Registration Dossier

Administrative data

Description of key information

Key value for chemical safety assessment

Skin sensitisation

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

Two samples of petroleum vacuum residue (CAS number 64741-56-6) were tested for dermal sensitisation in male albino guinea pigs (Hartley) using a closed patch technique (Buehler assay) (API, 1983a, b). The fur was removed from the animals (10 per assay) 24 hours prior to dosing. The material was heated slightly just prior to each application to decrease its viscosity. Three doses (one / week for three weeks) of 0.4 mL of the test material were applied on the shaven skin in a Hilltop chamber (25 mm diameter) and covered. After 6 hour the test material was removed using paraffin oil as a solvent. Two weeks after the third induction dose, a challenge dose of 0.4 mL was applied to a virgin site on the other flank of the animal. Twenty animals received 2,4-dinitrochlorobenzene in a similar fashion as a positive control and 10 animals received the challenge dose of the vacuum residue without pre-treatment as a negative control. Application sites were examined and scored for erythema and oedema 24 and 48 hours after application. Very slight erythema was observed in most animals during the induction phase (with sample 81-13, containing high sulphur levels, causing slightly more erythema than sample 81-14 which contained little sulphur), but no erythema or oedema was seen in the challenge phase (both scores averaged 0.0). It was concluded that neither of the vacuum residues tested were skin sensitisers.

Migrated from Short description of key information:

Two skin sensitisation (OECD 406) studies were identified, in which samples of petroleum vacuum residues were not found to be sensitizing to the skin of Hartley albino guinea pigs using the Buehler method.

Justification for selection of skin sensitisation endpoint:

Based on negative results in two key studies

Respiratory sensitisation

Endpoint conclusion
Endpoint conclusion:
no study available
Additional information:

Respiratory sensitisation is not an information requirement.

Migrated from Short description of key information:

No data identified.

Justification for classification or non-classification

Based on results of two in-vivo studies, bitumen is not considered a skin sensitiser. Therefore, bitumen does not meet the criteria for classification as a dermal sensitiser under the CLP Regulation, (EC)1272/2008. There are no data available for respiratory sensitisation for bitumen.