Octanal

Endpoint summary

Key value for chemical safety assessment

Effects on fertility

Link to relevant study records

Reference

Endpoint:

one-generation reproductive toxicity

Remarks:

based on generations indicated in Effect levels (migrated information)

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

animal arrival 25 April1989 to QA inspection of necropsy procedures on 8 August 1989, final report issued on 9 February 1990.

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: The study design is similar to the OECD Test Guideline 421, but primarily focussed on American screening objectives. Ony female rats were treated and so the data for male fertility parameters indicated in the OECD guideline are not available.

Qualifier:

no guideline followed

Principles of method if other than guideline:

One-generation reproductive toxicity study. Virgin female Sprague-Dawley rats (10/group) were orally administered a vehicle or the test material at 3 dosages for one week prior to a 7-day cohabitation period, daily treatment continued through gestation, parturition and a 4-day postpartum period. The overall study treatment period for the female rats was 39 days.
The screening test for reproductive and developmental toxicity investigated effects in treated females and offspring only, no males were treated in the study.

GLP compliance:

yes

Limit test:

no

Species:

rat

Strain:

Sprague-Dawley

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source:Charles River Laboratores Inc. or Charles River Breeding Laboratories Inc, St Constant , Canada. Virgin females of the Crl:CD BR VAF plus strain were obtained aged 60 days and acclimatised for 7 days
- Age at study initiation: females birhdate 12 February 1989, aged 72 days at initiation
- Weight at study initiation: (P) Females: 189-243g (the males used for breeding were obtained from the same source, aged 73 days and weighing between 238-336g on arrival)
- Fasting period before study: No
- Housing: individually in wire bottomed stainless steel cages exceot for pairhousing during cohabitation phase, from gestation day 20 the females were housed in individual nesting boxes
- Diet (e.g. ad libitum): certified Rodent Chow #5002 (Ralston Purina) ad libitum
- Acclimation period: at least 7 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21-25°C
- Humidity (%): 35-65%
- Air changes (per hr): 10
- Photoperiod (hrs dark / hrs light):12/12

IN-LIFE DATES: From: 25 April 1989 To: 9 June 1989

Route of administration:

oral: gavage

Vehicle:

corn oil

Details on exposure:

Virgin female Sprague-Dawley rats (10/group) were orally administered a vehicle or the test material at 3 dosages for one week prior to a 7-day cohabitation period, then through gestation, parturition and a 4-day postpartum period. Study duration was 39 days.

Virgin female rats were acclimatised for at least seven days then administered test material, melonal, at 300, 1500 or 3000 mg/kg bw/day for a period of seven days. The treated females were then paired with untreated males for a 7 day cohabitation period during which females continued to be dosed daily. Gestation day 0 was taken as the point at which spermatoza were observed in vaginal smears or when a copulatory plug was noted. Pairing was in a ratio of 1:1. Oestrous cycling was recorded daily until mating was confirmed.
Pup exposure to the test material potentially occurred via placental tranfer duriing gestation or via maternal milk post parturition but these possible exposures were not quantified.

Details on mating procedure:

Mating, day 0 of gestation was identified on basis of spermatozoa in vaginal smear.

Analytical verification of doses or concentrations:

not specified

Duration of treatment / exposure:

From 7 days prior to cohabitation through to day 4 post partum

Frequency of treatment:

Daily

Details on study schedule:

Virgin female Sprague-Dawley rats (10/group) were orally administered the vehicle, corn oil, or the test material (melonal) at 3 dosages for one week prior to a 7-day cohabitation period through gestation, parturition and a 4-day postpartum period. Study duration was 39 days.

Remarks:

Doses / Concentrations:
0, 300, 1500 and 3000 mg/kg bw/day
Basis:
actual ingested

No. of animals per sex per dose:

Ten females per group

Control animals:

yes, concurrent vehicle

Details on study design:

Mating, day 0 of gestation identified on basis of spermatozoa in vaginal smear. Viability was monitored twice daily during the study. Rats were observed daily for clinical signs approximately 30 minutes after gavage administration. Measurement of body weight was performed weekly. Food consumption measurement was also conducted weekly during the premating/premating period and then on days 0,6, 14, 16, 21, and 25 of gestation and on days 1 and 4 of lactation/postparturition. Mating performance was evaluated daily during the cohabitation period. Dams were evaluated daily during gestation for duration of gestation, maternal behavior, litter size and pup viability. Dams that did not deliver litters were sacrificed on day 25 of presumed gestation and dams that did deliver litters were sacrificed on days 4 or 5 of lactation. All dams were examined for gross lesions and implantation sites. Ovaries from all dams and any observed gross lesions were preserved in neutral 10% formalin for possible evaluation. Vital signs at birth were determined for pups that were stillborn or died before the initial examination of the litter. Each litter was evaluated for viability a minimum of twice daily during the 4-day lactation period. Dead pups were removed and necropsied.
Tissues with gross lesions were preserved for possible examination. Pups in each litter were counted and observed for nursing behavior and physical abnormalities daily. Pup body weights were measured on days 1 and 4 of postparturition.

Positive control:

Not required.

Parental animals: Observations and examinations:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: daily 30 mins after dosing

DETAILED CLINICAL OBSERVATIONS: No data

BODY WEIGHT: Yes
- Time schedule for examinations: weekly recording

FOOD CONSUMPTION :
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: Yes
weekly during the premating/premating period and then on days 0,6, 14, 16, 21, and 25 of gestation and on days 1 and 4 of lactation/postparturition

Oestrous cyclicity (parental animals):

Mating performance was evaluated daily during the cohabitation period. Oestrous cycling monitored throughout mating phase.

Sperm parameters (parental animals):

No data. No male rat investigation were included in the screening study - no male rats treated in this investigation

Litter observations:

STANDARDISATION OF LITTERS
- Performed on day 4 postpartum: Not applicable - necropsyof dams with litters and the litters occurred on day 4 post-partum. Dams without litters were necropsied n the presumed Gestation day 25.

Vital signs at birth were determined for pups that were stillborn or died before the initial examination of the litter. Each litter was evaluated for viability a minimum of twice daily during the 4-day lactation period. Dead pups were removed and necropsied. Tissues with gross lesions were preserved for possible examination. Pups in each litter were counted and observed for nursing behavior and physical abnormalities daily. Pup body weights were measured on days 1 and 4 of postparturition.

Postmortem examinations (parental animals):

SACRIFICE
- Maternal animals: dams that did not deliver litters were terminated on prsumed gestation day 25 and those that did produce litters were terminated on day 4 or 5 of lactation.

GROSS NECROPSY
- Gross necropsy consisted of examination of macroscopic lesions and implantation sites

HISTOPATHOLOGY / ORGAN WEIGHTS
No data

Postmortem examinations (offspring):

Number of pups in each litter were counted and they were observed for nursing behaviour and any physical abnormalities. Pup weights were recorded on post-partum days 1 and 4

Statistics:

Bartlett's Test of homogneity of variance and ANOVA folloed by Dunnett's test used to evaluate maternal bodyweight, bodyweight changes, food consumption, pup weight and sex ratio and pup mortality index.
For non-homogeneous data Fisher's Exact Test or Kruskal-Wallis Test was folowed by Dunnett's Multiple Comparison Method.
The significance level in all cases was p<0.05

Reproductive indices:

maternal indices include viability - dams observed at least twice a day; clinical toxicity - daily; bodyweights at weekly intervals; food consumption on days 0,6,10,14,16, 20 and 21 and/or 25 of gestation and day 1 and 4 post-partum; maternal and pup behaviour; duration of gestation and fertility indices including mating, fertility and gestation index, number of offspring per litter, dam and litter survival durng post parturition.

Offspring viability indices:

Viability recorded daily from birth; sex; clinical signs on day 1 and 4 post-partum, gross external malformations, bodyweights from birth to day 4 post partum; maternal and litter interactions following parturition

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:

not examined

Histopathological findings: non-neoplastic:

not specified

Other effects:

not specified

Reproductive function: oestrous cycle:

effects observed, treatment-related

Reproductive function: sperm measures:

not examined

Reproductive performance:

effects observed, treatment-related

Decreased body weights and food consumption reported at 300 mg/kg bw/d during premating period were not considered adverse.

Clinical signs at 1500 and 3000 mg/kg in dams included decreased activity and excess salivation during the pregestation period and increased (P<0.01) salivation in the high dose group during gestation. Significant (P<0.05 to <0.01) decreases in body weight and absolute and relative food consumption were measured during the premating period. Eight rats of 10 in the high dose group were moribund or found dead on days 2, 3,and 4 of the premating period. Maternal body weights were decreased during gestation for the mid-and high dose groups of dams. Decreased body weights and absolute
and relative food consumption in the 300 mg/kg bw/day group occurred only during premating and were not considered adverse effects. One of the two surviving high-dose dams delivered a litter that died during the 4-day lactation period. Mating and fertility at the high dose were similar to controls.
Measurements of mating success and fertility were similar for controls, low-and mid-dose groups.

Melonal produced maternal toxicity at dose levels of 1500 or 3000 mg/kg bw/day but the no observed adverse effect level was 300 mg/kg bw/day. Effects on offspring for food flavourings were generally decreased viability and lowered bodyweights, but these were only observed at maternally toxic dose levels. The test material had an A/D ratio (maternal:developmental NOAEL) of less than 1.0.

Melonal was not uniquely hazardous to the reproductive performance of female rats or on the growth and development of the offspring.

Maternal effects of melonal administration at 300, 1500 or 3000 mg/kg bw day were:
300: clinical observations and reduced bodyweight gains
1500: significant clinical observations, decreased bodyweight at one or more recording times and reduced bodyweight gains; significantly reduced food consumption.
3000: significant maternal mortality; significant clinical observations; reduced bodyweight gains and significantly reduced food consumption.

Dose descriptor:

NOAEL

Remarks:

maternal

Effect level:

300 mg/kg bw/day

Based on:

test mat.

Sex:

female

Basis for effect level:

other: see 'Remark'

Clinical signs:

effects observed, treatment-related

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:

effects observed, treatment-related

Histopathological findings:

not examined

Significant (P<0.05 to <0.01) decreases in pup viability occurred for middle and high dose groups as compared to controls. The mid-dose litters were significantly less (P<0.05) than control group litters. High-dose litters weighed remarkably less than controls. No changes in averages for duration of cohabitation or gestation, implantation sites or pup sex ratios were seen at any dose levels. No malformations or gross lesions in pups were attributable to the test material.

Offspring effects were only observed in the 1500 or 3000 mg/kg bw/day groups:
1500: significant increase in number of pups dying on days 1-4 post-partum (reduced viability); significant reduction in bodyweight
3000: significant increase in number of pups dying on days 1-4 post-partum (reduced viability); significant reduction in bodyweight gain

Based on the sjgnificant decrease in (P<0.05) in pup weight at birth and pup viability in the mid-dose group, the NOAEL for the F1 offspring was reported to be >300 mg/kg bw/day but <1500 mg/kg bw/day.

Dose descriptor:

NOAEL

Remarks:

offspring

Generation:

F1

Effect level:

300 mg/kg bw/day

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: see 'Remark'

Reproductive effects observed:

not specified

Conclusions:

Dose levels of 300 mg/kg bw/d of the test material melonal (5-heptenal, 2,6-dimethyl) had no adverse effects on the reproductive performance of female Sprague-Dawley rats or the growth or development of their offspring.

Executive summary:

Melonal was included in a group of 23 food flavourings tested in a screening study to determine whether the materials were uniquely hazardous to the reproductive performance of the dams or to the development of the offspring. Four groups of ten virgin female Sprague-Dawley rats were orally dosed with vehicle or melonal at 300, 1500 or 3000 mg/kg bw/day from one week prior to cohabitation, through mating and gestation and for four days post-partum. Various parameters were evaluated throughout the study to determine maternal reproductive indices and developmental indices for the offspring, including clinical signs, bodyweights, food consumption, mating performance, fertility, gestation length, time of parturition, maternal behaviour and dam/litter interactions, litter sizes, dystocia, number of implantation sites, macroscopic findings at necropsy. Offspring were examined for viability, sex, external morphology, birth weight and weight at day 4 post-partum. Melonal induced maternal toxicity in the high and intermediate dose groups. Toxic signs included death, clinical observations and reductions in bodyweight or lower weight gains, and reduced food consumption. Embryo-foetal effects were generally limited to reduced viability and reduced bodyweight but only occurring at maternally toxic doses. The NOAEL for melonal was 300 mg/kg bw/d. No uniquely hazardous effects were identified for female reproductive performance or offspring development.

Effect on fertility: via oral route

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

300 mg/kg bw/day

Study duration:

subacute

Species:

rat

Quality of whole database:

A number of reports refer to the same underlying dataset; a screening study performed with the read-across substance melonal.

Effect on fertility: via inhalation route

Endpoint conclusion:

no study available

Effect on fertility: via dermal route

Endpoint conclusion:

no study available

Additional information

In a screening study performed with the read-across substance melonal, maternal toxicity was observed at the high and intermediate dose levels of 1500 and 3000 mg/kg bw/d. Toxic signs included death, clinical observations and reductions in bodyweight or lower weight gains, and reduced food consumption. Embryofoetal effects were generally limited to reduced viability and reduced bodyweight but only occurring at maternally toxic doses. It should be noted that the effects in this study were apparent only at dose levels exceeding the limit dose and so are not considered to be directly relevant to the risk assessment or to classification. The NOAEL for this study (300 mg/kg bw/d) is the only dose level tested that was below the limit dose.

Short description of key information:

A screening study is available for the read-across substance melonal.

Justification for selection of Effect on fertility via oral route:

Only one study is available for this endpoint.

Justification for selection of Effect on fertility via inhalation route:

.

Effects on developmental toxicity

Description of key information

A rat developmental toxicity study is available for the read-across substance octanoic acid.

Link to relevant study records

Reference

Endpoint:

developmental toxicity

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

not stated - published information 15 July 1993

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: The structure-activity relationship assessment does not contain many of the guideline requirements for determination of developmental toxicity

Qualifier:

no guideline followed

Principles of method if other than guideline:

The teratogenic anticonvulsant valproic acid (VPA; 2-propylpentanoic acid) and related chemicals including octanoic acid were screened for developmental toxicity using the Chernoff/Kavlock assay. Test agents, in corn oil, were administered by gavage to Sprague-Dawley rats once daily during organogenesis. The dams were allowed to deliver and the pups were examined postnatally

GLP compliance:

not specified

Limit test:

no

Species:

rat

Strain:

Sprague-Dawley

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source:Charles River Laboratories
- Age at study initiation: timed-pregnant - no further details for age/weight
- Weight at study initiation: no data

- Housing:
- Diet (e.g. ad libitum): Purina Lab chow No. 5001 or Wayne Lab Blox
- Water (e.g. ad libitum): tap water ad libitum
- Acclimation period: no data

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22.2±1.1
- Humidity (%): 50±10%
- Air changes (per hr): not stated
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: To: no information

Route of administration:

oral: gavage

Vehicle:

unchanged (no vehicle)

Details on exposure:

Dose volume of 2 ml/ kg bw/day

Animals were treated by gavage once daily on gestation day 6 to 15. The doses were based on individual bodyweight recorded on gestation day 6.

Analytical verification of doses or concentrations:

not specified

Details on analytical verification of doses or concentrations:

No information

Details on mating procedure:

- Impregnation procedure: purchased timed pregnant

Duration of treatment / exposure:

Treated from gestation day 6-15

Frequency of treatment:

daily

Duration of test:

dams were terminated on postnatal day 6

Remarks:

Doses / Concentrations:
0, 1125 and 1500 mg/kg bw/day
Basis:
actual ingested

No. of animals per sex per dose:

For octanoic acid there were 15 control dams, 11 low dose and 9 high dose dams on study

Control animals:

yes

Maternal examinations:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: through out exposure period

BODY WEIGHT: Yes
- Time schedule for examinations: GD 6, 8, 10, 13, 16 and 20


POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on postnatal day 6, (gestation day 22 was defined as postnatal day 1)
- Organs examined: uterus for evidence of implantations

Ovaries and uterine content:

The ovaries and uterine content was examined after termination: Yes
Examinations included:
- Gravid uterus weight: No data
- Number of corpora lutea: No data
- Number of implantations: Yes
- Number of early resorptions: Yes
- Number of late resorptions: Yes

Number of implants, number of live pups, perinatal loss % and pup weights on postnatal days 1 and 6 are the only parameters reported

Fetal examinations:

- External examinations: Yes: all per litter on postnatal days 1, 3 and 6
- Soft tissue examinations: Yes: all externally malformed pups
- Skeletal examinations: Yes: on postnatal day 6 for two survivors per litter, one per sex where possible.
- Head examinations: No data

Statistics:

Student's t-test

Indices:

No further information

Historical control data:

No information presented in publication

Details on maternal toxic effects:

Maternal toxic effects:yes. Remark: Clinical signs - rales and dyspnoea commonly observed respiratory effects of treatment. Bodyweight loss particularly for decedents. Early, dose related, mortality.

Details on maternal toxic effects:
Chernoff/lKavlock Assays
Maternal data. Maternal toxicity was demonstrated for all compounds by weight loss or reduced weight gain, especially early in the treatment period and by clinical signs of respiratory effects including rales and dyspnoea. Vocalization and nasal breathing sounds, associated with nasal congestion, were also frequently observed.
Maternal mortality was observed for all compounds, including octanoic acid. Mortality was higher than expected on the basis of preliminary data with nongravid rats. Most deaths were attributed to the respiratory effects of treatment. Necropsy findings of foam or semi-solid material in the trachea were associated with rales, and gas in the gastrointestinal tract was associated with dyspnea. Several deaths, noted in the assay for octanoic acid (and other congeners - 2MP, VPA. 2EH, 2MO, 3MH, and 5MH) occurred shortly after dosing. The dose-related pattern of mortality suggested that they may have been treatment-related.
Transient motor depression, manifested by ataxia and/or decreased motoractivity generally within 4 hr after dosing, was pronounced in rats treated Not apparent for octanoic acid treated rats.

Dose descriptor:

LOAEL

Effect level:

1 125 mg/kg bw/day (actual dose received)

Based on:

test mat.

Basis for effect level:

other: maternal toxicity

Dose descriptor:

NOAEL

Effect level:

1 500 mg/kg bw/day (actual dose received)

Based on:

test mat.

Basis for effect level:

other: developmental toxicity

Details on embryotoxic / teratogenic effects:

Embryotoxic / teratogenic effects:yes

Details on embryotoxic / teratogenic effects:
Effects of treatment with VPA were not replicated in the study with octanoic acid.

Key result

Dose descriptor:

NOAEL

Effect level:

1 500 mg/kg bw/day (actual dose received)

Based on:

test mat.

Basis for effect level:

other: developmental toxicity

Abnormalities:

not specified

Developmental effects observed:

not specified

The Chernoff/Kavlock assays revealed

valproic acid (VPA)

-like developmental toxicity (delayed parturition, decreased progeny viability, and/or lumbar ribs) and some congeners, but no effects for octanoic acid.

Although perinatal mortality was noted for octanoic acid, despite the maternally lethal doses administered, these compounds clearly did not induce the developmental effects seen with

valproic acid (VPA)

. The frequency and severity of the maternal toxicity (respiratory effects) seen in the screening assays were sometimes greater than anticipated based on preliminary studies with non-pregnant rats, suggesting that pregnant rats may be more susceptible. The respiratory effects may be attributable to gastro-oesophageal reflux and subsequent aspiration of the dosing solution following gavage administration. Airway constriction and pulmonary edema may be related to irritation caused by aspirated test material.

Conclusions:

Maternal toxicity was evident for octanoic acid at both dose levels, 1500 and 1125 mg/kg bw/d but no signs of embryotoxicity were observed in rats or mice. No NOAEL was established but the maternal NOAEL is less than 1125 mg/kg bw/day.

Executive summary:

In this developmental toxicity study performed using the read-across substance octanoic acid, mated female rats were gavaged on Days 6 -15 of gestation at dose levels of 1125 or 1500 mg/kg bw/d. Maternal toxicity was apparent at both dose levels but no evidence of developmental toxicity was apparent. Specifically, octanoic acid did not demonstrate the embryotoxicity associated with the structurally related substance valproic acid.

Effect on developmental toxicity: via oral route

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

1 500 mg/kg bw/day

Study duration:

subacute

Species:

rat

Quality of whole database:

Study performed with the read-across substance octanoic acid does not show developmental toxicity, although not all parameters normally considered in a fully guideline compliant study have been addressed.

Effect on developmental toxicity: via inhalation route

Endpoint conclusion:

no study available

Effect on developmental toxicity: via dermal route

Endpoint conclusion:

no study available

Additional information

In this developmental toxicity study performed using the read-across substance octanoic acid, mated female rats were gavaged on Days 6 -15 of gestation at dose levels of 1125 or 1500 mg/kg bw/d. Maternal toxicity was apparent at both dose levels but no evidence of developmental toxicity was apparent. Specifically, octanoic acid did not demonstrate the embryotoxicity associated with the structrually related substance valproic acid.

Justification for selection of Effect on developmental toxicity: via oral route:

Only one study available for this endpoint

Justification for classification or non-classification

There is no evidence for the reproductive toxicity of octanal from the data available; no classification is therefore proposed for reproductive toxicity under CLP.