Sodium dithionite

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Remarks:

This study report is a revised version of a study report from 1973. Minor deviations from the guideline without an effect on the results: - The stability of the test material was missing. -According to the guideline the observation period should be at least 14 day. In this study an observation period of 7 days was used. This is considered to have no effect on the results, since none of the animals died after 24 hours. - The clinical signs were documented group-wise and there was no statement about how many animals showed signs of toxicity. According to the guideline individual records should be held and number of animals showing toxic signs should be stated. - Body weight was not determined weekly and at death, which should be done according to the guideline. -There were no details about acclimatisation period, strain, individual body weights, diet, and environmental conditions. Also, it was not stated if animals were fasted prior to substance e administration or how often clinical examinations were made.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2003

Report date:

1973

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

Version / remarks:

1987-02-24

Deviations:

yes

Remarks:

, "see rationale for reliability"

GLP compliance:

no

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Sodium dithionite

EC Number:

231-890-0

EC Name:

Sodium dithionite

Cas Number:

7775-14-6

Molecular formula:

H2O4S2.2Na

IUPAC Name:

disodium dithionite

Test material form:

not specified

Details on test material:

- Name of test material (as cited in study report): Hydrosulfit konz. BASF (Sodium dithionite)

Specific details on test material used for the study:

not specified

Test animals

Species:

rat

Strain:

other: not stated

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Gassner rats
- Age at study initiation: young adult laboratory rats were used.
- Weight at study initiation: average weight at beginning of the test: 170 - 203 g

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

other: 0.5 % CMC-solution (cleaned sodium carboxymethylcellulose) in doubly distilled water; Suspension

Details on oral exposure:

The doses were administered as aqueous suspensions of 2 %, 16 %, 20 % (2000 and 2500 mg/kg) and 30 % (3200 and 6400 mg/kg) test substance in 0.5 CMC-Solution (Hoechst AG).

MAXIMUM DOSE VOLUME APPLIED: The cocnetrations of the preparations were adjusted to achieve comparable volumes (about 10 -20 ml) per kg body weight.

Doses:

200, 1600, 2000, 2500, 3200 and 6400 mg/kg bw

No. of animals per sex per dose:

5 males / 5 females

Control animals:

no

Details on study design:

- Duration of observation period following administration: 7 days
- Necropsy performed: yes
- Examinations performed: group-wise documentation of clinical signs was performed over the 7-day study period. Body weight was determined before the start of the study for determination of dose.

Statistics:

On the basis of the observed lethality, the LD50 value was estimated or determined using a graphical evaluation of the dose response curve on probability paper.

Results and discussion

Effect levels

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

ca. 2 500 mg/kg bw

Based on:

test mat.

Mortality:

200 mg/kg bw: no deaths
1600 mg/kg bw: no deaths
2000 mg/kg bw: no deaths
2500 mg/kg bw: 3 males and 2 females died within the first 24 hours
3200 mg/kg bw: 4 males and 5 females died within the first 24 hours
6400 mg/kg bw: 5 males and 5 females died in the first hour.

Clinical signs:

other: 6400 mg/kg bw: intermittent respiration, squatting posture and atony immediately after application. 3200 mg/kg bw: intermittent respiration, squatting posture and atony immediately after application. No clinical signs and findings in the surviving animal

Gross pathology:

6400 and 3200 mg/kg bw: Congestive hyperemia, heart: dilation, stomach: dilatation, partly bloody ulcers and liquid content, intestine: hematinized, diarrheic content
2500 mg/kg bw: Congestive hyperemia, heart: dilatation, stomach: dilatation, liquid content, red discoloration of the glandular stomach, intestine: partly diffuse discoloration, diarrheic content
2000, 1600 and 200 mg/kg bw: Organs without particular findings.

Other findings:

not stated

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

LD50 (male and female rats): approx. 2500 mg/kg bw
According to the Regulation (EC) No 1272/2008 and subsequent adaptations, the substance is not acutely toxic via the oral route.