Registration Dossier
Registration Dossier
Diss Factsheets
Use of this information is subject to copyright laws and may require the permission of the owner of the information, as described in the ECHA Legal Notice.
EC number: 244-214-4 | CAS number: 21109-95-5
- 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

Toxicity to microorganisms
Administrative data
Link to relevant study record(s)
Description of key information
Reliable toxicity data on micro-organisms are available for barium and sulfate. Barium and sulfide are released upon dissolution of BaS in the aqueous environment. Sulfide is rapidly oxidised under natural environmental conditions, and thus, the toxicity of sulfate was considered. However, sulfate is of low toxicity based on the most sensitive endpoint for the presence of stalked ciliates corresponding to a NOEC of ca. 10 g BaS/L.
Regarding toxic effects of dissolved Ba, reliable 3h-IC50 and 3h-NOEC values of >622 and ≥622 mg Ba/L, respectively, were determined by Egeler and Kiefer (2010) corresponding to the 3h-IC50 and 3h-NOEC values of >767 and ≥767 mg BaS/L.
Key value for chemical safety assessment
Additional information
Because of the oxic nature of a typical test systems for this endpoint (activated sludge respiration inhibition tests or single-species tests with ciliates), it is considered technically very difficult to ascertain continuous exposure to a constant barium sulfide concentration is these specific tests.
Sulfide/sulfate:
Availabe studies with sulfide were considered unreliable because it was not clear if sulfide concentrations were measured, and/or the respective pH was not sufficiently reported. An estimate may be considered based on the lowest available effect concentration, i.e. the 16h-EC50of 1.6 mg S2-/L for the bacteriumPseudomonas putida; Bringmann and Kühn, 1980) corresponding to 8.45 mg BaS/L. However, these data are not relevant for the assessment of BaS.
When active aeration is applied (as is the case during several steps of a sewage treatment plant), any dissolved sulfides are expected to be oxidized to sulfate in less than an hour. Other routes of removal are the precipitation of metals (MeS) as sulfides (e.g. Na2S) are actually sometimes added during the treatment process for this purpose. Because any dissolved sulfide precipitates and is removed from the system or oxidizes to sulfate, read-across to sulfates is justified.
The study of Tokuz and Eckenfelder (1979) was identified as key study of sulfate toxicity to micro-organisms in the OECD SIDS for Na2SO4(the most relevant substance for assessing the risks of sulfate). Therein, activated sludge units were fed with wastewater with Na2SO4concentrations increasing stepwise from 8 to 35 g/L over 37 days. Sludge performance was monitored by measuring BOD, COD and TSS in the effluent, and sludge composition was examined microscopically. The most sensitive endpoint, i.e. the NOEC of approximately 8 g Na2SO4/L for the presence of stalked ciliates corresponds to a BaS concentration of 10 g/L.
Barium:
A reliable study (Klimisch 1, GLP) of barium toxicity to microbial respiration inhibition was conducted with activated sludge from a (predominantly) domestic sewage by Egeler et al (2010). An inhibition of the respiration rate was not observed at the highest tested concentration. The 3h-IC50and 3h-NOEC amount to >622 and ≥622 mg Ba/L,based on total measured barium, corresponding to a 3h-IC50and 3h-NOEC of >767 and ≥767 mg BaS/L, respectively.
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.
Reproduction or further distribution of this information may be subject to copyright protection. Use of the information without obtaining the permission from the owner(s) of the respective information might violate the rights of the owner.

EU Privacy Disclaimer
This website uses cookies to ensure you get the best experience on our websites.