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Diss Factsheets
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EC number: 206-490-4 | CAS number: 349-76-8
- 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
Dissociation constant
Administrative data
Link to relevant study record(s)
- Endpoint:
- dissociation constant
- Type of information:
- experimental study
- Adequacy of study:
- key study
- Study period:
- 16 Oct to 05 Nov 1996
- Reliability:
- 1 (reliable without restriction)
- Rationale for reliability incl. deficiencies:
- guideline study
- Qualifier:
- according to guideline
- Guideline:
- OECD Guideline 112 (Dissociation Constants in Water)
- GLP compliance:
- yes
- Dissociating properties:
- no
- Conclusions:
- The test item does not have a dissociation constant within the pH range 2 to 12.
- Executive summary:
A study was carried out in accordance with the OECD guideline number 112, dissociation constants in water, to assess the dissociation constant of the test substance.
A stock solution of the test substance was prepared in methanol with a concentration of 207.2 mg/L.
To obtain the spectra of the test substance in neutral solution, 5.0 mL of the stock solution were diluted to 100.0 mL with phosphate buffer solution pH 7.0 (composition: 0.041 M disodium hydrogen phosphate and 0.028 M potassium dihydrogen phosphate). The measured pH value of the prepared test solution was 7.0. To obtain the spectra in acidic solution (pH 1) and in basic solution (pH 13) 5.0 mL of the stock solution were diluted, as appropriate, to 100.0 mL with 0.1 M hydrochloric acid and 0.1 M sodium hydroxide. The measured pH values of these test solutions were 1.1 and 12.7 respectively.
The final concentration of the test substance in all three test solutions was 10.4 mg/L.
To record the spectra a Hitachi U-3200 spectrophotometer was used with quartz cells of 10 mm path length.
For each test solution absorption spectra were recorded in the range 200 nm to 400 nm.
The absorbance spectra recorded in 0.1 M hydrochloric acid, phosphate buffer solution and 0.1 M sodium hydroxide are identical. The same two characteristic absorbance maxima occur at 239 nm and 277 run in all three spectra, clearly demonstrating that there is no change in the absorption behaviour of the molecule and, consequently, that there can be no protonation or deprotonation of the test substance within the range pH 1.1 to pH 12.7.
Reference
The absorbance spectra recorded in 0.1 M hydrochloric acid, phosphate buffer solution and 0.1 M sodium hydroxide are identical. The same two characteristic absorbance maxima occur at 239 nm and 277 run in all three spectra, clearly demonstrating that there is no change in the absorption behaviour of the molecule and, consequently, that there can be no protonation or deprotonation of the test substance within the range pH 1.1 to pH 12.7.
Description of key information
A study was carried out in accordance with the OECD guideline number 112, Dissociation constants in water, to assess the dissociation constant of the test substance.
A stock solution of the test substance was prepared in methanol with a concentration of 207.2 mg/L.
To obtain the spectra of the test substance in neutral solution, 5.0 mL of the stock solution were diluted to 100.0 mL with phosphate buffer solution pH 7.0 (composition: 0.041 M disodium hydrogen phosphate and 0.028 M potassium dihydrogen phosphate). The measured pH value of the prepared test solution was 7.0. To obtain the spectra in acidic solution (pH 1) and in basic solution (pH 13) 5.0 mL of the stock solution were diluted, as appropriate, to 100.0 mL with 0.1 M hydrochloric acid and 0.1 M sodium hydroxide. The measured pH values of these test solutions were 1.1 and 12.7 respectively.
The final concentration of the test substance in all three test solutions was 10.4 mg/L.
For each test solution absorption spectra were recorded in the range 200 nm to 400 nm.
The absorbance spectra recorded in 0.1 M hydrochloric acid, phosphate buffer solution and 0.1 M sodium hydroxide are identical. The same two characteristic absorbance maxima occur at 239 nm and 277 run in all three spectra, clearly demonstrating that there is no change in the absorption behaviour of the molecule and, consequently, that there can be no protonation or deprotonation of the test substance within the range pH 1.1 to pH 12.7.
Key value for chemical safety assessment
Additional information
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