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EC number: 275-735-5 | CAS number: 71630-92-7 Substance obtained by burning the husk removed from the rice paddy. Contains silica as well as the elements aluminum, calcium, carbon, chromium, copper, indium, iron, lead, magnesium, manganese, molybdenum, phosphorus, silver, sodium, tin, and zinc.
- 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
Rice husk ashes are not irritating to the skin and eyes.
Key value for chemical safety assessment
Skin irritation / corrosion
Endpoint conclusion
- Endpoint conclusion:
- no adverse effect observed (not irritating)
Eye irritation
Endpoint conclusion
- Endpoint conclusion:
- no adverse effect observed (not irritating)
Additional information
Skin irritation
Rice husk ashes were tested for acute dermal irritation/corrosion according to OECD guideline 404 and complying with GLP. Three albino rabbits were exposed to 0.5 g of test substance, applied onto the clipped skin for 4 h using a semi-occlusive dressing. Skin reactions were evaluated after patch removal and observations were made at 1, 24, 48 and 72 hours and up to 9 days after exposure. The test substance was applied first on the skin of one rabbit (No. 1), in which no signs of irritation/corrosion were observed upon removal of the patch after the 4-hour exposure. In a confirmatory test, two more rabbits were used (No. 2 and 3). The test item showed irritant but reversible effects on the intact skin of the two animals after a contact time of 4 hours. From days 2-8 in animal No. 2, and from days 3-5 in animal No. 3, both the test site as well as the control site showed redness, which was more in the beginning and thereafter reduced. The irritant effects were fully reversible within 9 days in animal No. 2 and within 6 days in animal No. 3. Neither mortalities nor significant clinical signs of toxicity were observed. For each individual animal (No. 1/2/3), the mean erythema and edema scores over 24, 48 and 72 h were 0/2/1.34 and 0/0.34/0, respectively (Ahuja, 2010).
Eye irritation
Rice husk ashes were tested for eye irritation/corrosion inalbino rabbits in a study performed according to the OECD guideline 405 and complying with GLP. The test material (0.1 g) was applied into the conjunctival sac of one eye and removed after 24 h by rinsing with water; the other eye served as control. The eyes were examined and scored 1, 24, 48 and 72 h after application. Initially, one animal was tested only (No. 1), in which no corrosive or severe irritant effects were observed. The negative response was confirmed using two additional animals (No. 2 and 3). One hour post-instillation redness, chemosis and discharge of the conjunctiva were noted in all test animals. Redness of the conjunctiva was observed in animal No. 2 at 24 h, and in animals No. 1 and 3 at 48 h post-instillation. Changes were fully reversible within 72 h post-instillation in animals No. 1 and 3 and within 48 h post-instillation in animal No. 2. Neither mortalities nor significant clinical signs of toxicity were observed. For each individual animal (No. 1/2/3), the mean conjunctiva and chemosis scores over 24, 48 and 72 h were 0.67/0.33/0.67 and 0.33/0.0/0.0, respectively. The mean cornea and iris scores were both 0.0 for all animals (Ahuja, 2010).
Effect level: empty Endpoint conclusion: Adverse effect observed
Justification for classification or non-classification
The available data on the skin and eye irritating potential of rice husk ashes is conclusive but not sufficient for classification according to DSD and CLP criteria for classification and labelling.
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