Potassium 2-(4-chloro-2-methylphenoxy)propionate

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

24.10.2006 - 14.11.2006

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2006

Report date:

2006

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

EU Method B.1 bis (Acute Oral Toxicity - Fixed Dose Procedure)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test type:

fixed dose procedure

Test material

Test material information

Constituent 1

Reference substance name:

Mecoprop

EC Number:

230-386-8

EC Name:

Mecoprop

Cas Number:

7085-19-0

Molecular formula:

C10H11ClO3

IUPAC Name:

2-(4-chloro-2-methylphenoxy)propanoic acid

impurity 1

Reference substance name:

Water

EC Number:

231-791-2

EC Name:

Water

Cas Number:

7732-18-5

Molecular formula:

H2O

IUPAC Name:

water

Test material form:

solid

Test animals

Species:

rat

Strain:

Wistar

Sex:

female

Details on test animals or test system and environmental conditions:

Two 8-weeks female rats of an average weight 180 g were used in sighting study.
Four 10-weeks female rats of an average weight of 176.5 g were used in the main study.

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

other: Tylose solution

Doses:

In sighting study test material was administrated to one female in dose 2000 mg/kg b.w. Because the female died the test material was administrated to the next female in dose of 300 mg/kg b.w.

Taking into account the results of sighting study the test material was administrated to further four females in dose 300 mg/kg b.w.

No. of animals per sex per dose:

1 female rat administrated in dose of 2000 mg/kg b.w.
5 female rats administrated in dose of 300 mg/kg b.w. (1 rat in sighting study and 4 rats in main study).

Control animals:

no

Results and discussion

Effect levels

Key result

Sex:

female

Dose descriptor:

LD50

Effect level:

> 300 - <= 2 000 mg/kg bw

Mortality:

Following administration of the test material in dose of 2000 mg/kg b.w. (sighting study) to one female, the animal died in the first day of observation.

Clinical signs:

Following administration of the test material in dose of 2000 mg/kg b.w. (sighting study) to one female clinical signs were observed within 24 hours of administration of the test material. Changes in body posture, gait, locomotor activity and reactivity as well as bristled fur were noticed. The female died in the first day of observation.

Following administration of the test material in dose of 300 mg/kg b.w. (sighting study) to one female on day of administration of test material changes gait, locomotor activity and reactivity as well as bristled fur were noticed. Since the first day till the fourteenth day after administration of the test material no signs of toxicity were noticed in the female any more. The animal survived 14-day observation period.
Following administration of the test material in dose of 300 mg/kg b.w. (the main study) to further for females on day of administration of test material changes gait, locomotor activity and reactivity as well as bristled fur were noticed. Since the first day till the fourteenth day after administration of the test material no signs of toxicity were noticed in the all females any more. The females survived 14-day observation period.

Body weight:

All test animals showed body weight increase during 14-day observation period.

Gross pathology:

One female died after administration of the test material in dose of 2000 mg/kg b.w. In microscopic studied liver congestion and small amount of bloody liquid in pleura were showed.

The remaining females did not reveal any pathological changes in macroscopic studies.

Applicant's summary and conclusion

Interpretation of results:

Category 4 based on GHS criteria

Conclusions:

Taking into account the obtained results, one may say that the median oral acute dose (LD50) mecoprop is higher than 300 mg/kg b.w. and below of equal 2000 mg/kg b.w.