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EC number: 233-340-5 | CAS number: 10124-53-5
- 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
Genetic toxicity in vitro
Description of key information
Read across from ammonium thiosulfate (CAS 7783-18-8) was performed to determine whether magnesium thiosulfate has genetic toxicity properties. Ammonium thiosulfate has been tested in bacterial reverse mutation assays, in vitro gene mutation and clastogenicity tests . All tests show a negative response, thus ammonium thiosulfate does not require classification for mutagenic properties. This result can be read across to magnesium thiosulfate without restriction.
Endpoint conclusion
- Endpoint conclusion:
- no adverse effect observed (negative)
Additional information
Read-across concept for sulfites, hydrogensulfites, metabisulfites, dithionites and thiosulfates:
A comprehensive read-across concept has been developed for sulfites, hydrogensulfites and metabisulfites, based on the pH-dependant equilibrium in aqueous solutions which is summarised in the following equations:[1],[2]
SO2+ H2O <->`H2SO3´ H2SO3<->H++ HSO3-<->2H++SO32- 2HSO3-<->H2O +S2O52-
Since the nature of the cation (i.e., sodium, potassium, ammonium…) is not assumed to contribute substantially to differences in toxicity and solubility (all compounds are very soluble in water), only the chemical and biological properties of the anion are considered as relevant determinants. Based on the described equilibrium correlations, unrestricted read-across between the groups of sulfites, hydrogensulfites and metabisulfites is considered justified.
Additionally, it is known that sodium dithionite disproportionates in water to form sodium hydrogen sulfite and sodium thiosulfate (equation II)2,[1], so that this substance can also be considered to be covered by the read-across concept described above. Since it can easily be anticipated that the substance is not stable enough under physiological conditions to fulfil the requirements of study guidelines, instead the products of decomposition have to be considered:
2 S2O42-+ H2O→2HSO3-+ S2O32-
Not fully covered by this read-across concept is the substance class of thiosulfates: although the thiosulfates are also well known to disproportionate in aqueous solution to form polythionic acids and SO2(HSO3-), this requires somewhat different, more acidic conditions. Therefore, read-across to sulfites is primarily restricted to appropriate physiological conditions, i.e. oral administration where the gastric passage with the strongly acidic conditions in the stomach will facilitate the chemical disproportionation described above:
HS2O3-+ H2S2O3→HS3O3- + SO2+ H2O
[1]Hollemann Wiberg, Lehrbuch der Anorganischen Chemie, 101.Auflage
[2]Handbook of Chemistry and Physics, Ed. Lide, DR, 88thedition, CRC Press
In vitro genetic toxicity
Ammonium thiosulfate was assayed for the ability to induce mutation at the hypoxanthine-guanine phosphoribosyl transferase (hprt) locus (6-thioguanine [6TG] resistance) in mouse lymphoma cells according to OECD 476. The study consisted of a cytotoxicity Range-Finder experiment followed by two independent experiments, each conducted in the absence and presence of metabolic activation (S9). It is concluded that ammonium thiosulfate did not induce mutation at the HPRT locus of L5178Y mouse lymphoma cells when tested under the conditions employed in this study up to 1482µg/mL. Additionally ammonium thiosulfate did not induce chromosome aberrations in chinese hamster ovary cells (CHO) when tested under the conditions employed in this study (OECD 473) up to 1480µg/mL. These conditions included treatments in two independent experiments, in the absence and presence of a rat liver metabolic activation system (S-9). Based on the findings of this study, Ammonium thiosulfate was concluded to be negative for the induction of structural and numerical chromosome aberrations in CHO cells. Furthermore, ammonium thiosulfate, was tested in the Bacterial Reverse Mutation Assay using S. Typhimurium tester strains TA 98, TA 100, TA 1535 and TA 1537 and Escherichia coli strain WP2 uvrA in the presence and absence of metabolic activation system according to OECD 471. Neither precipitate nor appreciable toxicity was observed. Based on the findings of the toxicity-mutation assay, the maximum dose plated in the mutagenicity assay was 5000 µg/plate. In the confirmatory mutagenicity assay, no positive response was observed.
This result can be read across to magnesium thiosulfate without restriction.
Endpoint Conclusion: No adverse effect observed (negative)
Justification for classification or non-classification
Genetic toxicity, in vitro
None of the in vitro genotoxicity studies rated as reliable showed any effect in bacterial reverse mutation assays, in mammalian cell gene mutation tests (HPRT assay) or in mammalian cell chromosome aberration tests. The classification criteria according to Regulation (EC) 1272/2008 as germ cell mutagen are also not met.
This result can be read across to magnesium thiosulfate without restriction.
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