3,3'-dichlorobenzidine dihydrochloride

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From 02 APR 2009 to 28 APR 2009

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study (OECD 423; EU Method B.1. tris)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2009

Report date:

2009

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.1 tris (Acute Oral Toxicity - Acute Toxic Class Method)

Deviations:

no

GLP compliance:

yes

Test type:

acute toxic class method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

3,3'-dichlorobenzidine dihydrochloride

EC Number:

210-323-0

EC Name:

3,3'-dichlorobenzidine dihydrochloride

Cas Number:

612-83-9

Molecular formula:

C12H10Cl2N2.2ClH

IUPAC Name:

3,3'-dichloro-[1,1'-biphenyl]-4,4'-diamine dihydrochloride

Details on test material:

- Name of test material (as cited in study report): 3,3'-Dichlorbenzidin-dihydrochlorid

Test animals

Species:

rat

Strain:

other: HanRcc:WIST (SPF)

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Harlan Laboratories Ltd., Füllinsdorf, Switzerland
- Age at study initiation: 11 weeks
- Weight at study initiation: 181.1-200.9 g
- Fasting period before study: yes (overnight)
- Housing: in groups of three in Makrolon type-4 cages
- Diet: Pelleted standard Provimi Kliba 3433 rat/mouse maintenance diet (Provimi Kliba AG, Kaiseraugst, Switzerland); ad libitum except for fasting period (overnight prior to intubation and approximately 3-4 hours post dose)
- Water: community tap water, ad libitum
- Acclimation period: at least 5 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 +/- 3
- Humidity (%): 30-70%
- Air changes (per hr): 10-15
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

polyethylene glycol

Details on oral exposure:

VEHICLE (Polyethylene glycol 300: PEG 300)
- Concentration in vehicle: 0.2 g/mL
- Justification for choice of vehicle: vehicle selected, because test item was not soluble in purified water
- Lot/batch no.: S41673-128

MAXIMUM DOSE VOLUME APPLIED: 10 mL/kg bw

DOSAGE PREPARATION: shortly before dosing

CLASS METHOD
- Rationale for the selection of the starting dose: The dose of 2000 mg/kg bw was selected as available information point towards a low acute toxicity.

Doses:

2000 mg/kg

No. of animals per sex per dose:

6 females (two groups of 3 females)

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of weighing: on test days 1 (prior to administration), 8 and 15
- Frequency of observations: daily during acclimatization period, during the first 30 minutes and at approximately 1, 2, 3 and 5 hours after administration on test day 1, depending on the occurrence of clinical signs of toxicity; once daily during days 2-15
- Necropsy of survivors performed: yes

Statistics:

none

Results and discussion

Effect levels

Sex:

female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Remarks on result:

other: none of the animals died during the 14 day observation period

Mortality:

- none

Clinical signs:

other: - slight sedation, ocular opacity and slightly ruffled fur were observed in all animals from the first 30 minutes or 1 hour observation and persisted up to test day 3 at latest - hunched posture was seen in all animals from the 2- or 3-hour reading up to

Gross pathology:

- no macroscopic findings at necropsy

Applicant's summary and conclusion

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: expert judgment

Conclusions:

3,3'-Dichlorbenzidine dihydrochlorid does not cause lethality in female rats after single oral application of 2000 mg/kg bw, resulting in a LD50 of > 2000 mg/kg bw.

Executive summary:

Two groups, each of three female HanRcc:WIST (SPF) rats, were treated with 3,3'-Dichlorbenzidine-dihydrochlorid by oral gavage administration at a dosage of 2000 mg/kg bodyweight. The test item was formulated in PEG 300 at a concentration of 0.2 g/mL and administered at a dosing volume of 10 mL/kg.

The animals were examined daily during the acclimatization period and mortality, viability and clinical signs were recorded. All animals were examined for clinical signs during the first 30 minutes and approximately 1, 2, 3 and 5 hours after treatment on day 1 and once daily during test days 2-15. Mortality/viability was recorded during the first 30 minutes and approximately 1, 2, 3 and 5 hours after administration on test day 1 (with the clinical signs) and twice daily during days 2-15. Body weights were recorded on day 1 (prior to administration) and on days 8 and 15.All animals were necropsied and examined macroscopically.

All animals survived until the end of the study period.

Several clinical signs, such as slight sedation, ocular opacity and slightly ruffled fur were observed from the first 30 minutes or 1-hour observation and persisted up to test day 3 at the latest. Hunched posture was seen in all animals from the 2- or 3-hour reading up to the 5-hour reading or test day 2. Additionally, in two animals cyanosis was noted from the 5-hour observation to test day 2. Thereafter, all animals were free of clinical signs until test day 15, the end of observation.

The body weight of the animals was within the range commonly recorded for rats of this strain and age.

No macroscopic findings were recorded at necropsy.

The median lethal dose of 3,3'-Dichlorbenzidine-dihydrochlorid after single oral administration to female rats, observed over a period of 14 days is:

LD50 (female rat): greater than 2000 mg/kg body weight

LD₅₀ cut-off: infinite

In mg/kg b.w., according to ANNEX 3 of Regulation (EC) No 1907/2006, B. 1 tris.