Registration Dossier

Administrative data

Key value for chemical safety assessment

Effects on fertility

Link to relevant study records
Reference
Endpoint:
screening for reproductive / developmental toxicity
Remarks:
based on test type (migrated information)
Type of information:
experimental study
Adequacy of study:
key study
Study period:
March 2012-december 2013
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Recently performed Guideline study; GLP; scientifically well-performed and well-reported
Qualifier:
according to
Guideline:
OECD Guideline 421 (Reproduction / Developmental Toxicity Screening Test)
GLP compliance:
yes (incl. certificate)
Limit test:
no
Route of administration:
oral: gavage
Vehicle:
water
Details on mating procedure:
The mating began 2 weeks after the initiation of treatment with one female and one male of the same dose group (1:1 mating) in a single cage. Females remained with the same male until copulation occured or up to two weeks.
A vaginal smear was prepared daily during the mating period and stained with 1% aqueous methylene blue solution. The smears were examined with a light mictroscope, the presence of vaginal plug or sperm in the vaginal smear was considered as evidence of copulation. Sperm positive females were caged individually. Mating pairs were clearly identified in the data, mating of siblings was avoided.
Analytical verification of doses or concentrations:
yes
Duration of treatment / exposure:
28 days for males and up to 54 days for females (14 days pre-mating + up to 14 days for mating + gestation + 4 days of lacation)
Frequency of treatment:
once per day
Remarks:
Doses / Concentrations:
0, 12.5, 50, 200
Basis:
nominal in water
No. of animals per sex per dose:
12
Control animals:
yes, concurrent vehicle
Clinical signs:
effects observed, treatment-related
Body weight and weight changes:
effects observed, treatment-related
Food consumption and compound intake (if feeding study):
effects observed, treatment-related
Organ weight findings including organ / body weight ratios:
effects observed, treatment-related
Histopathological findings: non-neoplastic:
effects observed, treatment-related
Description (incidence and severity):
limited to organs with macroscopic changes
Reproductive function: oestrous cycle:
not examined
Reproductive function: sperm measures:
not examined
Reproductive performance:
effects observed, treatment-related
ORTALITY
At 200 mg/kg bw: one male animal was found dead after 22 treatments. Decreased activity, red liquid on the nose, piloerection and hunched back position were noted prior to the death. Upon histopathological investigation, malignant lymphoma that affected the spleen, thymus, liver, lungs and adrenal glands was considered to be cause of death.

Clinical signs
At 200 mg/kg bw, one surviving male displayed noisy respiration, piloerection and lack of grooming, and four females exhibited noisy respiration.

BODY WEIGHT AND WEIGHT GAIN
At 200 mg/kg bw, reduced body weight or body weight gain was noted for males and females.

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study)
At 200 mg/kg bw, reduced food consumption was noted for males and females

HAEMATOLOGY
No toxicologically significant effect was found.

CLINICAL CHEMISTRY
No toxicologically significant effect was found.
ORGAN WEIGHTS
No toxicologically significant effect was found.

GROSS PATHOLOGY
At 200 mg/kg bw, thickened/rough surface non glandular mucosa was noted.

HISTOPATHOLOGY: NON-NEOPLASTIC
At 200 mg/kg bw, minimal to mild diffuse parakeratotic hyperkeratosis of the non-glandular stomach was found.
Dose descriptor:
NOAEL
Effect level:
50 mg/kg bw/day
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: At 200 mg/kg bw, clinical signs and decreased body weight gain was observed.
Clinical signs:
no effects observed
Mortality / viability:
mortality observed, treatment-related
Body weight and weight changes:
effects observed, treatment-related
Sexual maturation:
not examined
Organ weight findings including organ / body weight ratios:
not examined
Gross pathological findings:
no effects observed
Histopathological findings:
not examined
VIABILITY (OFFSPRING)
At 200 mg/kg bw, reduced number of living pubs at the first observation after birth and increased postnatal mortality was found.
At 50 and 12.5, the number of living pubs were reduced when compared to the corresponding control, but the obtained values were within the historical control range and were considered as incidental.

CLINICAL SIGNS (OFFSPRING)
No finding

BODY WEIGHT (OFFSPRING)
The body weight at 200 mg/kg bw was reduced when compared to the corresponding control.
Dose descriptor:
NOAEL
Generation:
F1
Effect level:
50 mg/kg bw/day
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: At 200 mg/kg bw, reduced litter size at birth and increased postnatal mortality occured.
Reproductive effects observed:
not specified

Tab 1a: Body weight development for males [g]

Dose group

Day numbers relative to start date

 

Pre-mating

Mating

 

0

7

14

21

28

Control

Mean

421.25

442.67

436.75

475.33

495.67

S.D.

16.45

18.24

22.04

25.46

28.57

N

12

12

12

12

12

12.5 mg/kg bw/day

Mean

421.25

443.42

439.08

475.33

496.58

S.D.

15.49

14.28

14.32

18.89

20.99

N

12

12

12

12

12

50 mg/kg bw

Mean

420.75

441.75

437.67

473.25

498.17

S.D.

13.98

17.80

17.60

17.48

19.93

N

12

12

12

12

12

200 mg/kg bw/day

Mean

420.92

432.83

422.17*

450.10**

475.91*

S.D.

14.30

13.87

11.75

24.28

23.07

N

12

12

12

11

11

 

Tab 1b: Body weight development for females [g]

Dose group

 

Pre-mating

Gestation

Lactation

 

0

7

14

0

7

14

20

0

4

Control

Mean

239.67

251.00

248.89

262.00

297.67

335.78

424.00

330.67

347.56

S.D.

11.65

12.66

14.73

14.76

17.33

19.47

26.40

23.69

30.53

N

9

9

9

9

9

9

9

9

9

12.5 mg/kg bw/day

Mean

239.75

246.58

244.17

259.75

287.33

322.75

397.25

313.42

329.33

S.D.

10.64

12.24

14.44

14.64

15.71

20.04

25.07

24.48

25.66

N

12

12

12

12

12

12

12

12

12

50 mg/kg bw

Mean

240.73

249.64

245.18

260.00

294.91

329.18

401.36

327.55

335.82

S.D.

10.26

10.60

13.63

16.53

17.11

23.50

36.75

25.73

30.87

N

11

11

11

11

11

11

11

11

11

200 mg/kg bw/day

Mean

240.00

247.82

241.36

254.27

280.09

315.18

390.09*

296.91*

291.45**

S.D.

10.35

13.36

12.45

10.16

20.30

21.82

24.26

29.00

21.64

N

11

11

11

11

11

11

11

11

11

Tab 2a: Hematology for males

Dose group

 

Hb

RBC

Hct

MCH

MCV

MCHC

WBC

Neut

Lymph

PTT

PLT

MPV

APTT

Retic

 

g/dl

10^12/l

%

pg

g/dl

g/dl

10^9/l

%

%

sec

10^9/l

fl

sec

%

Control

Mean

17.63

9.14

48.61

19.33

53.18

36.30

9.12

21.55

71.46

24.67

868.08

7.88

16.01

1.99

S.D.

1.08

0.51

2.80

0.89

1.13

1.36

2.64

8.88

9.77

1.31

243.48

1.06

1.71

0.17

N

12

12

12

12

12

12

12

12

12

12

12

12

12

12

12.5

mg/kg bw/day

Mean

17.24

9.20

48.78

18.78

53.05

35.38*

9.75

17.23

76.58

24.83

948.92

9.28

17.18

2.19

S.D.

1.00

0.48

3.13

0.74

1.66

0.95

1.82

6.47

7.39

1.34

377.90

4.37

1.65

0.34

N

12

12

12

12

12

12

12

12

12

12

12

12

12

12

50

mg/kg bw/day

Mean

17.18

9.28

49.09

18.53*

52.93

35.00**

11.25

14.52*

80.48**

24.66

1111.33

9.24*

17.99

2.06

S.D.

0.78

0.35

2.06

0.64

1.24

0.93

2.70

6.49

6.69

2.38

341.82

2.07

2.70

0.36

N

12

12

12

12

12

12

12

12

12

12

12

12

12

12

200

mg/kg bw/day

Mean

16.26**

9.20

47.38

17.69**

51.49*

34.34**

10.97

15.72

78.71*

24.19

1076.10

8.37

18.48

1.73

S.D.

0.42

0.32

1.67

0.48

1.41

0.61

1.88

4.51

5.17

3.25

268.10

0.48

4.98

0.36

N

10

10

10

10

10

10

10

10

10

10

10

10

10

10

 

Tab 2b: Hematology for females

Dose group

 

Hb

RBC

Hct

MCH

MCV

MCHC

WBC

Neut

Lymph

PTT

PLT

MPV

APTT

Retic

 

g/dl

10^12/l

%

pg

g/dl

g/dl

10^9/l

%

%

sec

10^9/l

fl

sec

%

Control

Mean

16.34

8.67

47.12

18.84

54.33

34.68

4.61

21.10

74.02

23.51

951.78

8.13

18.28

2.49

S.D.

0.83

0.36

1.86

0.84

1.73

0.61

1.04

5.77

6.01

1.25

269.92

0.61

1.62

0.59

N

9

9

9

9

9

9

9

9

9

9

9

9

9

9

12.5

mg/kg bw/day

Mean

16.22

8.71

47.03

18.61

53.98

34.45

5.63

14.68

80.72*

23.05

1097.83

8.27

18.39

2.37

S.D.

0.72

0.31

2.01

0.48

1.36

0.62

2.27

4.16

4.24

2.54

139.50

0.35

2.25

0.51

N

12

12

12

12

12

12

12

12

12

12

12

12

12

12

50

mg/kg bw/day

Mean

16.17

8.52

46.78

19.00

54.92

34.59

6.40*

21.63

73.22

23.97

1068.82

8.62*

18.36

2.54

S.D.

0.65

0.36

1.83

0.73

1.50

0.49

1.69

21.87

24.43

1.04

245.42

0.54

1.00

0.51

N

11

11

11

11

11

11

11

11

11

11

11

11

11

11

200

mg/kg bw/day

Mean

15.67

8.39

45.74

18.71

54.57

34.29

8.46**

15.04

80.49*

24.78

1010.18

8.77*

18.67

2.26

S.D.

0.44

0.42

1.53

0.58

1.59

0.65

3.28

6.88

7.31

1.71

187.18

0.51

1.73

0.39

N

11

11

11

11

11

11

11

11

11

11

11

11

11

11

Tab 3: Summary report of effects on reproduction/development

 

Dose group

 

Control

12.5

mg/kg bw/day

50

mg/kg bw/day

200

mg/kg bw/day

No. of females paired

12

12

12

12

No. of females mated

9

12

11

11

No. of females pregnant

9

12

11

11

No. of dams with living pubs

9

12

11

11

Body weight on GD20 [g]

424

397

401

390*

Body weight on PN4 [g]

348

329

336

291**

Corpora lutea

17.3

15.2

12.6*

15.7

Implantation sites

15.2

13.7

11.3*

13.4

No. of pubs alive at birth

14.7

   12.4**

11.2*

     9.3**

No. of pubs alive at PN4

14.6

   12.1**

11.0*

     1.2**

* p < 0.05; ** p <0.01; ***p < 0.001

Conclusions:
The registration substance was investigated for its reproduction toxicity according to the OECD Guideline 421. The NOAEL of 50 mg/kg bw was derived for systemic toxicity and for reproductive toxicity.
Executive summary:

The registration substance was investigated for its reproduction toxicity according to the OECD Guideline 421. Rats were treated with the registration substance at doses of 12.5, 50 and 200 mg/kg bw.

The generation toxicity on parental animals at 200 mg/kg bw comprised noisy respiration, piloerection, lack of grooming. At this dose, the males exhibited remarkable decreased body weight gain in the pre-mating phasee and females significant body weight decrease in the lactation phase. Further observation included macroscopic and microscopic changes in the stomach at 200 mg/kg bw.

At 200 mg/kg bw, significantly reduced living pub numbers at first observation after birth and increased postnatal mortality was found.

The NOAEL of 50 mg/kg bw was derived for systemic toxicity and for reproductive toxicity.

Effect on fertility: via oral route
Endpoint conclusion:
adverse effect observed
Dose descriptor:
NOAEL
50 mg/kg bw/day
Study duration:
subacute
Species:
rat
Quality of whole database:
One key study on the registration substance and one supporting study on the read-across supporting substance; consistent results obtained; both studies of Klimish 1; database sufficiently high quality for the reliable and robust assessment
Effect on fertility: via inhalation route
Endpoint conclusion:
no study available
Effect on fertility: via dermal route
Endpoint conclusion:
no study available
Additional information

Reproduction toxicity assessment

For the reproduction toxicity assessment of the registration substance two screening tests (one OECD 421 study on the registration substance and one OECD 422 study on the read-across supporting substance) are available.

The registration substance induced at 200 mg/kg bw reduced number of pubs at the first observation after birth and increased post mortality. However, the dose level of 200 mg/kg bw was associated with the irritation effect in the gastro-intestinal tract for males and females, reduced body weight gain for males and females and remarkably reduced body weight for females in lactation phase. The fetal effects found at 200 mg/kg bw should be therefore considered as secondary to the maternal toxicity.

The read-across supporting substance induced at 125 mg/kg bw similar effects: reduced litter size at the first observation. The extent of the effect was less pronounced than that of the registration substance, but the highest dose applied was also less in this study. Similarly to the study outcome of the OECD 421 study on the registration substance, the dose level of 125 mg/kg bw was associated with clear irritation effect in the gastro-intestinal tract and body weight gain reduction.

Both studies consistently demonstrate that the reduced litter size is the major effect, which were likely to be secondary to the general toxicity. All other reproduction performance parameters were comparable for treated and control animals.

Justification for the proposed read-across approach

The registration substance is the oxidation product of the introduced read-across supporting substance N,N-Bis(2-hyydroxyethyl)-C12-18(even numbered)alkyl-1-amine.The underlying scientific rationale for the proposed read-across is based on:

(a) The source chemical (refers to read-across supporting substance) is a tertiary amine and the target chemical (refers to registration substance) the corresponding tertiary amine oxide, whereby an inter-convertibility within these two chemicals in biological systems can be presumed so that the subsequent metabolism pathway should be identical for both chemicals.

(b) For the verification purpose of the proposed read-across appraoch, the target chemical was investigated for its reproduction toxicity according to the OECD 421, because the reduction of live fetuses under given exposure conditions was predictable

based on the available data on the source chemical. The outcome of the OECD 421 on the target chemical confirmed the similarity of the toxicity profiles for target- and the source chemicals, which serves here as a crucial bridging evidence.

Further detailed justification is provided separately in Chapter 13.


Short description of key information:
The registration substance was investigated for its reproduction toxicity according to the OECD Guideline 421, in which the reduced number of living pubs and increased postnatal mortality was found as the major effect. These effects were observed in presence with significant maternal toxicity. The NOAEL of 50 mg/kg bw was derived for systemic toxicity and for reproductive toxicity. Similar findings were obtained for the read-across supporting substance that was investigated according to the OECD 422.

Justification for selection of Effect on fertility via oral route:
Recently performed Guideline study; GLP study; scientifically well-performed and well-reported

Effects on developmental toxicity

Description of key information
No study is available for the assessment of teratogenicity. 
The registrant submitted a dossier for the proposed read-across supporting substance, in which a OECD 414 on the read-across supporting substance is proposed. As soon as the corresponding data is available, the developmental toxicity will be re-evaluated.
Effect on developmental toxicity: via oral route
Endpoint conclusion:
no study available
Effect on developmental toxicity: via inhalation route
Endpoint conclusion:
no study available
Effect on developmental toxicity: via dermal route
Endpoint conclusion:
no study available

Justification for classification or non-classification

In studies available for the assessment of the reproduction toxicity (one OECd 421 study on the registration substance and one OECD 422 study on the read-across supporting substance), reproduction toxicity was found only at dose levels that were associated with clear maternal toxicity. No classification is warranted.