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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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: 603-758-6 | CAS number: 133647-88-8
- 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
Biodegradation in water: screening tests
Administrative data
Link to relevant study record(s)
Description of key information
Readily biodegradable, OECD 301B, Grade 1996, read-across
Key value for chemical safety assessment
- Biodegradation in water:
- readily biodegradable
Additional information
Validity of the read-across
Biodegradation of sodium (2R)-2-(4 -hydroxyphenoxy)propanoate, (CAS 133647-88-8) was determined by read-across from a biodegradation study conducted with the free acid, namely (R)-2-(4-hydroxyphenoxy)propanoic acid (CAS 94050-90 -5).
This read-across is valid as the test was performed in aqueous medium where the sodium salt of the acid normally dissociates into sodium cations and the free acid anion.
Regarding the pKa of (R)-2-(4-hydroxyphenoxy)propanoic acid of 3.32 it can be assumed that the acid, when dissolved in water under environmental relevant concentrations (pH > 4), will instantly be deprotonated and become the same acid anion as after dissociation of the sodium salt. As in the experiments (R)-2-(4-hydroxyphenoxy)propanoic acid showed no alteration of the test medium pH of 7.8 it can be assumed that also the sodium salt should not cause greater changes in pH.
The additional sodium ions dissociating from the salt should have no further impact on biodegradation as the concentration of sodium ions in the test medium according to OECD 301 is already 8 times higher. Furthermore, sodium ion concentration needs not to be assessed for biodegradation as these tests focus only on degradation of organic compounds.
At the highest tested concentration of (R)-2-(4-hydroxyphenoxy)propanoic acid (100 mg/L) for ecotoxicological studies, the molar concentration of the acid is 0.55 mmol/L. Due to the different molar weight of the sodium salt, the limit concentration of 100 mg/L corresponds to a lower molar concentration of only 0.5 mmol/L for the sodium salt.
It can therefore be concluded that biodegradation of sodium (2R)-2-(4-hydroxyphenoxy)propanoate is at least equal or even higher compared to the acid.
Biodegradation of (R)-2-(4-hydroxyphenoxy)propanoic acid
Ready biodegradability of (R)-2-(4-hydroxyphenoxy)propanoic acid was assessed using a CO2 evolution test with activated sludge from a domestic sewage treatment plant according to OECD 301/B.
Biodegradation of the test substance was 87 % in 29 days. The pass level (60 %) was achieved on day 12. Within the time window of 10 days after start of degradation at day 6, 76% degradation occurred.
Based on the criteria according to the Regulation (EC) No 1272/2008, Annex I, Part 4, 4.1.2.9 the test item was demonstrated to be rapidly (or readily) biodegradable.
Biodegradation of sodium (R)-2-(4-hydroxyphenoxy)propionate
As stated above, sodium (2R)-2-(4-hydroxyphenoxy)propanoate, when dissolved in water becomes equal to the test item (R)-2-(4-hydroxyphenoxy)propanoic acid and ready biodegradability of the sodium salt is therefore equal to the biodegradability measured for the acid. It can therefore be concluded without reasonable doubt that sodium (2R)-2-(4-hydroxyphenoxy)propanoate is also rapidly (or readily) biodegradable.
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.