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Toxicological information

Skin sensitisation

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Administrative data

Endpoint:
skin sensitisation: in vivo (non-LLNA)
Type of information:
experimental study
Adequacy of study:
key study
Study period:
19 Oct 2004 - 16 Dec 2004
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Meets national standard methods; GLP

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2004
Report date:
2004

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
EPA OPPTS 870.2600 (Skin Sensitisation)
Deviations:
yes
Remarks:
only historical positive control, one dose tested
GLP compliance:
yes
Remarks:
Product Safety Laboratories
Type of study:
Buehler test
Justification for non-LLNA method:
A non-LLNA test is available that was performed prior to the current data requirements, stipulated in Regulation (EC) No 1907/2006. In accordance with the same Regulation, the data were included to avoid unnecessary testing.

Test material

Constituent 1
Chemical structure
Reference substance name:
Silicic acid, potassium salt
EC Number:
215-199-1
EC Name:
Silicic acid, potassium salt
Cas Number:
1312-76-1
Molecular formula:
K2O x (SiO2)n with Molar Ratio (MR) (SiO2/K2O): 0.5 – 5 (with exception of MR = 1)
IUPAC Name:
potassium hydroxysilanoylolate
Details on test material:
- Name of test material (as cited in study report): AgSil TM 25 Potassium silicate solution
- Physical state: claer to hazy white, thick liquid
- Composition of test material, percentage of components: 70% water, 30% silicic acid, potassium salt, potassium silicate
- Lot/batch No.: C052804K1
- Stability under test conditions: stable for the duration of testing
- Storage condition of test material: at room temperature
- Other: ratio: 2.47; specific gravity: 1.231 g/mL

In vivo test system

Test animals

Species:
guinea pig
Strain:
Hartley
Sex:
male
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Elm Hill Breeding Labs
- Age at study initiation: young adult
- Weight at study initiation: 310 - 418 g
- Housing: group housing in stainless steeel cages
- Diet (e.g. ad libitum): pelleted Purina guinea pig chow #5025
- Water (e.g. ad libitum): filtered tap water
- Acclimation period: 3, 6 or 40 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18 - 22
- Photoperiod (hrs dark / hrs light): 12/12


IN-LIFE DATES: From: 20 Oct To: 19 Nov 2004

Study design: in vivo (non-LLNA)

Inductionopen allclose all
Route:
epicutaneous, occlusive
Vehicle:
water
Concentration / amount:
100% (undiluted, induction exposure), 75% (challenge exposure)
Challengeopen allclose all
Route:
epicutaneous, occlusive
Vehicle:
water
Concentration / amount:
100% (undiluted, induction exposure), 75% (challenge exposure)
No. of animals per dose:
20 in test group and 10 in naive control group
Details on study design:
RANGE FINDING TESTS:
Test to determine the highest non-irrritating concentration of the test substance to be used as challenge dose. The test substance was applied in concentrations of 100, 75, 50 and 25% to the shaved test side using an occlusive Hill Top Chamber and gently removed after 6h exposure (identical to main study). Approximately 24 h after application, each site was evaluated for local irritation reactions.

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 3
- Exposure period: 3 weeks
- Site: left side of each animal
- Frequency of applications: once a week
- Duration: 6 h
- Concentrations: 100%


B. CHALLENGE EXPOSURE
27 days after the first induction dose
- No. of exposures: 1
- Day(s) of challenge: 1
- Exposure period: 6 h
- Site: right side of each animal
- Concentrations: 75%
- Evaluation (hr after challenge): 24 and 48 h after the challenge application
Positive control substance(s):
yes
Remarks:
technical alpha-hexylcinnamaldehyde (historical control)

Results and discussion

In vivo (non-LLNA)

Resultsopen allclose all
Reading:
1st reading
Hours after challenge:
24
Group:
test chemical
Dose level:
100%/75%
No. with + reactions:
0
Total no. in group:
20
Clinical observations:
very faint erythema in 8/20 animals
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 100%/75%. No with. + reactions: 0.0. Total no. in groups: 20.0. Clinical observations: very faint erythema in 8/20 animals.
Reading:
2nd reading
Hours after challenge:
48
Group:
test chemical
Dose level:
100%/75%
No. with + reactions:
0
Total no. in group:
20
Clinical observations:
one animal with very faint erythema
Remarks on result:
other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: 100%/75%. No with. + reactions: 0.0. Total no. in groups: 20.0. Clinical observations: one animal with very faint erythema.
Reading:
1st reading
Hours after challenge:
24
Group:
negative control
Dose level:
0%/75%
No. with + reactions:
0
Total no. in group:
10
Clinical observations:
very faint erythema in 4/10 animals
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 24.0. Group: negative control. Dose level: 0%/75%. No with. + reactions: 0.0. Total no. in groups: 10.0. Clinical observations: very faint erythema in 4/10 animals.
Reading:
2nd reading
Hours after challenge:
48
Group:
negative control
Dose level:
0%/75%
No. with + reactions:
0
Total no. in group:
10
Clinical observations:
none
Remarks on result:
other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: negative control. Dose level: 0%/75%. No with. + reactions: 0.0. Total no. in groups: 10.0. Clinical observations: none.

Any other information on results incl. tables

The first and the second reading of the historical positive control group gave 6/10 animals with positive reactions whereas the corresponding negative control group (5 animals) gave no reactions at both time points.

Applicant's summary and conclusion

Interpretation of results:
not sensitising