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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:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Study was conducted in methods comparable to OECD guideline 401. However, animal acclimation information was not provided. Animals were only fasted for 3-4 hours before dosing. Body weight results are not provided in the report.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Report date:
1965

Materials and methods

Test guideline
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 401 (Acute Oral Toxicity)
Deviations:
yes
Remarks:
Animal acclimation information was not provided. Animals were only fasted for 3-4 hours before dosing. Body weight results are not provided in the report.
GLP compliance:
no
Test type:
standard acute method
Limit test:
no

Test material

Constituent 1
Reference substance name:
2,6 xylenol
IUPAC Name:
2,6 xylenol
Constituent 2
Chemical structure
Reference substance name:
2,6-xylenol
EC Number:
209-400-1
EC Name:
2,6-xylenol
Cas Number:
576-26-1
Molecular formula:
C8H10O
IUPAC Name:
2,6-dimethylphenol
Details on test material:
- Name of test material (as cited in study report): 2,6-xylenol (2,6-dimethylphenol)
- Physical state: white solid
- Analytical purity: The material was considered to be free of impurities.
- Other: received on February 25, 1965. The test substance has a strong pungent odor.

Test animals

Species:
rat
Strain:
Sprague-Dawley
Sex:
male
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Age at study initiation: 207 to 326 grams
- Fasting period before study: Food was withheld from the animals for a period of three to four hours prior to dosing.
- Housing: Following intubation, the animals were housed by groups in metal cages.
- Diet: ad libitum
- Water: ad libitum


Administration / exposure

Route of administration:
oral: gavage
Vehicle:
corn oil
Details on oral exposure:
VEHICLE
- Concentration in vehicle: 10 or 20% weight/volume solution
Doses:
100, 215, 464, 1000, 2150, and 4640 mg/kg bw
No. of animals per sex per dose:
five
Control animals:
no
Details on study design:
- Duration of observation period following administration: 14 days.
- Frequency of observations and weighing: Animals were closely observed for mortality and toxic effects at the following intervals after compound administration: immediately; at one, four, and 24 hours; and once daily thereafter for a total of 14 days. At the end of the observation period, the surviving animals were weighed, sacrificed by cerebral concussion, and necropsied.
- Necropsy of survivors performed: yes. At the end of the observation period, the surviving animals were weighed, sacrificed by cerebral concussion, and necropsied. Necropsies were also performed on the animals that succumbed during the course of the study.
- Other examinations performed: clinical signs
Statistics:
Statistical analysis of the mortality data was conducted by the method by Thompson, W.R., Bact. Rev., 11, 115, 1947, utilizing the tables of Horn, H. J., Biometrics, 12, 311, 1956.

Results and discussion

Effect levels
Sex:
male
Dose descriptor:
LD50
Effect level:
1 470 mg/kg bw
Based on:
test mat.
Mortality:
All animals in the 100, 215, 464, and 1000 mg/kg bw dose groups survived the 14 day study period. In the 2150 mg/kg bw dose group, three animals died 1 hour after treatment, one animal died 24 hours after treatment, and one animal died 2 days after treatment. In the 4640 mg/kg dose group, all animals died 1 hour after treatment.
Clinical signs:
No clinical signs were observed in animals in the 100 mg/kg dose group. The principle clinical signs for animals in the 215, 464, and 1000 mg/kg bw groups were depression and flushed appearance, labored respiration and ataxia (1000 mg/kg dose level only). The onset of signs started within one hour after treatment, complete recovery in all animals was observed within 48 hours.
For animals in the 2150 and 4640 groups, depression, flushed appearance, lacrimation, exophthalmos, salivation, slow labored respiration, ataxia, sprawling of the limbs, depressed righting and placement reflexes, prostration, coma, and death were observed.
Body weight:
no data
Gross pathology:
No necropsy findings were observed in the 100, 215, 464, or 1000 mg/kg bw dose groups.
At the 2150 and 4640 mg/kg bw dose level, congestion of the lungs, liver, spleen, kidney, and adrenals; gastrointestinal inflammation and apparent sloughing of stomach mucosa were observed.

Applicant's summary and conclusion

Interpretation of results:
Toxicity Category IV
Remarks:
Migrated information Criteria used for interpretation of results: EU
Conclusions:
The acute oral LD50 of 2,6-xylenol for adult male Sprague-Dawley rats is 1470 mg/kg body weight based on the results of this study.