Hydroxylammonium nitrate

Endpoint summary

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.