Distillates (petroleum), light thermal cracked, debutanized arom.

Endpoint summary

Description of key information

Available data for one stream within this category, 2 related streams and on specific components that are present in some streams (benzene, toluene, hexane, xylene and anthracene) provide some evidence of skin and eye irritation with controlled exposures to liquid test substances although the severity varies widely. Xylenes are also considered to be respiratory irritants. It is assumed that the total concentration of irritating components exceeds 20% and that High Benzene Naphtha streams should be considered to be skin and eye irritants and to be classified appropriately. The need for classification with respect to respiratory tract irritation is dependent upon available data for the specific stream or the concentration of xylenes in the stream.

Key value for chemical safety assessment

Skin irritation / corrosion

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Eye irritation

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Additional information

Non human data

Skin irritation

The stream E000144700(CAS 68516-20-1) has been tested in animal studies and shown to be irritating but not corrosive to rabbit skin (UBTL, 1990d), whereas related streams API 83-04 [CAS 64741-63-5, light catalytic reformed naphtha] and API 83-05 [CAS 68955-35-1, catalytic reformed naphtha] produced only minor effects and no classification is warranted (API, 1985a, b). API 83-04 and API 83-05 are two petroleum based naphthas comprising up to 100% aromatics, including substituted mono and di-aromatics with approximately 2-5% benzene and are considered appropriate for read-across to high benzene naphthas. Data on the specific components benzene (Jacobs et al, 1991), toluene (Exxon, 1988), hexane, xylene (Chatterjee et al, 2005; Chevron Chemical Company, 1973; Hines et al, 1970) and anthracene indicate some irritation following dermal contact with effects sufficiently severe to warrant classification.

Eye irritation

Data on E000144700(CAS 68516-20-1) related streams API 83-04 [CAS 64741-63-5, light catalytic reformed naphtha], API 83-05 [CAS 68955-35-1, catalytic reformed naphtha] (API, 1985 a, b) and on specific components toluene, hexane and anthracene indicate that instillation of liquid test substance into the eye may induce some evidence of eye irritation but not of a severity that warrants classification. For benzene (Wolf et al, 1956; Carpenter and Smyth, 1946) and xylene (Hine et al, 1970; HLA, 1983c, d) the effects are sufficient to warrant classification.

Respiratory irritation

There are no specific data on any of the streams but the component substance xylene is classified “irritating to respiratory system” (De Ceaurriz et al, 1981; HLA, 1983a, b).

Human information

There is no specific human information concerning skin or eye irritation on any of the streams or on the majority of specific components identified as present in some streams. Specific information of value to the risk assessment is available for benzene, toluene and xylene:

Benzene (Classification: EU -Harmful Xi, R36, R38; GHS/CLP - Category 2 H319, Category 2 H315): Liquid benzene on direct contact with the skin may cause erythema and blistering. Skin contact with benzene removes fat from the tissue which may result in the development of a dry, scaly dermatitis if exposure is repeated or prolonged. High concentrations of benzene vapours are irritating to the mucous membranes of the eyes, nose and respiratory tract (EU, 2008b).

Toluene (Classification: EU -Harmful Xi, R38; GHS/CLP - Category 2 H315): No data on skin irritation have been found. 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. A number of human experimental studies in volunteers have investigated reports of eye “irritation” resulting from exposures to toluene in ambient air. These studies indicate that toluene produces subjective sensations of eye irritation at concentrations ≥ 75 ppm (EU, 2003a). 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.

Xylene (Classification: EU -Harmful Xi, R38; Annex VI Harmonised GHS/- Category 2 H315; Self classification: EU -Harmful Xi, R36, R37, R38; GHS/- Category 2 H319, Category 3 H335, Category 2 H315): There is little human information available but the ATSDR (2007c) reports that dermal exposure of humans to xylene causes skin irritation, dryness and scaling of the skin, and vasodilation. Mild irritation of the eye and upper respiratory tract was reported in volunteer studies where individuals were exposed to 442 mg/m³(SCOEL, 1992) for 15-30 minutes (Carpenter, 1975; Hastings, 1984). No symptoms of nose or throat irritation have been reported in volunteers exposed to mixed xylenes up to 400 ppm (UK, 2001).

References

ATSDR (2007c). Toxicological profile for xylene. US Dept Health and Human Services.

EU (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

EU (2008b). European Union Risk Assessment Report for Benzene. EC Joint Research Centre. http: //ecb. jrc. ec. europa. eu/documents/Existing-chemicals/RISK_ASSESSMENT/REPORT/benzenereport063. pdf.

SCOEL (1992). Recommendation from the scientific expert group on occupational exposure limits for xylenes.

UK HSC (2001). UK HSC Consultation Document on EC Directive 2000/39/EC establishing a first list of indicative occupational exposure limit values at EC level in implementation of council directive 98/24/EC on the protection of the health and safety of workers from the risks related to chemical agents at work. UK Health and Safety Commission. Available from www.hse.gov.uk/condocs.

Effects on skin irritation/corrosion: irritating

Effects on eye irritation: irritating

Justification for classification or non-classification

There are sufficient data on the stream CAS 68516-20-1 and on component substances benzene, toluene, hexane, xylene and anthracene to indicate that they produce evidence of skin and eye irritation in animals although the response varies and is not always of a severity to warrant classification for eye irritation. However, based on likely concentrations of components and in order to be protective it is recommended that all High Benzene Naphtha streams should be considered to be skin and eye irritants. Classification and labelling will be required as follows: “Irritating to skin” Xi R38, “Irritating to eyes” Xi R36 according to Dir 1999/45/EC and “Causes skin irritation” Category 2 H315, “Causes serious eye damage” Category 2 H319 according to Reg (EC) 1272/2008.

High Benzene Naphtha streams containing ≥10% xylene should be classified “May cause respiratory irritation” Category 3 H335 under Reg (EC) 1272/2008. When the concentration is ≥20% the stream will need to be classified as “Irritating to respiratory system” Xi R37 according to Dir 1999/45/EC.