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EC number: 240-778-0 | CAS number: 16721-80-5
- Life Cycle description
- Uses advised against
- Endpoint summary
- Appearance / physical state / colour
- Melting point / freezing point
- Boiling point
- Density
- Particle size distribution (Granulometry)
- Vapour pressure
- Partition coefficient
- Water solubility
- Solubility in organic solvents / fat solubility
- Surface tension
- Flash point
- Auto flammability
- Flammability
- Explosiveness
- Oxidising properties
- Oxidation reduction potential
- Stability in organic solvents and identity of relevant degradation products
- Storage stability and reactivity towards container material
- Stability: thermal, sunlight, metals
- pH
- Dissociation constant
- Viscosity
- Additional physico-chemical information
- Additional physico-chemical properties of nanomaterials
- Nanomaterial agglomeration / aggregation
- Nanomaterial crystalline phase
- Nanomaterial crystallite and grain size
- Nanomaterial aspect ratio / shape
- Nanomaterial specific surface area
- Nanomaterial Zeta potential
- Nanomaterial surface chemistry
- Nanomaterial dustiness
- Nanomaterial porosity
- Nanomaterial pour density
- Nanomaterial photocatalytic activity
- Nanomaterial radical formation potential
- Nanomaterial catalytic activity
- Endpoint summary
- Stability
- Biodegradation
- Bioaccumulation
- Transport and distribution
- Environmental data
- Additional information on environmental fate and behaviour
- Ecotoxicological Summary
- Aquatic toxicity
- Endpoint summary
- Short-term toxicity to fish
- Long-term toxicity to fish
- Short-term toxicity to aquatic invertebrates
- Long-term toxicity to aquatic invertebrates
- Toxicity to aquatic algae and cyanobacteria
- Toxicity to aquatic plants other than algae
- Toxicity to microorganisms
- Endocrine disrupter testing in aquatic vertebrates – in vivo
- Toxicity to other aquatic organisms
- Sediment toxicity
- Terrestrial toxicity
- Biological effects monitoring
- Biotransformation and kinetics
- Additional ecotoxological information
- Toxicological Summary
- Toxicokinetics, metabolism and distribution
- Acute Toxicity
- Irritation / corrosion
- Sensitisation
- Repeated dose toxicity
- Genetic toxicity
- Carcinogenicity
- Toxicity to reproduction
- Specific investigations
- Exposure related observations in humans
- Toxic effects on livestock and pets
- Additional toxicological data
Endpoint summary
Administrative data
Key value for chemical safety assessment
Additional information
General
A literature search and evaluation programme on animal and human genetic toxicity data of sodium sulfide and sodium hydrogensulfide has been conducted.All data sources were assessed by expert toxicologists for quality and reliability, as well as relevance for regulatory risk assessment under REACH. The results are attached to the technical dossier in atabular report (IUCLID section 13).
Read-across from Na2S to NaHS:
Given that sodium sulfide and sodium hydrogensulfide dissociate in aqueous media, it can safely be assumed that under most physiologically relevant conditions ( i.e., neutral pH) sulfide and hydrogen sulfide anions are present at almost equimolar concentrations, thus facilitating unrestricted read-across between both species. Only under extreme conditions such as gastric juice (pH << 2), sulfides will be present predominantly in the form of the non-dissociated hydrogen sulfide. In turn,hydrogen sulfide (H2S) may be formed from both soluble sulfides, according to the following equilibria:
Na2S + H2O → NaOH + NaHS (2Na+/ OH-/ HS-)
NaHS + H2O → NaOH + H2S (Na+/ OH-/ H2S)
Similarly, hydrogen sulfide dissociates in aqueous solution to form two dissociation states involving the hydrogen sulfide anion and the sulfide anion, according to the following equilibrium:
H2S ↔ H+ + HS- ↔ 2 H+ + S2-
In conclusion, under physiological conditions, inorganic sulfides or hydrogensulfides as well as H2S will dissociate to the respective species relevant to the pH of the physiological medium, irrespective the nature of the “sulfide”, which is why read-across between these substances and H2S is considered to be feasible without any restrictions.
Results:
All three available studies, performed with sodium sulfide or sodium hydrogensulfide, yielded negative results concerning genetic toxicity
- in the reliable in-vitro HPRT test (Stone_2010) it is concluded that sodium sulfide, anhydrous did not induce mutation at thehprtlocus of mouse lymphoma cells when tested under the conditions employed in this study. Based on unlimited read-across the same result applies for sodium hydrogensulfide.
- in the reliable in-vitro Ames test (reverse gene mutation assay) reported by Gelbke_1989 it is concluded that sodium hydrogensulfide is not mutagenic under the experimental conditions.
- a reliable in-vivo micronucleus test (Gocke_1981) had a negative result for sodium sulfide: no significant exerted mutagenic action was observed. Based on unlimited read-across the same result applies for sodium hydrogensulfide.
The REACH requirements according to the endpoints in section 8.4, Annex VII-X in Regulation (EC) 1907/2006 are fulfilled. No further testing is required.
.Short description of key information:
In-vitro studies:
- The HPRT test (Covance_2010) performed with sodium sulfide (anhydrous) according to OECD guideline 476 was rated as RL=1 (reliable without restrictions) and used as a key study. The study had a negative result for induction of mutation at the hprt locus of mouse lymphoma cells. Read-across applies from sodium sulfide to sodium hydrogensulfide.
- The key study on in vitro gene mutation of sodium hydrogensulfide (bacterial reverse mutation assay; Gelbke_1989) was rated as reliable with restrictions and had a negative result for mutagenic properties.
In-vivo studies:
Chromosome aberration of sodium sulfide has been tested in-vivo in a micronucleus assay performed in mice similar to OECD guideline 474 (Gocke_1981). This study was rated as reliable with restrictions (RL=2) and is used as a key study. The study had a negative result. Read-across applies from sodium sulfide to sodium hydrogensulfide.
Endpoint Conclusion: No adverse effect observed (negative)
Justification for classification or non-classification
All available reliable studies showed no genetic toxicity for sodium sulfide or sodium hydrogensulfide. Read-across between the two compounds is unrestricted. Thus, no classification is required for sodium hydrogensulfide.
Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of a registration number does however not guarantee that the information in the dossier is correct or that the dossier is compliant with Regulation (EC) No 1907/2006 (the REACH Regulation). This information has not been reviewed or verified by the Agency or any other authority. The content is subject to change without prior notice.
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