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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
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EC number: 203-571-6 | CAS number: 108-31-6
- 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
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Hydrolysis
Administrative data
Link to relevant study record(s)
- Endpoint:
- hydrolysis
- Remarks:
- pH 7 only
- Type of information:
- experimental study
- Adequacy of study:
- key study
- Study period:
- no data
- Reliability:
- 2 (reliable with restrictions)
- Rationale for reliability incl. deficiencies:
- study well documented, meets generally accepted scientific principles, acceptable for assessment
- Qualifier:
- no guideline followed
- Principles of method if other than guideline:
- Titration
- GLP compliance:
- no
- Analytical monitoring:
- not specified
- Transformation products:
- yes
- pH:
- 7
- Temp.:
- 25.1 °C
- Hydrolysis rate constant:
- 3 140 s-1
- DT50:
- 0.3 min
- Validity criteria fulfilled:
- not specified
- Conclusions:
- The half-life/DT50 (50% decline time) of maleic anhydride was 0.3 minutes at pH 7 and the major transformation product was maleic acid.
- Executive summary:
Hydrolysis of maleic anhydride was studied at pH 7. The experiment was conducted as part of a scientific study on the hydrolysis rate of carboxylic anhydrides. At pH 7 the major transformation product was maleic acid.
The half-life/DT50 (50% decline time) of maleic anhydride was 0.3 minutes at pH 7.
Maleic acid is expected to be stable in water since there are no functional groups that would lead to further hydrolysis.
The study is classified acceptable and satiesfies the guideline requirement for hydrolysis study.
- Endpoint:
- hydrolysis
- Data waiving:
- study scientifically not necessary / other information available
- Justification for data waiving:
- the study does not need to be conducted because the substance is readily biodegradable
Referenceopen allclose all
Rate constant 105 k1 = 3140 sec -1 at 25 ºC,
initially neutral.
At 0 ºC, rate constant was 105 k1 = 348 sec -1
Authors noted rate of hydrolysis of maleic anhydride exceeded all other carboxylic anhydrides evaluated.
Maleic acid was identified as transformation product and is expected to be stable in water since there are no functional groups that would lead to further hydrolysis.
Description of key information
In a study investigating the hydrolysis of maleic anhydride to maleic acid at pH 7 and 25.1°C a half-life/DT50 (50 % decline times) of 0.3 minutes at a hydrolysis rate constant of 3140 sec-1 was determined (Bunton et al. 1963). The major transformation product is maleic acid, for which hydrolysis is not expected to be an important fate path due to the lack of labile functional groups.
Information on hydrolysis of maleic anhydride at pH 4 and 9 is not available. However, in line with REACH Annex VIII, endpoint 9.2.2.1, column 2, no further testing is required as the substance is readily biodegradable.
Key value for chemical safety assessment
- Half-life for hydrolysis:
- 0.3 min
- at the temperature of:
- 25.1 °C
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.
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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