4-chloro-o-cresol

Acute Toxicity: oral

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:

other: Taken from EU Risk Assessment Report - Reviewed by the Danish Environmental Protection Agency. Guideline Study.

Data source

Reference

Reference Type:

publication

Title:

Unnamed

Year:

2002

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

GLP compliance:

not specified

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

4-chloro-o-cresol

EC Number:

216-381-3

EC Name:

4-chloro-o-cresol

Cas Number:

1570-64-5

Molecular formula:

C7H7ClO

IUPAC Name:

4-chloro-2-methylphenol

Test animals

Species:

rat

Strain:

not specified

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS

- Fasting period before study: guideline states overnight.
- Diet (e.g. ad libitum): gavage
- Water (e.g. ad libitum): ad libitum
- Acclimation period: at least 5 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22°C +/- 3°C.
- Humidity (%): 30-70%
- Air changes (per hr): Not stated
- Photoperiod (hrs dark / hrs light): 12 hours light/dark

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

arachis oil

Doses:

Four dose rates were tested.
1,728 mg/kg bw
2,488 mg/kg bw
3,583 mg/kg bw
5,160 mg/kg bw

No. of animals per sex per dose:

5 female and 5 male animals were tested per dose rate.

Control animals:

not specified

Details on study design:

- Duration of observation period following administration: 14 days
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LD50

Effect level:

ca. 3 195 mg/kg bw

Remarks on result:

other: range 2,698 -3,834 mg/kg

Mortality:

In the 5,160mg/kg bw dose group all the animals died within 1 hour of dosing. In the 3,583 mg/kg bw group 5 deaths occurred up to 6 hours after dosing, in the 2,488 mg/kg bw group 3 deaths occurred up to 1 day after dosing and in the 1,728 mg/kg bw group no deaths were observed. The results are tabulated in table 1.0 in the remarks section below.

Clinical signs:

Symptoms observed immediately after dosing at all dose levels were paresis and depression.
On the second day after dosing the 3,583 mg/kg bw group had ruffled fur, which lasted to day 5.

Gross pathology:

Aminals that died during the observation period showed bleeding in the mucus membrane of the stomach at autopsy.
Those animals sacrificed after the 14 day observation period showed no dose related macroscopic changes.
Two of the animals from the 2,488 mg/kg bw group sacrificed after the 14 day observation period showed infiltrations between the oesophagus area of the ventricle and the diaphragm.
One animal in the high dose group showed infiltrations between the oesophagus area of the ventricle and the liver.

Any other information on results incl. tables

Table 1.0.

Doses, mortality/animals treated

Dose (mg/kg bw)	Males	Females	Combined
1,728	0/5	0/5	0/10
2,488	not specified/5	not specified/5	3/10
3,583	not specified/5	not specified/5	5/10
5,160	5/5	5/5	10/10

Applicant's summary and conclusion

Interpretation of results:

other: not classified

Remarks:

Criteria used for interpretation of results: other: Approved Classification and Labelling Guide (Sixth Edition), Chemicals (Hazard Information and Packaging for Supply) Regulations 2009 (CHIP 4)

Conclusions:

Based on the results obtained in the Scantox study - 4-chloro-o-cresol does not meet the criteria for classification as being hazardous by ingestion.

Executive summary:

Four groups of ten (5 male and 5 female) rats were dosed once with either 1,728 mg/kg bw, 2,488 mg/kg bw, 3,583 mg/kg bw, or 5,160 mg/kg bw of the test material by gavage.

Deaths and signs of toxicity were observed several times on the day of dosing and then at regular intervals over a 14-day observation period.

After 14 days the animals were killed and subjected to gross pathological examination. Based on the results obtained the LD50 was calculated to be 3195 mg/kg/bw.