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Description of key information

Oral repeated toxicity studies :
There are :

1 -One key 13-week toxicity study performed with Heptanal according to GLP and OECD 408 (Bentz, 2015) where no significant findings were observed. The NOAEL was set at 1000 mg/kg/day.
2 -One supporting repeated Dose 28-day oral rat toxicity study was available (OECD 407) (Terrill 1990) - Read-across with heptanoic acid. Rat (female/male): NOAEL = 1750 mg/kg bw/day and LOAEL = 3500 mg/kg bw/day

Key value for chemical safety assessment

Toxic effect type:
dose-dependent

Repeated dose toxicity: via oral route - systemic effects

Link to relevant study records
Reference
Endpoint:
chronic toxicity: oral
Type of information:
experimental study
Adequacy of study:
key study
Study period:
22 September 2014 - 28 January 2015
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Compliant to GLP and testing guidelines; adequate consistence between data, comments and conclusions.
Qualifier:
according to guideline
Guideline:
OECD Guideline 408 (Repeated Dose 90-Day Oral Toxicity Study in Rodents)
GLP compliance:
yes (incl. QA statement)
Limit test:
no
Species:
rat
Strain:
Sprague-Dawley
Sex:
male/female
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: breeder: Charles River Laboratories Italia, Calco, Italy.
- Age at study initiation: approximately 5 weeks old on the day of treatment.
- Mean body weight at study initiation: the males had a mean body weight of 141 g (range: 119 g to 167 g) and the females had a mean body weight of 134 g (range: 118 g to 151 g).
- Fasting period before study: no
- Housing: the animals were housed in twos, by sex and group, in polycarbonate cages with stainless steel lids (Tecniplast 2000P, 2065 cm²) containing autoclaved sawdust.
- Diet: SSNIFF R/M-H pelleted diet (free access)
- Water: tap water filtered with a 0.22 µm filter (free access)
- Acclimation period: 7 days before the beginning of the treatment period.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 2°C
- Humidity (%): 50 ± 20%
- Air changes (per hr): approximately 12 cycles/hour of filtered, non-recycled air
- Photoperiod (hrs dark / hrs light): 12 h/12 h.

IN-LIFE DATES: 28 October 2014 to 28 January 2015.
Route of administration:
oral: gavage
Vehicle:
corn oil
Details on oral exposure:
PREPARATION OF DOSING SOLUTIONS:
The test item was weighed and mixed with the required quantity of vehicle.

VEHICLE
- Justification for use and choice of vehicle: suitable formulation in corn oil, stable
- Concentration in vehicle: 0, 20, 60 and 200 mg/mL
- Amount of vehicle (if gavage): 5 mL/kg/day.
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
Type of method: GC-FID
Test item concentrations: remained within an acceptable range of variation compared to nominal values except for formulations used at the beginning of Week 6 (results between +13.0 and +18.5% but overdose of the animals was doubtful according to the laboratory investigation) and for the group 2 formulation used in Week 6/7 (result at +11.4%).
Stability: stable after 11 days of storage at room temperature protected from light and under nitrogen gas.
Duration of treatment / exposure:
13 weeks.
Frequency of treatment:
Daily
Remarks:
Doses / Concentrations:
0, 100, 300 and 1000 mg/kg/day
Basis:
actual ingested
No. of animals per sex per dose:
10 animals per sex per dose.
Control animals:
yes, concurrent vehicle
Details on study design:
- Dose selection rationale:
The dose-levels were selected in agreement with the Sponsor, based on the results of a previous 2-week toxicity study where five males and five females were administered orally the test item at 100, 300 or 1000 mg/kg/day in the same vehicle. In this study, there were no mortality, no relevant clinical signs or macroscopic post-mortem findings and no relevant effects on mean food consumption, mean body weight or mean organ weights.

- Rationale for animal assignment: computerized stratification procedure.
Positive control:
no (not required)
Observations and examinations performed and frequency:
MORBIDITY/MORTALITY:
- Time schedule: once a day during the acclimation period and at least twice a day during the treatment period.

DETAILED CLINICAL OBSERVATIONS:
- Time schedule: once before the beginning of the treatment period and then at least once a week until the end of the study.

FUNCTIONAL OBSERVATION BATTERY including motor activity:
- Time schedule: each animal was evaluated once in Week 12 (before the daily treatment).

BODY WEIGHT:
- Time schedule: once before the beginning of the treatment period, on the first day of treatment and then at least once a week until the end of the study.

FOOD CONSUMPTION:
- Time schedule: once a week, over a 7-day period, during the study.

OPHTHALMOSCOPIC EXAMINATION:
- Time schedule: before the beginning of the treatment period (all animals) and at the end of the treatment period (control and high-dose groups).

MONITORING OF ESTROUS CYCLE:
- Time schedule: the estrous cycle stage was determined for all females from a fresh vaginal lavage (stained with methylene blue) daily for 21 consecutive days before the end of the treatment period.

HEMATOLOGY, CLINICAL CHEMISTRY, URINALYSIS:
- Time schedule: towards the end of the treatment period.

SEMINOLOGY:
- Before sacrifice at the end of the treatment period.
Sacrifice and pathology:
ORGAN WEIGHTS: see table below
On completion of the treatment period, after at least 14 hours fasting, all animals were deeply anesthetized by an intraperitoneal injection of sodium pentobarbital and sacrificed by exsanguination.

GROSS PATHOLOGY:
A complete macroscopic post-mortem examination was performed on all animals. This included examination of the external surfaces, all orifices, the cranial cavity, the external surfaces of the brain and spinal cord, the thoracic, abdominal and pelvic cavities with their associated organs and tissues and the neck with its associated organs and tissues.

HISTOPATHOLOGY:
A microscopic examination was performed on all tissues listed in the table below for animals of the control and high-dose groups (groups 1 and 4), on forestomach (males and females) and kidneys (males) for animals of the low- and mid-dose groups (groups 2 and 3), on immunostained kidneys from control and high-dose males (groups 1 and 4), and on all macroscopic lesions.

In addition testicular staging was performed for control and high-dose males (groups 1 and 4). A detailed examination of the testes was performed, using a thorough understanding of tubule development through the different stages of the spermatogenic cycle. Transverse sections of the testes were stained with hematoxylin/PAS in order to detect retained spermatids, missing germ cell layers, multinucleated giant cells or sloughing of spermatogenic cells into the lumen, etc.
Clinical signs:
effects observed, treatment-related
Description (incidence and severity):
for clinical signs
Mortality:
mortality observed, treatment-related
Description (incidence):
for clinical signs
Body weight and weight changes:
no effects observed
Food consumption and compound intake (if feeding study):
no effects observed
Ophthalmological findings:
no effects observed
Haematological findings:
no effects observed
Clinical biochemistry findings:
effects observed, treatment-related
Urinalysis findings:
no effects observed
Behaviour (functional findings):
no effects observed
Organ weight findings including organ / body weight ratios:
no effects observed
Gross pathological findings:
no effects observed
Histopathological findings: non-neoplastic:
effects observed, treatment-related
Details on results:
MORTALITY:
There were no premature deaths.

CLINICAL SIGNS:
Ptyalism noted in all males and nearly all females at 1000 mg/kg/day was the only test item treatment related clinical sign.
The other clinical signs observed in test item-treated groups (thin appearance, alopecia, scabs, abnormal growth of teeth, loud breathing, chromorhynorrhea) were considered to be incidental. They were indeed observed in isolated animals within each sex and group, also noted in controls and/or were of limited duration.

BODY WEIGHT (GAIN):
There were no test item-treatment related effects on mean body weight and mean body weight change.

FOOD CONSUMPTION:
There were no test item treatment-related effects on mean food consumption.

OPHTHALMOSCOPIC EXAMINATION:
There were no test item-treatment related ophthalmology findings at the end of the treatment period: only one female treated at 1000 mg/kg/day had chorioretinopathy (at the left eye only), which was considered to be incidental in view of the limited incidence.

NEUROBEHAVIOURAL EXAMINATION:
In view of the amplitude of differences between mean number of movements of control and test item treated groups and of the standard deviations, there were no toxicologically relevant effects in mean motor activity data.
Presence of urine in more animals at 1000 mg/kg/day than in controls or excessive quantity of feces in both high doses were considered to be incidental in view of the absence of severity (no excessive quantity of urine noted) or of the limited incidence (1 animal in each group out of 20), respectively.
The findings described above for one animal were not ascribed to the test item treatment as there were observed in a single animal and not in the high-dose group.

The other differences from "normal" responses/reflexes were considered as fortuitous (not dose-related, in limited incidence and/or comparable with controls).

ESTROUS CYCLE:
There were no test item treatment-related effects on estrous cycles.
The statistically significant higher mean number of estrous stages at 100 and 1000 mg/kg/day were due to the fact that more females were blocked in diestrous in the control group instead of being cycling as expected. This difference was not considered to be test item treatment-related but incidental.

HEMATOLOGY:
There were no test item treatment-related effects on hematology parameters.
In females, the lower mean leucocyte count at 1000 mg/kg/day (4.94 G/L vs. 6.64 G/L in controls) and the statistically significantly lower mean monocyte counts at 100 and 1000 mg/kg/day (0.13 G/L in these groups, vs. 0.21 G/L in controls, p<0.05) were considered as incidental in absence of statistical significance or dose-relationship, respectively.

Females treated at 100 mg/kg/day had a statistically significantly prolonged mean prothrombin time compared with controls (23.5 s vs. 21.9 s, p<0.01), and the same trend was observed at 300 mg/kg/day (23.0 s vs. 21.9 s). However, as this variation was not seen at 1000 mg/kg/day, an effect of the test item treatment was considered to be unlikely.

CLINICAL CHEMISTRY:
There were no adverse findings in any group.
In males and when compared with controls, the statistically significant differences at 100 and 300 mg/kg/day were considered to be not toxicologically or biologically relevant in view of the slight amplitude or the direction of variation, in absence of dose-relationship, and/or in absence of correlating findings in other laboratory investigation parameters, clinical signs and pathology.
In females treated at 1000 mg/kg/day, mean albumin and cholesterol concentrations and mean albumin/globulin ratio were slightly higher than in controls; these slight variations were therefore considered to be of minor toxicological significance.
There were no test item treatment-related effects in females of the other dose-levels. Statistically significant variations noted in females in mean sodium and potassium concentrations were considered to be fortuitous (minimal differences and not dose-related).

URINALYSIS:
There were no variations from controls considered to be test item treatment-related.
The higher and not statistically significant mean urine volume in males treated at 1000 mg/kg/day was considered to be incidental.

SEMINOLOGY:
There were no test item treatment-related effects on epididymal sperm motility, morphology and count and on testicular sperm head count and daily sperm production rate.
Mean number of testicular sperm head count and mean daily sperm production rate noted at 1000 mg/kg/day were slightly lower compared with controls (-14% and -13%, respectively). However, these parameters can be highly variable in Sprague-Dawley rats and there were no differences in epididymis and testis absolute and relative weights at necropsy. No changes were noted at microscopic examination.

ORGAN WEIGHTS:
There were no test item-related changes in the mean organ weights.
The mean relative liver weight was statistically significantly higher in males treated at 1000 mg/kg/day (p<0.05). As this variation was small (+7%) regarding to the duration of the study (13 weeks), any relationship to treatment was considered to be unlikely.
The mean absolute brain weight was lower in females treated at 100 mg/kg/day (p<0.05). In the absence of similar trend at the higher dose levels, any relationship to treatment was excluded.
Other small variations observed between groups were considered to be part of the normal variability in rats and without relationship to the test item.

GROSS PATHOLOGY:
There were no test item-related changes at necropsy.
Changes observed were considered to be part of the normal background commonly seen in rats.

HISTOPATHOLOGY: NON-NEOPLASTIC:
Test item-related changes were observed in the forestomach of both sexes at 1000 mg/kg/day and in kidneys of males particularly at 1000 mg/kg/day.

. Forestomach
Minimal to moderate hyperplasia of squamous cells was observed in the forestomach of animals from both sexes with a higher incidence and severity in males than in females. In most animals, this was associated with minimal to moderate hyperkeratosis.
This was associated in one male with a slight infiltrate of mixed inflammatory cells in the submucosa.

No test item-related changes were observed in the forestomach at 100 and 300 mg/kg/day.

. Kidneys
No test item-related findings were observed in females.

Hyaline droplets were observed in the tubular cells of male kidneys at a slightly higher incidence and severity in animals treated at 300 or 1000 mg/kg/day than in controls as shown in the table below.

Kidneys from control males and those treated at 1000 mg/kg/day were immunostained with an antibody for alpha 2µ globulin protein. These hyaline droplets were weakly positive suggesting they corresponded to alpha 2µ globulin.

. Other organs
A minimal focus of hepatocytic necrosis was observed in one female treated at 1000 mg/kg/day. As this change was focal, seen in a single animal and may be occasionally seen in control animals, any relationship to treatment was excluded.

Careful examination of right testes in males did not reveal any test item-related changes.

Other changes were considered to be part of the normal background commonly seen in rats.
Dose descriptor:
NOAEL
Effect level:
1 000 mg/kg bw/day (actual dose received)
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: NO EFFECT
Critical effects observed:
not specified

Blood biochemistry

Sex

Male

Female

Dose-level (mg/kg/day)

0

100

300

1000

0

100

300

1000

Proteins (g/L)

64

63

66

64

65

68

68

70

Albumin (G/L)

38

38

39

38

39

42

42

44*

Albumin/globulin ratio

1.53

1.50

1.46

1.47

1.50

1.64

1.63

1.67*

Cholesterol (mmol/L)

1.3

1.5

1.5

1.6

1.7

1.8

1.7

2.0*

Statistically significant from controls: *: p<0.05.

 

 

 

 

 

 

 

 

Microscopic examination : forestomach

 

Sex

Males

Females

Group

1

2

3

4

1

2

3

4

Dose level (mg/kg/day)

0

100

300

1000

0

100

300

1000

Number of animals

10

10

10

10

10

10

10

10

Hyperplasia; squamous cells

Minimal

-

-

-

3

-

-

-

5

Slight

-

-

-

4

-

-

-

1

Moderate

-

-

-

3

-

-

-

-

Total

0

0

0

10

0

0

0

6

Hyperkeratosis

Minimal

-

-

-

3

-

-

-

4

Slight

-

-

-

4

-

-

-

1

Moderate

-

-

-

3

-

-

-

-

Total

0

0

0

10

0

0

0

5

Infiltrate; mixed inflammatory cells

Minimal

1

-

2

-

2

1

1

-

Slight

-

-

-

1

-

-

-

-

Total

1

0

2

1

2

1

1

0

 -: Not observed in this group.

 

Microscopic examination: kidneys

Sex

Males

Group

1

2

3

4

Dose-level (mg/kg/day)

0

100

300

1000

Number of animals

10

10

10

10

Hyaline droplets; tubular epithelium

Minimal

1

1

1

2

Slight

-

-

2

5

Total

1

1

3

7

- : Not observed in this group.

Conclusions:
The test item was administered daily for 13 weeks by gavage to male and female Sprague-Dawley rats at dose-levels of 100, 300 and 1000 mg/kg/day in corn oil.
There were no considered adverse findings in the study at all dose-levels.
Therefore, under the experimental conditions of this study, the No Observed Adverse Effect Level (NOAEL) was considered to be 1000 mg/kg/day.
Executive summary:

The objective of this study was to evaluate the potential toxicity of the test item, Heptanal, following daily oral administration (gavage) to rats for 13 weeks.

Methods

Three groups of ten male and ten female Sprague-Dawley rats received the test item by daily oral administration for 13 weeks. The test item was administered at 100, 300 and 1000 mg/kg/day in the vehicle (corn oil) under a constant dosage-volume of 5 mL/kg/day. A control group of ten animals per sex received the vehicle alone under the same experimental conditions.

 

Test item concentrations in the formulations were checked several times during the study.

 

The animals were checked at least twice daily during the treatment period for mortality and morbidity and once daily for clinical signs. In addition, detailed clinical examinations were performed once weekly. The body weight was recorded once before the beginning of the treatment period, and then at least once a week during the study as well as food consumption.

 

Ophthalmologic examinations were performed on all animals before the beginning of the treatment period and on control and high-dose animals at the end of the treatment period.The estrous cycle stage was determined for all females daily for 21 days before the end of the treatment period. Hematology, blood biochemistry and urinalysis were performed towards the end of the treatment period. A Functional Observation Battery including motor activity measurement was performed on all animals towards the end of the dosing period.

Animals were euthanized and submitted to a full macroscopic post-mortem examination. Sperm analysis was performed on all males at sacrifice. Designated organs were weighed and several tissues were preserved. A microscopic examination was performed on selected tissues from animals of the control and high-dose groups sacrificed at the end of the treatment period and on all macroscopic lesions.

Results

The test item concentrations in the administered dose formulations analyzed during the study were within an acceptable range when compared to the nominal values (± 10%), except for formulations used at the beginning of Week 6 (results between +13.0 and +18.5% but overdose of the animals was doubtful according to the laboratory investigation) and for the group 2 formulation used in Week 6/7 (result at +11.4%). No test item was detected in control formulations.

There were no premature deaths. Ptyalism noted in all males and nearly all females at 1000 mg/kg/day was the only test item treatment-related clinical sign.

There were no test item treatment-related effects on mean food consumption, mean body weight, mean body weight change, at ophthalmology, on estrous cycles and mean hematology, coagulation and urinalysis parameters.

In females treated at 1000 mg/kg/day, mean albumin (44 g/L vs. 39 g/L in controls, p<0.05) and cholesterol (2.0 mmol/L vs. 1.7 mmol/L in controls, p<0.05) concentrations and mean albumin/globulin ratio (1.67 vs. 1.50, p<0.05) were slightly higher than in controls; these differences were considered to be of minor toxicological significance. There were no toxicologically relevant effects in females of the other dose-levels or in males.

There were no toxicologically relevant effects during FOB tests including mean motor activity data and in sperm analysis data.

 

At histopathology examination, there were no test item-related changes in the mean organ weights and no test item-related changes at necropsy.

Microscopic test item-related changes were observed at 1000 mg/kg/day in the forestomach of both sexes (hyperplasia of squamous cells and hyperkeratosis considered non-adverse in the absence of ulceration or pronounced inflammation) and in kidneys of males (hyaline droplets in the tubular epithelial cells considered to be non-adverse due to its low magnitude and the absence of other renal changes).

 

At 300 mg/kg/day, a marginally, higher incidence and severity of hyaline droplets was observed in kidneys of males when compared with controls.

 

No test item-related changes were seen in the forestomach at 100 or 300 mg/kg/day or in kidneys of males at 100 mg/kg/day.

Conclusion

 

The test item was administered daily for 13 weeks by gavage to male and female Sprague-Dawley rats at dose-levels of 100, 300 and 1000 mg/kg/day in corn oil.

There were no considered adverse findings in the study at all dose-levels.

Therefore, under the experimental conditions of this study, the No Observed Adverse Effect Level (NOAEL) was considered to be 1000 mg/kg/day. 

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed
Dose descriptor:
NOAEL
1 000 mg/kg bw/day
Study duration:
subchronic
Species:
rat

Repeated dose toxicity: inhalation - systemic effects

Endpoint conclusion
Endpoint conclusion:
no study available

Repeated dose toxicity: inhalation - local effects

Endpoint conclusion
Endpoint conclusion:
no study available

Repeated dose toxicity: dermal - systemic effects

Endpoint conclusion
Endpoint conclusion:
no study available

Repeated dose toxicity: dermal - local effects

Endpoint conclusion
Endpoint conclusion:
no study available

Additional information

1-Studies with Heptanal:

2- weeks toxicity study (Bentz, 2015)

Heptanal was administered daily to Sprague-Dawley rats by gavage at dose levels of 100, 300 and 1000 mg/kg/day for 14 days. There were no test item treatment-related findings in the study. Under the experimental conditions of this study, the No Observable Effect Level (NOEL) was considered to be 1000 mg/kg/day.

13 -Weeks toxicity study performed with heptanal according to GLP and OECD 408 (Bentz, 2015)

Results

Heptanal concentrations in the administered dose formulations analyzed during the study were within an acceptable range when compared to the nominal values (± 10%), except for formulations used at the beginning of Week 6 (results between +13.0 and +18.5% but overdose of the animals was doubtful according to the laboratory investigation) and for the group 2 formulation used in Week 6/7 (result at +11.4%). No test item was detected in control formulations.

There were no premature deaths. Ptyalism noted in all males and nearly all females at 1000 mg/kg/day was the only test item treatment-related clinical sign.

There were no test item treatment-related effects on mean food consumption, mean body weight, mean body weight change, at ophthalmology, on estrous cycles and mean hematology, coagulation and urinalysis parameters.

In females treated at 1000 mg/kg/day, mean albumin (44 g/Lvs.39 g/L in controls, p<0.05) and cholesterol (2.0 mmol/Lvs.1.7 mmol/L in controls, p<0.05) concentrations and mean albumin/globulin ratio (1.67vs.1.50, p<0.05) were slightly higher than in controls; these differences were considered to be of minor toxicological significance. There were no toxicologically relevant effects in females of the other dose-levels or in males.

There were no toxicologically relevant effects during FOB tests including mean motor activity data and in sperm analysis data.

 

At pathology, there were no test item-related changes in the mean organ weights and no test item-related changes at necropsy.

Microscopic test item-related changes were observed at 1000 mg/kg/day in the forestomach of both sexes (hyperplasia of squamous cells and hyperkeratosis considered non-adverse in the absence of ulceration or pronounced inflammation) and in kidneys of males (hyaline droplets in the tubular epithelial cells considered to be non-adverse due to its low magnitude and the absence of other renal changes).

 

At 300 mg/kg/day, a marginally, higher incidence and severity of hyaline droplets was observed in kidneys of males when compared with controls.

 

No test item-related changes were seen in the forestomach at 100 or 300 mg/kg/day or in kidneys of males at 100 mg/kg/day.

Conclusion

 

Heptanal was administered daily for 13 weeks by gavage to male and female Sprague-Dawley rats at dose-levels of 100, 300 and 1000 mg/kg/day in corn oil.

There were no considered adverse findings in the study at all dose-levels.

Therefore, under the experimental conditions of this study, the No Observed Adverse Effect Level (NOAEL) was considered to be 1000 mg/kg/day. 

2- Studies with Heptanoic acid :

Read across with the metabolite heptanoic acid to fulfill the subacute azard assesment endpoint (see document for read across justification attached in section 13):

As no 28 days toxicity study with Heptanal is available and as a toxicokinetic study (Jaillet 2013) confirms that Heptanal undergo degradation to heptanoic acid (heptanoic plasma levels were quantified from the first collected time-point of 0.125 h to 12 h), it is suggested to use the 28 days study performed with heptanoic acid for the subacute hazard assessment (see Read across justification document attached in section 13).

The degradation of heptanal to heptanoic acid confirm the litterature data. Indeed, as a combination of high capacity dehydrogenase (alcohol (ADH) and aldehyde (ALD) dehydrogenase and oxidase enzymes is known to be rapidly oxidize in linear saturated aldehydes to the corresponding carboxylic acids which is subsequently completely oxidized to carbon dioxide and water in the fatty acid pathway and tricarboxylic acid cycle (see HPV on the category for Aliphatic and carboxylic acids ).

28-days oral study in rats with heptanoic acid according to OECD 407 (Terrill, 1990):

Group (10/sex/group) of male and female Sprague-Dawley rats were given dose levels of 0, 850, 1750, or 3500 mg/kg bw of heptanoic acid by gavage in corn oil (10 ml/kg) daily for 27 days. In this study, clinical signs were monitored twice weekly and body weights and food consumption were measured weekly. At necropsy, blood was drawn and clinical chemistry, hematological determinations, and organ weights were measured. A variety of tissues were prepared and preserved in 10% formalin. All tissues from the control and high-dose groups and tissue from the heart, liver, kidneys, and gross lesions from the low- and mid-dose group were embedded in paraffin, stained with hematoxylin and eosin, and examined microscopically.

Six animals (3 low-dose females, two high-dose females and one high-dose male) died during the study. The cause of death for five of the six unscheduled deaths was considered related to gavage administration. In one low-dose females marked pyelonephritis and inflammation throughout the lower urinary tract with an associated urinary calculus were present which was considered as typical spontaneous lesions for this age and strain of test animal. Treatment-related findings included physical signs such as salivation, languid behavior, polypnea, dyspnea, tremors, wheezing, thin appearance, ataxia and hunch posture; these findings were observed, predominately in the high-dose animals, approximately one hour post-dosing. At the weekly observations which were performed prior to dosing only respiratory distress (wheezing) was exhibited by the high-dose males and mid- and high-dose females. The mean body weight change and mean total food consumption in high-dose males was significantly decreased compared to control males. Pathology findings included hyperkeratosis that was present in the non-glandular region of the stomach of almost all of the high-dose male and female animals sacrificed at termination. Hyperkeratosis was generally diffuse and was graded minimal to moderate. This change correlates with the rough and thickened mucosa noted in the non-glandular region of the stomach at necropsy. The presence of this change suggests a mild local irritating effect associated with the gavage administration of heptanoic acid. There was however no evidence of degeneration/necrosis or inflammation. Microscopic examination of the non-glandular region of the stomach in the low- and mid-dose groups showed no evidence of hyperkeratosis.

In conclusion, the high-dose animals (3500 mg/kg/day of heptanoic acid) exhibited wheezing; decrease in body weight change and total food consumption (males only); gross lesions of the stomach and microscopic lesions in the non-glandular region of the stomach. The few signs exhibited by the animals receiving 1750 mg/kg/day, or less, suggested that these animals were unaffected by treatment.

Based on decreased body weights and food consumption, gross lesions of the stomach, and microscopic lesions of the non-glandular region of the stomach at 3500 mg/kg/day, the lowest observable adverse effect level (LOAEL) and the no observable adverse effect level (NOAEL) for heptanoic acid were concluded to be 3500 and 1750 mg/kg/day, respectively. Except for tissue already discussed, there was no evidence of histopathology of other tissue including the testes and ovaries.


Repeated dose toxicity: via oral route - systemic effects (target organ) digestive: stomach

Justification for classification or non-classification

There are conclusive data available including the 13-weeks toxicity study performed according to OECD 408 with the registered susbtance Heptanal for the classification with regard to repeated toxicity.

No classification for repeated toxicity has to be applied for heptanal according to EU regulation (EC) No 1272/2008 (CLP).

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