Registration Dossier

Administrative data

Description of key information

Cracked gas oil was found to be irritating to the skin after 4 hour, semi-occlusive exposure.  The mean erythema score was 2.7 (24,48,72 hours), while the mean oedema score was 1.33 (24,48,72 hours).  

Cracked gas oils are not considered irritating to the rabbit eye.  

Key value for chemical safety assessment

Skin irritation / corrosion

Endpoint conclusion
Endpoint conclusion:
adverse effect observed (irritating)

Eye irritation

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

Respiratory irritation

Endpoint conclusion
Endpoint conclusion:
no study available

Additional information

Cracked gas oils are found to be irritating to the skin, but not irritating to the eye.

Skin Irritation

In the key dermal irritation study, three male New Zealand White rabbits were exposed to 0.5 mL of light catalytic cracked distillate under semi-occlusive conditions for 4 hours (Exxon1996). Animals were observed for 10 days following exposure, during which no clinical signs were observed. Well-defined erythema was observed in one animal, and moderate to severe erythema was observed in two animals at the 1, 24, 48, and 72 hour observation time points. Moderate to slight oedema was observed in all animals. The mean erythema score was 2.7 (24, 48, and 72 hours), while the mean oedema score was 1.33 (24, 48, and 72 hours). Erythema and oedema resolved by day 10, and therefore the study was terminated at that time. 

 

In supporting studies, rabbits were dermally exposed to cracked gas oil under semi-occlusive conditions for 24 hours. In ARCO 1992f, the mean erythema score was 2.19 (24, 72 hours), while the mean oedema score was 2.29 (24, 72 hours). In ARCO 1989f, 1989g, and 1989h, individual animal data were not provided, so mean erythema and oedema scores useful for classification cannot be calculated. However, provided data do indicate irritation to rabbit skin after dermal exposure. 

Based on results of available studies, cracked gas oils are classified as irritating to skin. 

Eye Irritation

In the key study identified for eye irritation (API 1985a), light catalytically cracked distillate was tested for eye irritation potential in a group of nine male New Zealand White rabbits. No pain response, corneal or iridial irritation was observed. Blanching conjunctivae was exhibited by one animal with unwashed eyes at the 1-hour time point. Irritation resolved by 72 hours, and no systemic toxicity was observed throughout the study period.  The mean irritation scores were 0/80 for corneal, 0/10 for iridial, and 0.44/20 for conjunctival irritation, for both washed and unwashed eyes.

In additional eye irritation supporting studies ( ARCO 1991a, 1989i, 1989j, 1989k), rabbits were exposed to cracked gas oil and observed for irritation. Any irritation noted was mild and fully reversible.  

Based on these results, cracked gas oils are not classified as irritating to the rabbit eye.

Additional data support that cracked gas oils are skin irritants (API, 1985a; API, 1985b;). Additional data support that cracked gas oils are not eye irritants (API, 1985b;). This information is presented in the dossier.

Justification for selection of skin irritation / corrosion endpoint:

one of 7 acute irritation studies producing similar results

Justification for selection of eye irritation endpoint:

One of 6 acute occular irritation studies showing similar results.

Effects on skin irritation/corrosion: irritating

Justification for classification or non-classification

Based on a mean erythema score of 2.7 (24, 48, 72 hours), and a mean oedema score of 1.33 (24, 48, 72 hours), cracked gas oils are classified as Skin Irritant Cat.2, H 315, irritating to the skin according to EU CLP Regulation (EC No. 1272/2008)

 

Based on a lack of corneal and iridial irritation, and a conjunctival irritation score of 0.44/20, cracked gas oils are not classified as irritating to eyes according to EU CLP Regulation (EC No. 1272/2008).