Alkanes, C12-26-branched and linear

Endpoint summary

Description of key information

Other gas oils were found to be irritating to rabbit skin over a 24 to 72 hour period with a 24 hour exposure period (similar to OECD 404, mean erythema 2.75, mean oedema 3.1).  Provided the test would be conducted under standard conditions, slight irritation could be expected and sufficient to classify as irritating to the skin.  
Other gas oils are considered not irritating to the eye (OECD 405).

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)

Additional information

The key dermal irritation studies on other gas oils (Klimisch scores = 2, API 1982a,b) each tested a different sample of hydrodesulfurised middle distillate with a 24 -hour, occluded exposure.  Both samples of hydrodesulfurised middle distillate produced moderate erythema and oedema at 24 hours that subsequently increased in severity at 72 hours and 96 hours before decreasing by day 7. Oedema had fully resolved by day 14, however minimal to mild erythema was still detectable. In the first study, the mean erythema and oedema scores (24 and 72 hours) were 1.9 and 2.25 respectively. In the second study, the mean erythema and oedema scores (24 and 72 hours) were 2.75 and 3.1 respectively. 

Although these tests are valid in their methodology, they differ from the current OECD guidelines in that animals were exposed under occluded conditions for 24 hours instead of semi-occluded conditions for 4 hours.  Considering the conditions of the tests, results must be interpreted carefully for the purposes of classification and labelling.  The mean scores for erythema and oedema have been assessed against the deviations, and provided the test would be conducted under standard conditions, irritation could be expected. Other gas oils are conservatively classified as irritating to the skin.

 

Key studies (Klimisch scores = 2, API 1982a,b) investigated the eye irritation potential of hydrodesulfurised middle distillate in male and female New Zealand White rabbits. In both studies, minimal irritation was present in both washed and unwashed eyes 1 hour after treatment, but this resolved over 24-48 hours. No individual animal data were provided, and the primary irritation scores did not allow classification of the test material according to EU regulations. However, because both samples of hydrodesulfurised middle distillate appeared to cause no more than mild to moderate irritation after instillation into rabbit eye, which was reversible, this resulted in a classification of “not irritating” to the eye. 

 

Effects on skin irritation/corrosion: irritating

Justification for classification or non-classification

The mean scores for erythema and oedema have been assessed against guideline deviations, and provided the test would be conducted under standard conditions, irritation might be expected; therefore Other Gas Oils meet the criteria for classification as Skin Irritant Category 2 (H315) according to EU CLP Regulation (EC No. 1272/2008). 

 

Based on mild to moderate reversible eye irritation after exposure to hydrodesulfurised middle distillates, Other Gas Oils are not classified as irritating to eyes according to EU CLP Regulation (EC No. 1272/2008).