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EC number: 207-821-5 | CAS number: 496-46-8
- 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)
- Endpoint:
- activated sludge respiration inhibition testing
- Type of information:
- experimental study
- Adequacy of study:
- key study
- Study period:
- 1999
- Reliability:
- 1 (reliable without restriction)
- Rationale for reliability incl. deficiencies:
- guideline study
- Qualifier:
- according to guideline
- Guideline:
- OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test
- Deviations:
- no
- Qualifier:
- according to guideline
- Guideline:
- ISO 8192 (Water quality - Test for inhibition of oxygen consumption by activated sludge for carbonaceous and ammonium oxidation)
- Deviations:
- no
- GLP compliance:
- yes (incl. QA statement)
- Specific details on test material used for the study:
- Test substance: Tetrahydra-imidaza-(4,5-d)-imidazol-2,5-dion.
Batch number: Intermediate product from partie 692.
Date of manufacturing: 27 July 1998.
Purity: 97,6 % resp. 109,3 % based an elementary analysis of carbon and nitrogen respectively.
Impurities: 0.024% urea and 0.02% water. - Analytical monitoring:
- yes
- Details on sampling:
- Not specified.
- Vehicle:
- yes
- Remarks:
- Synthetic medium 8mL/vessel 100-fold concentrated OECD Medium.
- Details on test solutions:
- The highest concentration tested for the test substance was 1000mg/L.
The highest concentration tested for the reference substance was 100mg/L. - Test organisms (species):
- activated sludge
- Details on inoculum:
- The inoculum waws washed, brought to a concentration of 5g/L dry substance and aerated for 24 hours. 50mL were added to a total volume of 250mL to obtain a concentration of 1g/L dry susbtance in the test.
- Test type:
- not specified
- Water media type:
- not specified
- Limit test:
- no
- Total exposure duration:
- 30 min
- Remarks on exposure duration:
- Exposure was carried out in Erlenmeyer-vessels.
- Post exposure observation period:
- Observation was carried out 30 minutes post exposure to the test substance.
- Hardness:
- Not specified.
- Test temperature:
- 20 ± 2 °C.
- pH:
- 6.7-7.2.
- Dissolved oxygen:
- Oxygen concentration during aeration: >2.5mg/L.
Oxygen concentration immediately before measurement: >6.5mg/L.
Duration of the measurement of oxygen consumption: 6-10mins. - Salinity:
- Not specified.
- Conductivity:
- Not specified.
- Nominal and measured concentrations:
- The nominal concentration was the highest concentration tested; 1000mg/L.
- Details on test conditions:
- The EC20 is regarded as a limit value tor possible toxic effects in wastewater treatment plants. The test concentration in biodegradation tests should not exceed the EC20. The EC-values are based an added nominal concentrations and not an analytically determined values. The nominai concentrations which indicate a respiration inhibition of 20, 50 and 80 % can be taken from the graph of the inhibition curve.
- Reference substance (positive control):
- yes
- Remarks:
- 3,5-dichlorophenol
- Key result
- Duration:
- 30 min
- Dose descriptor:
- EC50
- Effect conc.:
- > 1 000 mg/L
- Nominal / measured:
- nominal
- Conc. based on:
- test mat.
- Basis for effect:
- inhibition of total respiration
- Remarks on result:
- other: negative
- Details on results:
- No significant inhibition of respiration was measured up to the highest tested concentration of 1000mg/L.
- Validity criteria fulfilled:
- yes
- Conclusions:
- No significant inhibition of respiration was measured up to the highest tested concentration of 1000mg/L. It can therefore be concluded that the test substance showed no signs of toxicity to micro-organisms.
- Executive summary:
This study aimed to determine the inhibition of oxygen consumption by aerobic micro-organisms (activated sludge) by the test substance in the activated sludge respiration inhibition test. This was conducted according to Annex of EEC Directive 88/302/EEC (November 1987), and corresponding to OECD guideline 209 (1993) and ISO standard 8192 (1986). The test results were reported as effective concentrations, indicating a respiration inhibition of 20,50, and 80% compared to a control assay without the test substance.
The results showed that no significant inhibition of respiration was measured up to the highest tested concentration of 1000mg/L. Based on the results it can be concluded that the test substance is non-toxic to micro-organisms under EC 1272/2008, within the experimental conditions of this study.
Reference
EC20 mg/L | EC50 mg/L | EC 80 mg/L | Highest concentration tested | |
Test Substance | - | - | - | 1000 |
Reference substance | ca. 2 | ca. 21 | ca. 77 | 100 |
Description of key information
A study was performed to assess the inhibitory effect of the test substance on the oxygen consumption rate of aerobic micro-organims (activated sludge) after short term exposure (30 minutes). This was conducted according to; Annex of EEC Directive 88/302/EEC (November 1987), and corresponding to OECD Guideline 209 (1993) and ISO 8192 (1986). The test results were reported as effective concentrations, indicating a respiration inhibition of 20,50, and 80% compared to a control assay without the test substance.
EC50 = >1000 mg/L (nominal)
EC10 = >1000 mg/L (nominal)
NOEC = >1000 mg/L (nominal)
The results showed that no significant inhibition of respiration was measured up to the highest tested concentration of 1000mg/L. Therefore based on the test results, the test substance is non-toxic to micro-organisms under EC 1272/2008.
Key value for chemical safety assessment
- EC10 or NOEC for microorganisms:
- 1 000 mg/L
Additional information
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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