Registration Dossier
Registration Dossier
Data platform availability banner - registered substances factsheets
Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.
The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.
Diss Factsheets
Use of this information is subject to copyright laws and may require the permission of the owner of the information, as described in the ECHA Legal Notice.
EC number: 202-075-7 | CAS number: 91-53-2
- 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
Hydrolysis
Administrative data
Link to relevant study record(s)
- Endpoint:
- hydrolysis
- Type of information:
- experimental study
- Adequacy of study:
- key study
- Reliability:
- 2 (reliable with restrictions)
- Rationale for reliability incl. deficiencies:
- data from handbook or collection of data
- Remarks:
- Peer-reviewed draft assessment report (attached in section 13)
- Qualifier:
- according to guideline
- Guideline:
- other: US EPA PAG 161-1
- GLP compliance:
- yes
- Specific details on test material used for the study:
- The hydrolysis of ethoxyquin in the dark was studied at 25 °C in sterile aqueous buffered solutions at pH 5, pH 7 and pH 9. The nominal concentration of ring-labelled ethoxyquin was 0.01 mg as/mL for pH 5, 7 and 9. Acetonitrile (< 1.0 % v/v) was used as a cosolvent.
- Radiolabelling:
- yes
- Remarks:
- Total recovery of radioactivity was in the range of 98 – 102 %
- Analytical monitoring:
- yes
- Buffers:
- sterile aqueous buffered solutions at pH 5, pH 7 and pH 9 with < 1.0 % v/v acetonitrile
- Transformation products:
- not specified
- pH:
- 5
- Temp.:
- 25 °C
- DT50:
- 3.7 d
- Type:
- not specified
- pH:
- 7
- Temp.:
- 25 °C
- DT50:
- 6.7 d
- Type:
- not specified
- pH:
- 9
- Temp.:
- 25 °C
- DT50:
- 9.3 d
- Type:
- not specified
- Details on results:
- Under sterile conditions at 25 °C in the dark, ethoxyquin is unstable and undergoes appreciable and rapid hydrolytic degradation in buffered aqueous solutions at pH levels of 5, 7 and 9. Additionally, stability decreases as pH decreases. In all of the samples analysed, one significant radioactive component detected in the organic fractions throughout the sampling intervals was confirmed chromatographically by RP-HPLC and LC/MS to be the parent compound. In addition to parent compound, seven degradates were observed during the course of the study. Deg-1 (except in pH 5 buffer), Deg-2, Deg-3, and Deg-4 (except in pH 7 and 9 buffers) were the major products. Lesser amounts (< 5 %) of Deg-5, Deg-6, and Deg-7 also were detected. Mass spectral data showed the formation of methylation, demethylation, deethylation, quinoline and dimeric ethoxyquin, which indicated that ethoxyquin was degraded primarily via intermolecular rearrangement and dimerisation. The observed halflives of ethoxyquin in pH 5, 7 and 9 test solutions are 3.7, 6.7 and 9.3 days, respectively.
- Validity criteria fulfilled:
- not specified
- Conclusions:
- As information was provided via a peer-reviewed assessment report, it can be considered as sufficiently reliable. The hydrolysis of ethoxyquin in the dark was studied at 25 °C in sterile aqueous buffered solutions at pH 5, pH 7 and pH 9. The nominal concentration of ring-labelled ethoxyquin was 0.01 mg as/mL for pH 5, 7 and 9. Acetonitrile (< 1.0 % v/v) was used as a cosolvent. Total recovery of radioactivity was in the range of 98 – 102 %.
- Executive summary:
Under sterile conditions at 25 °C in the dark, ethoxyquin is unstable and undergoes appreciable and rapid hydrolytic degradation in buffered aqueous solutions at pH levels of 5, 7 and 9 ( US EPA PAG 161-1, GLP). Additionally, stability decreases as pH decreases. In all of the samples analysed, one significant radioactive component detected in the organic fractions throughout the sampling intervals was confirmed chromatographically by RP-HPLC and LC/MS to be the parent compound. In addition to parent compound, seven degradates were observed during the course of the study. Deg-1 (except in pH 5 buffer), Deg-2, Deg-3, and Deg-4 (except in pH 7 and 9 buffers) were the major products. Lesser amounts (< %) of Deg-5, Deg-6, and Deg-7 also were detected. Mass spectral data showed the formation of methylation, demethylation, deethylation, quinoline and dimeric ethoxyquin, which indicated that ethoxyquin was degraded primarily via intermolecular rearrangement and dimerisation. The observed halflives of ethoxyquin in pH 5, 7 and 9 test solutions are 3.7, 6.7 and 9.3 days, respectively.
Reference
Description of key information
-Hydrolysis: hydrolytically unstable; halflives at 25 °C are 3.7 days (pH 5), 6.7 days (pH 7) and 9.3 days (pH 9) (US EPA PAG 161 -1)
Key value for chemical safety assessment
- Half-life for hydrolysis:
- 6.7 d
- at the temperature of:
- 25 °C
Additional information
There is a valid, peer-reviewed US EPA PAG 161-1 study on the hydrolysis of ethoxyquin available, assessed with Klimisch 2 and hence considered as sufficiently reliable to cover this endpoint. It has been observed that ethoxyquin is unstable and undergoes appreciable and rapid hydrolytic degradation in buffered aqueous solutions at pH levels of 5, 7 and 9. Additionally, stability decreases as pH decreases with half-lives at 25°C of 3.6 days (pH 5), 6.7 days (pH 7), and 9.3 days (pH 9). In all of the samples analysed, one significant radioactive component detected in the organic fractions throughout the sampling intervals was confirmed chromatographically by RP-HPLC and LC/MS to be the parent compound. In addition to parent compound, seven degradates were observed during the course of the study. Deg-1 (except in pH 5 buffer), Deg-2, Deg-3, and Deg-4 (except in pH 7 and 9 buffers) were the major products. Lesser amounts (< 5 %) of Deg-5, Deg-6, and Deg-7 also were detected. Mass spectral data showed the formation of methylation, demethylation, deethylation, quinoline and dimeric ethoxyquin, which indicated that ethoxyquin was degraded primarily via intermolecular rearrangement and dimerisation.
There is no reason to believe that this result is not reliable, and consequently, there is no data gap identified.
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.