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Diss Factsheets
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EC number: 201-222-2 | CAS number: 79-74-3
- 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
![](https://echa.europa.eu/o/diss-blank-theme/images/factsheets/A-REACH/factsheet/print_physical-and-chemical-properties.png)
Dissociation constant
Administrative data
- Endpoint:
- dissociation constant
- Type of information:
- (Q)SAR
- Adequacy of study:
- supporting study
- Study period:
- 23 June 2015
- Reliability:
- 2 (reliable with restrictions)
- Rationale for reliability incl. deficiencies:
- accepted calculation method
Data source
Reference
- Reference Type:
- study report
- Title:
- Unnamed
- Year:
- 2 015
- Report date:
- 2015
Materials and methods
Test guideline
- Qualifier:
- no guideline followed
- Principles of method if other than guideline:
- The dissociation constants (pKa’s) of LOWINOX® AH-25 (2,5-di-tert-pentyl-hydroquinone) were estimated using the pKalc function of the PALLAS estimation software program (CompuDrug, version 3.6.2.1).
- GLP compliance:
- no
Test material
- Test material form:
- solid: particulate/powder
- Details on test material:
- Test substance: 206774/A (formerly known as 202199)
Identification: Lowinox® AH25
Appearance: White to cream coloured powder
Batch: WAH4L0016/WAH8E0007
Purity/Composition: 95.1%/95.88%
Test substance storage: At room temperature
Stable under storage conditions until: 09 November 2018 (retest date)/07 May 2022 (retest date)
Purity/composition correction factor: No correction factor required
Test substance handling: No specific handling conditions required
Stability at higher temperatures: Not indicated
Chemical name (IUPAC), synonym or trade name: 2,5-di-tert-pentylhydroquinone
CAS Number: 79-74-3
Molecular formula: C16H26O2
Molecular weight: 250.38
Highly reactive to water: Not indicated
Highly reactive to oxygen: Not indicated
Volatile: Not indicated
Vehicle information
Solubility in water: 1 g/L at 20°C
Stability in water: Not indicated
Constituent 1
- Specific details on test material used for the study:
- None - QSAR Assessment only.
Results and discussion
- Dissociating properties:
- yes
Dissociation constantopen allclose all
- No.:
- #1
- pKa:
- 9.67
- Remarks on result:
- other:
- Remarks:
- acidic group 1. Refer to appended report.
- No.:
- #2
- pKa:
- 11.7
- Remarks on result:
- other:
- Remarks:
- acidic group 2. Refer to appended report.
Any other information on results incl. tables
The PALLAS pKa prediction for LOWINOX® AH-25 (2,5-di-tert-pentyl-hydroquinone) demonstrates that the compound possesses two acidic groups, with pKa values of 9.67 and 11.70.
The detailed pKa prediction is attached in Appendix 1 of the appended report below.
Applicant's summary and conclusion
- Conclusions:
- The PALLAS pKa prediction for LOWINOX® AH-25 (2,5-di-tert-pentyl-hydroquinone) demonstrates that the compound possesses two acidic groups, with pKa values of 9.67 and 11.70.
- Executive summary:
The PALLAS pKa prediction for LOWINOX® AH-25 (2,5-di-tert-pentyl-hydroquinone) demonstrates that the compound possesses two acidic groups, with pKa values of 9.67 and 11.70.
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.
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