Registration Dossier
Registration Dossier
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EC number: 205-736-8 | CAS number: 149-30-4
Ecotoxicological Summary
Administrative data
Hazard for aquatic organisms
Freshwater
- Hazard assessment conclusion:
- PNEC aqua (freshwater)
- PNEC value:
- 0.004 mg/L
- Assessment factor:
- 10
- Extrapolation method:
- assessment factor
- PNEC freshwater (intermittent releases):
- 0.005 mg/L
Marine water
- Hazard assessment conclusion:
- PNEC aqua (marine water)
- PNEC value:
- 0 mg/L
- Assessment factor:
- 100
- Extrapolation method:
- assessment factor
STP
- Hazard assessment conclusion:
- PNEC STP
- PNEC value:
- 0.3 mg/L
- Assessment factor:
- 10
- Extrapolation method:
- assessment factor
Sediment (freshwater)
- Hazard assessment conclusion:
- PNEC sediment (freshwater)
- PNEC value:
- 0.147 mg/kg sediment dw
- Extrapolation method:
- equilibrium partitioning method
Sediment (marine water)
- Hazard assessment conclusion:
- PNEC sediment (marine water)
- PNEC value:
- 0.015 mg/kg sediment dw
- Extrapolation method:
- equilibrium partitioning method
Hazard for air
Hazard for terrestrial organisms
Soil
- Hazard assessment conclusion:
- PNEC soil
- PNEC value:
- 0.027 mg/kg soil dw
- Extrapolation method:
- equilibrium partitioning method
Hazard for predators
Secondary poisoning
- Hazard assessment conclusion:
- no potential for bioaccumulation
Additional information
In up-to-data assessment, latest and more reliable data are found and hence used for the estimation of PNEC values. Therefore the PNEC values reported here are different in comparison to the ones in EU-risk assessment.
Conclusion on classification
According to Directive 67/548/EEC and the regulation (EC) No 1272/2008, MBT is legally classified as "Very toxic to aquatic organisms, may cause long-term adverse effects in the aquatic environment" with the phrase of R 50/53 in Annex I and aquatic acute 1 (H400) and aquatic chronic 1 (H410), respectively. The up-to-date information summarised above confirmed this classification and is listed below:
- The most sensitive acute toxicity of MBT is to aquatic algae (Selenastrum capricornutum): 72h-ECr50 of 0.5mg/L (MITI, 1999), which is lower than 1 mg/l.
- The most sensitive chronic toxicity of MBT was determined in a long-term study with fish (rainbow trout): NOEC (89d) of 0.041 mg/L (CMA, 1989), which is lower than 0.1 mg/L.
- MBT is not readily biodegradable (MITI, 1992).
With the data listed above, MBT should be classified as aquatic acute 1 (H400) and aquatic chronic 1 (410) according to GHS (Regulation EC 1272/2008) and as R50/53 according the Directive 67/548/EEC. The appropriate multiplying factors for acute and chronic toxicity are both 1.
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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