Sodium dithionite

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

Type of information:

read-across based on grouping of substances (category approach)

Adequacy of study:

key study

Study period:

2009-01-27 to 2009-02-11

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

see attachment “Read-across concept – Human Health/Environment - Category approach for Inorganic sulfites/thiosulfates/dithionite" in section 13.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2009

Report date:

2009

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Version / remarks:

1987-02-24

Deviations:

yes

Remarks:

, - Solid test substance was applied as a solution; - Humidity range (animal housing): 20- 80 %

GLP compliance:

yes (incl. QA statement)

Remarks:

signed 2008-04-17

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Sodium sulphite

EC Number:

231-821-4

EC Name:

Sodium sulphite

Cas Number:

7757-83-7

Molecular formula:

NA2SO3

IUPAC Name:

disodium sulfite

Test material form:

solid

Details on test material:

- Name of test material (as cited in study report): Natriumsulfit wasserfrei food grade (E221)/(PRD30042389)
- Physical state: Solid / white

Specific details on test material used for the study:

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Room temperature; under N2; protect against humidity

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Wiga GmbH, Sandhofer Weg 7, 97633 Sulzfeld, Germany
- Age at study initiation: Young adult animals (male animals approx. 8 weeks, female animals approx. 12 weeks)
- Weight at study initiation: Animals of comparable weight (+/- 20% of the mean weight); mean weights males: 255 g; mean weights females: 218 g
- Housing: The animals were housed individually. The animals were housed in fully air-conditioned rooms. Type of cage: Makrolon cage, type III. Bedding: H 15005-29; Ssniff, Spezialitäten GmbH (Experimental Animal Diets Inc., 59494 Soest, Germany).
- Diet: VRF1(P); SDS Special Diets Services, 67122 Altrip, Germany.
- Water (ad libitum): Tap water
- Acclimation period: At least 5 days before the beginning of the experimental phase; during the acclimatization period, the animals were accustomed to the environmental conditions of the study and to the diet
- Enrichment: NGM E-022; ABEDD®LAB & VET Service GmbH, Hasnerstraße 84/6; 1160 Wien - Austria

ENVIRONMENTAL CONDITIONS
- Temperature: 22 – 26°C
- Relative humidity: 20 – 80%
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Type of coverage:

semiocclusive

Vehicle:

water

Details on dermal exposure:

TEST SITE
- Area of exposure: About 24 hours before administration the fur was clipped. Then a single application to the clipped epidermis (dorsal and dorsolateral parts of the trunk) was applied.
- % coverage: At least 10 % of the body surface (about 40 cm^2)
- Type of wrap: Covering of the application site with a semi-occlusive dressing (the bandage consists of four layers absorbent gauze, Ph. Eur. Lohmann GmbH & Co. KG and Fixomull stretch (adhesive fleece), Beiersdorf AG) for 24 hours, afterwards removal of the dressing.

REMOVAL OF TEST SUBSTANCE
- Washing (if done): Rinsing of the application site with warm water.
- Time after start of exposure: 24 hours

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 10 ml/kg (application volume)
- Concentration: 20 g/100 ml
- Constant volume or concentration used: yes, constant volume
- For solids, paste formed: No, a solution was used for application. The test substanc epreparation was produced for the application group shortly before application by stirring with a magnetic stirrer.
VEHICLE: Doubly distilled water

Duration of exposure:

24 hours

Doses:

2000 mg/kg

No. of animals per sex per dose:

5 males / 5 females

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Body weight determination: Individual body weights shortly before administration (day 0), weekly thereafter and on the last day of observation.
- Signs and symptoms: Recording of signs and symptoms several times on the day of application, at least once each workday for the individual animals.
- Scoring of skin findings: Individual readings 30 – 60 minutes after removal of the semi-occlusive dressing (day 1), as a rule weekly thereafter and on the last day of observation.
- Mortality: A check for any dead or moribund animal was made twice each workday and once on weekends and on public holidays, these records are archived by Bioassay.
- Pathology: Necropsy with gross-pathology examination on the last day of the observation period after sacrifice with CO2 in a chamber with increasing concentrations over time.
Assessment of skin reactions: The evaluation of skin reactions was performed according to Draize, J.H. (1959): Appraisal of the safety of chemicals in foods, drugs and cosmetics. The association of food and drug officials of the United States Austin, Texas. Descriptions of any dermal findings not covered by this scale were recorded.

Statistics:

The means and standard deviation were calculated by using MS Excel 2003.

Results and discussion

Effect levels

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

No mortality occurred.

Clinical signs:

other: No systemic clinical observations were observed during clinical examination. No local effects were observed.

Gross pathology:

No macroscopic pathologic abnormalities were noted in the animals (5 males and 5 females) examined on the last day of observation.

Other findings:

No data

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

LD50 (male and female rats) > 2000 mg/kg bw
According to the EC Regulation No. 1272/2008 and subsequent regulations, the test item is not classified as acute toxic via the dermal route.