(Z)-N-[2-(2-hydroxyethoxy)ethyl]-9-octadecenamide

Endpoint summary

Key value for chemical safety assessment

Repeated dose toxicity: via oral route - systemic effects

Link to relevant study records

Reference

Reference 1

Endpoint:

short-term repeated dose toxicity: oral

Type of information:

read-across based on grouping of substances (category approach)

Adequacy of study:

key study

Study period:

1983

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Read across study

Remarks:

Not GLP

Justification for type of information:

Refer to Section 13 for details on the read across justification.

Reason / purpose for cross-reference:

read-across source

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 407 (Repeated Dose 28-Day Oral Toxicity Study in Rodents)

Deviations:

not specified

GLP compliance:

no

Limit test:

no

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Mus-Rattus, Brunntal, Germany
- Age at study initiation: between 6-7 wk
- Weight at study initiation: 111 (f) - 125 (m) g
- Housing: plastic cages, 3 males and 5 females/cage
- Diet (e.g. ad libitum): ad libitum (Altromin Ratdiet No. 1424 DK, Altromin GmbH, Lage, Germany)
- Water (e.g. ad libitum): ad libitum (tap water)
- Acclimation period: 6 d

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18-20
- Humidity (%): 60-75
- Air changes (per hr): 11
- Photoperiod (hrs dark / hrs light): 12/12

Route of administration:

oral: gavage

Vehicle:

olive oil

Details on oral exposure:

doses were adpated weekly to the body weight

Analytical verification of doses or concentrations:

no

Duration of treatment / exposure:

28 d

Frequency of treatment:

daily once, 5 times/wk

Remarks:

Doses / Concentrations:
70 mg/kg bw/d (Days 1-28)
Basis:
actual ingested

Remarks:

Doses / Concentrations:
250 mg/kg bw/d (Days 1-28)
Basis:
actual ingested

Remarks:

Doses / Concentrations:
750 mg/kg bw/d (Days 1-14)
Basis:
actual ingested

Remarks:

Doses / Concentrations:
1500 mg/kg bw/d (Days 15-28)
Basis:
actual ingested

No. of animals per sex per dose:

10/sex/dose for main study; 5/sex/dose for 4 month recovery period

Control animals:

yes, concurrent no treatment

Details on study design:

according to standard procedure

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: daily


DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: end of study


BODY WEIGHT: Yes
- Time schedule for examinations: weekly


HAEMATOLOGY: Yes
- Time schedule for collection of blood: end of study
- Anaesthetic used for blood collection: Yes (ether)
- How many animals: 10 per dose and sex
- Parameters checked: Hematocrit, erythrocytes, leukocytes, hemoglobin, thrombocytes, mean corpuscular volume, white blood cell differntial


CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: end of study
- How many animals: 10 per sex and dose
- Parameters checked: GPT, GOT, AP, glucose, urea, total protein, calcium, phosphate, cholestrol


URINALYSIS: Yes
- Time schedule for collection of urine: end of study
- Metabolism cages used for collection of urine: No
- Parameters checked: urea, creatinin, sodium, potassium, glucose, calcium, ap


NEUROBEHAVIOURAL EXAMINATION: No


Other: Groups of 5 male and 5 female rats kept for an additional 4 month recovery period.

Sacrifice and pathology:

GROSS PATHOLOGY: Yes
the following tissues/organs were examined:
adrenal gland (2)
aorta thoracica
brain (cornu ammonis)
coagulating gland with seminal vesicle
epididymis (2)
eye with optic nerve (2)
heart
intestine, large
intestine, small
kidney (2)
liver
lungs
lymph node (cervical) (1)
lymph node (mesenteric) (1)
mucles
oesophagus
ovary (2)
pancreas
prostate
salivary glands (mandibular,
parotid and sublingual gland)
skin
spleen
stomach
testicle (2)
thymus
thyroid (2) (incl. parathyroids)
tongue
trachea (incl. larynx)
urinary bladder
uterus (incl. cervix and oviducts)



HISTOPATHOLOGY: Yes
see gross pathology

Statistics:

't' test used for statistical analysis of all parameters except organ weight (U-test)

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:

no effects observed

Clinical biochemistry findings:

effects observed, treatment-related

Urinalysis findings:

no effects observed

Behaviour (functional findings):

not examined

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Gross pathological findings:

no effects observed

Histopathological findings: non-neoplastic:

no effects observed

Histopathological findings: neoplastic:

no effects observed

Details on results:

The doses up to 1500 mg/kg bw/d were tolerated by all animals without lethality. The body weight gain and total increase of body weights did not differ from the control group. Absolute and relative organ weights showed no significant changes in the substance groups compared to the control group, accept the organ weight of the adrenal gland which is increased for the females of group 3 (250 mg/kg) and 4 (750/1500 mg/kg bw). This result is considered of no relevance. The pathological, histological evaluation did not show significant compound related gross or microscocopic organ injury of liver, kidneys, adrenals, heart, lung, spleen and gonads; dose independent reversible local findings were restricted to the fore stomach mucose of the highest group (hyperplastic and cellular changes in the forestomach but not dose-related and also found in controls. Attributed to the use of olive oil as carrier. Effects disappeared during 4 month recovery period). The biochemical parameters calcium, blood sugar, urea, creatinine, cholesterine, GGT, GOT, GPT and LDH did not show any irregular signs. Slight alterations of phosphate in the highest group were noted and regarded as dose/compound related but not critical effect.

Key result

Dose descriptor:

NOAEL

Effect level:

> 750 mg/kg bw/day (nominal)

Sex:

male/female

Basis for effect level:

other: No biologically relevant effects observed on any of the parameters recorded at any dose. Also, test animals treated with 1500 mg/kg bw /d (Day 15-28) showed no adverse effect

Key result

Critical effects observed:

no

Conclusions:

Under the study conditions, the systemic NOAEL was considered to be >750 mg/kg bw.

Executive summary:

A study was conducted to determine the repeated dose oral toxicity of the read across substance, Amides, C12-18 (even-numbered) and C18-unsatd., N-(hydroxyethyl), to rats according to a method similar or equivalent to OECD Guideline 407. Groups of 10 male and 10 female rats were orally gavaged with the test substance diluted in olive oil 5 d/wk at 0, 70, 250, 750 (Days 1-14) or 1500 (Days 15-28) for 28 d. Clinical signs, bodyweight, hematology, clinical chemistry, urinalysis, gross and microscopic pathology were recorded. Additional groups of 5 male and 5 female rats were kept for a 4 month recovery period. No treatment-related adverse effects were observed at any of the doses. Changes in the forestomach at some doses including controls were attributed to the use of olive oil and found to be reversible after end of exposure. The doses up to 1500 mg/kg bw/d were tolerated by all animals without lethality. The body weight gain and total increase of body weights did not differ from the control group. The pathological, histological evaluation did not show significant compound related gross or microscopic organ injury of liver, kidneys, adrenals, heart, lung, spleen and gonads. Dose-independent reversible local findings were restricted to the fore stomach mucosa of the highest group. The biochemical parameters calcium, blood sugar, urea, creatinine, cholesterol, GGT, GOT, GPT and LDH did not show any irregular signs. Slight alterations of phosphate in the highest group were noted and regarded as dose/compound related but not critical effect. Hence, under the study conditions, the systemic NOAEL was considered to be >750 mg/kg bw (Gloxhuber, 1983).

Reference 2

Endpoint:

short-term repeated dose toxicity: oral

Type of information:

read-across based on grouping of substances (category approach)

Adequacy of study:

supporting study

Study period:

31 January 2013 - 17 June 2013

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

Reda across study

Justification for type of information:

Refer to Section 13 for details on the read across justification.

Reason / purpose for cross-reference:

read-across source

Qualifier:

according to guideline

Guideline:

OECD Guideline 422 (Combined Repeated Dose Toxicity Study with the Reproduction / Developmental Toxicity Screening Test)

GLP compliance:

yes

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/weight at study initiation: on the first day of treatment, the males were approximately 10 weeks old and had a mean body weight of 388 g (range: 335 g to 438 g) and the females were approximately 9 weeks old had a mean body weight of 236 g (range: 203 g to 270 g)
- Housing: the animals were individually housed, except during pairing and lactation, in polycarbonate cages
- Diet: SSNIFF R/M-H pelleted diet (free access)
- Water: tap water filtered with a 0.22 µm filter (free access)
- Acclimation period: 8 days before the beginning of the study.

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: 13 February 2013 to 09 April 2013.

Route of administration:

oral: gavage

Vehicle:

corn oil

Details on oral exposure:

PREPARATION OF DOSING SOLUTIONS:
The test item was administered as a suspension in the vehicle. The dose formulations were prepared according to the following process, as described in an homogeneity/stability study:
- a small amount of test item was melt using water bath at a temperature of +50°C,
- the vehicle was warmed at +50°C using water bath,
- the appropriate amount of melt test item was weighed in the preparation beaker and the corresponding amount of vehicle was added,
- the test item and the vehicle were mixed using magnetic stirrer in the water bath at +50°C during 10 minutes,
- the obtained suspension was stirred at ambient temperature at least 30 minutes.

No correction factor was applied.
The test item dose formulations were prepared on a weekly basis, stored at room temperature protected from light prior to use and delivered to the study room at room temperature and protected from light.

When not on the day of formulation preparation, test item formulations were warmed under magnetic stirring at +50°C using water bath during at least 30 minutes and then kept under magnetically stirring at ambient temperature for at least 30 minutes before daily delivery to the study room.

VEHICLE
- Choice of vehicle: good suspension in corn oil
- Concentration in vehicle: 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.
Homogeneity: assessed in homogeneity study (satisfactory results)
Stability: assessed in stability study (stable after 9 days at room temperature and protected from light)

Duration of treatment / exposure:

In the males:
− 2 weeks before mating,
− during the mating period,
− until sacrifice (at least 5 weeks in total),

In the females:
− 2 weeks before mating,
− during the mating period (1 week),
− during pregnancy,
− during lactation until day 5 post-partum inclusive,
− until sacrifice for females which had not delivered.

Frequency of treatment:

Daily

Dose / conc.:

0 mg/kg bw/day (actual dose received)

Remarks:

Controls

Dose / conc.:

100 mg/kg bw/day (actual dose received)

Dose / conc.:

300 mg/kg bw/day (actual dose received)

Dose / conc.:

1 000 mg/kg bw/day (actual dose received)

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, following the results of a previous 2-week toxicity study. In this study, three groups of three male and three female Sprague-Dawley rats received the test item as a suspension in corn oil at 100, 300 or 1000 mg/kg/day for 2 weeks by gavage. There were no unscheduled deaths. Reduced mean body weight gain and mean food consumption were noted in males during the first week of treatment. Clinical signs were ptyalism in all test item-treated animals and hunched posture in two males and one female at the high-dose during the second week of treatment. There were no test item-related macroscopic findings.

- Animal assignment: computerized stratification procedure.

Positive control:

no (not required)

Observations and examinations performed and frequency:

The animals were checked at least twice daily during the dosing period for mortality and morbidity and once daily for clinical signs. Detailed clinical observations were performed once a week. Body weight and food consumption were recorded once a week during premating and mating periods (food consumption not during mating), and during gestation on days 0, 7, 14 and 20 p.c. and lactation on days 1 and 5 p.p.. The animals were
paired for mating after 2 weeks of treatment and the females were allowed to litter and rear their progeny until day 5 p.p.. At the end of the treatment period, Functional Observation Battery, motor activity and laboratory investigations (hematology and blood biochemistry) were carried out on five males and five females.

Sacrifice and pathology:

The males were sacrificed after at least 5 weeks of treatment and the females on day 6 p.p.. Final body weights and selected organs weights (adrenals, brain, epididymides, heart, kidneys, liver, spleen, testes and thymus) were recorded and a complete macroscopic post-mortem examination was performed, with particular attention paid to the reproductive organs. A microscopic examination was performed on selected organs from five males and five females in the control- and high-dose groups, on liver, thymus, seminal vesicles and bone marrow from five males and/or five females in the low- and intermediate-dose groups and on all macroscopic lesions.

Statistics:

Body weight, food consumption and reproductive data :
Data were compared by one-way analysis of variances and Dunnett test (mean values being considered as normally distributed, variances being
considered as homogenous) or by Fischer exact probability test (proportions).

Hematology and blood biochemistry:
A specific sequence was used for the statistical analyses of hematology and blood biochemistry data.

Organ weight:
PathData software was used to perform the statistical analysis of organ weight data (level of significance:
0.05 or 0.01) according to a specific sequence

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

Ptyalism, considered of minor toxicological significance, was observed in all animals at 300 and 1000 mg/kg/day from the first or second week of treatment and in most of the animals at 100 mg/kg/day but later. Hypoactivity, loud breathing, piloerection and/or round back observed for some days in a few animals at 300 mg/kg/day but more at 1000 mg/kg/day were considered to be of limited toxicological significance. Incidental findings consisted of half-closed eyes, reflux at dosing, cutaneous lesion and abnormal growth of teeth.

Mortality:

mortality observed, treatment-related

Description (incidence):

Ptyalism, considered of minor toxicological significance, was observed in all animals at 300 and 1000 mg/kg/day from the first or second week of treatment and in most of the animals at 100 mg/kg/day but later. Hypoactivity, loud breathing, piloerection and/or round back observed for some days in a few animals at 300 mg/kg/day but more at 1000 mg/kg/day were considered to be of limited toxicological significance. Incidental findings consisted of half-closed eyes, reflux at dosing, cutaneous lesion and abnormal growth of teeth.

Body weight and weight changes:

no effects observed

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

See details below.

Food efficiency:

not examined

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

not examined

Ophthalmological findings:

not examined

Haematological findings:

effects observed, treatment-related

Description (incidence and severity):

See details below.

Clinical biochemistry findings:

effects observed, treatment-related

Description (incidence and severity):

See details below.

Urinalysis findings:

not examined

Behaviour (functional findings):

effects observed, treatment-related

Description (incidence and severity):

See details below.

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Description (incidence and severity):

See details below.

Gross pathological findings:

effects observed, treatment-related

Description (incidence and severity):

See details below.

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Description (incidence and severity):

See details below.

Histopathological findings: neoplastic:

not examined

Description (incidence and severity):

See details below.

Other effects:

not examined

Details on results:

Food consumption:
In males, mean food consumption at 1000 mg/kg/day was statistically significantly reduced in the first week of treatment when compared with
controls (which correlated with a non-statistically significantly lower mean body weight gain at that time). It became similar to controls in the second week of dosing. This slight and transient effect was considered to be of limited toxicological significance. Mean food consumption at 100 and 300 mg/kg/day was not affected. Mean food consumption in females was considered to be unaffected by the test item treatment.

Hematology:
APPT values were not considered to be affected (one control data in males was higher than the others hence the shortened mean values in the test item-treated groups; there was no dose-relationship in females). For the slightly higher mean white blood cell counts when compared with controls, a relationship with the test item treatment was considered to be doubtful (no clear dose-relationship, individual values generally included in historical control data, see Appendix 38, and no statistical level).

Blood biochemistry:
Mean cholesterol level was higher in test item-treated female groups in a dose-related manner, reaching statistical and toxicological significance at 300 and 1000 mg/kg/day. All individual values in both groups were included in historical control data (see Appendix 38) and in absence of adverse correlates in the study, this was considered to be non-adverse. There was no dose-relationship in males, but an effect of the test item may be
suspected in two males treated at 1000 mg/kg/day which had a high cholesterol level (2.3 and 2.4 mmol/L).
Mean sodium concentration was also statistically significant higher in females treated at 1000 mg/kg/daywhen compared with controls. Males or
other electrolytes in females were not affected and the variation was not severe. Therefore, this finding was not considered to be of toxicological
significance.
An effect of the test item treatment on mean albumin concentration at 300 mg/kg/day in both sexes was considered unlikely as there was no
dose-relationship. The increase observed in triglyceride levels at 300 and 1000 mg/kg/day in both sexes was considered to be incidental as there
was no statistical level reached for the group means and no dose-relationship seen in individual data. Moreover, the increase at 1000 mg/kg/day
was due to isolated animals per sex only.

Functional Observation Battery (FOB) and motor activity:
An effect of the test item treatment in males and females at 300 and/or 1000 mg/kg/day on mean motor activity data was considered to be
equivocal but of limited toxicological significance. The vast majority of the individual data were similar to what can usually be seen in this type of
study

Organ weights:
When compared with controls, the mean absolute and relative liver weights were higher in males and females given 1000 mg/kg/day and in males
given 300 mg/kg/day, reaching statistically significant values in both sexes at 1000 mg/kg/day (p<0.01 except for the absolute weight in females where it was p<0.05). This correlated histologically with minimal hepatocellular hypertrophy and was considered to be test item-related.
The mean absolute and relative thymus weights were lower in females given 1000 mg/kg/day, without reaching a statistically significant value. This correlated with minimal to slight atrophy in two females and was considered to be probably test item-related.
The mean absolute heart weight was higher in males given 100 mg/kg/day. In the absence of a dose-related trend, any relationship with the test item was considered to be excluded.
Other changes in the mean organ weights were considered to be part of the normal variation in rats and without relationship with the test item.

Macroscopic post-mortem examination:
The thymus was reduced in one female given 1000 mg/kg/day correlating in this animal with a small weight (0.1200 g) and histologically with slight atrophy. A relationship with the test item was considered to be likely.
Irregular color was seen in the lungs of 3/5 males given 1000 mg/kg/day. This correlated histologically with presence of mucus and inflammation
(chronic) and/or alveolar macrophages. These changes were consistent with aspiration or regurgitation of the oily vehicle or test item during the
technical gavage procedures.

Microscopic examination:
Test item-related changes were observed in the liver and the thymus.
Liver
Minimal hepatocellular hypertrophy was seen in 1/5 males given the test item at 300 mg/kg/day and 4/6 males and 2/5 females given
1000 mg/kg/day. This non-adverse change was considered to be test item-related and correlated with the higher weight noted at necropsy.
Other changes seen in the liver, including the minimal foci of subcapsular necrosis seen in 1/5 control females, 1/5 males at 300 mg/kg/day and
2/5 females at 1000 mg/kg/day were considered to be fortuitous and without any relationship with the test item.
Thymus
Minimal or slight lymphoid atrophy was seen in 2/5 females given 1000 mg/kg/day, correlating with the lower weight at necropsy. Any relationship
with the test item was considered to be likely but non-adverse (low number of animals affected and low grades). No test item-related changes were
seen at 100 or 300 mg/kg/day.

Key result

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: Parental toxicity (non adverse)

Key result

Critical effects observed:

not specified

Conclusions:

The test item, N-(2-hydroxypropyl) Oleamide, was administered daily by oral gavage to male and female Sprague-Dawley rats, for 2 weeks before mating, during mating, gestation and until up to day 5 p.p., at dose-levels of 100, 300 or 1000 mg/kg/day.
At 1000 mg/kg/day, the main clinical sign noted was ptyalism in all animals. Hypoactivity, loud breathing, piloerection and/or round back were also recorded transiently in a few animals. Mean food consumption was slightly reduced in males in the first week of treatment only. Mean cholesterol level was higher in females than in controls but considered non-adverse in absence of adverse correlates. Hepatocellular
hypertrophy (correlating with higher mean liver weight) in both sexes and lymphoid atrophy in the thymus of a few females (correlating with lower mean thymus weight) were considered non-adverse in view of the low number of animals affected and/or minimal to slight grades.
At 300 mg/kg/day, ptyalism, hypoactivity, loud breathing, piloerection and/or round back was also noted with comparable incidence. The same effect on mean cholesterol level was seen in females and also considered non-adverse. Minimal hepatocellular hypertrophy was seen in the liver of a single male correlating with minor higher mean absolute weight in this group.
At 100 mg/kg/day, the only finding was ptyalism in most animals. No effects in the study were considered to be adverse.
Based on the experimental conditions of this study, the NOAEL for parental toxicity was considered to be 1000 mg/kg/day.

Executive summary:

A study was conducted to evaluate the potential toxic effects of the test substance, N-(2-hydroxypropyl) oleamide, following daily oral administration (gavage) to male and female rats from before mating, through mating and, for females, through gestation until Day 5 post-partum (p.p.). This study provides initial information on the possible health hazards (including neurological and immunological effects) likely to arise from repeated exposure over a relatively limited period of time.

Three groups of ten male and ten female Sprague-Dawley rats received the test substance daily by oral (gavage) administration before mating, through mating and, for the females, through gestation until Day 5 p.p. The test substance was administered as a suspension in the vehicle, corn oil, at dose-levels of 100, 300 or 1000 mg/kg bw/day. Another group of ten males and ten females received the vehicle alone, under the same experimental conditions and acted as a control group. A constant dosage-volume of 5 mL/kg/day was used. The concentration of the dose formulation was checked in study Weeks 1, 3 and 6. The animals were checked at least twice daily during the dosing period for mortality and morbidity and once daily for clinical signs. Detailed clinical observations were performed once a week. Body weight and food consumption were recorded once a week during premating and mating periods (food consumption not during mating), and during gestation on days 0, 7, 14 and 20 p.c. and lactation on days 1 and 5 p.p.. The animals were paired for mating after 2 weeks of treatment and the females were allowed to litter and rear their progeny until Day 5 p.p. At the end of the treatment period, Functional Observation Battery, motor activity and laboratory investigations (hematology and blood biochemistry) were carried out on five males and five females. The males were sacrificed after at least 5 weeks of treatment and the females on Day 6 p.p. Final body weights and selected organs weights (adrenals, brain, epididymides, heart, kidneys, liver, spleen, testes and thymus) were recorded and a complete macroscopic post-mortem examination was performed, with particular attention paid to the reproductive organs. A microscopic examination was performed on selected organs from five males and five females in the control- and high-dose groups, on liver, thymus, seminal vesicles and bone marrow from five males and/or five females in the low- and intermediate-dose groups and on all macroscopic lesions.

The test substance concentrations checked during the study were within an acceptable range of variations when compared to the nominal values (± 15%). There was no test substance in control formulations. There were no test substance-related deaths. Clinical signs consisted of ptyalism in all animals at 300 and 1000 mg/kg bw/day and in most of the animals at 100 mg/kg bw/day (minor toxicological significance), as well as hypoactivity, loud breathing, piloerection and/or round back observed in a few animals at 300 and 1000 mg/kg bw/day for a few days (limited toxicological significance). There were no relevant effects on mean body weight, mean Functional Observation Battery (FOB), as well as on mean hematology parameters in any group and sex. An effect of the test substance treatment on mean motor activity data at 300 and/or 1000 mg/kg bw/day was considered to be equivocal but of limited toxicological significance. In males, mean food consumption at 1000 mg/kg bw/day was reduced in the first week of treatment only (23 g/male/day, vs. 27, p<0.001). This effect was considered to be of limited toxicological significance. Mean food consumption in males at 100 and 300 mg/kg bw/day and in females were not affected. In females, mean cholesterol level was higher than in controls at 300 and 1000 mg/kg bw/day (up to 1.9 mmol/L, vs. 1.2, p<0.01) and considered to be non-adverse in absence of adverse correlates in the study. There were no relevant blood biochemistry findings in females at 100 mg/kg bw/day or in males. At histopathology at 1000 mg/kg bw/day, minimal hepatocellular hypertrophy correlating with higher mean liver weight was seen in the liver of both sexes (about +28% in males and +20% in females compared to controls, p<0.01 generally). In females, mild lymphoid atrophy was seen in the thymus of 2/5 females, correlating with lower mean weight at necropsy (about -22% from controls). At 300 mg/kg bw/day, only minimal hepatocellular hypertrophy was seen in the liver of a single male correlating with minor higher mean absolute weight in this group. All these microscopic findings were considered to be non-adverse (low number of animals affected and/or minimal to slight grades). There were no histopathological effects at 100 mg/kg bw/day.

In conclusion, the test substance was administered daily by oral gavage to male and female Sprague-Dawley rats, for 2 weeks before mating, during mating, gestation and until up to Day 5 p.p., at dose-levels of 100, 300 or 1000 mg/kg bw/day. At 1000 mg/kg bw/day, the main clinical sign noted was ptyalism in all animals. Hypoactivity, loud breathing, piloerection and/or round back were also recorded transiently in a few animals. Mean food consumption was slightly reduced in males in the first week of treatment only. Mean cholesterol level was higher in females than in controls but considered non-adverse in absence of adverse correlates. Hepatocellular hypertrophy (correlating with higher mean liver weight) in both sexes and lymphoid atrophy in the thymus of a few females (correlating with lower mean thymus weight) were considered non-adverse in view of the low number of animals affected and/or minimal to slight grades. At 300 mg/kg bw/day, ptyalism, hypoactivity, loud breathing, piloerection and/or round back was also noted with comparable incidence. The same effect on mean cholesterol level was seen in females and also considered non-adverse. Minimal hepatocellular hypertrophy was seen in the liver of a single male correlating with minor higher mean absolute weight in this group. At 100 mg/kg bw/day, the only finding was ptyalism in most animals. No effects in the study were considered to be adverse. Under the study conditions, the NOAEL for parental toxicity was considered to be 1000 mg/kg bw/day (Bentz, 2013).

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

NOAEL

750 mg/kg bw/day

Study duration:

subacute

Species:

rat

System:

other: Slight alterations of phosphate in the highest group

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

Study 1:

A study was conducted to determine the repeated dose oral toxicity of the read across substance, amides, C12-18 (even-numbered) and C18-unsatd., N-(hydroxyethyl), to rats according to a method similar or equivalent to OECD Guideline 407. Groups of 10 male and 10 female rats were orally gavaged with the test substance diluted in olive oil 5 d/wk at 0, 70, 250, 750 (Days 1-14) or 1500 (Days 15-28) for 28 d. Clinical signs, bodyweight, hematology, clinical chemistry, urinalysis, gross and microscopic pathology were recorded. Additional groups of 5 male and 5 female rats were kept for a 4 month recovery period. No treatment-related adverse effects were observed at any of the doses. Changes in the forestomach at some doses including controls were attributed to the use of olive oil and found to be reversible after end of exposure. The doses up to 1500 mg/kg bw/d were tolerated by all animals without lethality. The body weight gain and total increase of body weights did not differ from the control group. The pathological, histological evaluation did not show significant compound related gross or microscopic organ injury of liver, kidneys, adrenals, heart, lung, spleen and gonads. Dose-independent reversible local findings were restricted to the fore stomach mucosa of the highest group. The biochemical parameters calcium, blood sugar, urea, creatinine, cholesterol, GGT, GOT, GPT and LDH did not show any irregular signs. Slight alterations of phosphate in the highest group were noted and regarded as dose/compound related but not critical effect. Hence, under the study conditions, the systemic NOAEL was considered to be >750 mg/kg bw (Gloxhuber, 1983).

Study 2:

A study was conducted to evaluate the potential toxic effects of the read across substance, N-(2-hydroxypropyl) oleamide, following daily oral administration (gavage) to male and female rats from before mating, through mating and, for females, through gestation until Day 5 post-partum (p.p.). This study provides initial information on the possible health hazards (including neurological and immunological effects) likely to arise from repeated exposure over a relatively limited period of time.

Three groups of ten male and ten female Sprague-Dawley rats received the test substance daily by oral (gavage) administration before mating, through mating and, for the females, through gestation until Day 5 p.p. The test substance was administered as a suspension in the vehicle, corn oil, at dose-levels of 100, 300 or 1000 mg/kg bw/day. Another group of ten males and ten females received the vehicle alone, under the same experimental conditions and acted as a control group. A constant dosage-volume of 5 mL/kg/day was used. The concentration of the dose formulation was checked in study Weeks 1, 3 and 6. The animals were checked at least twice daily during the dosing period for mortality and morbidity and once daily for clinical signs. Detailed clinical observations were performed once a week. Body weight and food consumption were recorded once a week during premating and mating periods (food consumption not during mating), and during gestation on days 0, 7, 14 and 20 p.c. and lactation on days 1 and 5 p.p.. The animals were paired for mating after 2 weeks of treatment and the females were allowed to litter and rear their progeny until Day 5 p.p. At the end of the treatment period, Functional Observation Battery, motor activity and laboratory investigations (hematology and blood biochemistry) were carried out on five males and five females. The males were sacrificed after at least 5 weeks of treatment and the females on Day 6 p.p. Final body weights and selected organs weights (adrenals, brain, epididymides, heart, kidneys, liver, spleen, testes and thymus) were recorded and a complete macroscopic post-mortem examination was performed, with particular attention paid to the reproductive organs. A microscopic examination was performed on selected organs from five males and five females in the control- and high-dose groups, on liver, thymus, seminal vesicles and bone marrow from five males and/or five females in the low- and intermediate-dose groups and on all macroscopic lesions.

The test substance concentrations checked during the study were within an acceptable range of variations when compared to the nominal values (± 15%). There was no test substance in control formulations. There were no test substance-related deaths. Clinical signs consisted of ptyalism in all animals at 300 and 1000 mg/kg bw/day and in most of the animals at 100 mg/kg bw/day (minor toxicological significance), as well as hypoactivity, loud breathing, piloerection and/or round back observed in a few animals at 300 and 1000 mg/kg bw/day for a few days (limited toxicological significance). There were no relevant effects on mean body weight, mean Functional Observation Battery (FOB), as well as on mean hematology parameters in any group and sex. An effect of the test substance treatment on mean motor activity data at 300 and/or 1000 mg/kg bw/day was considered to be equivocal but of limited toxicological significance. In males, mean food consumption at 1000 mg/kg bw/day was reduced in the first week of treatment only (23 g/male/day, vs. 27, p<0.001). This effect was considered to be of limited toxicological significance. Mean food consumption in males at 100 and 300 mg/kg bw/day and in females were not affected. In females, mean cholesterol level was higher than in controls at 300 and 1000 mg/kg bw/day (up to 1.9 mmol/L, vs. 1.2, p<0.01) and considered to be non-adverse in absence of adverse correlates in the study. There were no relevant blood biochemistry findings in females at 100 mg/kg bw/day or in males. At histopathology at 1000 mg/kg bw/day, minimal hepatocellular hypertrophy correlating with higher mean liver weight was seen in the liver of both sexes (about +28% in males and +20% in females compared to controls, p<0.01 generally). In females, mild lymphoid atrophy was seen in the thymus of 2/5 females, correlating with lower mean weight at necropsy (about -22% from controls). At 300 mg/kg bw/day, only minimal hepatocellular hypertrophy was seen in the liver of a single male correlating with minor higher mean absolute weight in this group. All these microscopic findings were considered to be non-adverse (low number of animals affected and/or minimal to slight grades). There were no histopathological effects at 100 mg/kg bw/day.

In conclusion, the test substance was administered daily by oral gavage to male and female Sprague-Dawley rats, for 2 weeks before mating, during mating, gestation and until up to Day 5 p.p., at dose-levels of 100, 300 or 1000 mg/kg bw/day. At 1000 mg/kg bw/day, the main clinical sign noted was ptyalism in all animals. Hypoactivity, loud breathing, piloerection and/or round back were also recorded transiently in a few animals. Mean food consumption was slightly reduced in males in the first week of treatment only. Mean cholesterol level was higher in females than in controls but considered non-adverse in absence of adverse correlates. Hepatocellular hypertrophy (correlating with higher mean liver weight) in both sexes and lymphoid atrophy in the thymus of a few females (correlating with lower mean thymus weight) were considered non-adverse in view of the low number of animals affected and/or minimal to slight grades. At 300 mg/kg bw/day, ptyalism, hypoactivity, loud breathing, piloerection and/or round back was also noted with comparable incidence. The same effect on mean cholesterol level was seen in females and also considered non-adverse. Minimal hepatocellular hypertrophy was seen in the liver of a single male correlating with minor higher mean absolute weight in this group. At 100 mg/kg bw/day, the only finding was ptyalism in most animals. No effects in the study were considered to be adverse. Under the study conditions, the NOAEL for parental toxicity was considered to be 1000 mg/kg bw/day (Bentz, 2013).

Justification for classification or non-classification

Based on the results of a repeated dose oral toxicity study with the structurally similar read across substance, amides, C12-18 (even numbered) and C18-unsatd., N-(hydroxypropyl), the test substance does not require classification for this endpoint according to EU CLP (EC 1272/2008) criteria.