Registration Dossier

Administrative data

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

No mutagenic activity was observed in two Ames Tests with the strains TA 1535, TA 1537, TA 98 and TA 100. Additionally, negative results were obtained in an in vitro gene mutation assay in mammalian cells (HPRT Assay).

Link to relevant study records

Referenceopen allclose all

Endpoint:
in vitro gene mutation study in bacteria
Type of information:
experimental study
Adequacy of study:
weight of evidence
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Comparable to guideline study, part of NTP/USA, but incomplete test strain set according to OECD guideline 471
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
yes
Remarks:
preincubation assay, two different sources of a microsomal metabolic system, 4 instead of 5 tester strains
Principles of method if other than guideline:
Method: Ames test acc. to Haworth, S. et al. (1983): Environ. Mutagen. 5, Suppl. 1, 3-142
GLP compliance:
not specified
Type of assay:
bacterial reverse mutation assay
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Metabolic activation:
with and without
Metabolic activation system:
Metabolic activation systems were derived from Arochlor-induced livers of male SD rats and male Syrian hamsters.
Test concentrations with justification for top dose:
3.3, 10.0, 33.0, 100.0, 333.0, 1000, 3333 µg/plate
Vehicle / solvent:
- Vehicle(s)/solvent(s) used: water
- Justification for choice of solvent/vehicle: Test substance well soluble in water
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
Remarks:
distilled water
Positive controls:
yes
Positive control substance:
other: -S9: Sodium azide (TA1535, TA100); 9-aminoacridine (TA1537); 4-nitro-o-phenylenediamine (TA98) // +S9: 2-aminoanthracene (all strains).
Details on test system and experimental conditions:
METHOD OF APPLICATION: preincubation, agar plate

DURATION
- Preincubation period: 20 min
- Exposure duration: 2 days at 37 °C


NUMBER OF REPLICATIONS: 3


DETERMINATION OF CYTOTOXICITY
- relative total growth (background lawn)
Evaluation criteria:
Mutagenic (+) or weakly mutagenic (+w) if a reproducible, dose-related increase in revertants over the corresponding solvent controls in replicate trials was seen.
Questionable (?) if a reproducible increase in revertants did not meet the criteria of either "+" or "+w", or if single doses produced an increase in repeat trials.
Key result
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Remarks:
>= 3.333 mg/plate (see Appendix 2, p. 37)
Vehicle controls validity:
valid
Positive controls validity:
valid
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'. Remarks: Salmonella typhimurium TA 98, TA 100, TA 1535, TA 1537
Conclusions:
Under the conditions of this test no mutagenic activity was observed at concentrations up to 3333 mg/plate.
Endpoint:
in vitro gene mutation study in mammalian cells
Type of information:
experimental study
Adequacy of study:
weight of evidence
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to guideline
Guideline:
OECD Guideline 476 (In Vitro Mammalian Cell Gene Mutation Test)
Version / remarks:
as of 1997
Principles of method if other than guideline:
HPRT assay for the detection of mutations at the hypoxanthine-guanine phosphoribosyl transferase (hprt) locus (6-thioguanine [6TG] resistance) in mouse lymphoma cells using a fluctuation protocol according to Cole et al. 1983.
Reference:
Cole J, Arlett C F, Green M H L, Lowe J and Muriel W 1983: A comparison of the agar cloning and microtitration techniques for assaying cell survival and mutation frequency in L5178Y mouse lymphoma cells. Mutation Research, 111, 317-386
GLP compliance:
yes (incl. QA statement)
Type of assay:
mammalian cell gene mutation assay
Target gene:
Induction of a forward mutation in the X-linked hprt locus: Resistance to the toxic analogue 6-thioguanine (6TG) results from lack of hypoxanthine-guanine phosphoribosyl transferase (HPRT) activity. Thus, the hprt-negative mutants are unable to use 6TG and survive in its presence.
Species / strain / cell type:
mouse lymphoma L5178Y cells
Details on mammalian cell type (if applicable):
- Type and identity of media: RPMI media (containing antibiotics and varying concentrations of horse serum, heat-inactivated, from 0 - 20 %)
- Properly maintained: yes
- Periodically checked for Mycoplasma contamination: yes
- Periodically "cleansed" against high spontaneous background: yes,
- Other procedures: purge of TK-negative mutants
Additional strain / cell type characteristics:
other: TK proficient (TK+)
Metabolic activation:
with and without
Metabolic activation system:
post-mitochondrial fraction from livers of male SD rats previously induced with Arochlor-1254
Test concentrations with justification for top dose:
Experiment 1: 0, 50, 100, 210, 280, 320, 360, 400, and 500 µg/mL (evaluated)
Experiment 2: 0, 50, 200, 300, 400, 425, and 450 µg/mL (evaluated)
Vehicle / solvent:
- Vehicle(s)/solvent(s) used: water
- Justification for choice of solvent/vehicle: sufficient water solubility of the test substance
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
Remarks:
water as vehicle
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: 4-nitroquinoline-N-oxide (-S9); benzo(a)pyrene (+S9)
Details on test system and experimental conditions:
METHOD OF APPLICATION: in medium, incubation in centrifuge tubes, culture flasks, and wells of microtiter plates,
depending on the operation step

DURATION
- Preincubation period: no data, pre-culture in RPMI 10 after thawing up to an appropriate cell density
- Exposure duration: 3 h
- Incubation temperature: 37 +- 1 °C
- Expression time (cells in growth medium): 7 d
- Selection time (if incubation with a selection agent): 12 d

SELECTION AGENT (mutation assays): 6-thioguanine (6-TG)

NUMBER OF REPLICATIONS: 2

NUMBER OF CELLS EVALUATED: Selection of 6-TG resistance: 4 microtiter plates of 90 wells at 2 x10^4 cells per well each
(= 384 x2 x10^4 cells per test concentration)

DETERMINATION OF CYTOTOXICITY
- Method: Relative survival in the presence and absence of test substance (by visual counting of viable clones in microtiter plates)

DETERMINATION of VIABILITY (after expression period)
- Method: visual counting of viable clones in microtiter plates

DETERMINATION of 6-TG RESISTANCE (after expression period)
- Method: visual inspection of microtiter plates for the number wells containing clones.
Evaluation criteria:
ACCEPTANCE CRITERIA
The assay was considered valid if the following criteria were met:
1. the mutant frequencies in the negative (vehicle) control cultures fell within the normal range (not more than three times the historical mean value)
2. at least one concentration of each of the positive control chemicals induced a clear increase in mutant frequency (the difference between the positive and negative control mutant frequencies was greater than half the historical mean value).

EV ALUATION CRITERIA
For valid data, the test article was considered to induce forward mutation at the hprt locus in mouse lymphoma L5178Y cells if:
1. the mutant frequency at one or more concentrations was significantly greater than that of the negative control (p < 0.05)
2. there was a significant concentration﷓relationship as indicated by the linear trend analysis (p < 0.05)
3. the effects described above were reproducible.
Results that only partially satisfied the assessment criteria described above were considered on a case-by-case basis.

Statistics:
Statistical significance of mutant frequencies was carried out according to the UKEMS guidelines. Thus the control log mutant frequency (LMF) was compared with the LMF from each treatment concentration, and secondly the data were checked for a linear trend in mutant frequency with test article treatment. These tests require the calculation of the heterogeneity factor to obtain a modified estimate of variance.

Reference:
Robinson et al. 1990: Statistical evaluation of bacterial/mammalian fluctuation tests. In Statistical Evaluation of Mutagenicity Test Data (Ed D J Kirkland), Cambridge University Press, pp 102 – 140.
Key result
Species / strain:
mouse lymphoma L5178Y cells
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Remarks:
dose-related: The highest concentration to reliably provide >10 % RS was 366 µg/mL (+-S9).
Vehicle controls validity:
valid
Untreated negative controls validity:
not examined
Positive controls validity:
valid
Additional information on results:
TEST-SPECIFIC CONFOUNDING FACTORS
- Effects of pH: marked increases of >= 1 pH unit at >= 360 µg/mL
- Effects of osmolality: no
- Evaporation from medium: no
- Precipitation: no

RANGE-FINDING/SCREENING STUDIES: for cytotoxicity testing up to solublity limit of 732 µg/mL

COMPARISON WITH HISTORICAL CONTROL DATA: Acceptance criterion, Control/Historical ratio > 0.5, fulfilled for positive controls


Summary of mutation data [mean of two replicate cultures]

Experiment 1 (3 hour treatment in the absence and presence of S-9)

[for individual replicates, see Appendix 2, Table 10 (-S9), and Appendix 3, Table 18 (+S9)]

Treatment

(µg/mL)

-S-9

Treatment

(µg/mL)

+S-9

% RS

MF§

% RS

MF§

0

100

4.44

0

100

5.03

50

93

3.81

NS

100

93

3.20

NS

100

84

4.88

NS

350

80

3.40

NS

280

67

3.14

NS

400

64

3.25

NS

320

64

2.65

NS

450

55

3.24

NS

360

47

4.28

NS

500

28

1.85

NS

400

34

7.47

NS

600

6

8.18

NS

500

3

4.32

NS

Linear trend

NS

Linear trend

NS

NQO

B[a]P

0.1

43

29.73

2

62

28.91

0.15

49

46.32

3

40

62.84

Experiment 2 (3 hour treatment in the absence and presence of S-9)

[for individual replicates, see Appendix 4, Table 26 (-S9), and Appendix 5, Table 34 (+S9)]

Treatment

(µg/mL)

-S-9

Treatment

(µg/mL)

+S-9

% RS

MF§

% RS

MF§

0

100

6.02

0

100

6.56

50

111

2.12

NS

100

122

5.53

NS

200

115

1.68

NS

200

109

4.58

NS

300

89

4.07

NS

300

108

3.02

NS

400

40

4.47

NS

400

41

1.69

NS

425

22

7.51

NS

500

16

5.39

NS

450

14

3.12

NS

525

14

10.71

NS

Linear trend

NS

Linear trend

NS

NQO

B[a]P

0.1

120

25.00

2

40

70.51

0.15

63

22.66

3

27

155.93

§       6TG resistant mutants/106viable cells 7 days after treatment

% RS = Percent relative survival adjusted by post treatment cell counts

NS    = not significant

    

         

Conclusions:
n-Butylamine did not induce mutation at the hprt locus of L5178Y mouse lymphoma cells under test conditions employed in this study. This included treatments up to highly toxic concentrations in two independent experiments, in the absence and presence of a rat liver metabolic activation system.
Executive summary:

A HPRT gene mutation test was performed mouse lymphoma L5178Y cells in two independent experiments with the test substance in concentrations up to 500 µg/mL, in the absence and presence of a rat liver metabolic activation system. Concentration above 360 µg/ml caused cytotoxicity > 50 %. The test substance did not induce mutations. The positive controls (4-nitroquinoline-N-oxide (-S9); benzo(a)pyrene (+S9)) were mutagenic, thus confirming the validity of the test system.

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

Genetic toxicity in vivo

Description of key information

No mutagenic activity was observed in two in vivo mice micronuclei assays.

Link to relevant study records

Referenceopen allclose all

Endpoint:
in vivo mammalian somatic cell study: cytogenicity / erythrocyte micronucleus
Type of information:
experimental study
Adequacy of study:
weight of evidence
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to guideline
Guideline:
OECD Guideline 474 (Mammalian Erythrocyte Micronucleus Test)
Qualifier:
according to guideline
Guideline:
EPA OTS 798.5395 (In Vivo Mammalian Cytogenics Tests: Erythrocyte Micronucleus Assay)
GLP compliance:
yes
Type of assay:
micronucleus assay
Species:
mouse
Strain:
ICR
Sex:
male/female
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: Harlan Sprague Dawley, Inc., MD
- Age at study initiation: 6 - 8 weeks
- Weight at study initiation: 25 - 33 g (m); 24 - 33 (f)
- Assigned to test groups randomly: yes
- Fasting period before study:
- Housing: 5/cage/sex
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: >= 5 d


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 23 +-3 °C (74 +-6 °F)
- Humidity (%): 50 +-20
- Photoperiod (hrs dark / hrs light): 12 / 12


IN-LIFE DATES: From: To:
Route of administration:
oral: gavage
Vehicle:
Distilled water
Details on exposure:
Dosage volume: 20 mL/kg bw
Duration of treatment / exposure:
24, 48, and 72 h post-application
Frequency of treatment:
1x
Remarks:
Doses / Concentrations:
125, 250, and 500 mg/kg bw
Basis:
other: 6.25, 12.5, and 25 mg/mL, dose volume 20 mL/kg bw
No. of animals per sex per dose:
15 (5 per time interval per sex)
Control animals:
yes, concurrent vehicle
Positive control(s):
Cyclophosphamide, 40 mg/kg bw (oral, gavage)
Tissues and cell types examined:
Bone-marrow from femurs, polychromatic erythrocytes (PE), normocytes (NE)

EXAMINATIONS:  
- Clinical observations: after dose administration  
- Number of micronucleated polychromatic erythrocytes per 1000 PCE  
- The proportion of polychromatic erythrocytes to total erythrocytes  
Details of tissue and slide preparation:
CRITERIA FOR DOSE SELECTION:
prior toxicity testing/range finding


TREATMENT AND SAMPLING TIMES: 1x dosing / 3x sampling 24, 48, and 72 h p.a.


DETAILS OF SLIDE PREPARATION: air-drying, fixing in methanol, staining with May-Grünwald-Giemsa cocktail


METHOD OF ANALYSIS: Light microscopy

Evaluation criteria:
Validity:
The mean incidence of micronucleated PCE (MPCE) must not exceed 5/1000 PCE (0.5 %) in the negative (vehicle) control.
The incidence of micronucleated PCE (MPCE) in the positive control must be significantly increased relative to the neg. control (p =<0.05).

Determinations in test groups:
Incidence of MPCE; proportion of PCE to total erythrocytes (impact on erythropoiesis) in each animal and group:
- positive response when there is a dose-response and one or more doses result in significant increases above neg. control.
- questionable when a single treatment results in a significant increase with no evidence of dose-response.
- negative when no significant increase is seen above the neg. control.

Statistics:
Kastenbaum-Bowman tables (binominal distribution) for significance of differences from neg. control
Key result
Sex:
male/female
Genotoxicity:
negative
Toxicity:
yes
Remarks:
Mortality of males at 72 h
Vehicle controls validity:
valid
Negative controls validity:
not examined
Positive controls validity:
valid
Additional information on results:
RESULTS OF RANGE-FINDING STUDY
- Dose range for acute toxicity: 50 - 1500 mg/kg bw
- Solubility: miscible
- Clinical signs of toxicity in test animals: lethargy, prostration, mortality
- Result: LD50/3 = approx. 500 mg/kg bw, selected as upper dose level

RESULTS OF DEFINITIVE STUDY
- Induction of micronuclei (for Micronucleus assay): no increase
- Ratio of PCE/NCE (for Micronucleus assay):
- Appropriateness of dose levels and route: Highest dose causing treatment-related mortality,
reduction in the ratio of PCE/total erys =<44% indicating bioavailability at the target tissue.

Summary of the bone-marrow study with n-butylamine in ICR mice (from Report, Table 2)

Dose [mg/kg]

Sex

Time [h]

Animal number
[m / f]

Ratio PCE/total Erys
[m / f]

Ratio MPCE/5000 Erys scored
[m / f]

Water

m / f

24

5 / 5

0.57 / 0.53

2 / 0

48

5 / 5

0.52 / 0.49

3 / 2

72

5 / 5

0.53 / 0.61

3 / 4

125

m / f

24

5 / 5

0.51 / 0.42

1 / 1

48

5 / 5

0.48 / 0.52

1 / 4

72

5 / 5

0.43 / 0.64

5 / 7

250

m / f

24

5 / 5

0.52 / 0.51

0 / 1

48

5 / 5

0.52 / 0.46

3 / 4

72

5 / 5

0.47 / 0.62

3 / 0

500

m / f

24

5 / 5

0.45 / 0.48

0 / 0

48

4/ 5

0.29 / 0.35

~1 / 3

72

0+ / 5

-- / 0.53

- / 5

CP [40]

m / f

24

5 / 5

0.42 / 0.54

71 / 92*


                  
EFFECT ON PCE/NCE RATIO:
Maximum reduction of 44% in the male animals of 500 mg/kg at 48-h treatment time. 

All other PCE/NCE ratios were less than 30% compared to the respective vehicle animals.

GENOTOXIC EFFECTS:
Not clastogenic


MPCE FREQUENCY:
No statistically significant increase in the number of micronucleated polychromatic 

erythrocytes per 1000 polychromatic erythrocytes relative  to their respective vehicle controls.
   -------------------------

Conclusions:
Not clastogenic under the conditions of this study.
Executive summary:

In this in vivo micronucleus assay 15 mice per group were once gavaged with 0, 125, 250 or 500 mg/kg bw test substance or the positive control cyclophosphamide. Polychromatic erythrocytes (PE) and normocytes (NE) in bone-marrow  from femurs were analysed 24, 48 anf 72 h following treatment and examined for micronucleated polychromatic erythrocytes. No clastogenic response was observed in the test substance groups. The positve control induced micronuclei, thus confirming the validity of this assay.

Endpoint:
in vivo mammalian somatic cell study: cytogenicity / erythrocyte micronucleus
Type of information:
experimental study
Adequacy of study:
supporting study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to guideline
Guideline:
OECD Guideline 474 (Mammalian Erythrocyte Micronucleus Test)
GLP compliance:
yes
Type of assay:
micronucleus assay
Species:
mouse
Strain:
NMRI
Sex:
male/female
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: Charles River GmbH, WIGA, Sulzfeld, Germany
- Weight at study initiation: ca. 28 g
- Housing: groups of 5 in Makrolon cages
- Assigned to test groups randomly: yes, under following basis: computer program
- Diet: Standardized pelleted feed (Kliba Haltungsdiaet), ad libitum
- Water: tap water ad libitum
- Acclimation period: 1 week


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20-24 °C
- Humidity (%): 30-70 %
- Photoperiod (hrs dark / hrs light): 12/12
Route of administration:
intraperitoneal
Vehicle:
- Vehicle(s)/solvent(s) used: water
Duration of treatment / exposure:
24 h and 48 h.
Frequency of treatment:
single intraperitoneal application
Post exposure period:
24 h and 48 h
Remarks:
Doses / Concentrations:
0, 200, 400, 800mg/kg bw in a vol of 10ml/kg bw
Basis:
nominal in water
related to the salt
Remarks:
Doses / Concentrations:
0, 1
Basis:

No. of animals per sex per dose:
5
Control animals:
yes, concurrent vehicle
Positive control(s):
cyclophosphamide; vincristine
- Route of administration: intraperitoneal
- Doses / concentrations: 20 mg/kg bw of cyclophosphamide or 0.15 mg/kg bw of vincristine
Tissues and cell types examined:
Polychromatic erythrocytes from the bone marrow
Details of tissue and slide preparation:
CRITERIA FOR DOSE SELECTION: acute intraperitoneal toxicity pretests

DETAILS OF SLIDE PREPARATION:
The bone marrow was prepared according to the method described by SCHMID, W., Chemical Mutagens, Principles and Methods for their Detection, Volume 4, Plenum Press, New York (1976)

METHOD OF ANALYSIS: microscopic analysis

Evaluation criteria:
The following parameters were recorded:
-Number of polychromatic erythrocytes,
-Number of polychromatic erythrocytes containing micronuclei,
-Number of normochromatic erythrocytes,
-Number of normochromatic erythrocytes containing micronuclei,
- Ratio of polychromatic to normochromatic erythrocytes,
-Number of small micronuclei (d < D/4) and of large micronuclei (d > D/M) (d = diameter of micronucleus, D =cell diameter).
Statistics:
The statistical evaluation of the data was carried out using the program system MUKERN (BASF AG). A comparison of the dose group with the vehicle control was carried out using the Wilcoxon test (5) for the hypothesis of equal medians.
Sex:
male/female
Genotoxicity:
negative
Toxicity:
yes
Remarks:
800 mg/kg bw: irregular respiration, abdominal position and salivation about 15 minutes after administration. 400 mg/kg bw or 200 mg/kg bw: irregular respiration only were observed.
Vehicle controls validity:
valid
Negative controls validity:
not specified
Positive controls validity:
valid
Additional information on results:
RESULTS OF RANGE-FINDING STUDY
- Dose range: 800 - 1000 mg/kg bw
- Clinical signs of toxicity in test animals: irregular respiration, abdominal position, salivation and squatting posture and the general state of the animals was poor.


Summary of Micronucleus Test Results:

Dose: mg/kg bw Total No. PCE´s NCE´s/PCE´s

Micronuclei in PCE´s ()

Micronuclei in PCE´s ()

 
 0 (24 h) 10000 4252  1.8 1.2
 0 (48 h) 10000 4609  2.5 0.9
200 (24 h) 10000 4966 1.2  1.2
400 (24 h) 10000 3621  1.7 2.8
800 (24 h) 10000 4676 1.8 2.1
800 (48 h) 10000 4792  1.1 1.3  
20 mg/kg bw Cyclophosphamide (24 h) 5000 2109   22.6x 2.8  
0.15 mg/kg bw Vincristine (24 h) 5000 4828 91.2x  2.8  

x: p ≤ 0.01

After the single administration of the highest dose of 800 mg/kg body weight, 1.8 ‰ polychromatic erythrocytes containing micronuclei were found after 24 hours and 1.1 ‰ after 48 hours. In the two lower dose groups rates of micronuclei of about 1.7 ‰ (400 mg/kg group) and 1.2 ‰ (200 mg/kg group) were detected after a sacrifice interval of 24 hours in each case.

 

With 22.6 ‰ the positive control substance cyclophosphamide for clastogenicity, as expected, led to a clear increase in the number of polychromatic erythrocytes containing exclusively small micronuclei at a dose level of 20 mg/kg body weight. With 91.2 ‰ the positive control vincristine for spindle poison effects also led to a clearly enhanced number of micronuclei containing polychromatic erythrocytes with the expected amount of large micronuclei, i.e. 10.8 ‰

 

The number of normochromatic erythrocytes containing micronuclei did not differ to any appreciable extent in the negative control or in the various dose groups at any of the sacrifice intervals. Thus, the test substance Mono-n-butylamin-hydrochlorid 63% did not lead to any increase in the rate of micronuclei. The number of normochromatic or polychromatic erythrocytes containing small micronuclei (d < D/4) or large micronuclei (d > D/4) did not deviate from the solvent control value at any of the sacrifice intervals.

Thus, under experimental conditions chosen here, mono-n-butylamin-hydrochlorid 63% does not have any clastogenic effect, and there were no indications of any impairment of chromosome distribution in the course of mitosis.

Conclusions:
Under the conditions of this test no mutagenic activity was observed.
Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (negative)

Mode of Action Analysis / Human Relevance Framework

In the absence of any information on species specific modes of action the available information is regarded as relevant for humans.

Additional information

No mutagenic activity of the test substance was demonstrated in any in vitro or in vivo assay in the presence or absence of metabolic activation.

n-Butylamine showed no mutagenicity in a well performed Ames test. Even though the set of test strains did not include the strain TA102 or E. Coli WP2 uvrA which can detect mutations due to formation of reactive oxygen species (ROS) or DNA cross-links, this is not regarded as a major drawback for the overall evaluation of possible mutagenicity of the registration substance. It can reasonably be assumed that in case n-butylamine would induce ROS or DNA cross-links effects would have been detected in the other available mutagenicity tests. However, as neither gene mutations in mammalian cells in vitro (HPRT test) nor micronuclei in vivo (mouse micronucleus tests) were induced in these reliable genotoxicity tests, it can reasonably be assumed that n-butylamine would not have been mutagenic in the lacking tester strain in the Ames test. Therefore, it is concluded, that on basis of this overall weight of evidence n-butylamine is not mutagenic and has not to be classsified for mutagenicity.

This assessment is supported by negative findings in a OECD 471 -compliant Ames test for the structurally related n-propylamine (see corresponding IUCLID dossier) where negative results were also obtained in E.Coli WP2 uvrA.



Justification for classification or non-classification

Due to the negative findings in all mutagenicity assays, both in vitro and in vivo, no classification for mutagenicity according to Regulation (EC) No 1272/2008 is required.