Registration Dossier

Administrative data

Endpoint:
acute toxicity: dermal
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: Comparable to guideline study with acceptable restrictions. Read-across to synthetic amorphous silica.

Data source

Referenceopen allclose all

Reference Type:
study report
Title:
Unnamed
Year:
1978
Report Date:
1978
Reference Type:
study report
Title:
Unnamed
Year:
1978
Report Date:
1978

Materials and methods

Test guideline
Qualifier:
no guideline available
Principles of method if other than guideline:
Four animals per group used, two each treated on the intact and abraded skin: The substance was mixed with distilled water to form an aqueous paste
GLP compliance:
no
Test type:
standard acute method

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
ZEO 49, ZEOSYL 113, ZEOSYL 200, and ZEOFREE 153 (not further specified): CAS-Name: Silica, precipitated, cryst.-free; CAS-No.: 112926-00-8

Test animals

Species:
rabbit
Strain:
New Zealand White
Sex:
not specified

Administration / exposure

Type of coverage:
occlusive
Vehicle:
water
Details on dermal exposure:
Four animals per group used, two each treated on the intact and abraded skin: The substance was mixed with distilled water to form an aqueous paste
Duration of exposure:
24 h
Doses:
2000, 3000, 4000, and 5000 mg/kg
No. of animals per sex per dose:
4 per dose group
Details on study design:
- Duration of observation period following administration: 14 days
- Frequency of observations and weighing:
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight, organ weights

Results and discussion

Effect levels
Sex:
not specified
Dose descriptor:
LD50
Effect level:
> 5 000 mg/kg bw

Any other information on results incl. tables

Local effect: very slight erythema (score 1 of 4), reversible after 2 days (ZEO 49), after 4 d (ZEOSYL) or 5 d (ZEOFREE) in one or a few animals. No systemic signs of toxicity or organ toxicity.
 

Applicant's summary and conclusion

Interpretation of results:
other: non-toxic
Executive summary:

In 1978, Woltjen and Calkins presented their study results on the acute dermal toxicity of precipitated synthetic silicas in four different reports. After acute dermal application of up to 5,000 mg/kg bw of aqueous pastes of precipitated synthetic amorphous silica to the intact and abraded skin of rabbits for 24 hours under occlusive conditions, no signs of systemic or organ toxicity were noted. There were only very slight transient erythemas at the site of treatment in solitary animals. In conclusion, the dermal exposure to high doses of synthetic amorphous silica will produce no systemic toxicity and the LD50 is >5,000 mg/kg.