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Toxicological information

Skin sensitisation

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Administrative data

Endpoint:
skin sensitisation: in vivo (LLNA)
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Study period:
2007
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Well conducted study according to GLP

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2007
Report Date:
2007

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)
Deviations:
no
Qualifier:
according to
Guideline:
EU Method B.42 (Skin Sensitisation: Local Lymph Node Assay)
Deviations:
no
GLP compliance:
yes (incl. certificate)
Type of study:
mouse local lymph node assay (LLNA)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Details on test material:
Product brand: Sigma
Lot: 016K0107
Iron by ICP-AES: 14.4%
Sodium by ICP-AES: 6.1%
EDTA content: 69.9%

In vivo test system

Test animals

Species:
mouse
Strain:
CBA
Sex:
female

Study design: in vivo (non-LLNA)

Induction
Route:
epicutaneous, open
Vehicle:
other: Acetone/Olive oil (3+1 v/v)

Study design: in vivo (LLNA)

Vehicle:
acetone/olive oil (4:1 v/v)
Concentration:
10%, 25%, 50%
No. of animals per dose:
6
Details on study design:
RANGE FINDING TESTS:
In order to determine the dose levels, a preliminary dose-range-finding study was conducted in 2 animals per dose level. Seven (7) concentrations of 0.5, 1, 2.5, 5, 10, 25 and 50% of FeNaEDTA in acetone/olive oil (3+1 v/v) and a negative control were examined. No sensitising potential could be
observed.

MAIN STUDY
ANIMAL ASSIGNMENT AND TREATMENT
- Criteria used to consider a positive response: The so-called stimulation (or LLN-) indices were calculated by dividing the average lymph node cell
counts or ear weights (punch biopsies) per group of the test item treated animals by the vehicle treated ones. Thus, in case of no stimulating effect
the index for the lymph node cell count is always below 1.4, for the ear weights 1.1 (cut-off values). Indices above 1.4 or 1.1, respectively, are
considered positive. A possible dose-relationship between the test item groups regarding the lymph node weights would have been examined by
linear regression analysis employing PEARSON's correlation coefficient. A significant dose-relationship of lypmph node weights is considered
positive. In addition, the average ear thickness per group was compared to the vehicle control group.

TREATMENT PREPARATION AND ADMINISTRATION:
Positive control substance(s):
hexyl cinnamic aldehyde (CAS No 101-86-0)
Statistics:
U-test according to MANN and WHITNEY

Results and discussion

Any other information on results incl. tables

Parameter

Group 1, negative control

Group 2,

10%

Group 3, 25%

Group 4, 50%

Group 5,

positive control

Cell count

1.000

1.098

1.170

1.045

1.461

Lymph node weight

1.000

1.034

1.138

1.172

1.517

Ear weight

1.000

1.037

1.043

1.049

1.238

Difference of

ear thickness

1.000

1.070

1.113

1.116

1.135

Applicant's summary and conclusion

Interpretation of results:
not sensitising
Remarks:
Migrated information
Conclusions:
Under the conditions of this test, EDTA-FeNa was not considered to be a skin sensitizer.
Executive summary:

In a local lymph node assay according to OECD guideline 426 the skin senitisation potential of NaFeEDTA was evaluated.

Three concentrations of FeNaEDTA (10%, 25% and 50%, w/w) dissolved in acetone/olive oil (4:1 v/v) were tested in six female CBA mice per group and compared to a vehicle control group. In addition, a positive control group (30% solution v/v of hexyl cinnamic aldehyde in acetone/olive oil (4:1 v/v)) was employed. Open application of 25 μL of the appropriate dilution of the test item, the vehicle alone or the positive control (as appropriate) were administered to the dorsum of each ear on 3 consecutive days. On test day 4 lymph node cell count, ear weight (punch biopsies), ear swelling and weight of the lymph nodes were measured.

The positive control group caused the expected increases in lymph node cell count and ear weights (statistically significant at p ≤ 0.01). The values for the stimulation index of lymph node cell count and ear weight were 1.5 and 1.2, respectively.

Treatment with FeNaEDTA at concentrations of 10%, 25% or 50% (w/w) did not reveal any statistically significant increased values (p ≤ 0.01) for the lymph node cell counts and ear weights. The stimulation index of the lymph node cell count did not exceed the threshold level of 1.4, whereas the stimulation index of ear weights did not exceed the threshold level of 1.1. The slight increase of the lymph node weight in the 10%, 25% and 50% (w/w) test item treated groups is regarded as spontaneous, as no statistical significance was noted and the weights obtained are within the normal range observed for control animals.