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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
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2010
Report Date:
2010

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:
deviation: no analytical data on chemical composition of the test item were submitted by the sponsor; however, this deviation did not limit the assessment of the results.
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): Desmodur VP.PU 60WF14
- Physical state: liquid
- Purity: 100 % (as indicated by the sponsor)
- Lot/batch No.: P1DE000345
- Storage condition of test material: room temperature

Method

Species / strain
Species / strain / cell type:
S. typhimurium, other: TA 98, TA 100, TA 102, TA 1535, TA 1537
Additional strain / cell type characteristics:
not applicable
Metabolic activation:
with and without
Metabolic activation system:
Aroclor 1254 induced male rat liver S9 mix
Test concentrations with justification for top dose:
First test: 0, 50, 158, 500, 1581, 5000 µg/plate (without and with S9 mix)
Repeat test: 0, 60, 120, 240, 480, 960, 1920 µg/plate (only TA 98, TA 102 and TA 1537, only with S9 mix)
Vehicle / solvent:
Solvents used: ethylene glycol dimethylether (EGDE) dried with a molecular sieve 0.3nm (test substance), deionized water (mitomycin C), DMSO (sodium azide, nitrofurantoin, 4-nitro-1,2-phenylene diamine, cumene hydroperoxide, 2-aminoanthracene)
Controls
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: sodium azide (only TA 1535), nitrofurantoin (only TA 100), 4-nitro-1,2-phenylene diamine (TA 1537 and TA 98), mitomycin C (only TA 102 in plate incorporation assay), 2-aminoanthracene.
Remarks:
The positive controls sodium azide, nitrofurantoin, 4-nitro-1,2-phenylene diamine and mitomycin C were only used without S9 mix; the positive control 2-aminoanthracene was only used with S9 mix.
Evaluation criteria:
A reproducible and dose-related increase in mutant counts of at least one strain is considered to be a positive result. For TA 1535, TA 100 and TA 98 this increase should be about twice that of negative controls, whereas for TA 1537, at least a threefold increase should be reached. For TA 102 an increase of about 100 mutants should be reached. Otherwise, the result is evaluated as negative. However, these guidelines may be overruled by good scientific judgment. In case of questionable results, investigations should continue, possibly with modifications, until a final evaluation is possible.
Statistics:
Not specified.

Results and discussion

Test resultsopen allclose all
Species / strain:
S. typhimurium, other: TA 98, TA 100, TA 102, TA 1535, TA 1537
Metabolic activation:
with
Genotoxicity:
positive
Cytotoxicity / choice of top concentrations:
other: strain-specific bacteriotoxic effect at 1581 and 5000 µg/plate
Vehicle controls validity:
valid
Untreated negative controls validity:
not examined
Positive controls validity:
valid
Species / strain:
S. typhimurium, other: TA 98, TA 100, TA 102, TA 1535, TA 1537
Metabolic activation:
with
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
other: strain-specific bacteriotoxic effect at 1581 and 5000 µg/plate
Vehicle controls validity:
valid
Untreated negative controls validity:
not examined
Positive controls validity:
valid
Species / strain:
S. typhimurium, other: TA 98, TA 100, TA 102, TA 1535, TA 1537
Metabolic activation:
without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
other: strain-specific bacteriotoxic effect at 1581 and 5000 µg/plate
Vehicle controls validity:
valid
Untreated negative controls validity:
not examined
Positive controls validity:
valid
Remarks on result:
other: strain/cell type: TA 98, TA 102, TA 1537
Remarks:
Migrated from field 'Test system'.

Any other information on results incl. tables

Table 1: Summary of results from the Salmonella mutagenicity assay (first test) with Desmodur VP.PU 60WF14 (mean values of revertants per plate)

 Dose (µg per plate)

Without metabolic activation

 

 TA 1535

 TA 100

 TA 1537

 TA 98

 TA 102

 Solvent EGDE

8

116

6

14

250

 50

7

95

6

14

189

 158

9

83

6

9

172

500

7

108

4

13

143

1581

3

33

5

16

184

5000

3

37

0

 9

157

 Positive control

1259

358

42

91

1482 

 Dose ( µg per plate )

With metabolic activation (liver S9 mix)

 

 TA 1535

 TA 100

 TA 1537

 TA 98

TA 102

 Solvent EGDE

9

182

8

24

316

50

7

187

9

30

325

 158

10

239 

13

51

249

 500

8

242

23

115

411

 1581

7

160

20

98

350

 5000

2

72

0

38

234

 Positive control

157

2415

134

2364

675

Table 2: Summary of results from the Salmonella mutagenicity assay (repeat test) with Desmodur VP.PU 60WF14 (mean values of revertants per plate)

Dose ( µg per plate )

With metabolic activation (liver S9 mix)

 

 TA 1535

 TA 100

 TA 1537

 TA 98

TA 102

 Solvent EGDE

---

---

7

36

341

60

---

---

16

92

289

120

---

---

14

128

295

240

---

---

20

185

411

480

---

---

26

236

462

960

---

---

21

257

450

1920

---

---

21

160

356

 Positive control --- --- 103 2640 936

Doses up to and including 960 µg per plate did not cause any bacteriotoxic effects. Total bacteria counts remained unchanged and no inhibition of growth was observed. At higher doses, the substance had a strain-specific bacteriotoxic effect, so that this range could only be used up to and including 1920 µg per plate for assessment purposes. Substance precipitation occurred at the dose 960 µg per plate and above.

Evidence of mutagenic activity of Desmodur VP.PU 60WF14 was seen. On Salmonella typhimurium strains TA 1537, TA 98 and TA 102, a biologically relevant increase was found in the mutant count compared to the corresponding negative control. Positive response was found only with S9 mix. The lowest reproducible effective dose was 158 µg per plate for TA 98 and 500 µg per plate for TA 1537 and TA 102. The Salmonella/microsome test thus showed Desmodur VP.PU 60WF14 to have a mutagenic effect.

The positive controls sodium azide, nitrofurantoin, 4-nitro-1,2-phenylene diamine, mitomycin C and 2-aminoanthracene had a marked mutagenic effect, as was seen by a biologically relevant increase in mutant colonies compared to the corresponding negative controls.

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
positive with metabolic activation
Executive summary:

In an Ames test according to OECD TG 471 evidence of mutagenic activity of Desmodur VP.PU 60WF14 was seen. On Salmonella typhimurium strains TA 98, TA 102 and TA 1537 a biologically relevant increase was found in the mutant count compared to the corresponding negative control. Positive response was found only with S9 mix. In the absence of a metabolic activation system no mutagenic activity was found with the strains TA 98, TA 100, TA 102, TA 1535 and TA 1537. Based on these results, Desmodur

VP.PU 60WF14 is considered to be mutagenic in the Ames test with metabolic activation.