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Description of key information

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records
Reference
Endpoint:
skin sensitisation: in vivo (LLNA)
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2015
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: modern guideline study, conducted according to GLP
Qualifier:
according to
Guideline:
OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)
GLP compliance:
yes (incl. certificate)
Type of study:
mouse local lymph node assay (LLNA)
Species:
mouse
Strain:
CBA
Sex:
female
Vehicle:
dimethyl sulphoxide
Concentration:
0.1, 0.25, and 0.5% (w/w)
No. of animals per dose:
5 females (nulliparous and non-pregnant)
Parameter:
SI
Remarks on result:
other: mean S.I. (n = 5) 0.1%: 1.18 0.25%: 1.31 0.5%: 1.21
Parameter:
other: disintegrations per minute (DPM)
Remarks on result:
other: mean DPM (n = 5) 0.1%: 2440.5 +- 858.9 0.25%: 2720.1 +- 513.7 0.5%: 2509.1 +- 483.9
Interpretation of results:
not sensitising
Remarks:
Migrated information
Conclusions:
The test item Anthranilamide was not a skin sensitizer.
Executive summary:

In order to study a possible skin sensitising potential of Anthranilamide, three groups each of five female mice were treated once daily with the test item at concentrations of 0.1, 0.25, and 0.5% in DMSO by topical application to the dorsum of each ear for three consecutive days. The test item could be dissolved in the vehicle. The appropriateness of the used concentrations was previously assessed by four pre-experiments. A control group of five mice was treated with the vehicle DMSO only. Five days after the first topical application the mice were injected intravenously into a tail vein with radio-labelled thymidine (3H-methyl thymidine). Approximately five hours after intravenous injection, the mice were sacrificed, the draining auricular lymph nodes excised, pooled per animal and immediately weighed. Furthermore, after excision of the lymph nodes, both ears of the mice were punched at the apical area using a biopsy punch and were immediately weighed pooled per animal using an analytical balance. Afterwards single cell suspensions of lymph node cells were prepared from pooled lymph nodes per animal. An aliquot of each cell suspension was used for determination of lymph node cell count. Subsequently the suspensions were washed and incubated with trichloroacetic acid overnight. The proliferative capacity of pooled lymph node cells was determined by the incorporation of 3H-methyl thymidine measured in a β-scintillation counter. The animals showed neither signs of systemic toxicity nor mortality during the course of the study. From day 3 to 5, the animals treated with 0.25 and 0.5% showed an erythema of the ear skin (score 1). A statistically significant or biologically relevant increase in ear weights was not observed in any treated group in comparison to the vehicle control group. Furthermore, for BALB/c mice, a cut-off value of 1.1 for the ear weight index was reported for a positive response regarding ear skin irritation (see Ref. 9). None of the indices determined for the test item treated groups reached or exceeded this threshold. A test item is regarded as a sensitiser in the LLNA if exposure to one or more test item concentration results in a 3-fold or greater increase in incorporation of 3HTdR compared with concurrent controls, as indicated by the Stimulation Index (S.I.). The estimated test item concentration required to produce a S.I. of 3 is referred to as the EC3 value. In this study Stimulation Indices (S.I.) of 1.18, 1.31, and 1.21 were determined with the test item at concentrations of 0.1, 0.25, and 0.5% (w/w) in DMSO, respectively. A statistically significant or biologically relevant increase in DPM value and also in lymph node weight and - cell count was not observed in any treated group in comparison to the vehicle control group. Furthermore, the cut-off value of 1.55 for a positive response regarding the lymph node cell count index reported for BALB/c mice (see Ref. 8) was not reached or exceeded in any dose group. The EC3 value could not be calculated, since none of the tested concentrations induced a S.I. greater than the threshold value of 3.

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not sensitising)
Additional information:

In this study the test item Anthranilamide was assessed for its skin sensitising potential using the Local Lymph Node Assay (LLNA) in mice. Test item solution at different concentrations was prepared in the vehicle DMSO. The local lymph node assay is recommended by international test guidelines (e.g., OECD) as an animal test for predicting skin sensitisation in humans and provides a rational basis for risk assessment. The basic principle underlying the LLNA is that sensitisers induce a primary proliferation of lymphocytes in the lymph node draining the application site. The ratio of proliferation in test item treated groups compared to that in vehicle controls is termed the Stimulation Index (S.I.). Radioactive labeling is used to measure cell proliferations. For this purpose a local lymph node assay was performed using test item concentrations of 0.1, 0.25, and 0.5% (w/w). The highest concentration tested was the highest concentration that could be achieved whilst avoiding systemic toxicity and excessive local skin irritation (as determined four pre-experiments). The animals showed neither signs of systemic toxicity nor mortality during the course of the study. From day 3 to 5, the animals treated with 0.25 and 0.5% showed an erythema of the ear skin (score 1). A statistically significant or biologically relevant increase in ear weights was not observed in any treated group in comparison to the vehicle control group. Furthermore, for BALB/c mice, a cut-off value of 1.1 for the ear weight index was reported for a positive response regarding ear skin irritation (see Ref. 9). None of the indices determined for the test item treated groups reached or exceeded this threshold. A test item is regarded as a sensitiser in the LLNA if exposure to one or more test item concentration results in a 3-fold or greater increase in incorporation of 3HTdR compared with concurrent controls, as indicated by the Stimulation Index (S.I.). The estimated test item concentration required to produce a S.I. of 3 is referred to as the EC3 value. In this study Stimulation Indices (S.I.) of 1.18, 1.31, and 1.21 were determined with the test item at concentrations of 0.1, 0.25, and 0.5% (w/w) in DMSO, respectively. A statistically significant or biologically relevant increase in DPM value and also in lymph node weight and – cell count was not observed in any treated group in comparison to the vehicle control group. Furthermore, the cut-off value of 1.55 for a positive response regarding the lymph node cell count index reported for BALB/c mice (see Ref. 8) was not reached or exceeded in any dose group. The test item Anthranilamide was thus not a skin sensitiser under the test conditions of this study.


Migrated from Short description of key information:
The substance is considered to be not skin sensitizing.

Respiratory sensitisation

Endpoint conclusion
Endpoint conclusion:
no study available

Justification for classification or non-classification

Based on the absence of effects after skin exposure, classification for skin sensitization is not warranted in accordance with EU Classification, Labeling and Packaging of Substances and Mixtures (CLP) Regulation No. 1272/2008. Furthermore, no classification and labeling is needed in accordance with EU Classification, Labeling and Packaging of Substances and Mixtures (CLP) Regulation No. 1272/2008.