Solvent naphtha (petroleum), heavy arom.

Carcinogenicity

Description of key information

There are no robust GLP carcinogenicity data on any of the streams within this category although Pyrolysis Fuel Oil was shown to be carcinogenic following skin painting in mice. Specific components present in some streams, benzene and naphthalene, have been shown to be carcinogenic, while the boiling range of Fuel Oils (130-500°C) indicates the probable presence of 3-7 ring PAH. This information supports overall classification of these streams as carcinogenic.

Justification for classification or non-classification

Information on the probable components benzene (up to 2.5 %) and naphthalene (up to 70%) and based on the boiling range of Fuel Oils (130 -500°C) (indicating the probable presence of 3-7 ring PAH) supports overall classification of Fuel Oils as carcinogenic.

PAH containing streams and streams listed in CLP Annex VI (CAS Numbers: 101631-14-5, 64742-90-1, 68475-80-9, 68477-38-3, 68513-69-9, 68527-18-4, 98219-64-8) are classified as follows Carcinogenic Cat 2, R45 according to Dir 1999/45/EC and Cat 1B, H350 under CLP Reg (EC) 1272/2008.

For other Fuel Oils streams that contain ≥0.1% benzene classification should be as follows: “May cause cancer” Carcinogenic Cat 1, R45 according to Dir 1999/45/EC and “May cause cancer” Cat 1A, H350 under Reg (EC) 1272/2008.

Additional information

The only carcinogenicity information on streams identified for this category is a skin painting study on pyrolysis fuel oils:

Pyrolysis Fuel Oils: Groups of 40 mice were painted with one brushful of neat Water Quench Pyrolysis Fuel Oil or Oil Quench Pyrolysis Fuel Oil on the midline of clipped dorsal skin 3 times per week from 7 weeks of age until death. Two groups of 40 control mice were similarly dosed with distilled water or benzene. Animals were monitored for development of papillomas and carcinomas. Both samples were highly carcinogenic. For the water quenched oil, the papilloma and carcinoma indices were 100 and 97.2, respectively. For the oil quenched oils, the indices were 94.4 and 94.4, respectively. The malignant tumours were squamous cell carcinomas. No tumours were seen in any control animal (Weil and Condra, 1977).

Specific components which have been identified as present in some streams and shown to be carcinogenic in animals and man are benzene and naphthalene:

Benzene (Classification: EU -Toxic T, Carcinogen Cat 1 R45; GHS/CLP - Category 1A, H350): Long term experimental carcinogenicity bioassays have shown that benzene is a carcinogen producing a variety of tumours in animals (including lymphomas and leukaemia). Human epidemiological studies indicate a causal relationship between benzene exposure and acute non-lymphatic leukaemia (Crump, 1994; Glass et al, 2003, 2004, 2006; Rinsky et al, 2002; Schnatter, 2004).

Naphthalene (Classification: EU -Harmful Xn, Carcinogen Cat 3 R40; GHS/CLP - Category 2, H352): According to the EU RAR (EU, 2003b) the limited information available in humans are considered insufficient conclude on carcinogenicity. However, naphthalene produced an increase in the incidence of respiratory epithelial adenomas and olfactory epithelial neuroblastomas (at the lowest exposure concentration of 10 ppm (50 mg/m³) in rats and an increase in the incidence of benign lung tumours (alveolar/bronchiolar adenomas) in mice. The tumours are considered to arise via a non-genotoxic mechanism and there is some uncertainty surrounding the relevance for human health. The LOAEL for carcinogenicity was considered to be 5 mg/m³.

References

EU (2003b). European Union Risk Assessment Report: Naphthalene.http://ecb.jrc.ec.europa.eu/DOCUMENTS/Existing-Chemicals/RISK_ASSESSMENT/REPORT/naphthalenereport020.pdf