (1400 to 2200) mg/kg bodyweight.

Males only: 1800 (1300 to 2400) mg/kg bodyweight.

Females only: 1700 (1200 to 2400) mg/kg bodyweight.

The slope of the probit line used in the calculation was 4.0 with a standard error of 0.8 using log transformation of dose in al cases. The heterogenicity factor was not significant. A chi-squared test for parallelism gave no evidence of non-parallelism.

Applicant's summary and conclusion

Interpretation of results:
Migrated information Criteria used for interpretation of results: EU
Based on the results, this substance is classified at "Harmful" by oral ingestion, and the risk phrase "R22 : Harmful if swallowed" shall be applied.
Executive summary:

The substances was tested according to the OECD 401 method to assess the acute oral toxicity of the material in male and female rats (5 of each sex). Based on results of exposure of the substance the LD50 of the substance has been determined to be 1800mg/kg bodyweight