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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:
read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Justification for type of information:
REPORTING FORMAT FOR THE ANALOGUE APPROACH
For the assessment of skin sensitisation read across to the structurally similar Bayscript Blaukomponente MDA (EC No 916-916-7; source component) is performed. For further information on the read across see separate document attached to this study endpoint record.

HYPOTHESIS FOR THE ANALOGUE APPROACH
Both, the substance (target) and its read across substance (source), consist of three nearly identical main constituents and further isomers in minor amounts. These are naphthylenesulfonic acid moieties linked with azo groups. Target and source mainly differ in their ammonium counter ion, which is TEA (CAS 102-71-6) for the target and MDA (CAS 105-59-9) for the source.

For the ammonium counter ion TEA itself a low skin sensitization potential was concluded, not meeting the criteria for classification according to Regulation (EU) 1272/2008 (references: Substance Evaluation Report for 2,2’,2”-NITRILOTRIETHANOL (TEA), CAS 02-71-6, by UK REACH CA, August 2015).
Parameter:
SI
Remarks:
relative Cell Count (compared to vehicle control)
Value:
0.92
Test group / Remarks:
2.5 %
Remarks on result:
other: The positive level, which is 1.4, has not been exceeded.
Parameter:
SI
Remarks:
relative Cell Count (compared to vehicle control)
Value:
0.97
Test group / Remarks:
10 %
Remarks on result:
other: The positive level, which is 1.4, has not been exceeded.
Parameter:
SI
Remarks:
relative Cell Count (compared to vehicle control)
Value:
1.16
Test group / Remarks:
41.2 %
Remarks on result:
other: The positive level, which is 1.4, has not been exceeded.
Parameter:
other: disintegrations per minute (DPM)
Remarks on result:
other: modified LLNA; measurement of cell counts instead of radioactive labelling.

Compared to vehicle treated animals, none of the parameter measured in the test substance groups i.e. cell counts, weights of the draining lymph nodes, ear weights and ear swelling reached or exceeded the 'positive level' defined for this assay. The cell count indices were determined 1.0 (vehicle control), 0.92, 0.97, 1.16. Thus, the positive level, which is 1.4  for cell count index was never reached or exceeded. The respective value for the positive controls was 1.61. (It has to be clarified that the positive levels are exclusively defined for the NMRI mice used in this study.)

Conclusions:
A LLNA/IMDS according to OECD TG 429 in female NMRI mice at formulation concentrations of 0%, 2.5 %, 10 %, or 41.2 % of the substance showed no sensitizing potential and no indication for a non-specific (irritant) potential up to and including 41.2 %.
Executive summary:

Based on read across an LLNA/IMDS is available with female NMRI mice receiving epicutaneous application of formulations containing 0 % (vehicle control), 2.5 %, 10 %, or 41.2 % of the substance Bayscript Blaukomponente MDA (source substance, EC No. 916-916-7) in DMF for 3 consecutive days onto both ears of the animals. The study was conducted according to OECD TG No. 429. The substance showed no sensitizing potential in the modified Local Lymph Node Assay (IMDS) in female NMRI mice after dermal application of up to and including a 41.2 % concentration. Additionally, no indication for a non-specific(irritant) activation by the test item was detected. The positive control hexyl cinnamic aldehyde (CAS-No. 101 -86 -0) was functional for each parameter (Vohr 2012).

The test result can be used for assessment of Bayscript Blaukomponente TEA (target substance), since both, the target and the source substance consist of three nearly identical main constituents of naphthylenesulfonic acid moieties linked with azo groups and further such isomers in minor amounts. Target and source mainly differ in their ammonium counter ion, which is TEA (CAS 102-71-6) for the target and MDA (CAS 105-59-9) for the source.

For the ammonium counter ion TEA itself a low skin sensitization potential was concluded, not meeting the the criteria for classification according to Regulation (EU) 1272/2008 (references: Substance Evaluation Report for 2,2’,2”-NITRILOTRIETHANOL (TEA), CAS 02-71-6, by UK REACH CA, August 2015).

For further information on the read across see separate document attached to this record.

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

Based on read across an LLNA/IMDS is available with female NMRI mice receiving epicutaneous application of formulations containing 0 % (vehicle control), 2.5 %, 10 %, or 41.2 % of the substance Bayscript Blaukomponente MDA (source substance) in DMF for 3 consecutive days onto both ears of the animals. The study was conducted according to OECD TG 429. In this study the substance showed no sensitizing potential in the modified Local Lymph Node Assay (IMDS) in female NMRI mice after dermal application of up to and including a 41.2 % concentration. Additionally, no indication for a non-specific(irritant) activation by the test item was detected. The positive control hexyl cinnamic aldehyde (CAS-No. 101 -86 -0) was functional for each parameter (Vohr 2012).

The test result can be used for assessment of Bayscript Blaukomponente TEA (target substance), since both, the target and the source substance consist of three nearly identical main constituents of naphthylenesulfonic acid moieties linked with azo groups and further such isomers in minor amounts. Target and source mainly differ in their ammonium counter ion, which is TEA (CAS 102-71-6) for the target and MDA (CAS 105-59-9) for the source.

For the ammonium counter ion TEA itself a low skin sensitization potential was concluded, not meeting the the criteria for classification according to Regulation (EU) 1272/2008 (references: Substance Evaluation Report for 2,2’,2”-NITRILOTRIETHANOL (TEA), CAS 02-71-6, by UK REACH CA, August 2015).

Respiratory sensitisation

Endpoint conclusion
Endpoint conclusion:
no study available

Justification for classification or non-classification

No classification concluded for Skin Sensitization according to Regulation (EC) No 1272/2008, Annex I.