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Toxicological information

Genetic toxicity: in vitro

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Administrative data

Endpoint:
in vitro gene mutation study in bacteria
Remarks:
Type of genotoxicity: gene mutation
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1989
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Well reported study for which original report available. Only four strains of bacteria tested. Not to GLP.

Data source

Reference
Reference Type:
other company data
Title:
Unnamed
Year:
1989

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Version / remarks:
1983 version
Deviations:
yes
Remarks:
Only four strains of bacteria tested.
GLP compliance:
no
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
Test material contained 87.2% of 2-(2-(2-butoxyethoxy)ethoxy)ethanol. Remainder not stated but likely to be higher glycol ethers.

Method

Species / strain
Species / strain:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Details on mammalian cell lines (if applicable):
- Periodically checked for karyotype stability: yes. The Salmonella stains were periodically checked for deep rough character (rfa), UV sensitivity (uvrB), and ampicillin resistance (R factor plasmid).
- Periodically "cleansed" against high spontaneous background: Histidine auxotrophy was automatically checked in each experiment via the spontaneous mutation rate.
Metabolic activation:
with and without
Metabolic activation system:
S9 mix from Aroclor 1254 induced male SD rats.
Test concentrations with justification for top dose:
20-5000ug per plate
Controlsopen allclose all
Negative controls:
yes
Solvent controls:
no
Positive controls:
yes
Remarks:
Dissolved in DMSO
Positive control substance:
N-ethyl-N-nitro-N-nitrosoguanidine
Remarks:
Migrated to IUCLID6: 5 ug for strains TA100 and TA1535 in the absence of S9
Negative controls:
yes
Solvent controls:
no
Positive controls:
yes
Remarks:
Dissolved in DMSO
Positive control substance:
other: 10ug of 4-nitro-o-phenylenediamine for TA98 in the absence of S9
Negative controls:
yes
Solvent controls:
no
Positive controls:
yes
Remarks:
Dissolved in DMSO
Positive control substance:
9-aminoacridine
Remarks:
Migrated to IUCLID6: as the chloride monohydrate at 100ug for strain TA1537 in the absence of S9.
Negative controls:
yes
Solvent controls:
no
Positive controls:
yes
Remarks:
Dissolved in DMSO
Positive control substance:
other: 2-amino anthracene at 10ug/plate for all strains with S9
Details on test system and conditions:
METHOD OF APPLICATION; in agar (plate incorporation) and preincubation method used.

DURATION
- Preincubation period: 20 mins
- Exposure duration: continuous
- Expression time (cells in growth medium): 48 hours

NUMBER OF REPLICATIONS: 3
Evaluation criteria:
Evaluation Criteria: The test material was considered a mutagen if both the mean number of revertant colonies was at least 2 times higher than the
mean of the negative (solvent) control and it induced a reproducible doseresponse relationship over several concentrations. If the dose-response
was not definitive, it was considered to be a presumptive mutagen. If the reversion rates were between 2 and 3 times that of negative controls, the
results were considered equivocal or inconclusive.

Results and discussion

Test resultsopen allclose all
Species / strain:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity:
not specified
Vehicle controls valid:
not specified
Negative controls valid:
not specified
Positive controls valid:
yes
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'. Remarks: Results for standard test
Species / strain:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity:
not specified
Vehicle controls valid:
not specified
Negative controls valid:
not specified
Positive controls valid:
yes
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'. Remarks: Results for pre-incubation test
Additional information on results:
Toxicity : No bacteriotoxic effect was observed.
Mutagenicity: An increase in the number of his+ revertants was not observed both in the standard plate test and in the preincubation test either without S-9 mix or after the addition of a metabolizing system.

Any other information on results incl. tables

Standard test: The average number of revertant in the controls for strains TA98, TA100, TA1535, and TA1537 in the absence of S-9 were 23, 114, 16, and 9 respectively. Addition of S-9 to strain TA98 increased the control mutation frequency to 34. S-9 had no effect on the frequency of mutations in the other strains. Positive controls induced an average of from 152 revertants in TA1535 to 1690 revertants in TA100. The number of revertants induced by test material was not increased from that of control at any concentration. The average number of revertants in cultures treated with test material (in the absence or presence of S-9) ranged from 109 to 140 in TA100, 12 to 21 in TA1535, and 8 to11 in TA1537. Similar to control TA98 cultures, the average number of revertants in TA98 cultures treated with test material in the presence of S-9 (33 to 36) were higher than in the absence of S-9 (19 to 24).

Preincubation test:The average number of revertant in the controls for strains TA98, TA100, TA1535, and TA1537 in the absence of S-9 were 24, 111, 17, and 8. Addition of S-9 to strains TA98 and TA1535 increased the control mutation frequency to 33 and 23, respectively. S-9 had no substantial effect on the frequency of mutations in the other strains. Positive controls induced an average of from 94 revertants in TA1537 to 1127 revertants in TA100. The number of revertants induced by test material was not increased from that of control at any concentration. The average number of revertants in cultures treated with test material (in the absence or presence of S-9) ranged from 108 to 135 in TA100 and 7 to11 in TA1537. Similar to control TA98 cultures, the average number of revertants in TA98 and TA1535 cultures treated with test material in the presence of S-9 (35 to 41 and 18 to 26, respectively) were higher than in the absence of S-9 (19 to 24 and 14 to18, respectively).

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
negative with metabolic activation
negative without metabolic activation

The test substance does not cause reverse gene mutation in bacterial strains.
Executive summary:

In a guideline bacterial gene mutation study (Ames), 2-(2-(2-butoxyethoxy)ethoxy)ethanol (87% pure) did not cause an increase in mutations when tested at up to 5mg/plate with and without S9 metabolic activation using both a standard plate incorporation and pre-incubation methods of application.