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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:
27 May 1998 - 10 June 1998
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Study was performed to OECD and EC test guidelines and according to GLP.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1998
Report Date:
1998

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
no
Qualifier:
according to
Guideline:
EU Method B.13/14 (Mutagenicity - Reverse Mutation Test Using Bacteria)
Deviations:
no
GLP compliance:
yes (incl. certificate)
Remarks:
Netherlands GLP Compliance Monitoring Programme
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Type:
Constituent
Details on test material:
2,2-dimethylol propionic acid (DMPA), supplied by Mallinckrodt as a free flowing granular solid, off-white in colour, impurities (identity and concentrations): moisture, 0.13%; ash, 0.008%. Lot/batch No.: DO 374. The material was stored under ambient conditions.

Method

Target gene:
TA98: His D3052, TA100: His G46, TA1535: His G46, TA1537: His C3076.
Species / strain
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Metabolic activation:
with and without
Metabolic activation system:
S9-Mix obtained from the livers of male Wistar rats injected i.p. with Arocolor 1254
Test concentrations with justification for top dose:
Nominal concentrations: 0, 62, 185, 556, 1667, 5000 µg/plate
Vehicle / solvent:
Water: Just before use, a stock solution of the test substance was prepared in water at 50000 µg/ml, resulting in a clear solution. Thereafter, the stock solution was sterilised by passage through a micorpore filter and serial dilutions were prepared in water.
Controlsopen allclose all
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
sodium azide
Remarks:
1.0 µg/plate; positive control for strains TA1535 and TA100
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
9-aminoacridine
Remarks:
80 µg/plate; positive control for strain TA1537
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
2-nitrofluorene
Remarks:
2.0 µg/plate; positive control for strain TA98
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: 2-aminoanthracene
Remarks:
2.0 µg/plate; positive control for strains TA1535, TA98, and TA100 in the presence of S9-mix.
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
benzo(a)pyrene
Remarks:
4.0 µg/plate; positive control for strain TA1537 in the presence of S9-mix.
Details on test system and experimental conditions:
Two independent mutagenicity assays were performed. A preliminary toxicity test was not conducted, because excessive toxicity was not expected. Therefore, the toxicity test was incorporated into the first mutagenicity assay.
Frozen stocks of each strain were checked for histidine or tryptophan requirement and for sensitivity to ampicillin, crystal violet and UV radiation.
To 2 ml molten top agar (containing 0.6% agar, 0.5% NaCl and 0.05 mM L-histidine.HCl/0.05 mM biotin), maintained at 46°C, were added subsequently:0.1 ml of a fully grown culture of the appropriate tester strain, 0.1 ml of the appropriate dilution of the test substance or of the negative control (vehicle: water), of or the positive control substance and 0.5 ml S9 mix or 0.5 ml sodium phosphate 100 m (pH7.4) as appropriate. The ingredients were thoroughly mixed and the mix was immediately poured onto minimal glucose agar plates (1.5% agar in Vogel and Bonner medium E with 2% glucose). All determinations were made in triplicate. The plates were incubated at c. 37°C for 3 days. Revertant colonies were then counted.
Evaluation criteria:
A reproducible two-fold or greater increase in the mean number of revertant colonies appearing in the test plates over and above the background
spontaneous reversion rate observed in the vehicle, or a demonstrable concentration-related effect, was taken to indicate a positive response in this assay system.
Statistics:
No statistical analysis was performed; not required for this study type

Results and discussion

Test results
Species / strain:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
not applicable
Positive controls validity:
valid
Additional information on results:
The substance was not toxic to the bacteria (evidenced by the absence of a drastic decrease in the mean number of revertant colonies).
In both the absence and presence of S9 mix in all strains tested, the test substance did not cause a reproducible two-fold or greater increase in the mean number of revertant colonies appearing in the test plates compared to the background spontaneous reversion rate observed with the vehicle, and did not give evidence of a dose response. The positive controls gave the expected increase in the mean number of his+ revertants both with and without S9.
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.

Any other information on results incl. tables

It was concluded that 2,2 -dimethylol propionic acid is not mutagenic up to concentrations of 5000 µg/plate.

Applicant's summary and conclusion

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

It was concluded that the results obtained with the test substance 2,2-dimethylol propionic acid (DPMA) in Salmonella typhimurium strains TA 1535,
TA 1537, TA 98, and TA 100, in both the absence and in the presence of the S9-mix indicate that 2,2-dimethylol propionic acid (DMPA) was not
mutagenic under the conditions employed in this study.
Executive summary:

A study was conducted by TNO Nutrition and Food Research Institute, Netherlands on behalf of Mallinckrodt Chemical GmbH, Germany, to assess the potential of the the test substance 2,2 -dimethylol propionic acid (DMPA) to cause genetic damage. A bacterial reverse mutation test was performed in several Salmonella typhimurium strains (TA1535, TA1537, TA98 and TA100), both with and without metabolic activation. The study was performed to GLP and according to OECD 471 and EC B14 Test Guidelines. There was no evidence of toxicity, or mutagenicity up to concentrations of 5000 µg/plate. Therefore it was concluded that 2,2 -dimethylol propionic acid was not mutagenic under the conditions of the study.