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Administrative data

Description of key information

It can be concluded that low benzene naphtha streams are irritating to rabbit skin but not irritating to the rabbit eye.  Data for the specific components toluene and anthracene are consistent with this classification.  Although the related stream, CAS 64741-68-0, warrants a classification as corrosive to the skin, this is not consistent with data for the specific stream in this category or for toluene. In addition it is noted that the exposure to this C7-C12 petroleum-derived aromatic stream was more severe than required by the test guidelines (24 hr contact time under occluded conditions), and therefore classification is based on data obtained for the specific low benzene naphtha stream in this category.

Key value for chemical safety assessment

Additional information

Non human data

Skin irritation

Skin irritation studies are available for a low benzene naphtha streams and one related stream.CAS 68516-20-1 was concluded to be irritating, but not corrosive, to rabbit skin. The related stream, CAS 64741-68-0 (heavy catalytic reformed naphtha, petroleum, comprising predominantly C7 -C12 aromatic hydrocarbons with no benzene present) produced evidence of necrosis following a 24 hour application using occlusive dressings to abraded and non abraded rabbit skin. Although the exposure was more severe in terms of both duration and type of dressing used than is required by the guideline and classification scheme, under the conditions of the test it was concluded that CAS 64741-68-0 was corrosive to rabbit skin.The skin irritation potential of toluene was assessed in 7 rabbits according to EU method B4 (Exxon, 1988). Toluene caused significant inflammation of the skin and was classified as irritating to skin.

Eye irritation

Eye irritation studies are available for one low benzene naphtha stream and one related stream. These streams (CAS 68516-20-1 and CAS 64741-68-0) were concluded not to be irritating to the rabbit eye. Data on the specific component toluene indicates that instillation of liquid test substance into the eye may induce some evidence of eye irritation but not of a severity that warrants labelling (Exxon, 1995).

Respiratory irritation

There are no specific data on low benzene naphtha streams or on toluene relating to irritation of the respiratory system.

Human information

There is no specific human information concerning skin or eye irritation on the low benzene naphtha streams. Although no data have been found for toluene, the EU RAR (2003) stated “it is well known that toluene has a degreasing effect on the skin. After repeated exposures, toxic contact dermatitis may develop. ”

There are no data from direct exposure of human eyes to liquid toluene. In a recent study, Muttray et al (2005) exposed twenty healthy men to a constant level of 50 ppm toluene. Acute symptoms related to eye irritation were assessed with the Swedish Performance Evaluation System (SPES) self-assessment questionnaire, once before and 3 times during exposure. Values obtained during exposure were related to pre-exposure values. There was no effect of toluene exposure on "irritation to the eye", "watering eyes" or "blurred vision”. 50 ppm (188 mg/m3) toluene is a NOAEC for eye irritation in humans.

 

References

EU RAR (2003a). European Union Risk Assessment Report for Toluene. EC Joint Research Centre http: //ecb. jrc. ec. europa. eu/DOCUMENTS/Existing- Chemicals/RISK_ASSESSMENT/REPORT/toluenereport032. pdf

Exxon (1988). Primary dermal irritation study in the rabbit. Testing laboratory: Exxon Biomedical Sciences, Toxicology Laboratory, Mettlers Road, CN 2350, East Millstone, New Jersey 08875-2350. Owner company: Exxon. Study number: 225904. Report date: 1988-07-29.

Exxon (1995). Ocular irritation study in the rabbit without eyewash with toluene (compliant with OECD test guideline 405). Testing laboratory: Exxon Biomedical Sciences Inc, Toxicology laboratory, Mettlers Road, CN 2350, East Millstone, New Jersey 08875-2350. Owner company: Exxon. Study number: 191813.

Muttray A, Spelmeyer U, Hommel G, Oesch F, Jung D, Rose D, Mayer-Popken O, Rossbach B and Letzel S (2005). Acute exposure to 50 ppm toluene does not increase sleepiness. Environ. Toxicol. Pharmacol. 19, 665-669.

Justification for classification or non-classification

There are sufficient data on the low benzene naphtha stream and CAS 68516-20-1 and the specific component, toluene, to indicate that low benzene naphtha streams are irritating to rabbit skin but not irritating to the eye and should be classified as Xi R38 according to Dir 67/548/EEC and Category 2 H315 according to GHS/CLP.