methyl (2,3-dichlorophenoxy)acetate

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: The study had been performed in accordance with OECD Guideline No.: 423.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2006

Report date:

2006

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 423 (Acute Oral toxicity - Acute Toxic Class Method)

GLP compliance:

yes (incl. QA statement)

Test type:

acute toxic class method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

methyl (2,3-dichlorophenoxy)acetate

EC Number:

606-285-3

Cas Number:

1928-56-9

Molecular formula:

C9H8Cl2O3

IUPAC Name:

methyl (2,3-dichlorophenoxy)acetate

Test material form:

solid: crystalline

Details on test material:

- Name of test material (as cited in study report): Dichlorophenoxyacetic acid methyl ester
- Physical state: almost white powder
- Purity test date: 26. 09. 2005
- Lot/batch No.: 3
- Expiration date of the lot/batch: : 07. 2006
- Storage condition of test material: at room temperature, protected from light

Test animals

Species:

rat

Strain:

Wistar

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: TOXI COOP KKT. Budapest, HUNGARY
- Age at study initiation: 40-45 days
- Weight at study initiation: 131.8-150.5 g
- Fasting period before study: approx. 20 hours (after the test item administration food was withheld for 3 hours)
- Housing: 3 animals / cage, in Techniplast 1291 type plastic cages. (425x266x180 mm)
- Diet (e.g. ad libitum): ad libitum, ssniff SM r/M-z+H complete feed for rats and mice supplied by TOXI COOP KKT.
- Water (e.g. ad libitum): potable water, ad libitum, offered daily in 500-ml drinking bottles sterilized before use (121 °C, 20 minutes)
- Acclimation period: 7 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20.3-22.6 °C
- Humidity (%): 36-53 %
- Air changes (per hr): 10-15 / h
- Photoperiod (hrs dark / hrs light): 12 h dark / 12 h artificial light

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

other: 1% Methylcellulose

Details on oral exposure:

MAXIMUM DOSE VOLUME APPLIED: 2000 mg / kg bodyweight = 20 ml / kg test item in vehicle suspension
3.000 g, 0.450 g dichlorophenoxyacetic acid methyl ester + 1% mucilage methylcellulose ad 30.0 ml

Doses:

2000 mg / kg
300 mg / kg

No. of animals per sex per dose:

3 at dose 2000 mg/kg
2x3 at dose 300 mg/kg

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: for 6 hours after treatment and then at least twice a day
- Necropsy of survivors performed: yes ( gross)
- Other examinations performed: clinical signs of toxicity, status of skin, fur, eyes, mucous membranes, respiratory, circulatory, autonomic and central nervous system, somatomotor activity, body weight

Results and discussion

Effect levels

Sex:

female

Dose descriptor:

approximate LD50

Effect level:

> 200 - <= 2 000 mg/kg bw

Mortality:

All animals given 2000 mg/kg test item died within three days after dosing (Day 1, 2 and 3). No lethalities occurred in the other six animals dosed with 300 mg/kg on the dosing day or during the 14-day observation period.

Clinical signs:

other: Before death, somnolence of different degree, incoordinated movement and haemorrhagic nasal discharge were seen in the animals which died (2000 mg/kg). No changes were observed in the appearance and behaviour of animals dosed with 300 mg/kg on the dosing

Gross pathology:

The following necropsy findings were found in the died animals (2000 mg/kg): bad condition; disseminated haemorrhages in the thymus; enlarged stomach containing dosing preparation, dark-coloured, point-like deposits, and mucosal erosions in the stomach; red-coloured gaseous, mucous content in the small intestines; mottled lungs with haemorrhages; congested brain.
No macroscopic changes were detected at he necropsy of animals dosed with 300 mg/kg.

Applicant's summary and conclusion

Interpretation of results:

harmful

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

Under the applied test conditions, the approximate calculated cut-off LD50 value of dichlorophenoxyacetic acid methyl ester administered by oral route to Crl:(WI)BR rats was above 300 mg/kg, therefore, according to the requirements of the Minister of Health 44/2000.(XII.27.) EüM regulation the test item could be classified as harmful (>200-2000 mg/kg).