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EC number: 219-660-8 | CAS number: 2492-26-4
- 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
PBT assessment
Administrative data
PBT assessment: overall result
- PBT status:
- the substance is not PBT / vPvB
- Justification:
SMBT is an organic salt of strong base NaOH and weak acid of MBT and it is solely marketed as aqueous solution. The presence of MBT determines the hazard profile of SMBT aqueous solution; and hence the read-across approach is used to support the risk assessment and PBT assessment of SMBT. MBT being released into the waste water and the atmosphere undergo different degradation reactions. The known reaction pathways and relevant metabolites of MBT are already described in the appendix A of the EU-Risk Assessment for CBS from 2008. These described metabolites are MBTS (CAS: 120-78-5), BT (CAS: 95-16-9), BTon (CAS: 934-34-9), MeSBT (CAS: 615-22-5). All these compounds are detected in waste water and environmental compartments; therefore they are included into the MBT risk assessment and PBT/vPvB assessment. The assessment of PBT and vPvB is performed by comparison of the relevant intrinsic properties of MBT and its described metabolites with the criteria of the REACH regulation (Annex XIII) as shown in the following table:
PBT and vPvB criteria and the corresponding properties of MBT and its described metabolites
Criterion PBT criteria vPvB criteria MBT and its described metabolites Criterion fulfilled? P Half-life in marine water > 60 d, or half-life in fresh- or estuarine water > 40 d, or half-life in marine sediment > 180 d, or half-life in fresh- or estuarine water sediment > 120 d, or half-life in soil > 120 d Half-life in marine, fresh or esturarine water > 60 d, or half-life in marine, fresh or esturarine sediment > 180 d, or half-life in soil > 180 d Not readily biodegradable (MITI, 1992) Fast hydrolysis (CMA, 1989) The main hydrolysis products BT and BTon are persistent (EU-RAR, 2008) yes B BCF > 2000 BCF > 5000 BCF of MBT <2000 (MITI, 1992) BCF of the described metabolites of MBT <2000 (EU-RAR, 2008) no T Long-term NOEC for marine or freshwater organisms 89d-NOEC (fish) = 0.041 mg/L (CMA, 1989d) no T CMR n.a. Not classified as CMR no T Other evidence of chronic toxicity, as identified by the classifications: T, R48, or Xn, R48 according to Directive 67/548/EEC n.a. Not classified as T, R48, or Xn, R48 according to Directive 67/548/EEC no Persistence Assessment
MBT is not readily biodegradable (MITI, 1992), but it photolyzes in water fast with a half-life of ca. 30 mins (CMA, 1989d). The main photolysis products of MBT are BT and BTon (Brownlee, 1992). They are also not readily biodegradable and already reported as persistent under environmental conditions in EU-Risk Assessment for CBS from 2008. As the described metabolites of MBT, MBTS is also not readily biodegradable but can be hydrolyzed or photolyzed to BT and BTon. MeSBT is also reported in EU-Risk Assessment of CBS from 2008 as resistant both to biodegradation and abiotic degradation. Accordingly MBT is not persistent due to fast hydrolysis but its photolysis products BT and BTon are persistent and the described metabolite MeSBT is also persistent.
Bioaccumulation Assessment
The BCFs of MBT and all of its described metabolites are smaller than 2000, either from experiment or from estimation. Therefore MBT together with its described metabolites does not fulfil the B criterion.
Toxicity Assessment
The chronic effects of MBT are tested for three trophic species and the most sensitive result is from fish (89d-NOEC of 0.041 mg/L) (CMA, 1989d) above the criterion of 0.01 mg/L and hence MBT does not fulfil the T criterion. The metabolites of MBT are all less toxic to aquatic organisms than MBT itself and hence they do not fulfil the toxic criterion as well. MBT and its described metabolites are all not classified as carcinogenic, mutagenic or toxic for reproduction.
Summary and overall Conclusions on PBT or vPvB Properties
Due to the B and T criteria are not fulfilled; MBT is neither PBT nor a vPvB substance. Based on the read across approach, SMBT is also not a PBT or vPvB substance.
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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