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Diss Factsheets
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EC number: 231-545-4 | CAS number: 7631-86-9
- 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
Toxicological Summary
- Administrative data
- Workers - Hazard via inhalation route
- Workers - Hazard via dermal route
- Workers - Hazard for the eyes
- Additional information - workers
- General Population - Hazard via inhalation route
- General Population - Hazard via dermal route
- General Population - Hazard via oral route
- General Population - Hazard for the eyes
- Additional information - General Population
Administrative data
Workers - Hazard via inhalation route
Systemic effects
Long term exposure
- Hazard assessment conclusion:
- no hazard identified
Acute/short term exposure
- Hazard assessment conclusion:
- no hazard identified
DNEL related information
Local effects
Long term exposure
- Hazard assessment conclusion:
- no hazard identified
Acute/short term exposure
- Hazard assessment conclusion:
- no hazard identified
DNEL related information
Workers - Hazard via dermal route
Systemic effects
Long term exposure
- Hazard assessment conclusion:
- no hazard identified
Acute/short term exposure
- Hazard assessment conclusion:
- no hazard identified
DNEL related information
Local effects
Long term exposure
- Hazard assessment conclusion:
- no hazard identified
Acute/short term exposure
- Hazard assessment conclusion:
- no hazard identified
Workers - Hazard for the eyes
Local effects
- Hazard assessment conclusion:
- no hazard identified
Additional information - workers
A large number of key and supporting studies have evaluated repeated dose toxicity by the inhalation route. These studies have been carried out on a variety of different untreated SAS materials.
In the studies, dose-dependent and particle-related local inflammation in lung and lung-associated tissues (lymph nodes) have been observed, accompanied by corresponding changes of inflammatory markers in the bronchoalveolar fluid. There are no substantial different pathological findings when comparing different SAS forms included in this set. Test item-related changes in lungs are dose-dependent and characterized by increased perivascular infiltration, alveolar macrophages and macrophage aggregations, as well as macrophage type II hyperplasia. Accordingly, reactive changes have been observed in BALT (bronchus-associated lymphoid tissues) and regional lymph nodes. Any clinical effects or morphological changes of other tissues indicating systemic toxicity are not associated with SAS exposure. Observed effects are not substance-specific, all respirable particles will show such response directly after exposure.
Historically, some concerns on the toxicity of pyrogenic untreated SAS materials were mainly based on the publication by Reuzel et al. (1991, Food Chem Toxicol 29:341-354), which documented indications for the occurrence of lung fibrosis in a 13-week inhalation study with 3 different SAS forms. In However in 2016, an expert pathology working group (PWG) subsequently re-evaluated and discussed this finding by re-analysing the identical lung sections as used by Reuzel et al. according to current histopathological standards. This expert group concluded that irreversible changes, such as fibrosis and granulomas were not induced by any of the 3 SAS forms in the 13-week inhalation study (PWG Report, Hardisty et al. 2016; Weber et al., 2018, Toxicology Research and Application, Vol. 2, p. 1-17).
Nevertheless, ECHAs decision on substance evaluation pursuant to article 46(1) of Regulation (EC) No 1907/2006 for silicon dioxide requested additional sub-chronic toxicity studies in rats via the inhalation route with fully characterized forms of pyrogenic SAS to examine the induction of pulmonary fibrosis as main toxicological endpoint. Such studies have been carried out with the high BET pyrogenic SAS and the low BET pyrogenic SAS. Neither of these 2 key studies evidenced lung fibrosis or, correspondingly, increases in collagen content even after extending the post-inhalation recovery period up to 12 months. Overall the results confirm biosolubility of SAS over time. Lung clearance from Si-particles is deemed to be via lymph flow, i.e., Si-particles should be filtered out and deposited within the associated lymph nodes. Based on the results of these examinations it can be concluded that the Si-content decreases in lymph nodes over the time. The morphological changes in lymph nodes only in low BET pyrogenic SAS exposed animals are not fully reversed by the end of recovery.
General Population - Hazard via inhalation route
Systemic effects
Long term exposure
- Hazard assessment conclusion:
- no hazard identified
Acute/short term exposure
- Hazard assessment conclusion:
- no hazard identified
DNEL related information
Local effects
Long term exposure
- Hazard assessment conclusion:
- no hazard identified
Acute/short term exposure
- Hazard assessment conclusion:
- no hazard identified
DNEL related information
General Population - Hazard via dermal route
Systemic effects
Long term exposure
- Hazard assessment conclusion:
- no hazard identified
Acute/short term exposure
- Hazard assessment conclusion:
- no hazard identified
DNEL related information
Local effects
Long term exposure
- Hazard assessment conclusion:
- no hazard identified
Acute/short term exposure
- Hazard assessment conclusion:
- no hazard identified
General Population - Hazard via oral route
Systemic effects
Long term exposure
- Hazard assessment conclusion:
- no hazard identified
Acute/short term exposure
- Hazard assessment conclusion:
- no hazard identified
DNEL related information
General Population - Hazard for the eyes
Local effects
- Hazard assessment conclusion:
- no hazard identified
Additional information - General Population
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.