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Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information
Hydroxylammonium nitrate and its analogues gave negative results in vivo and for bacterial strains in vitro. Results from in vitro assays with mammalian cells were equivocal.
Link to relevant study records
Reference
Endpoint:
in vitro gene mutation study in bacteria
Remarks:
Type of genotoxicity: gene mutation
Type of information:
experimental study
Adequacy of study:
weight of evidence
Study period:
1992
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: No indication if laboratoty was operating to GLP, no untreated controls were included in the assay.
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
yes
Remarks:
No untreated controls
GLP compliance:
not specified
Type of assay:
bacterial reverse mutation assay
Target gene:
Histidine
Species / strain / cell type:
S. typhimurium TA 97
Additional strain / cell type characteristics:
not applicable
Species / strain / cell type:
S. typhimurium TA 98
Additional strain / cell type characteristics:
not applicable
Species / strain / cell type:
S. typhimurium TA 100
Additional strain / cell type characteristics:
not applicable
Species / strain / cell type:
S. typhimurium TA 1535
Additional strain / cell type characteristics:
not applicable
Metabolic activation:
with and without
Metabolic activation system:
S9 liver fraction from arochlor 1524 induced Sprague Dawley rats and Syrian Hamsters
Test concentrations with justification for top dose:
10, 33, 100, 200, 250, 251, 333, 500, 667, 750, 1000, 2000 µg/plate.
Vehicle / solvent:
Water.
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
Positive controls:
yes
Positive control substance:
other: 2-aminoanthracene
Evaluation criteria:
A chemical was considered mutagenic if it produced a reproducible, dose-related response over the solvent control under a single metabolic activation condition, in replicate trials.
Statistics:
Mutagenic responses were reported as the mean +/- SEM based on three plates.
Species / strain:
S. typhimurium TA 97
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
not determined
Vehicle controls validity:
valid
Untreated negative controls validity:
not applicable
Positive controls validity:
valid
Species / strain:
S. typhimurium TA 98
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Remarks:
1000 µg/plate
Vehicle controls validity:
valid
Untreated negative controls validity:
not applicable
Positive controls validity:
valid
Species / strain:
S. typhimurium TA 100
Metabolic activation:
with and without
Genotoxicity:
other: Weakly mutagenic and some questionable results
Cytotoxicity / choice of top concentrations:
cytotoxicity
Remarks:
750 µg/plate
Vehicle controls validity:
valid
Untreated negative controls validity:
not applicable
Positive controls validity:
valid
Species / strain:
S. typhimurium TA 1535
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Remarks:
667 µg/plate
Vehicle controls validity:
valid
Untreated negative controls validity:
not applicable
Positive controls validity:
valid

 

TA 100

Dose (µg/plate)

No activation

 

No activation

10% Hamster S9

10%

Hamster S9

30% Hamster S9

30% Hamster S9

30%

Hamster S9

30% Hamster S9

Mutagenicity

-

-

-

?

?

?

?

-

0.00 (solvent control)

118 ± 6.6

160 ± 11.3

118 ± 7.3

124 ± 2.3

123 ± 5.8

132 ± 5.8

132 ± 5.8

176 ± 18.0

10

103 ± 3.8

147 ± 11.6

 

 

 

 

 

 

33

102 ± 5.0

138 ± 3.3

 

110 ± 4.2

126 ± 4.1

164 ± 4.1

 

141 ± 5.4

100

100 ± 3.7

174 ± 3.1

117 ± 6.4

120 ± 1.3

100 ± 2.6

158 ± 3.5

132 ± 1.9

115 ± 7.4

200

 

 

 

 

 

 

 

 

250

 

 

 

 

 

 

 

 

251

 

 

 

151 ± 8.4

 

 

 

146 ± 9.9

333

126 ± 2.6

173 ± 4.9

139 ± 3.3

155 ± 0.6

166 ± 4.6

210 ± 6.9

216 ± 8.0

158 ± 9.5

500

 

 

62 ± 2.3

 

 

 

201 ± 6.9

 

667

64 ± 3.2

94 ± 10.8

 

198 ± 6.1

 

 

 

214 ± 11.9

750

 

 

0 s

 

 

 

9.1 ± 7.1

 

1000

 

 

0 s

 

104 ± 7.4

130 ± 7.8 s

20 ± 6.3 s

 

2000

 

 

 

 

45 s ± 12.3

60 ± 3.2 s

 

 

Positive control

440 ± 3.1

570 ± 42.9

440 ± 12.5

383 ± 16.7

856 ± 40.5

748 ± 11.3

578 ± 14.0

503 ± 13.5

 

TA 100       

Dose (µg/plate)

10% rat S9

10%

rat S9

10% rat S9

10% rat S9

30%

rat S9

30% rat S9

30%

rat S9

30%

rat S9

30% rat S9

Mutagenicity

?

+W

?

+W

+W

-

-

-

?

0.00 (solvent control)

126 ± 10.5

121 ± 1.8

132 ± 4.2

136 ± 12.1

110 ± 3.0

190 ± 4.3

161 ± 3.7

138 ± 5.7

159 ± 3.7

10

 

 

 

 

 

 

 

 

 

33

128 ± 7.1

148 ± 9.2

 

156 ± 6.7

117 ± 6.7

187 ± 11.4

164 ± 4.3

 

161 ± 4.5

100

169 ± 7.8

151 ± 3.6

122 ± 4.2

162 ± 8.8

130 ± 3.5

191 ± 6.0

125 ± 5.5

143 ± 8.5

174 ± 6.2

200

 

182 ± 4.5

 

 

 

 

143 ± 9.0

 

 

250

 

 

 

 

 

 

 

 

 

251

 

 

 

193 ± 13.7

 

 

 

 

165 ± 1.7

333

188 ± 3.5

206 ± 5.9

170 ± 7.7

195 ± 11.0

172 ± 4.9

184 ± 5.9

175 ± 7.0

162 ± 5.5

178 ± 6.4

500

 

 

105 ± 3.8

 

 

 

 

143 ± 2.8

 

667

 

185 ± 8.5

 

229 ± 13.5

 

 

173 ± 12.1

 

242 ± 20.5

750

 

 

14 ± 2.3 s

 

 

 

 

21 ± 0.3

 

1000

142 ± 9.6

 

0 ± 0.0 s

 

211 ± 13.3

225 ± 18.1

 

0 ± 0.0 s

 

2000

74 ± 3.2 s

854 ± 155.7

 

 

66 ± 3.1 s

86 ± 3.1 s

 

 

1161 ± 19.9

Positive control

1215 ± 17.1

 

1582 ± 29.0

650 ± 64.0

1536 ± 1.3

673 ± 11.6

1536 ± 16.6

1525 ± 23.7

 

 

TA 1535

Dose (µg/plate)

Not applicable

10% hamster S9

30% hamster S9

10% rat S9

30% rat S9

Mutagenicity

-

-

-

-

-

0.00 (solvent control)

27 ± 2.1

15 ± 2.4

12 ± 1.3

12 ± 1.5

13 ± 0.9

10

 

 

 

 

 

33

28 ± 3.2

16 ± 1.5

17 ± 0.9

15 ± 1.5

12 ± 3.5

100

22 ± 3.6

14 ± 1.5

11 ± 0.9

19 ± 3.0

18 ± 1.5

200

17 ± 2.0

 

13 ± 1.5

 

18 ± 0.9

250

 

 

 

17 ± 4.1

 

251

 

21 ± 1.0

 

 

 

333

11 ± 1.8

19 ± 2.7

15 ± 0.9

17 ± 3.1

18 ± 1.2

500

 

 

 

 

 

667

9 ± 2.0 s

24 ± 0.9

14 ± 2.3

15 ± 2.3

12 ± 2.6

750

 

 

 

 

 

1000

 

 

 

 

 

2000

 

 

 

 

 

Positive control

257 ± 33.5

111 ± 6.7

130 ± 7.6

302 ± 7.3

71 ± 10.3

 

TA 97

Dose (µg/plate)

Not applicable

10% hamster S9

30% hamster S9

10% rat S9

30% rat S9

Mutagenicity

-

-

-

-

-

0.00 (solvent control)

86 ± 7.8

208 ± 7.5

161 ± 9.4

145 ± 6.0

139 ± 19.7

10

 

 

 

 

 

33

105 ± 5.8

216 ± 6.0

183 ± 9.0

136 ± 6.2

130 ± 7.5

100

82 ± 7.4

207 ± 6.9

169 ± 7.4

136 ± 6.6

138 ± 3.5

200

 

 

154 ± 23.8

 

96 ± 4.8

250

 

 

 

 

 

251

64 ± 5.5

197 ± 5.2

 

159 ± 6.1

 

333

41 ± 4.0 s

156 ± 1.8

138 ± 18.2

156 ± 4.0

99 ± 11.5

500

 

 

 

 

 

667

18 ± 1.5 s

101 ± 11

105 ± 11.1

84 ± 2.6s

69 ± 4.2

750

 

 

 

 

 

1000

 

 

 

 

 

2000

 

 

 

 

 

Positive control

692 ± 11.7

646 ± 8.1

898 ± 51.3

1421 ± 8.7

537 ± 34/9

 

TA 98

Dose (µg/plate)

Not applicable

10% hamster S9

30% hamster S9

10% rat S9

30% rat S9

Mutagenicity

-

-

-

-

-

0.00 (solvent control)

28 ± 4.3

32 ± 2.6

31 ± 0.9

50 ± 2.7

34 ± 3.3

10

 

 

 

 

 

33

23 ± 0.0

29 ± 1.5

41 ± 1.5

51 ± 4.6

33 ± 1.9

100

24 ± 2.8

26 ± 2.9

31 ± 2.0

49 ± 2.3

32 ± 0.9

200

 

 

 

 

 

250

 

 

 

 

 

251

24 ± 0.3

26 ± 0.9

 

46 ± 5.5

 

333

20 ± 1.7

25 ± 3.2

27 ± 7.6 s

54 ± 5.9

36 ± 3.2

500

 

 

 

 

 

667

21 ± 0.0

29 ± 3.0

 

55 ± 7.4

 

750

 

 

 

 

 

1000

 

 

0 ± 0.0 s

 

28 ± 1.3

2000

 

 

T

 

18 ± 3.5 s

Positive control

582 ± 21.3

244 ± 12.5

171 ± 13.5

118 ± 9.5

499 ± 10.4

+W, weakly mutagenic

?, questionnable response

-, nonmutagenic

s, slight clearing of background lawn

t, complete clearing of background

Results are mean (of three plates) ± SEM

Conclusions:
Interpretation of results (migrated information):
ambiguous with metabolic activation

Hydroxylammonium hydrochloride was not genotoxic in Salmonella typhimurium strains TA 97, TA98 or TA 1535, although genotoxicity was observed at concentrations of 1000 and 667 µg/plate for the strains TA 98 and TA 1535, respectively. In the Salmonella typhimurium strain TA 100, hydroxylamine hydrochloride was found to increase the number of revertant colonies in some tests. Genotoxicity was also observed at 667 µg/plate. The genotoxicity of hydroxylammonium hydrochloride is therefore considered equivocal.
Executive summary:

In a bacterial reverse mutation assay (Ames test) similar to OECD guideline 471, hydroxylammonium hydrochloide was found to be weakly mutagenic in Salmonella typhimurium strain TA100 with metabolic activation, it was mutagenic without activation. Negative results were achieved with Salmonella typhimurium strains TA97, TA98 and TA1535 with and without activation. This study is considered reliable wth restrictions.

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (negative)

Additional information

Additional information from genetic toxicity in vitro:

Hydroxylammonium nitrate and it analogues gave predominantly negative results for in-vitro genotoxicity tests. Assays in mammalian cells gave equivocal results, although the assays in general were conducted to none-standardised guidelines with non-standardised cell lines. Assays in bacterial strains gave predominantly negative results, although one weakly positive result was reported in Salmonella typhimurium strain TA100 without activation (with activation, the assay gave negative results). At high doses, cytotoxicity was observed in cells. The results from in vivo tests were all negative even at doses that produced toxic signs in test animals.


Justification for selection of genetic toxicity endpoint
Well reported study conducted to an equivalent or similar study level as OECD guideline 471. The results are well reported with a wide range of doses used and metabolic activation.

Justification for classification or non-classification

No classification is proposed.