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Diss Factsheets

Toxicological information

Acute Toxicity: dermal

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Administrative data

Endpoint:
acute toxicity: dermal
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Well documented study,

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:
no
GLP compliance:
no
Test type:
standard acute method
Limit test:
no

Test material

Constituent 1
Chemical structure
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
- Analytical purity: ca. 31-32 % NaHS (concentration of a current batch, the analytical purity of the batch used for the study is not available)
- Impurities (identity and concentrations): Na2S<1%, Na2S2O3 ca. 0.3%, Na2SO4<2% (concentration of a current batch, the impurities of the batch used for the study are not available)
- Composition of test material: ca. 30 % solution of NaHS in water.

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 bw
No. of animals per sex per dose:
6
Control animals:
no
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:
In aqueous environments, H2S and the correponding salt NaHS are immediately hydrolyzed and, as a function of pH, an equilibrium is established between S2-, HS-, and H2S, with increasing H2S formation at decreasing pH.
As there is no acute dermal toxicity study with H2S available the present acute dermal toxicity study with 31 -32% NaHS ist taken to evaluate the acute dermal toxicity of H2S.
A LD50 of 632 mg/kg bw with a 95% range from 458 to 872 mg/kg bw. was found.
The lethal effects emerged within 2 hours after application. No later fatalities were observed. The application was done in an occlusive way. After 24 hours the skin at the application site showed mild reddening and eschar. Beside this local effect all dosed animals showed symptoms of unbalancing (lowest dosage: 100 mg/kg bw.).
Calculation to 100% NaHS: LD50 204 mg/kg bw.
Calculation of the acute dermal LD50 of H2S for the rat:
molecular weight of NaHS: 56.06;
molecular weight of H2S: 34.08;
LD50 of H2S: 124 mg/kg bw.
According to the criteria specified by Directive 67/548/EC, Regulation (EC) No 1272/2008 and subsequent regulations the test item is toxic and requires classification. (toxic category II according to GHS)
Executive summary:

Up to a limit concentration H2S dissolves in water in a temperature dependent way. At 20 °C the limit is 3,98 g/l. H2S can stay present in water for several hours. In aqueous environments, H2S and the corresponding salt NaHS are immediately hydrolyzed and, as a function of pH, an equilibrium is established between S2-, HS-, and H2S, with increasing H2S formation at decreasing pH. Temperature and salinity also affect this equilibrium but to a much lesser extent than pH.

As there is no acute dermal toxicity study with H2S available. The present acute dermal toxicity study with 31 -32% NaHS is taken to evaluate the acute dermal toxicity of H2S.

A LD50 of 632 mg/kg bw with a 95% range from 458 to 872 mg/kg bw. was found.

The lethal effects emerged within 2 hours after application. No later fatalities were observed. The application was done in an occlusive way. After 24 hours the skin at the application site showed mild reddening and eschar. Beside this local effect all dosed animals showed symptoms of unbalancing (lowest dosage: 100 mg/kg bw.).

Calculation to 100% NaHS: LD50 204 mg/kg bw.

Calculation of the acute dermal LD50 of H2S:

molecular weight of NaHS: 56.06;

molecular weight of H2S: 34.08;

dermal LD50 of H2S with rats: 124 mg/kg bw.