4-chloro-o-cresol

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

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 402 (Acute Dermal Toxicity)

GLP compliance:

not specified

Test type:

standard acute method

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
- Housing: Individually caged.
- Diet (e.g. ad libitum): conventional laboratory diet
- Water (e.g. ad libitum): Unlimited supply
- Acclimation period: at least 5 days prior to the test

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20°C +/- 3°C
- Humidity (%): 30-70%
- Air changes (per hr): Not specified
- Photoperiod (hrs dark / hrs light): 12 hours light/12 hours dark

Administration / exposure

Type of coverage:

occlusive

Vehicle:

other: arachidis oil

Details on dermal exposure:

TEST SITE
- Area of exposure: Dorsal area of the trunk
- % coverage: approximately 10% of the total body suface area

REMOVAL OF TEST SUBSTANCE
- Washing (if done): Residual test material removed by washing with water or a suitable solvent 24 hours after dosing.
- Time after start of exposure: 24hours

Duration of exposure:

24 hours

Doses:

The doses tested were as follows:
1,667, 2,000, 2,400 and 2,880 mg PCOC

No. of animals per sex per dose:

There were 5 male and 5 female rats per dose

Control animals:

not specified

Details on study design:

- Duration of observation period following administration: 14 days
- Necropsy of survivors performed: yes

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LD50

Effect level:

ca. 2 240 mg/kg bw

Remarks on result:

other: Range 2023 -2484 mg/kg/bw

Mortality:

See table below (Table 1) for mortality details

Clinical signs:

During the first 24 hours after treatment blood was observed in the urine of all the rats. The day after treatment erythema and oedema were observed at the application sites. Paresis occurred in nearly all the animals 1-6 hours after treatment.
Depressions occurred up to 2 days after treatment and ruffled fur up to 3 days after treatment.

Gross pathology:

At necropsy, bleeding of the lungs, a mucous, red-yellow content of the jejunum (intestine), enlarged kidneys and blood or blood coagulum in the bladder and bleeding of the bladder walls were all observed.
In animals sacrificed on day 14, weak bleeding of the intestine was observed in five of the rats, the dose levels were not stated.

Any other information on results incl. tables

Table 1. Summary of mortality rates.

Dose Level, mg/kg bw	Mortality (out of 10)	Time Period
1667	0/10	-
2000	4/10	within 1 day of dosing
2400	6/10	within 1 day of dosing
2880	9/10	within 6 hours of dosing

                                  

Applicant's summary and conclusion

Interpretation of results:

other: Not classified as harmful in contact with skin

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 this study, 4-chloro-o-cresol is not classified as harmful in contact with skin.

Executive summary:

 A guideline study was performed on groups of five male and five female rats at dose levels ranging from 1667 - 2880 mg/kg bw.

In the 2880 mg/kg dose group 9 animals died within 6 hours of dosing, in the 2400 mg/kg dose group 6 animals died within 1 day of dosing, in the 2000 mg/kg dose group 4 animals died within 1 day of dosing, no animals died in the 1667 mg/kg dose group.

At necropsy bleeding of the lungs, a mucous, red-yellow content of the jejunum (intestine), enlarged kidneys and blood or blood coagulum in the bladder and bleeding of the bladder walls were all observed.

In animals sacrificed on day 14, weak bleeding of the intestine was observed in five of the rats; the dose levels were not stated.

During the first 24 hours after treatment blood was observed in the urine of all the rats. The day after treatment erythema and oedema were observed at the application sites. Paresis occurred in nearly all the animals 1-6 hours after treatment. Depressions occurred up to 2 days after treatment and ruffled fur up to 3 days after treatment. The LD50 was derived to be 2240 mg/kg/bw.