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EC number: 295-458-3
CAS number: 92045-76-6
A complex combination of hydrocarbons obtained from residual oils by solvent crystallisation and treated with hydrogen in the presence of a catalyst. It consists predominantly of saturated straight and branched chain hydrocarbons having carbon numbers predominantly greater than C25.
Three in vitro gene mutation studies on a synthetic paraffin wax extract and one in vivo study on lubricant base oils were selected as key studies to support genetic toxicity data. Overall, these studies demonstrate that the substances tested were not mutagenic.
Additional information from genetic toxicity in vitro:
In vitro gene
Three key studies
(all with a Klimisch score=1) examined in vitro gene mutation of
paraffin waxes (TNO, 2005a; TNA, 2005b; TNO, 2005c). A
DMSO extract of Fischer-Tropsch synthetic paraffin wax (CAS No. 8002 -74 -2)
was examined for mutagenic activity in the bacterial reverse mutation
assay (TNO, 2005a). Salmonella
typhimuriumstrains TA 1535, TA
1537, TA 98, TA 100 andEscherichia colistrain WP2uvrAwere
incubated with the extract of the test substance at 62 to 5000 μg/plate
in the absence and presence of a liver fraction of Aroclor 1254-induced
rats (S9-mix) for metabolic activation. In
both the absence and presence of metabolic activation, the extract of
paraffin wax did not cause either a dose related or a more than two-fold
increase in the mean number of revertant colonies compared to the
negative control (DMSO). The
extract of Fischer-Tropsch synthetic paraffin wax was judged to be not
mutagenic under the conditions employed in this study. Supporting
data from other bacterial reverse mutation assays (BIBRA, 1993g;
SafePharm Laboratories Limited, 2006a) also indicate that paraffin and
hydrocarbon waxes are negative in the AMES test, both in the presence
and absence of metabolic activation.
In a mouse
lymphoma assay (TNO 2005b), L5178Y cells were exposed to 0.018 to 10
mmol/l of the extract for 4 hours with and without metabolic activation. In
both the absence and presence of S9-mix, the extract of test substance
was not cytotoxic to the L5178Y cells, and no relevant increase of the
mutant frequency was observed at any dose level; therefore, the test
substance was not judged to be mutagenic at the TK locus.
In a chromosomal
aberration test (TNO 2005c), Chinese Hamster Ovary cells were exposed to
the paraffin wax extract at concentrations ranging from 0.034 to 10
mmol/l. None of the
extract concentrations analysed induced a statistically significant
increase in the number of aberrant cells with or without metabolic
activation at pulse or continuous exposures. Taken
together, these studies indicate that the paraffin wax extract is not
mutagenic under the assay conditions specified. Supporting data from in
vitro chromosomal aberration tests conducted on human lymphocytes
(Shell, 2006) indicate that paraffin and hydrocarbon waxes are
non-clastogenic and non-aneugenic to human lymphocytes in vitro.
In vivo mouse
No in vivo
genetic toxicity studies have been conducted with paraffin or
hydrocarbon wax, but a key in vivo mouse micronucleus study (Klimisch
score=1) performed on lubricant base oils was selected as a read-across
study (McKee, 1990). In
a CD-1 mouse bone marrow micronucleus assay, male and female mice were
given a single intraperitoneal injection of 5 different
solvent-extracted, dewaxed paraffin oils in corn oil vehicle at doses of
0, 1.0, 2.5, or 5.0 g/kg. Bone
marrow cells were harvested at 24, 48, and 72 hours post-dosing. One
animal did not survive to scheduled sacrifice, but there were no gross
signs of toxicity. The
micronucleus frequency was significantly greater than the concurrent
negative control in bone marrow cells of male mice given 5.0 g/kg at 48
hours post-dosing, but the negative control was unusually low in this
instance, and therefore this result is not considered toxicologically
data support the conclusion that the five mineral hydrocarbons tested
were not clastogenic.
Paraffin and hydrocarbon waxes are not
expected to be mutagenic in vitro or in vivo and therefore do not meet
the EU classification criteria. The polycyclic aromatic compounds (PAC)
in oil products are poorly bioavailable due to their physico-chemical
properties (low water solubility and high molecular weight), making it
unlikely that the genotoxic constituents can reach and cause damage to
germ cells (Roy, 2007; Potter, 1999). Considering their poor
bioavailability, oil products which have been classified as carcinogenic
do not need to be classified as mutagenic unless there is clear evidence
that germ cells are affected by exposure, consistent with EU
CLP Regulation (EC No. 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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