Sodium hydrogensulphide

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

disregarded due to major methodological deficiencies

Reliability:

3 (not reliable)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Well documented study, however, the evaluation and interpretation of the testing results leads to the rating as a non-reliable study: because of the corrosive nature of NaHS the results of the study should be considered as questionable as the skin is hurt by application of a corrosive substance and an intact skin area, which is the basis for the acute dermal toxicity testing, is no longer given.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1974

Report date:

1974

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Deviations:

yes

Remarks:

Test substance identity not identified.

GLP compliance:

no

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Sodium hydrogensulphide

EC Number:

240-778-0

EC Name:

Sodium hydrogensulphide

Cas Number:

16721-80-5

Molecular formula:

NaHS

IUPAC Name:

sodium hydrogensulfide

Constituent 2

Reference substance name:

sodium sulfhydrate

IUPAC Name:

sodium sulfhydrate

Details on test material:

- Name of test material (as cited in study report): Sulfhydrat F150, NAtriumsulfhydratlauge
- Molecular formula (if other than submission substance): NaHS (aqueous solution)
- Substance type: technical product
- Physical state: yellow liquid
- Storage condition of test material: In tightly closed original container, in a cool, well-ventilated place; protect from sunlight; do not store with acids; do not store together with oxidizing agents
- Other: pH value: 12 - 13; the test substance is an aqueous solution of the reference substance
No further information on the test material was stated.

Test animals

Species:

rat

Strain:

Wistar

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- female SPF Wistar rats
- Source: self-breeding
- Age at study initiation:
- Weight at study initiation: 160-200 g(mean:172 g)
- Fasting period before study:
- Housing: Animals were caged individually
- Diet: standard diet ALTROMIN 1324 (Firma Altrogge in Lage/Lippe, Germany), ad libitum
- Water: tap water, ad libitum
- Acclimation period:


ENVIRONMENTAL CONDITIONS
- Temperature (°C):
- Humidity (%):
- Air changes (per hr):
- Photoperiod (hrs dark / hrs light):


IN-LIFE DATES: From: To:

Administration / exposure

Type of coverage:

not specified

Vehicle:

unchanged (no vehicle)

Details on dermal exposure:

TEST SITE
- fur was mechanically removed from the test site
- animals were checked for intact skin
- Area of exposure: skin on the back of the test animals
- Type of wrap if used: exposure site was covered for 24 hours by an aluminium film (6 x 8 cm) fixed with tape (Elastoplast)


REMOVAL OF TEST SUBSTANCE
- Washing (if done): after 24 h the film was removed and the test side was washed - residual test substance was removed

TEST MATERIAL
- Concentration (if solution): undiluted test substance was applied (yellow liquid, ca. 30 % NaHS*xH2O)

Duration of exposure:

single exposure

Doses:

100, 200, 400, 800, 1600 mg/kg of the test substance "Sulfhydrat"

No. of animals per sex per dose:

6

Control animals:

not specified

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: following application of the test substance, the animals were observed frequently during the first day, then during the 14 days of observation the animals were weighed daily (except on weekends) and clinically examined (daily)
- animals which died were necropsied
- Necropsy of survivors performed: yes, after 14 days of exposure and examined macroscopically

Statistics:

LD50 was calculated by Probitanalysis (acc. to Lindner and Weber method). The confidence limit was calculated acc. to Cavalli-Sforza.

Results and discussion

Effect levels

Sex:

female

Dose descriptor:

LD50

Effect level:

632 mg/kg bw

Based on:

test mat.

Remarks:

NaHS, ca. 30 %

95% CL:

1 260

Remarks on result:

other: p=0.05; LD50 range 458-872 mg/kg bw. Because of corrosive nature of NaHS the results should be considered as questionable since the skin may be hurt by application of a corrosive substance.

Mortality:

- 100 mg/kg dose: 0/6; 200 mg/kg dose: 0/6; 400 mg/kg dose: 1/6; 800 mg/kg dose: 4/6; 1600 mg/kg dose: 6/6 rats died
- animals of the 1600 mg/kg group died within 106-117 minutes after application of the test substance in face-down position with symptoms of unbalancing
- the same symptoms were observed in the animals which received the lower test substance concentrations, however these died later after application
- the individual values are given in a table, attached to the report

Clinical signs:

other: - symptoms of unbalancing in all groups - the skin at the exposure site (back) showed mild reddening and eschar in all groups after removing the bandage

Gross pathology:

- no significant findings

Any other information on results incl. tables

Authors comment: Because of the high toxicity of Sulfhydrat on skin, the contact to skin and eyes should be avoided.

Applicant's summary and conclusion

Interpretation of results:

harmful

Remarks:

Migrated information according to CLP Criteria used for interpretation of results: EU

Conclusions:

An LD50 of 632 mg/kg bw was calculated from this study with Sulfhydrat (sodium hydrogensulfide, ca. 30 %).
According to the criteria specified by Directive 67/548/EC, Regulation (EC) No 1272/2008 and subsequent regulations the test item is harmful and requires classification. Although the LD50 values from the dermal toxicity study performed with Sulfhydrat F150 theoretically triggers classification with harmful to toxic (DSD/GHS) for sodium hydrogensulfide, 77 %, this is not justified, because of the corrosive nature of NaHS. The results of the study should be considered as questionable since the skin is hurt by application of a corrosive substance and an intact skin area, which is the basis for the acute dermal toxicity testing, is no longer given. No classification is proposed for acute dermal toxicity in the absence of an appropriate study; the acute dermal toxicity of sodium hydrogensulfide is dominated by local corrosivity and irritancy and is therefore sufficiently addressed by the classification of the substance as corrosive to skin.

Executive summary:

Calculation of the LD50 for the most concentrated commercial form sodium hydrogensulfide, 77 %:

LD50 = 632 mg/kg bw for NaHS, ca. 30 %

--> LD50 = 246 mg/kg bw for NaHS, 77 %