Registration Dossier

Administrative data

Description of key information

Skin irritation:
No skin irritating or corrosive property were reported for 1,8-naphthylenediamine in two 3D skin models.
Eye irritation:
No eye irritating or corrosive property is predicted for 1,8-naphthylenediamine in a 3D-cornea model.

Key value for chemical safety assessment

Skin irritation / corrosion

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not irritating)

Eye irritation

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not irritating)

Respiratory irritation

Endpoint conclusion
Endpoint conclusion:
no study available

Additional information

Skin:

A study for predicting non-specific, corrosive potentials of 1,8 -naphthylenediamine was performed by using reconstructed human skin. The experiment was carried out on a reconstructed human epidermis EST-1000 (CellSystems, ST. Katharinen, Germany) for detection of topically applied skin corrosives with the test item. Corrosive skin effects of substances are defined as irreversible damage of skin; namely, visible necrosis through the epidermis and into the dermis, following the application of a test substance for up to 4 hours. A 100% concentration was tested on the skin/ epidermal equivalents in triplicate. For the determination of time related cytotoxic effects the incubation periods were 3 min. and 60 min. respectively. Thus the study was conducted in accordance with the 431 guideline as well as with an EC guideline (amending Council Directive 67/548/EEC, B.40 Skin Corrosion) using the test item concentrations and incubation periods recommended there. These tests are also related to the revised OECD 404 guideline "Acute Dermal Irritation/Corrosion". To check the reliability of this test procedure a blinded positive/negative control study is conducted at regular interval in the lab. The reliability check is always performed by two technicians, in two laboratories in parallel using the same batches of the control test items.

The test item was applied at a 100% concentration, i.e. 25 mg per insert (plus 50µl 0.9% NaCl to moisten and ensure good contact with the skin).

The test result shows that no corrosive property of the test item was determined by the assay used.

Another study which allows the hazard identification of irritant substances in accordance with UN GHS category 2, was performed. The experiment was carried out according to EU Test Method B.46 using commercially available reconstructed human epidermis (RHS) model EST-1000 (CellSystems, St.Katharinen, Germany). Undiluted test substance was applied topically to the RHS model, i.e. 30 mg per insert (plus 30 µg 0.9% NaCl to moisten and ensure good contact with the skin; three replicates). After an exposure period of 20 minutes, followed by a 42 hours post treatment incubation period, the cell viability was measured to be 99.56% in the MIT (Methylthiazoletetrazolium) conversion assay. The results of the concurrent negative control (NC, 0.9% NaCl) and positive control (PC, 5% SOS) demonstrated the viability (NC) and sensitivity (PC) of the test model. Thus, the results show that the test substance is considered to have no skin irritation category.

Eye:

In an vitro study for assessing ocular irritation of compounds a human epithelial corneal cell model is used. The model used is standardized and commercially available (SkinEthic™ Human Corneal Epithelial Model (HCE); SkinEthic, France).

Undiluted 1,8-naphthylenediamine was applied topically to the HCE tissue, i.e. 30 mg per insert (plus 30 µl PBS to moisten and ensure good contact with the skin; three replicates). After an exposure period of 60 minutes, followed by a 16 hours post-treatment incubation period, the cell viability was 57% (rounded) as measured by a MTT conversion assay. The results of the concurrent negative (NC, PBS) and positive control (PC, 1 H-1 ,2,4-Triazole-3-thiol) demonstrated the viability (NC) and sensitivity (PC) of the test model. The results show that 1,8 -naphthylenediamine is predicted as non-irritant under the conditions of this test method.

Justification for classification or non-classification

Due to the negative results of the 3D-skin models and the negative results of the 3D-cornea model a classification is not justified.