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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Administrative data

Description of key information

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records
Reference
Endpoint:
acute toxicity: oral
Type of information:
migrated information: read-across based on grouping of substances (category approach)
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: A scientific review by authorative international body
Principles of method if other than guideline:
OECD evaluated the available test data on synthetic amorphous silica.
GLP compliance:
no
Remarks:
review - both yes and no status
Test type:
other: different acute oral toxicity tests
Species:
other: rat and mouse
Sex:
male/female
Dose descriptor:
LD50
Effect level:
> 5 110 mg/kg bw
Remarks on result:
other: hydrophilic precipitated silica
Sex:
male/female
Dose descriptor:
LD50
Effect level:
> 5 000 mg/kg bw
Remarks on result:
other: hydrophilic precipitated silica
Sex:
male/female
Dose descriptor:
LD50
Effect level:
> 10 000 mg/kg bw
Remarks on result:
other: several silica types
Sex:
male/female
Dose descriptor:
LD0
Effect level:
> 20 000 mg/kg bw
Remarks on result:
other: hydrophilic precipitated silica
Sex:
male
Dose descriptor:
LD50
Effect level:
> 3 160 mg/kg bw
Remarks on result:
other: hydrophilic pyrogenic silica
Interpretation of results:
practically nontoxic
Remarks:
Migrated information Criteria used for interpretation of results: OECD GHS
Conclusions:
OECD (2004) includes 12 acute oral toxicity studies with synthetic amorphous silica, of which five is regarded as critical study for SIDS endpoint. These five studies are conducted with hydrophilic precipitated or pyrogenic silica. In the critical studies, the LD50 or LDO value was at least >3160 mg/kg bw, thus showing no acute oral toxicity.
Executive summary:

In OECD (2004), the acute oral administration of hydrophilic precipitated or pyrogenic silica either by gavage or in the diet

failed to produce signs of toxicity or deaths in treated animals with LD50values greater than the top doses applied. Thus, the LD50values varied from >3100 to >20000 mg/kg bw. In conclusion, acute oral ingestion to high doses of synthetic amorphous silica will produce no systemic toxicity.
Endpoint conclusion
Endpoint conclusion:
no adverse effect observed
Dose descriptor:
LD50
Value:
mg/kg bw

Acute toxicity: via inhalation route

Link to relevant study records
Reference
Endpoint:
acute toxicity: inhalation
Type of information:
migrated information: read-across based on grouping of substances (category approach)
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: A scientific review by authorative international body
Principles of method if other than guideline:
OECD evaluated the available test data on synthetic amorphous silica.
GLP compliance:
no
Remarks:
'yes' status in critical studies
Test type:
other: different acute inhalation toxicity tests
Species:
rat
Sex:
male/female
Dose descriptor:
LC0
Effect level:
> 0.139 mg/L air
Exp. duration:
4 h
Remarks on result:
other: hydrophilic pyrogenic silica
Sex:
male/female
Dose descriptor:
LC0
Effect level:
> 0.691 mg/L air
Exp. duration:
4 h
Remarks on result:
other: hydrophilic precipitated silica
Sex:
male/female
Dose descriptor:
LC50
Effect level:
> 2.08 mg/L air
Exp. duration:
4 h
Remarks on result:
other: hydrophilic pyrogenic silica

All acute inhalation studies performed with dry dust were hampered by the technical problem to achieve the recommended highest test concentration of 5 mg/l, apparently attributable to the high adhesive forces which caused rapid precipitation onto equipment walls. Therefore, the maximum attainable chamber concentrations were distinctly lower than envisaged.

Interpretation of results:
practically nontoxic
Remarks:
Migrated information Criteria used for interpretation of results: OECD GHS
Conclusions:
OECD (2004) includes seven acute inhalation toxicity studies with synthetic amorphous silica, of which three is regarded as critical study for SIDS endpoint. These three studies are conducted with hydrophilic pyrogenic or precipitated silica. In a study where LC50 > 2.08 mg/L was suggested, none of the animals died. The SAS dusts are considered as acutely non-toxic.
Executive summary:

OECD (2004) reviewed that there was no lethal effects following inhalation exposure of rats to the highest technically feasible concentrations of 140 to 2000 mg/m3of hydrophilic precipitated or pyrogenic silica. However, the acute inhalation of synthetic amorphous silica dust may cause discomfort and stress as well as sign of local irritation to nasal, bronchiolar and ocular mucous membranes. In conclusion, the synthetic amorphous silica dusts are considered acutely non-toxic via inhalation route.

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed
Dose descriptor:
LC50
Value:
140 mg/m³ air

Additional information

Justification for classification or non-classification