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EC number: 270-658-3
CAS number: 68475-70-7
A complex combination of hydrocarbons obtained by the fractionation pyrolysis at 816°C (1500°F) of naphtha and raffinate. It consists predominantly of aromatic hydrocarbons having carbon numbers predominantly in the range of C6 through C8, including benzene.
Data available data for one stream within this category (CAS
68516-20-1) and on specific constituents that are present in some
streams (benzene, DCPD, toluene, and xylene) 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.
dermal irritation of E000144700 (CAS 68516-20-1) was investigated in a
group of 6 albino rabbits. 0.5 mL of neat test substance was applied to
approximately 1 square inch of shaved dorsal skin and retained in
contact for 4 hours under an occlusive dressing. Erythema and oedema was
seen in all six animals from 1 hour until 72 hours after removal of the
dressing. Mean erythema and oedema scores over 24, 48 and 72 hours were
greater than 2.
(CAS 68516-20-1) is irritating to rabbit skin and warrants
classification Category 2, H315 under GHS/CLP.
Moderate conjunctival irritation (i.e.
inflammation and slight swelling of the eyelids) and very slight
transient corneal injury (i.e. questionable or just perceptible
superficial necrosis in very small areas of the cornea) were recorded.
Instillation of benzene into the rabbit eye
caused moderate conjunctival irritation and very slight, transient
corneal injury. It is concluded that benzene is irritating to rabbit
eyes and should be classified as Category 2, H319 under GHS/CLP.
Non human data
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). Data on the specific
constituents benzene (Jacobs et al, 1991), toluene (Exxon, 1988), and
xylene (Chatterjee et al, 2005; Chevron Chemical Company, 1973; Hines et
al, 1970), and DCPD (Safepharm 1989) indicate some irritation following
dermal contact with effects sufficiently severe to warrant
Data on E000144700 (CAS 68516-20-1) and on
specific component toluene and DCPD, 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
There are no specific data on any of the
streams but the constituent xylene is classified as “irritating to
respiratory system” (De Ceaurriz et al, 1981; HLA, 1983a, b).
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: 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: 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: Category 2 H315;
Self classification: 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).
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.
EU (2008b). European Union Risk Assessment
Report for Benzene. EC Joint Research Centre. http: //ecb. jrc. ec.
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.
Justification for selection of skin
irritation / corrosion endpoint:
Information available for representative
streamand the marker constituents indicates a potential to cause skin
Justification for selection of eye
Information available for representative and the
marker constituents present in these streams indicates a potential to
cause eye irritation.
Effects on skin irritation/corrosion:
Effects on eye irritation:
sufficient data on the stream CAS 68516-20-1 and on component substances
benzene, toluene and xylene 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: “Causes skin irritation” Category
2 H315, “Causes serious eye damage” Category 2 H319 according to Reg
High Benzene Naphtha streams containing ≥10%
xylene and/or DCPD should be classified “May cause respiratory
irritation” Category 3 H335 under Reg (EC) 1272/2008.
Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of a registration number does however not guarantee that the information in the dossier is correct or that the dossier is compliant with Regulation (EC) No 1907/2006 (the REACH Regulation). This information has not been reviewed or verified by the Agency or any other authority. The content is subject to change without prior notice.Reproduction or further distribution of this information may be subject to copyright protection. Use of the information without obtaining the permission from the owner(s) of the respective information might violate the rights of the owner.
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