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Toxicological information

Acute Toxicity: oral

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Administrative data

Endpoint:
acute toxicity: oral
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1999

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 401 (Acute Oral Toxicity)
GLP compliance:
yes
Test type:
standard acute method
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: granular
Specific details on test material used for the study:
SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: MANAC, Hiroshima, JAPAN; Lot No.: 70909
- Purity test date: 99.8 wt %

Test animals

Species:
rat
Strain:
Crj: CD(SD)
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Japan Charles River, Atsugi-city, Kanagawa prefecture
- Age at study initiation: 6 weeks
- Weight at study initiation: 5 males of 175 to 202 g body weight and 5 females of 130 to 156 g body weight were selected.
- Fasting period before study: 16 hours
- Housing: 5 rats per cage, breeding cages of 21.5 x 27.5 x 19.5 cm were used; bedding and cage bottom not specified.
- Diet (e.g. ad libitum): ad libitum to food pellets from Oriental Yeast Co, Ltd. No diet details given. Contaminants in food were confirmed within allowable standards.
- Water: tap water ad libitum
- Acclimation period: 1 week

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 23 +/- 2°C
- Humidity (%): 55 +/- 10%
- Air changes (per hr): 20
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
corn oil
Details on oral exposure:
VEHICLE
- Concentration in vehicle: 200, 260, 338, 439.4 and 571.2 mg of the test substance (99.8 wt % purity) were suspended in corn oil.
- Amount of vehicle (if gavage): 0.5 mL/100 g bw suspended solution.
Doses:
1000, 1300; 1690; 2197 and 2856 mg/kg bw
No. of animals per sex per dose:
5
Control animals:
yes
Details on study design:
- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: every 1 hr till 6 hrs after administration. After 6 hrs, twice/day
- Necropsy of survivors performed: yes
- Other examinations performed: Appearances and activities of surviving animals were observed. Dead animals and survived animals were dessected just after died and after 14 days test respectively. Macroscopical and pathological findings were recorded.

Results and discussion

Effect levels
Key result
Sex:
male/female
Dose descriptor:
LD50
Effect level:
ca. 1 486 mg/kg bw
Based on:
test mat.
95% CL:
ca. 1 215 - ca. 1 792
Mortality:
Deaths of both sexes occurred in the 1300 mg/kg and more groups.
1000 mg/kg - 0%
1300 mg/kg - 40%
1690 mg/kg - 80%
2197 mg/kg - 80%
2866 mg/kg - 100%
Clinical signs:
Hypoactivity was observed in all groups and salivation appeared in most of animals.
Furtheremore, in 1300 mg/kg or higher groups of both sexes, chlonic convulsions, tremors, adoption of a prone and/or lateral position were observed before the animals died.
Body weight:
The body weight of survived animals increased on day 7 and 14 after administration.
Gross pathology:
No macroscopic abnormalities were observed by autopsy for either of the dead animals and the survived animals.

Any other information on results incl. tables

Numbers of dead animals by doses

[Males]

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Dose        Number of       Number of deaths       Mortality

(mg/kg)       animals         day 1   day 2-14

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1000              5                     0         0              0 / 5

1300              5                     2         0                 2 / 5

1690              5               4        0                 4 / 5

2197              5                    4         0                 4 / 5

2856              5                     5        -                 5 / 5

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[Females]

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Dose       Number of       Number of deaths       Mortality

(mg/kg)       animals         day 1 day 2 -14

------------------------------------------------------------------------------------------

1000              5               0        0                0 / 5

1300              5                    2        0               2 / 5

1690              5                    4          0               4 / 5

2197              5               4          0                4 / 5

2856              5                    5          -               5 / 5

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Applicant's summary and conclusion

Interpretation of results:
Category 4 based on GHS criteria
Conclusions:
Based on the data obtained, the LD50 of 2,4,6-tribromophenol was determined to be 1486 mg/kg with 95% confidence intervals of 1215 - 1792 mg/kg when administered once orally via gavage to male and female rats.