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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
Toxicity to reproduction
Administrative data
- Endpoint:
- one-generation reproductive toxicity
- Remarks:
- based on test type (migrated information)
- Type of information:
- migrated information: read-across from supporting substance (structural analogue or surrogate)
- Adequacy of study:
- supporting study
- Reliability:
- 2 (reliable with restrictions)
- Rationale for reliability incl. deficiencies:
- other: Basic data given
Data source
Reference
- Reference Type:
- publication
- Title:
- Characterization and toxicological behavior of synthetic amorphous hydrophobic silica
- Author:
- Lewinson, J. et al.
- Year:
- 1 994
- Bibliographic source:
- Regul Toxicol Pharmacol. 20(1 Pt 1):37-57
Materials and methods
- Principles of method if other than guideline:
- One-generation reproduction study over two breeding sequences
- GLP compliance:
- not specified
Test material
- Reference substance name:
- Silane, dichlorodimethyl-, reaction products with silica
- EC Number:
- 271-893-4
- EC Name:
- Silane, dichlorodimethyl-, reaction products with silica
- Cas Number:
- 68611-44-9
- IUPAC Name:
- 271-893-4
- Details on test material:
- - Name of test material (as cited in study report): Aerosil R 972 (Fumed Hydrophobic Silica, FHS)
- Analytical purity: >99.8%
Constituent 1
Test animals
- Species:
- rat
- Strain:
- Wistar
- Sex:
- female
- Details on test animals or test system and environmental conditions:
- TEST ANIMALS
- Weight at study initiation: (P) Males: 131 g; Females: 120 +/- 4 g
- Diet (e.g. ad libitum): powder diet Altromin (Altromin GmbH, Germany)
- Water (e.g. ad libitum): ad libitum
ENVIRONMENTAL CONDITIONS
- Temperature (°C): 23 +/- 2
Administration / exposure
- Route of administration:
- oral: feed
- Vehicle:
- unchanged (no vehicle)
- Details on exposure:
- DIET PREPARATION
- Rate of preparation of diet (frequency): weekly
- Mixing appropriate amounts with (Type of food): the test compound was mixed into the powder diet Altromin (supplied by Altromin GmbH), and adapted weekly to the food consumption and the body weight gain. - Details on mating procedure:
- - M/F ratio per cage: 1/5
- Analytical verification of doses or concentrations:
- not specified
- Duration of treatment / exposure:
- 6 months
- Frequency of treatment:
- continuous
Doses / concentrations
- Remarks:
- Doses / Concentrations:
500 mg/kg bw
Basis:
nominal conc.
- No. of animals per sex per dose:
- 10
- Control animals:
- yes, plain diet
Examinations
- Parental animals: Observations and examinations:
- CAGE SIDE OBSERVATIONS: Yes
- Time schedule: daily
BODY WEIGHT: Yes
- Time schedule for examinations: weekly
FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study):
- Time schedule for examinations: daily
HAEMATOLOGY
- Hemoglobin, erythrocytes, leukocytes, and blood smears were examined at week 0 and then monthly, but not during pregnancy and lactation.
Results and discussion
Results: P0 (first parental generation)
General toxicity (P0)
- Clinical signs:
- no effects observed
- Body weight and weight changes:
- no effects observed
- Food consumption and compound intake (if feeding study):
- no effects observed
- Organ weight findings including organ / body weight ratios:
- no effects observed
- Histopathological findings: non-neoplastic:
- no effects observed
- Other effects:
- not specified
Reproductive function / performance (P0)
- Reproductive function: oestrous cycle:
- not specified
- Reproductive function: sperm measures:
- not specified
- Reproductive performance:
- no effects observed
Effect levels (P0)
- Dose descriptor:
- NOEL
- Effect level:
- 500 mg/kg bw/day (nominal)
- Sex:
- female
- Basis for effect level:
- other: overall effects
Results: F1 generation
General toxicity (F1)
- Clinical signs:
- not specified
- Mortality / viability:
- no mortality observed
- Body weight and weight changes:
- no effects observed
- Sexual maturation:
- not specified
- Organ weight findings including organ / body weight ratios:
- not specified
- Gross pathological findings:
- no effects observed
- Histopathological findings:
- not examined
Effect levels (F1)
- Dose descriptor:
- NOEL
- Generation:
- F1
- Effect level:
- 500 mg/kg bw/day (nominal)
- Sex:
- male/female
- Basis for effect level:
- other: overall effects
Overall reproductive toxicity
- Reproductive effects observed:
- not specified
Any other information on results incl. tables
There were no changes in behavior, appearance, or occurrence of clinical symptoms in the parental treatment and control groups. The body weight gain and food consumption were comparable in treated and control groups. No differences were seen in the hematological parameters or in organ weights at autopsy during pathological examination. Reproductive performance was not altered in the treated rats. The results of the pathological examination of the parents were comparable to those found in the simultaneously performed chronic 6 -month study described in the same publication.
After the first mating procedure, at week 8, 15 rats became pregnant, 6 in the control group and 9 in the treated group. Seven dams from each group were pregnant after the second mating period after week 17. There were no treatment-related effects in the litter size or birth weights. This was true for all parameters evaluated (s. table). Physical or behavioral abnormalities were not observed and runts did not occurred in either breeding experiment. Hematomas on the heads of three pups were seen only in the litter of one control animal. The development of the progeny during lactation was without adverse effects. The weight gains of both generations were normal. After 4 weeks the pups were examined for gross pathology. No treatment-related changes were found. Therefore, a dose of 500 mg/kg was concluded to be the no-observed effect level for developmental and reproductive toxicity in this study.
Developmental parameters for progeny and pregnant female rats fed 500 mg/kg test material for 6 months
|
Control group |
Treated group |
||
|
Litter 1 |
Litter 2 |
Litter 1 |
Litter 2 |
Pre-treatment period (weeks) |
- |
- |
8 |
17 |
Number of females |
10 |
10 |
10 |
10 |
Number pregnant |
6 |
7 |
9 |
7 |
Number of pups |
62 |
60 |
91 |
70 |
Mean litter size |
10.3 |
8.6 |
10.1 |
8.6 |
Mean birth weight (g) |
5.1 |
5.3 |
5.6 |
5.5 |
Dead pups |
2 |
1 |
0 |
2 |
Runts |
0 |
0 |
0 |
0 |
Gross anomalies and other changes |
3* |
0 |
0 |
0 |
Breeding rate (%): Birth Week 1 Week 2 Week 3 Week 4 |
100 90 84 84 84 |
100 97 93 92 92 |
100 97 96 92 92 |
100 93 76 76 76 |
* Hematomas on the heads of three pups in the same litter were observed.
Applicant's summary and conclusion
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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