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Diss Factsheets
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EC number: 910-245-3 | CAS number: -
- 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
Key value for chemical safety assessment
Acute toxicity: via oral route
Link to relevant study records
- Endpoint:
- acute toxicity: oral
- Type of information:
- other: Expert Assessment
- Adequacy of study:
- key study
- Study period:
- 2015
- Reliability:
- 2 (reliable with restrictions)
- Rationale for reliability incl. deficiencies:
- other: Expert assessment as opposed to experimental result
- Reason / purpose for cross-reference:
- reference to other study
- Principles of method if other than guideline:
- Assessment
- GLP compliance:
- no
- Test type:
- other: Assessment
- Remarks on result:
- not measured/tested
- Remarks:
- due to pH>11
- Interpretation of results:
- Category 4 based on GHS criteria
- Remarks:
- Migrated information
- Executive summary:
This substance is a multi-constituent substance consisting of sodium hydroxide (215-185-5, 1310-73-2) and disodium metasilicate (229-912-9, 6834-92-0). It is the by-product of a reaction between zircon and sodium hydroxide (EC 304-802-4, Frit); after hydrolysis, this substance (EC 910-245-3) is the water-soluble fraction.
There are two acute oral toxicity studies with a Klimisch rating of 2 reported for disodium metasilicate which gives the LD50 for (male/female) rats of 770-820 mg/kg and 1152 -1349 mg/kg.
There are no reliable LD50 values for sodium hydroxide reported. This could in part be due to the severe localised effects of dosing such a corrosive substance (pH>11), which would also preclude conducting further acute toxicity tests in animals due to animal welfare issues.
There is an acute toxicity study for the precursor to reaction mass of disodium metasilicate and sodium hydroxide (910-245-3), that is Silicic acid (H4SiO4), zirconium(4+) salt (1:1), reaction products with sodium hydroxide (EC 304-802-4, Frit). This study has a Klimisch rating of 2 and reports an LD50 for (male/female) rats of 1,372 mg/kg.
The reaction mass of disodium metasilicate and sodium hydroxide (EC 910-245-3) has a pH of >13 which, if tested for acute toxicity, would give localised effects due to its corrosiveness and preclude conducting further acute toxicity tests in animals due to animal welfare issues.
As such, the lowest acute toxicity for disodium metasilicate which gave an LD50 for (male/female) rats of 770-820 mg/kg will be used as surrogate for the reaction mass of disodium metasilicate and sodium hydroxide.
Reference
Assessment
Endpoint conclusion
- Endpoint conclusion:
- adverse effect observed
- Dose descriptor:
- LD50
- Value:
- 770 mg/kg bw
Acute toxicity: via inhalation route
Endpoint conclusion
- Endpoint conclusion:
- adverse effect observed
- Dose descriptor:
- LC50
- Value:
- 2 060 mg/m³ air
Acute toxicity: via dermal route
Endpoint conclusion
- Endpoint conclusion:
- no study available
Additional information
Sodium Hydroxide: Source - the sodium hydroxide summary risk assessment report JRC EC 2008
No valid human and animal data are available on the acute systemic inhalation toxicity of NaOH. Limited animal data is available on acute systemic dermal toxicity. The hair of adult mice was clipped and a circular area 2 cm in diameter was painted by applicator with 50% NaOH. Afterwards the area was rinsed with water at various intervals. The mortality of mice was 20, 40, 80 and 71% when they were rinsed 30 minutes, 1 hour, 2 hours or not at all after the application. No mortality was observed when the mice were rinsed immediately after the application.
No acute oral toxicity study with animals has been carried out using (inter)national guidelines. Human case reports involving oral exposure were available in literature. The degree and type of injury after ingestion of NaOH depend on the physical form. Solid NaOH produces injury to the mouth and pharynx and is difficult to swallow. On the other hand liquid NaOH is easily swallowed, being tasteless and odourless, and is more likely to damage the oesophagus and stomach.
As NaOH is a corrosive substance, there is no need for further acute toxicity testing.
Justification for selection of acute toxicity – dermal endpoint
Running an acute dermal study on the reaction mass of disodium metasilicate and sodium hydroxide would add nothing to the hazard assessment for this substance, and risk management measures are driven primarily by its corrosive nature due to the high pH.
Justification for classification or non-classification
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.