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EC number: 231-633-2 | CAS number: 7664-38-2
- 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
Toxicity to microorganisms
Administrative data
Link to relevant study record(s)
Description of key information
Activated sludge respiration inhibition test: EC50 (3h) >1000 mg/L for activated sludge of a predominantly domestic sewage (OECD TG 209, static, Klimisch reliability 1)
Key value for chemical safety assessment
- EC50 for microorganisms:
- 1 000 mg/L
- EC10 or NOEC for microorganisms:
- 1 000 mg/L
Additional information
According to Annex VIII, section 9.1.4, column 2 of Regulation (EC) No. 1907/2006 (REACH) a study for activated sludge respiration inhibition testing does not need to be performed if there are mitigating factors indicating that microbial toxicity is unlikely to occur. Phosphoric acid will dissociate in water to phosphate anions and H+ ions, the latter causing a decrease of pH. However, pH levels in wastewater are typically adjusted in the wastewater treatment plant to ensure a neutral discharge to the receiving water (e.g., pH between 6-9) and in order to prevent inhibitory effects on the growth of microorganisms. Therefore, the microorganisms are essentially not exposed to phosphoric acid, but to phosphate instead.
Furthermore, phosphate is an essential nutrient for activated sludge systems, as it comprises part of the biomass in the activated sludge. Typical influent values in domestic sewage are as follows: Total phosphate as P: 4 – 15 mg/L; Inorganic phosphate as P: 3-10 mg/L.
When influent phosphate levels are at such levels that phosphate could pass through a treatment plant and result in excessive levels in a receiving water, additional unit operations are added to a treatment plant (e.g., precipitation) to remove excess phosphate.
A study on dipotassium orthophosphate was available and as such in accordance with Annex XI, Section 1.5 of REACH which states that read-across may be used in the case of substances whose physicochemical, toxicological and ecotoxicological properties are likely to be similar. Similarities may be based on:
1) A common functional group
2) The common precursors and/or the likelihood of common breakdown products via physiological and biological processes, which result in structurally similar chemicals; or
3) A constant pattern in the changing of the potency of the properties across the category
Orthophosphoric acid and dipotassium orthophosphate have the following similarities:
1). Both substances share the PO43-anion as common functional groups.
2) Both substances will ultimately dissociate into the common breakdown products of the PO43-anion.
The supporting study (Ishii et al) assessed the toxicity of phosphoric acid itself to microorganisms by using the oxygen absorption rate of activated sludge. The toxicity of phosphoric acid to protozoa was measured by looking at mortality. The IC50 values were 270 and 240 mg/L, respectively. It can be concluded that phosphoric acid is of low toxicity to microorganisms.
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.
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