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EC number: 209-008-0 | CAS number: 552-30-7
- 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
Endpoint summary
Administrative data
Description of key information
Additional information
Trimellitic anhydride (TMA) is unstable in the presence of moisture and undergoes rapid hydrolysis to trimellitic acid (TMLA). The hydrolysis of trimellitic anhydride acid chloride was virtually instantaneous at 40 degrees C (Lord and Cooper, 1992) and similarly fast hydrolysis of TMA would also be anticipated in production and manufacturing waste waters, with complete conversion to trimellitic acid occurring even before reaching waste water treatment facilities. In view of its rapid hydrolysis, it is not technically possible to determine the aqueous solubility limit of the parent anhydride, however TMLA is very soluble in water: its solubility in water is 24,400 mg/L at 20 degrees C and pH 1.8 (Villa, 2010, see Point 4.8).
None of the uses of trimellitic anhydride involve direct application to surface water. The potential for unintended exposure of the aquatic compartment is therefore confined to TMA residues contained in treatment plant effluents discharged to surface waters and, for the reasons given above, these residues will comprise derivatives of the hydrolysis product TMLA rather than the acid anhydride. Moreover, it should be noted that any production/manufacturing process effluents would be pH-balanced (neutralised) prior to treatment, to safeguard the treatment plant infrastructure from corrosion damage as well as to protect the biological purification process from adverse impacts of pH-shock. Even without this deliberate intervention, TMLA would rapidly be converted to trimellitate salts during treatment and/or in the aquatic environment. In terms of environmental exposure, trimellitate salts may therefore be more relevant than free trimellitic acid.
A number of reliable studies address the aquatic toxicity of TMA (TMLA). In these studies (Knackeret al., 1992, 1993a & b; Lebertz, 1991) TMA was first treated with aqueous NaOH solution, to convert the acid anhydride to the sodium salt(s) of TMLA, and exposure in these studies was consequently to sodium trimellitate (following neutralisation of excess alkali). No toxicity was observed under these conditions:
Acute toxicity to fish - Golden orfe (L. idus melanotus) 96 hour LC50 (static): >957 mg TMA-equiv/L, 96 hour NOEC: 957 mg TMA-equiv/L;
Acute daphnia inhibition -D. magna48 hour EC50 (static): >792 mg TMA-equiv/L, 48 hour NOEC: 792 mg TMA-equiv/L;
Algal growth inhibition -D. subspicatus72 hour ErC50: >739 mg TMA-equiv/L, 72 hour NOEC: 739 mg TMA-equiv/L.
All these endpoints are mean measured values and represent the highest concentration applied.
Toxicity to aquatic microorganisms: 3 hour EC50, based on inhibition of respiration of activated sludge, was in the range >100, <500 mg/L. Inhibition, relative to the untreated control, was observed at concentrations >/= 500 mg/L and the NOEC was 100 mg/L.
No aquatic toxicity studies with chronic exposure are available on TMA (TMLA) itself. Reliable data on fish are available for two structural analogues of the substance, methyl-tetrahydrophthalic anhydride (THPA) and phthalic anhydride, with determined NOEC values of 100 and 10 mg/L, respectively. The lower NOEC value of 10 mg/L determined for phthalic anhydride may be used as suitable read-across value for TMA considering a worst case approach. The NOEC from this study was 10 mg/L which, when corrected for differences in molecular weight, results in a calculated NOEC of 13 mg/L for TMA. Data from chronicDaphniastudies are available on three structural analogues of the substance, which after considering the differences in molecular weight, lead to comparable NOEC values. The best quality data originates from a recent study with MTHPA. The NOEC from this study was 20 mg/L which, when corrected for differences in molecular weight, results in a calculated NOEC of 23 mg/L for TMA.
In conclusion, trimellitic anhydride (TMA) and the more environmentally relevant trimellitic acid (TMLA) exhibit very low toxicity to fish, aquatic invertebrates, unicellular algae and to aquatic microorganisms including biological waste water treatment processes.
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