Reaction mass of Silicic acid, calcium salt and Silicic acid, magnesium salt

Repeated dose toxicity: dermal

Administrative data

Endpoint:

repeated dose toxicity: dermal, other

Remarks:

Repeated sub-acute, dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Report from year 1958 (Cabot, unpublished report).

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Remarks:

ECETOC (2006)

Data source

Reference

Reference Type:

review article or handbook

Title:

Unnamed

Year:

2006

Materials and methods

Principles of method if other than guideline:

Dermal toxicity and irritative potential of pyrogenic silicon dioxide was studied using the rabbit as a test organism. Exposure followed a serie of 15 applications to intact and abraded skin.

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

Silicon dioxide

EC Number:

231-545-4

EC Name:

Silicon dioxide

Cas Number:

7631-86-9

Molecular formula:

O2Si

IUPAC Name:

Silicon dioxide

Test material form:

solid

Specific details on test material used for the study:

Hydrophilic synthetic amorphous silicon dioxide, pyrogenic (Cab-O-Sil fluffy), CAS 112945-52-5.

Test animals

Species:

rabbit

Strain:

not specified

Details on species / strain selection:

Albino, strain not specified.

Sex:

male/female

Details on test animals or test system and environmental conditions:

Two males, two females.

Administration / exposure

Type of coverage:

not specified

Vehicle:

not specified

Details on exposure:

Doses administred were 0, 5000, 10 000 mg/kgbw/d in a serie of 15 applications to intact and abraded skin.

Analytical verification of doses or concentrations:

not specified

Duration of treatment / exposure:

18 h per day, 5 days per week over three weeks.

Doses / concentrations

Doses / concentrations 1

Dose / conc.:

0 mg/kg bw/day

Doses / concentrations 2

Dose / conc.:

5 000 mg/kg bw/day

Doses / concentrations 3

Dose / conc.:

10 000 mg/kg bw/day

Doses / concentrations 4

Dose / conc.:

10 000 mg/kg bw/day

Remarks:

+ ve control (cosmetic talc).

No. of animals per sex per dose:

Two males and two females were included in the study.

Control animals:

yes

Details on study design:

Doses administred were 0, 5000, 10 000 mg/kgbw/d in a serie of 15 applications to intact and abraded skin. Rabbits were exposed for 18 h per day, 5 days per week over a three week period.

Positive control:

Methylcellulose

Examinations

Observations and examinations performed and frequency:

Systemic toxicity.
Gross or microscopic pathological changes.
Silica content of blood, urine, spleen, liver and kidney.
Dermal irritation (erythema, stonia, desquamation).

Results and discussion

Results of examinations

Clinical signs:

no effects observed

Description (incidence and severity):

No evidence of systemic toxicity.

Dermal irritation:

effects observed, non-treatment-related

Description (incidence and severity):

No significant difference in dermal irritation between control and dose groups.

Gross pathological findings:

no effects observed

Effect levels

Key result

Dose descriptor:

other:

Sex:

male/female

Remarks on result:

other: See "Remarks"

Remarks:

As summarized in ECETOC (2006), no toxicity of synthetic amorphous silicon dioxide was seen by the dermal route of expsoure.

Target system / organ toxicity

Key result

Critical effects observed:

no

Any other information on results incl. tables

The silica content of blood, urine, spleen, liver and kidney of treated animals was comparable to that of controls.

Applicant's summary and conclusion

Conclusions:

Data available indicate no toxicity of synthetic amorphous silicone dioxide (pyrogenic) in rabbit by the dermal route of exposure.

Executive summary:

Repeated sub-acute toxicity of synthetic amorphous silicone dioxide (pyrogenic) by the dermal route of exposure was evaluated in rabbit. Males and females were exposed to 0, 5000 and 10 000 mg/kgbw/d substance in a serie of 15 applications (18 h/day, five days/week over a period of three weeks). Methylcellulose and cosmetic talc were used as positve and negative controls, respectively. No evidence of systemic toxicology or gross or microscopic pathological changes in control and dose groups. No difference in silica content of blood and investigated organs between control and dose groups. No significant difference in dermal irritation between control and dose groups.