Registration Dossier

Administrative data

Endpoint:
acute toxicity: inhalation
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
weight of evidence
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: A scientific evaluation by an authoritative international body. Read-across to synthetic amorphous silica.

Data source

Reference
Reference Type:
other: evaluation
Title:
SIDS initial assessment report for SIAM 19. Synthetic amorphous silica and silicates.
Author:
OECD
Year:
2004
Bibliographic source:
UNEP Publications, Berlin.

Materials and methods

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: evaluation of available data

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent

Test animals

Species:
rat

Results and discussion

Effect levelsopen allclose all
Sex:
male/female
Dose descriptor:
LC0
Effect level:
> 0.139 mg/L air
Exp. duration:
4 h
Sex:
male/female
Dose descriptor:
LC0
Effect level:
> 0.691 mg/L air
Exp. duration:
4 h
Sex:
male/female
Dose descriptor:
LC50
Effect level:
> 2.08 mg/L air
Exp. duration:
4 h

Any other information on results incl. tables

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.

Applicant's summary and conclusion

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 of which three is regarded as critical study for SIDS endpoint. 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)evaluated the available studies on acute toxicity of silica after inhalation. Following inhalation exposure of rats to the highest technically feasible concentrations of 140 to ca. 2000 mg/m3synthetic amorphous silica, no lethal effects were observed. The acute inhalation of synthetic amorphous silica dust may cause discomfort and stress as well as signs of local irritation to nasal, bronchiolar and ocular mucous membranes. In conclusion, the synthetic amorphous silica dusts are considered acutely non-toxic via the inhalation route.