Use of this information is subject to copyright laws and may require the permission of the owner of the information, as described in the ECHA Legal Notice.
EC number: 619-217-2
CAS number: 96487-85-3
An AMES test was performed with Norethyl according to OECD guideline and
In the dose range finding study, Norethyl was initially tested up to
concentrations of 5000 μg/plate in the strains TA100 and WP2uvrA in the
direct plate assay. The test item precipitated on the plates at dose
levels of 512 μg/plate and upwards, except in tester strain TA100
(absence of S9-mix) where precipitation was observed at 164 μg/plate
already. Since Norethyl precipitated heavily on the plates at the test
item concentrations of 1600 and 5000 μg/plate in tester strains TA100
(presence of S9-mix) and WP2uvrA (absence and presence of S9-mix), the
number of revertants of these dose levels could not be determined.
Cytotoxicity, as evidenced by a decrease in the number of revertants,
was observed in tester strain TA100 in the presence of S9-mix at the
dose level of 512 μg/plate. In the first mutation experiment, Norethyl
was tested up to concentrations of 1600 μg/plate in the strains TA1535,
TA1537 and TA98. The test item precipitated on the plates at dose levels
of 164 μg/plate and upwards. The bacterial background lawn was not
reduced at any of the concentrations tested and no biologically relevant
decrease in the number of revertants was observed. In the second
mutation experiment, Norethyl was tested up to concentrations of 512
μg/plate in the tester strains TA1535, TA1537, TA98, TA100 and WP2uvrA
in the pre-incubation assay. The test item precipitated on the plates at
dose levels of 164 μg/plate and upwards. The bacterial background lawn
was not reduced at any of the concentrations tested and no biologically
relevant decrease in the number of revertants was observed.
In this study, acceptable responses were obtained for the negative and
strain-specific positive control items indicating that the test
conditions were adequate and that the metabolic activation system
functioned properly. Norethyl did not induce a significant dose-related
increase in the number of revertant (His+) colonies in each of the four
tester strains (TA1535, TA1537, TA98 and TA100) and in the number of
revertant (Trp+) colonies in tester strain WP2uvrA both in the absence
and presence of S9-metabolic activation. These results were confirmed in
an independently repeated experiment.
Based on the results of this study it is concluded that Norethyl is not
mutagenic in the Salmonella typhimurium reverse mutation assay and in
the Escherichia coli reverse mutation assay with or without metabolic
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.
Welcome to the ECHA website. This site is not fully supported in Internet Explorer 7 (and earlier versions). Please upgrade your Internet Explorer to a newer version.
Do not show this message again