Octan-3-ol

Toxicity to reproduction

Administrative data

Endpoint:

screening for reproductive / developmental toxicity

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Justification for type of information:

Data from peer reviewed journal

Data source

Reference

Reference Type:

publication

Title:

The Developmental Toxicity of 2-Ethylhexanol Applied Dermally to Pregnant Fischer 344 Rats

Author:

R . W . TYL, L. C. FISHER, M. F. KUBENA, M. A. VRBANIC , R. GINGELL, D. GUEST,
J. R. HoDGsON, S. R. MURPHY, T. R. TYLER, and B. D. ASTILL

Year:

1992

Bibliographic source:

Fundamental and Applied Toxicology 19, 176-185 (1992)

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

other: As mentioned below

Principles of method if other than guideline:

Reproductive toxicity study of 2-Ethyl-1-Hexanol was performed in Pregnant Fischer 344 Rats by dermal application

GLP compliance:

not specified

Limit test:

no

Justification for study design:

No data available

Test material

Test material information

Constituent 1

Reference substance name:

2-ethylhexan-1-ol

EC Number:

203-234-3

EC Name:

2-ethylhexan-1-ol

Cas Number:

104-76-7

Molecular formula:

C8H18O

IUPAC Name:

2 ethylhexan-1-ol

Test material form:

liquid

Details on test material:

- Name of test material: 2-Ethyl-1-hexanol
- IUPAC name: 1-Hexanol, 2-ethyl-
- Molecular formula: C8H18O
- Molecular weight: 130.2292 g//mol
- Substance type: Organic
- Physical State: Liquid

Specific details on test material used for the study:

- Name of test material: 2-Ethyl-1-hexanol
- IUPAC name: 1-Hexanol, 2-ethyl-
- Molecular formula: C8H18O
- Molecular weight: 130.2292 g//mol
- Substance type: Organic
- Physical State: Liquid

Test animals

Species:

rat

Strain:

Fischer 344

Details on species / strain selection:

No data available

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Breeding Laboratories (Kingston, NY)
- Age at study initiation: male: 70 days old and female: 63 days old.
- Weight at study initiation: male :175-200 g and female : 130-150 g
- Fasting period before study: No data available
- Housing: No data available
- Diet (e.g. ad libitum): feed -ProLab Certified Ground Rodent Chow ad libitum
- Water (e.g. ad libitum): water ad libitum
- Acclimation period: No data available

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20-22.7°C
- Humidity (%):42-65%
- Air changes (per hr): No data available
- Photoperiod (hrs dark / hrs light): a 12hr photoperiod

Administration / exposure

Route of administration:

dermal

Vehicle:

unchanged (no vehicle)

Details on exposure:

Details on dermal exposure
For dermal treatment the appropriate volume of was dispensed from a 1.0-cc syringe on to the clipped and shaved dorsal skin (ca. I .5 in.) between the scapulae, under a 2-in. gauze square.
The application site was occluded with a Lycra-Spandex jacket with Velcro closures. A 1 .5 X 2.5-in. polyethylene patch was attached at the application site under the jacket. After a 6-hr exposure period the gauze and jacket were removed, and the application site was wiped gently with moist gauze and blotted dry.

Details on mating procedure:

- M/F ratio per cage:1:1
- Length of cohabitation:
- Proof of pregnancy: [vaginal plug / sperm in vaginal smear] referred to as [day 0 / day 1] of pregnancy:Gestational Day 0 was dated from the appearance of a copulatory plug
- After ... days of unsuccessful pairing replacement of first male by another male with proven fertility.
- Further matings after two unsuccessful attempts: [no / yes (explain)]
- After successful mating each pregnant female was caged (how): Pregnant females were housed singly in stainless steel wire mesh cages
- Any other deviations from standard protocol:

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Gas chromatographic analysis.

Duration of treatment / exposure:

10 days (Treatment days were gds 6 through 15)

Frequency of treatment:

Daily (6hr)

Details on study schedule:

No data available

Doses / concentrations

Remarks:

0.0, 252, 840, 2520 mg/kg bw

No. of animals per sex per dose:

Total:100
0.0 mg/kg bw: 25 females
252mg/kg bw: 25 females
840 mg/kg bw: 25 females
2520 mg/kg bw: 25 females

Control animals:

yes

Details on study design:

No data available

Positive control:

No data available

Examinations

Parental animals: Observations and examinations:

Parental animals observation and examinations
CAGE SIDE OBSERVATIONS: Yes
- Time schedule once daily
- Cage side observations checked in table [No.?] were included. No data available

DETAILED CLINICAL OBSERVATIONS: No data available
- Time schedule: No data available

BODY WEIGHT: Yes
- Time schedule for examinations: Body weights were recorded on gds 0,6. 9, 12, 15 and 2 1.
FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): Food consumption was measured for each 3-day interval from gds 0 through 2 I.
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: No data available
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: No data available

WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): No data available
- Time schedule for examinations: No data available

OTHER: No data available

Oestrous cyclicity (parental animals):

No data available

Sperm parameters (parental animals):

No data available

Litter observations:

All live fetuses were sexed, weighed, and examined for external malformations and for variations

Postmortem examinations (parental animals):

Post-mortem examinations (Parent Animal)
SACRIFICE:
- Male animals: No data available
- Maternal animals: yes (by CO2 asphyxiation on Day 21)

GROSS NECROPSY:
- Maternal uterine and liver weights and spleen, adrenals, kidneys, and thymus weights (main study) were recorded. Corpora lutea and uterine implantation sites were counted, and ovaries, cervices, vaginas, and abdominal and thoracic cavities were examined grossly. Uteri were examined externally, removed, and dissected longitudinally to expose the contents.
All live and dead fetuses and resorption sites were noted; uteri from non-gravid females were tested for early resorptions with ammonium sulfide solution

Postmortem examinations (offspring):

SACRIFICE
- The F1 offspring not selected as parental animals and all F2 offspring were sacrificed at [#?] days of age.
- These animals were subjected to postmortem examinations (macroscopic and/or microscopic examination) as follows:

GROSS NECROPSY
- All live fetuses were sexed, weighed, and examined for external malformations and for variations.approximately 50% of the live fetuses per litter from the main study were examined for visceral (thoracic and abdominal: Staples, 1914,modified) and craniofacial abnormalities (Wilson, 1965, 1973, modified; Van Hulsingha and Bennett, 1911). The remainder were examined for skeletalmalformations and variations after evisceration, fixation in ethanol, andstaining with alizarin red S (Crary, 1962; Pletzer and Schardein, 1966).



HISTOPATHOLOGY / ORGAN WEIGTHS
The tissues indicated in Table [#] were prepared for microscopic examination and weighed, respectively.

Statistics:

The units of comparison were the pregnant rat or the litter. Quantitative continuous variables such as maternal body and organ weights were compared between 2-EH and sham control groups, between dermal reference and sham control groups, and between gavage reference and naive control groups. Levene’s test for equal variances (Levene, 1960) ANOVA, and t tests with Bonferroni probabilities for pairwise comparisons were used. The pooled t test was used when Levene’s test indicated homogeneous variances and ANOVA was significant. When Levene’s test indicated heterogeneous variances, all groups were compared by an ANOVA for unequal variances (Brown and Forsythe, 1914) followed when necessary by the separate variance t test. Nonparametric data following laparohysterectomy were evaluated using the Kruskal-Wahis test followed by the Mann-Whitney test when appropriate
(Sokal and Rohif, 1969). Incidence data were compared using Fisher’s exact test (Sokal and Rohif, 1969). The fiducial limit of0.05 (two-tailed) was used as the criterion for significance.

Reproductive indices:

No data available

Offspring viability indices:

No data available

Results and discussion

Results: P0 (first parental generation)

General toxicity (P0)

Clinical signs:

no effects observed

Dermal irritation (if dermal study):

effects observed, treatment-related

Description (incidence and severity):

Treatment-related effects attributable to test material at the application site were exfoliation, encrustation,and erythema. There was no edema.Erythema occurred during treatment with test material at levels of 840 mg/kg/day and above. Draize scores for irritation were essentially mild. Maximum mean treatment scores occurred on gd 14 at 1680mg/kg/day(0.3, main study).

Mortality:

no mortality observed

Description (incidence):

No females died, aborted, or were removed from either study in any control or treated group

Body weight and weight changes:

no effects observed

Description (incidence and severity):

Gestational weight changes (gds 0 through 2 1) were not significantly different from sham controls.

Food consumption and compound intake (if feeding study):

no effects observed

Description (incidence and severity):

There were no significant changes in food consumption at any treatment level of study throughout gestation

Food efficiency:

not specified

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

not specified

Ophthalmological findings:

not specified

Haematological findings:

not specified

Clinical biochemistry findings:

not specified

Urinalysis findings:

not specified

Behaviour (functional findings):

not specified

Immunological findings:

not specified

Organ weight findings including organ / body weight ratios:

no effects observed

Histopathological findings: non-neoplastic:

not specified

Histopathological findings: neoplastic:

not specified

Other effects:

not specified

Reproductive function / performance (P0)

Reproductive function: oestrous cycle:

not specified

Reproductive function: sperm measures:

not specified

Reproductive performance:

effects observed, treatment-related

Description (incidence and severity):

Weight gain was significantly reduced for gds 6 through 9 at 2520 mg/kg/day compared with the sham control.The test material was without adverse effect at any treatment level i.e. 252, 840, 2520 mg/kg bw compared with controls, on total and nonviable implants, early
or late resorptions, live or dead fetuses, fetal sex ratio, and mean fetal body weights per litter.

Effect levels (P0)

Dose descriptor:

NOAEL

Effect level:

840 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

female

Basis for effect level:

clinical signs

mortality

dermal irritation

body weight and weight gain

food consumption and compound intake

organ weights and organ / body weight ratios

gross pathology

reproductive performance

Remarks on result:

other: overall no toxic effects on reproductive performance

Target system / organ toxicity (P0)

Critical effects observed:

not specified

System:

other: not specified

Organ:

not specified

Treatment related:

not specified

Dose response relationship:

not specified

Relevant for humans:

not specified

Results: F1 generation

General toxicity (F1)

Clinical signs:

not specified

Dermal irritation (if dermal study):

not specified

Mortality / viability:

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 specified

Haematological findings:

not specified

Clinical biochemistry findings:

not specified

Urinalysis findings:

not specified

Sexual maturation:

not specified

Organ weight findings including organ / body weight ratios:

not specified

Gross pathological findings:

no effects observed

Description (incidence and severity):

There were no external, visceral, or skeletal malformations associated with any treatment level i.e. 252, 840, 2520 mg/kg bw of test material

Histopathological findings:

not specified

Other effects:

not specified

Developmental neurotoxicity (F1)

Behaviour (functional findings):

not specified

Developmental immunotoxicity (F1)

Developmental immunotoxicity:

not specified

Effect levels (F1)

Dose descriptor:

NOAEL

Generation:

F1

Effect level:

2 520 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

not specified

Basis for effect level:

viability

mortality

body weight and weight gain

gross pathology

Remarks on result:

other: overall no developmental toxic effects was observed

Target system / organ toxicity (F1)

Critical effects observed:

not specified

System:

other: not specified

Organ:

not specified

Treatment related:

not specified

Dose response relationship:

not specified

Relevant for humans:

not specified

Overall reproductive toxicity

Reproductive effects observed:

not specified

Treatment related:

not specified

Relation to other toxic effects:

not specified

Dose response relationship:

not specified

Relevant for humans:

not specified

Any other information on results incl. tables

Table.Maternal Distribution and Fate of Pregnant F344 Rats Following Dermal Administration of 2-ethylhexanol (2-EH)

Treatment group: Mg/kg/day Females in study^a	2-ethylhexanol (2-EH)
	Sham 0 25	252 25	840 25	2520 25
Delivered	2	2	0	0
Necropsied^c
nonpregnant	3	4	2	5
Pregnant	20	19	23	20
With only nonviable implants	2	0	0	0
With viable fetuses	18	19	23	20
% Pregnant	88	84	92	92

a No females died, aborted, or were removed from the study.

b Values are numbers of animals.

c’ At scheduled necropsy.

Gestational Parameters for Pregnant F344 Rats, Following Dermal Administration of 2-Ethylhexanol

Treatment group: Mg/kg/day Females in study^a	2-ethylhexanol (2-EH)
	Sham 0 20	252 19	840 23	2520 20
Corpora lutea  SD (±)	11.6 1.33	10.4 2.45	11.3 1.94	10.8 2
Total implants SD (±)	5.9 4.25	6.7 4.32	8.3 4.2	7.4 3.3
Viable implants SD (±)	5.5 4.24	6.5 4.36	8 4.2	7.3 3.2
Nonviable implants”  SD (±)	0.4 0.82	0.2 0.37	0.1 0.42	0.1 0.31
Early resorptions” SD (±)	0.82 0.4	0.37 0.2	0.42 0.1	0.31 0.1
Late resorptions” SD (±)	0.82 0	0.37 0	0.34 0	0.31 0
Dead fetuses” SD (±)	0	0	0.1 0.29	0
Percentage of live fetuses SD (±)	86 31.7	96.8 8.8	97.8 4.36	99 3.1
Sex ratio (% males) SD (±)	62.8 29.3	41.8 29.4	43.7 20.4	53.4 20
Fetal body weightg SD (±)	4.59 0.33	4.51 0.57	4.4 0.32	4.5 0.38

’ Means and standard deviations calculated from numbers per animal.

bN= 18.

‘p < 0.05 compared with naive control.

‘p < 0.0 1 compared with appropriate sham control.

’ p < 0.05 compared with appropriate sham control.

‘Based on two fetuses from one surviving litter.

g Based on numbers of fetuses per litter in grams.

Malformations in Fetuses from Pregnant F344 Rats Following Dermal Administration of 2-Ethylhexanol

Treatment group: Mg/kg/day Females in study^a	2-ethylhexanol (2-EH)
	Sham 0 20	252 19	840 23	2520 20
	Number examined^b
Externally	18	19	23	20
Edematous fetus	0	0	0	0
%	0	0	0	0
Protruding tongue	0	0	0	0
%	0	0	0	0
Viscerally	18	19	23	20
Lateral ventricles dilated-tissue depressed	0	1	0	2
%	0	5.3	0	10
Innominate artery missing	0	0	0	0
%	0	0	0	0
Skeletally	17	15	21	18
Significant findings	0	0	0	0
%	0	0	0	0
	Number with malformations
External	0	0	0	0
%	0	0	0	0
Soft tissue	0	2	0	3
%	0	10.5	0	15
Skeletal	0	0	0	0
%	0	0	0	0
Total with malformations	0	2	0	3
%	0	10.5	0	15

* Main study only.

a Number of fetuses or litters.

c p < 0.05 compared with sham control.

d p < 0.01 compared with sham control.

e Includes one fetus with ocular defects.

F Includes one fetus with a divided olfactory lobe.

 

Applicant's summary and conclusion

Conclusions:

The no observed adverse effect level (NOALE) was considered to be 840 mg/kgbw for reproductive toxicity and no observed adverse effect level (NOALE) was considered to be 2520 mg/kg bw for developmental toxicity as no toxic effects observed at highest dose tested . When female rats were treated with 2-Ethyl-1-Hexanol (104-76-7) by dermal application.

Executive summary:

The reproductive and developmental toxicity study of 2-Ethyl-1-Hexanol(104-76-7) was performed on male and femaleFischer 344 rats. 25 females /sex /dose group were used. The test material in dose concentration 0.0, 0.3, 1.0, and 3.0 ml/ kg/day (equivalent to 0,252,840, and 2520 mg/kg/day). Controls (0.0 ml/kg/day, sham controls) received deionized water at 3.0 ml/kg/day from gestation day 6 to 15.The test material in undiluted form applied in appropriate volume was dispensed from a 1.0-cc syringe on to the clipped and shaved dorsal skin (ca. I .5 in.) Between the scapulae, under a 2-in. gauze square. The application site was occluded with a Lycra-Spandex jacket with Velcro closures. A 1 .5 X 2.5-in. polyethylene patch was attached at the application site under the jacket. After a 6-hr exposure period the gauze and jacket were removed, and the application site was wiped gently with moist gauze and blotted dry.

Body weights were recorded on gds 0,6. 9, 12, 15. and 2 1. Food consumption was measured for each 3-day interval from gds 0 through 2 I. Observations were made at least once daily for clinical signs and skin irritation. Females which delivered early were terminated, examined grossly, and removed from the study. Surviving females in both studies were euthanized by CO2 asphyxiation on Day2 1. Maternal uterine and liver weights (both studies) and spleen, adrenals, kidneys, and thymus weights (main study) were recorded. Corpora lutea and uterine implantation sites were counted, and ovaries, cervices, vaginas, and abdominal and thoracic cavities were examined grossly. Uteri were examined externally, removed, and dissected longitudinally to expose the contents.All live and dead fetuses and resorption sites were noted; uteri from non-gravid females were tested for early resorptions with ammonium sulfide solution. All live fetuses were sexed, weighed, and examined for external malformations and for variations. After external examination approximately 50% of the live fetuses per litter from the main study were examined for visceral and craniofacial abnormalities .The remainder were examined for skeletal malformations and variations after evisceration, fixation in ethanol, and staining with alizarin red S

 

 No females died, aborted, or were removed from either study in any control or treated group. Gestational weight changes (gds 0 through 2 1) were not significantly different from sham controls. Weight gain was significantly reduced for gds 6 through 9 at 2520 mg/kg/day compared with the sham control There were no significant changes in food consumption at any treatment level of study throughout gestation. Treatment-related effects attributable to test material at the application site were exfoliation, encrustation,and erythema. There was no edema. Erythema occurred during treatment with test material at levels of 840 mg/kg/day and above. Draize scores for irritation were essentially mild. Maximum mean treatment scores occurred on gd 14 at 168mg/kg/day(0.3, main study). The test material was without adverse effect at any treatment level i.e. 252, 840, 2520 mg/kg bwcompared with controls, on total and nonviable implants, early or late resorptions, live or dead fetuses, fetal sex ratio, and mean fetal body weights per litter There were no differences from controls for any treatment level i.e. 252, 840, 2520 mg/kg bwin maternal body weights, gravid uterine or corrected body weights, or in relative or absolute liver, thymus, spleen, adrenal and kidney weights. There were no differences from controls for any treatment level i.e. 252, 840, 2520 mg/kg bwin maternal body weights, gravid uterine or corrected body weights, or in relative or absolute liver, thymus, spleen, adrenal and kidney weights. There were no external, visceral, or skeletal malformations associated with any treatment level i.e. 252, 840, 2520 mg/kg bw of test material. Hencetheno observed adverse effect level (NOALE) was considered to be 840 mg/kgbw for reproductive toxicity and no observed adverse effect level (NOALE) was considered to be 2520 mg/kg bw for developmental toxicity as no toxic effects observed at highest dose tested. When female rats were treated with2-Ethyl-1-Hexanol(104-76-7) by dermal application.