Residues (petroleum), vacuum

Endpoint summary

Description of key information

Two skin (OECD 404) and three eye (OECD 405) irritation studies were identified. Petroleum vacuum residues tested in these studies were not found to be irritating to the skin or eyes of rabbits.  A further supporting eye irritation study on asphalt gave similar results. A long term repeat dose inhalation study with rats indicates that exposure to bitumen fume can lead to slight irritation of the respiratory tract (see section 7.5).

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)

Additional information

Two samples pf petroleum vacuum residue (CAS# 64741-56-6) were tested for primary skin irritation (API, 1982a, b). Aliquots of 0.5 mL of the two materials were slightly warmed to decrease the viscosity and subsequently applied under occlusion to the skin of 6 male white rabbits. After 24 hours, the occluding patches were removed and the skin was scored for erythema and oedema (according to Draize) at 1, 24, 72, 96 hours and at 1 and 2 weeks. The mean erythema and oedema scores for 24 and 72 hours for both residues ranged from 0 to 0.1. This study was performed under occlusion and during 24 hours, rather than 4 hour semi-occluded exposure recommended by current OECD guidelines. Regardless, mean erythema and oedema scores over the 72 hour period were low. Consequently, the result from a shorter exposure time will not meet the criteria for classification.

Primary eye irritation for two neat petroleum vacuum residues (CAS# 64741-56-6) was tested in 4 male and 4 female white rabbits (API, 1982a, b). The neat material (0.1 mL) was placed into the everted eyelid. In one male and two of the female animals the eye was washed 30 seconds after application, for 1 minute. The animals were observed for 7 days following application. In the study with sample 81 -13, the primary eye irritation score were 2.0, 4.0, 4.2, 1.8, and 0.0 at 1, 24, 48, 72 and 168 hours, respectively for the unwashed eye (6 animals) and 1.3, 5.3, 2.0, 0.7, and 0.0 at 1, 24, 48, 72 and 168 hours, respectively for the washed eye (3 animals) (API, 1982a). In the study with sample 81 -14, the primary eye irritation scores were 1.0, 4.7, 1.8, 0.0 and 0.0 at 1, 24, 48, 72 and 168 hours, respectively for the unwashed eye (6 animals) and 1.3, 3.3, 0.0, 0.0, 0.0 at 1, 24, 48, 72 and 168 hours, respectively for the washed eye (3 animals). Black material was surrounding the eye in a number of animals and one male animal, of which the eye was not washed, showed alopecia around the eye along with dark brown material (API, 1982b). In addition, one animal had diarrhoea, which was not considered treatment related (API, 1982b).

Additional eye irritation data on a sample of asphalt, supports that bitumen is not irritating to the eyes (ARCO, 1973b). This information is presented in the dossier.

Justification for selection of skin irritation / corrosion endpoint:

based on no significant irritation in 2 studies

Justification for selection of eye irritation endpoint:

Based on no significant irritation in 3 studies (One key and two supporting)

Justification for classification or non-classification

Based on results of in-vivo studies, bitumen is not considered to be a skin or eye irritant and does not meet the criteria for classification and labelling under the CLP Regulation, (EC)1272/2008.