2,6-xylenol

Acute Toxicity: oral

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

Test material information

Constituent 1

Reference substance name:

2,6 xylenol

IUPAC Name:

2,6 xylenol

Constituent 2

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:

other: 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)

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.