Butylamine

Developmental toxicity / teratogenicity

Administrative data

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Cross-reference

Reason / purpose for cross-reference:

reference to same study

Reference

Endpoint:

short-term repeated dose toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

OECD 414 guideline study which does not address all aspects relevant for repeated dose toxicity

Reason / purpose for cross-reference:

reference to same study

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 412 (Subacute Inhalation Toxicity: 28-Day Study)

Deviations:

yes

Remarks:

according to OECD Guideline 414 (Prenatal Developmental Toxicity Study) [see 7.8.2]

GLP compliance:

yes

Limit test:

no

Species:

rat

Strain:

Wistar

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: K. Thomae GmbH/Boehringer Ingelheim, Biberach/Germany
- Age at study initiation: approx. 70 d
- Weight at study initiation: 198 - 246 g
- Housing: single
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: 5 d before mating


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 - 24
- Humidity (%): 30 - 70
- Photoperiod (hrs dark / hrs light): 12 / 12

Route of administration:

inhalation: vapour

Type of inhalation exposure:

whole body

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus:glass-steel inhalation exposure chamber, 1.4 m3, space for 6x6 cages
- Method of holding animals in test chamber: 1 animal/cage
- Source and rate of air: charcoal-filtered air
- System of generating particulates/aerosols: In a thermostated vaporiser (25 - 35 °C), the vapor-air mixture was generated by spraying the TS
with compressed air into a counter current of conditioned air, followed by further mixing with air to achieve required
exposure concentrations.
- Temperature, humidity, pressure in air chamber: 21.2 - 22.5 °C; 50.5 - 62.0 %
- Air change rate: Air changes: 20/hour


TEST ATMOSPHERE
- Brief description of analytical method used: GC/FID after absorption in DMF
- Samples taken from breathing zone: yes

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

- Method: GC with FID detection
- Sampling time: 2 times during each exposure (for controls 2 times during the study)

Duration of treatment / exposure:

14 d (6 - 19 day of gestation)

Frequency of treatment:

6 h/d

Remarks:

Doses / Concentrations:
51.4 +-2.2; 151.8 +-9.2; and 460 +-17.5 mg/m3 (= 17, 50.1, and 151.8 ml/m3)
Basis:
analytical conc.

No. of animals per sex per dose:

20 - 24 pregnant female rats

Control animals:

yes, concurrent no treatment

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: daily

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: 3x during exposure, other days 1x


BODY WEIGHT: Yes
- Time schedule for examinations: on day 1, 3, 6, 8, 10, 13, 15, 17, 19 and 20


FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): No


POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestation day 20
- Organs examined: ovary, uterus, placenta
- macroscopy of dams
- histopathological examination of 4 sections of the nasal cavity

Clinical signs:

no effects observed

Mortality:

no mortality observed

Body weight and weight changes:

no effects observed

Food consumption and compound intake (if feeding study):

not specified

Food efficiency:

not specified

Water consumption and compound intake (if drinking water study):

not specified

Ophthalmological findings:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

not examined

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

not examined

Gross pathological findings:

effects observed, treatment-related

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Histopathological findings: neoplastic:

not examined

Details on results:

- Mortality: none
- Body weight: no treatment related effects
- Clinical signs: no treatment related effects
- Gross pathology incidence and severity: no treatment related effects [incidental congestion, oedema and/or marginal emphysema
of the lungs (due to method of sacrifice)]
- Histopathology incidence and severity: anterior nasal section showing squamous metaplasia, inflammatory cells and hyperplasia of
transitional cells at all concentrations (dose dependent effect). At 450 mg/m3, necrosis of the nasal mucosa (5 animals) and the underlying
nasal bone (1 animal).

Key result

Dose descriptor:

LOAEC

Effect level:

51 mg/m³ air (analytical)

Based on:

test mat.

Sex:

female

Basis for effect level:

other: Histopathology: local effects (nasal irritation)

Dose descriptor:

NOAEC

Effect level:

< 51 mg/m³ air (analytical)

Based on:

test mat.

Sex:

female

Basis for effect level:

other: Histopathology: local effects (nasal irritation)

Key result

Dose descriptor:

NOAEC

Effect level:

460 mg/m³ air (analytical)

Based on:

test mat.

Sex:

female

Basis for effect level:

other: systemic toxicity

Key result

Critical effects observed:

not specified

Nasal irritation in dams following inhalation exposure to n-butylamine during gestation (14 d):

	Percentage of dams (n = 10) showing lesions exposed to the following concentrations in ppm [mg/m^3], nominal
Histopathological findings	0	17 [50]	50 [150]	150 [450]
Squamous cell metaplasia	0	10	50	100
Purulent to mixed inflammatory cell infiltration	0	30	90	100
Focal necrosis of nasal mucosa	0	0	0	50
Necrosis of nasal bone	0	0	0	10

Conclusions:

Under the conditions of this study, the LOAEC for irritation of the upper respiratory tract was 51 mg/m3. In the absence of systemic toxicity a NOAEC of 460 mg/m3 can be determined.

Executive summary:

Twenty-five mated female Wistar rats per test group were whole-body exposed to dynamic atmospheres of Mono-n-Butylamin vapors for 6 hours per day on day 6 through day 19 post coitum (p.c.; 14 exposures). The target concentrations were 50, 150 and 450 mg/m 3. A concurrent control group was exposed to clean air.

No treatment related clinical findings were observed. A concentration dependent increase in incidence and severity of changes in the epithelium of the anterior nasal cavity (necrosis, hyper- and metaplasia, inflammatory cell infiltration) occurred. Under the conditions of this prenatal developmental toxicity study, the inhalation exposure of pregnant Wistar rats to vapours of Mono-n-Butylamin from implantation to one day prior to the expected day of parturition (days 6 - 19 p.c.) elicited maternal toxicity at all tested concentrations. Maternal toxicity was substantiated by changes of the respiratory epithelium in the nasal cavity.

Data source

Reference

Reference 1

Reference Type:

study report

Title:

Unnamed

Year:

2001

Report date:

2001

Reference 2

Reference Type:

publication

Title:

Unnamed

Year:

2002

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 414 (Prenatal Developmental Toxicity Study)

Version / remarks:

- for inhalation exposure considering OECD - Guideline method 412

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Butylamine

EC Number:

203-699-2

EC Name:

Butylamine

Cas Number:

109-73-9

Molecular formula:

C4H11N

IUPAC Name:

butan-1-amine

Test material form:

liquid

Details on test material:

- Name of test material (as cited in study report): Mono-n-Butylamin
- Physical state: liquid / colorless
- Analytical purity: 99.9%
- Lot/batch No.: Vessel 78
- Storage condition of test material: Room temperature, in closed containers under N2

Test animals

Species:

rat

Strain:

Wistar

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Boehringer Ingelheim Pharma KG, Biberach an der Riss, Germany
- Age at study initiation: about 9-10 weeks
- Weight at study initiation:
- Housing: singly in DK 111 stainless steel wire mesh cages
- Diet: rat/mouse/hamster laboratory diet, 10 mm pellets (Provimi Kliba SA, Kaiseraugst, Switzerland), ad libitum.
- Water: tap water ad libitum.
- Acclimation period: 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 - 24 °C
- Humidity (%): 30-70 %
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Route of administration:

inhalation

Type of inhalation exposure (if applicable):

whole body

Vehicle:

unchanged (no vehicle)

Details on exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: glass-steel inhalation chamber, volume of 1.4 m3 (BASF AG)
- Method of holding animals in test chamber: whole body exposure
- Temperature, humidity, in air chamber: 21.2 - 22.5 %; 50.5 - 62.0 %
- Air change rate: ca. 20 x h

TEST ATMOSPHERE
- Brief description of analytical method used: GC/FID after absorption in DMF
- Samples taken from breathing zone: yes

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Gas chromatograph equipped with autosampler, split injector and flame ionization detector (FID) and adapted to a chromatography data system

Details on mating procedure:

- Impregnation procedure: cohoused
- If cohoused:
- M/F ratio per cage: 1/1-3
- Length of cohabitation: 4.00 pm - 7.30 am (15.5 h)
- Proof of pregnancy: sperm in vaginal smear referred to as day 0 of pregnancy

Duration of treatment / exposure:

days 6-19 p.c.

Frequency of treatment:

6 h/day

Duration of test:

20 days

Doses / concentrations

Remarks:

Doses / Concentrations:
51.4 +-2.2; 151.8 +-9.2; and 460 +-17.5 mg/m3 [= 17, 50.1, and 151.8 mL/m3]
Basis:
analytical conc.

No. of animals per sex per dose:

25 (Implantation sites were present in 20, 23, 24 and 23 animals of test groups 0, 1, 2 and 3, respectively).

Control animals:

yes, sham-exposed

Details on study design:

- Dose selection rationale: pretest

Examinations

Maternal examinations:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: twice a day


DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: at least 3 times on exposure days and, as a rule, once during the day 0, preflow period and post-exposure observation day.


BODY WEIGHT: Yes
- Time schedule for examinations: day 0, 1, 3, 6, 8, 10, 13, 15,17, 19 and 20 p.c..


POST-MORTEM EXAMINATIONS: Yes, gross pathology
- Sacrifice on gestation day # 20


OTHER: Histopathology of head with larynx

Ovaries and uterine content:

The ovaries and uterine content was examined after termination: Yes
Examinations included:
- Gravid uterus weight: Yes
- Number of corpora lutea: Yes
- Number of implantations: Yes
- Number of early resorptions: Yes
- Number of late resorptions: Yes

Fetal examinations:

- External examinations: Yes: all per litter
- Soft tissue examinations: Yes: half per litter
- Skeletal examinations: Yes: half per litter
- Head examinations: Yes: all per litter

Statistics:

The Dunnett-test was used for a simultaneous comparison of several dose groups with the control. Fisher's Exact test was used for pairwise comparisons. The WILCOXIN test was used for a comparison of each dose with the control for the hypothesis of equal medians.

Results and discussion

Results: maternal animals

General toxicity (maternal animals)

Clinical signs:

no effects observed

Mortality:

no mortality observed

Body weight and weight changes:

no effects observed

Food consumption and compound intake (if feeding study):

not specified

Food efficiency:

not specified

Ophthalmological findings:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

not examined

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

no effects observed

Description (incidence and severity):

gravid uterine weights were unaffected by exposure

Gross pathological findings:

effects observed, treatment-related

Description (incidence and severity):

Only local effects in the upper respiratory tract due to irritation, details see below
No gross effects were observed in the uterus. Further other organs were not examined

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Description (incidence and severity):

Only local effects in the upper respiratory tract due to irritation, details see below

Histopathological findings: neoplastic:

not examined

Maternal developmental toxicity

Number of abortions:

no effects observed

Pre- and post-implantation loss:

no effects observed

Total litter losses by resorption:

no effects observed

Early or late resorptions:

no effects observed

Dead fetuses:

no effects observed

Changes in pregnancy duration:

not specified

Description (incidence and severity):

Migrated Data from removed field(s)
Field "Effects on pregnancy duration" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsMaternalAnimals.MaternalDevelopmentalToxicity.EffectsOnPregnancyDuration): not specified

Changes in number of pregnant:

no effects observed

Details on maternal toxic effects:

Maternal toxic effects:yes

Details on maternal toxic effects:
Treatment-related findings were confined to the anterior section (level 1) of the nasal cavity. Minimal to slight focal necrosis of the nasal mucosa was seen in five, necrosis of the underlying nasal bone in one female of the high concentration group. Necrosis was predominantly located at the nasoturbinates, thus affecting transitional epithelium. (Multi)focal squamous cell metaplasia and purulent to mixed inflammatory cell infiltration were found in all treatment groups in the anterior part of the nose (level 1). The predominant location were the turbinates and the lateral wall. Focal hyperplasia of the transitional epithelium was observed in 6 animals of the mid and one animal of the low concentration group. Predilection sites were the nasal turbinates and the lateral wall. Incidence and severity decreased from top concentration to low concentration group for all treatment-related findings.

Effect levels (maternal animals)

1

Key result

Dose descriptor:

LOAEC

Effect level:

51 mg/m³ air (analytical)

Based on:

test mat.

Basis for effect level:

other: maternal toxicity

2

Key result

Dose descriptor:

NOAEC

Effect level:

460 mg/m³ air (analytical)

Based on:

test mat.

Basis for effect level:

other: developmental toxicity

Maternal abnormalities

Key result

Abnormalities:

effects observed, treatment-related

Localisation:

other: local irritation in the upper respiratory tract

Description (incidence and severity):

Effects were observed at all exposure concentrations

Results (fetuses)

Fetal body weight changes:

no effects observed

Description (incidence and severity):

Migrated Data from removed field(s)
Field "Fetal/pup body weight changes" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsFetuses.FetalPupBodyWeightChanges): no effects observed

Reduction in number of live offspring:

no effects observed

Changes in sex ratio:

no effects observed

Changes in litter size and weights:

no effects observed

Changes in postnatal survival:

not specified

External malformations:

no effects observed

Skeletal malformations:

no effects observed

Visceral malformations:

no effects observed

Details on embryotoxic / teratogenic effects:

Embryotoxic / teratogenic effects:no effects

Effect levels (fetuses)

Key result

Dose descriptor:

NOAEC

Effect level:

460 mg/m³ air (analytical)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: developmental toxicity, highest dose tested

Fetal abnormalities

Key result

Abnormalities:

not specified

Overall developmental toxicity

Key result

Developmental effects observed:

not specified

Any other information on results incl. tables

Mono-n-butylamine elicited maternal toxicity at all tested concentrations. Maternal toxicity was substantiated by changes of the respiratory epithelium in the nasal cavity.

There were no substance-induced, concentration-related influences on the gestational parameters and no signs of prenatal developmental toxicity, especially no substance induced indications of teratogenicity, up to the highest concentration.

Based an these results, the no observed adverse effect concentration (NOAEC) for prenatal developmental toxicity is 0.45 mg/L air (152 mL/m3).

Summary of maternal and fetal data after inhalation exposure to n-butylamine (from Gamer et al. 2002, Tab. 3)

Inhalation concentration [ppm]	0	17	50	152
Females mated	25	25	25	25
Number of maternal deaths, abortions, premature births and total resorptions	0	0	0	0
Females pregnant at scheduled necropsy	20	23	24	23
Mean gravid uterus weight (g)	78.4±13.0	82.5±12.5	82.7±11.6	80.8±13.9
Mean net maternal body weight gain from day 6 post coitum (g)	42.5±8.6	46.3±10.9	47.6±9.6	40.4±9.8
Mean corpora lutea	15.9±1.9	16.8±2.4	16.8±1.4	16.4±1.6
Mean implantation sites	15.1±2.8	15.7±2.2	16.3±1.9	15.4±2.4
Mean % pre-implantation loss	5.8	6.9	3.4	5.8
Mean % post-implantation loss	6.4	6.5	10.9	7.9
Mean % early resorptions	6.4	6.5	10.1	7.1
Mean % late resorptions	0.0	1.2	0.8	0.8
Mean number of live fetuses per litter	14.1±2.6	14.4±2.3	14.5±2.2	14.2±2.5
Number of dead fetuses	0	0	0	0
Mean placenta weight (g)	0.45±0.04	0.46±0.04	0.46±0.06	0.47±0.05
Mean fetal weight (g)	3.7±0.2	3.8±0.3	3.8±0.2	3.8±0.2
Percentage of litters with any malformation	5	13	17	17
Mean % of fetuses/litter with any malformation	0.4	1.2	1.1	1.2

Group means±standard deviation

Fetal and litter incidence of external, soft tissue and skeletal malformations after inhalation exposure

to n-butylamine (from Gamer et al. 2002, Tab. 4)

Inhalation concentration [ppm]	0	17	50	152
Number of litters with live fetuses	20	23	24	23
Total number of fetuses examined (soft tissue/skeletal examination)	282 (134/148)	332 (159/173)	348 (169/179)	327 (158/169)
Number (%) of litters with external malformation	0 (0 %)	0 (0 %)	1 (4 %)	0 (0 %)
Number of fetuses (mean % fetuses/litter) with external malformation	0 (0 %)	0 (0 %)	1(0.3 %)	0 (0 %)
Number (%) of litters with soft tissue malformation	0 (0 %)	1 (4 %)	1 (4 %)	0 (0 %)
Number of fetuses (mean % fetuses/litter) with soft tissue malformation	0 (0 %)	1 (0.5 %)	1 (0.5 %)	0 (0 %)
Number (%) of litters with skeletal malformation	1 (5 %)	2 (9 %)	3 (13 %)	4 (17 %)
Number of fetuses (mean % fetuses/litter) with skeletal malformation	1 (1 %)	3 (2 %)	3 (2 %)	4 (2 %)
Number (%) of litters with any malformation	1 (5 %)	3 (13 %)	4 (17 %)	4 (17 %)
Number of fetuses (mean % fetuses/litter) with any malformation	1 (0.4 %)	4 (1 %)	4 (1 %)	4 (1 %)

Group means±standard deviation

Applicant's summary and conclusion

Conclusions:

Under the conditions of this study, local effects were observed in the nose of dams. No effects on gestational parameters and offspring were evident.

Executive summary:

Twenty-five mated female Wistar rats per test group were whole-body exposed to dynamic atmospheres of Mono-n-Butylamin vapors for 6 hours per day on day 6 through day 19 post coitum (p.c.; 14 exposures). The target concentrations were 50, 150 and 450 mg/m 3. A concurrent control group was exposed to clean air.

No treatment related clinical findings were observed. A concentration dependent increase in incidence and severity of changes in the epithelium of the anterior nasal cavity (necrosis, hyper- and metaplasia, inflammatory cell infiltration) occurred. Under the conditions of this prenatal developmental toxicity study, the inhalation exposure of pregnant Wistar rats to vapours of Mono-n-Butylamin from implantation to one day prior to the expected day of parturition (days 6 - 19 p.c.) elicited maternal toxicity at all tested concentrations. Maternal toxicity was substantiated by changes of the respiratory epithelium in the nasal cavity.

There were no substance-induced, concentration-related influences on the gestational parameters and no signs of prenatal developmental toxicity, especially no substance-induced indications of teratogenicity, up to and including the highest concentration (450 mg/m 3).