11-methyldodecyl laurate

Endpoint summary

Description of key information

Read-across from supporting substance (structural analogue).

The experimental data obtained by testing 8-methylnonyl octadec-9-enoate can be reliably extrapolated (by read-across) to 11-methyldodecyl laurate and support the absence of repeated dose toxicity effect.

Overall, 11-methyldodecyl laurate should not be classified for repeated dose toxicity in accordance with Regulation (EC) n. 1272/2008.

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

Remarks:

combined repeated dose and reproduction / developmental screening

Type of information:

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

Adequacy of study:

key study

Justification for type of information:

The justification for type of information is provided in attachment.

Reason / purpose for cross-reference:

read-across source

Clinical signs:

no effects observed

Mortality:

no mortality observed

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

statistically significant decrease (-9.4%) in body weight in females during lactation at 1000 mg/kg bw/day

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

In the high dose group (females: gestation/lactation period) a statistically significant reduction in food consumption by 21.7% was noted.

Food efficiency:

not examined

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

no effects observed

Ophthalmological findings:

no effects observed

Haematological findings:

no effects observed

Clinical biochemistry findings:

no effects observed

Urinalysis findings:

not examined

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:

no effects observed

Histopathological findings: neoplastic:

not examined

Details on results:

CLINICAL SIGNS AND MORTALITY
Piloerection was seen in 1 female of the high dose group at on day 2-4 of lactation.

BODY WEIGHT AND WEIGHT GAIN
A reduction in body weight (-9.7%) in high dose females during lactation period.

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study)
Reduction in food intake (-21.7%) in high dose females during gestation/lactation.

WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study)
No effects on water consumption in any treatment group were observed.

OPHTHALMOSCOPIC EXAMINATION
No effects were observend in any treatment group.

HAEMATOLOGY
No effects on water consumption in any treatment group were observed.

CLINICAL CHEMISTRY
An decrease of ASAT activity was seen in high dose females on day 15. This effects was considered to be due to the relative low or high value observed for the control group and not to be test item related.

NEUROBEHAVIOUR
No effects observed.

ORGAN WEIGHTS
All effects observed (slight increase in absolute and relative liver weight in males) were still within the historical control data of the laboratory and thus not of toxicological relevance.

GROSS PATHOLOGY
No effects observed.

HISTOPATHOLOGY:
No effects observed.

OTHER FINDINGS
The qualitative sperm staging revealed no test item-related specific spermatogenic changes in the male animals from the high dose group (1000 mg/kg b.w./day).

Key result

Dose descriptor:

NOAEL

Effect level:

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

Based on:

test mat.

Sex:

female

Basis for effect level:

other: adverse effects on body weight and body weight gain and food consumption

Key result

Dose descriptor:

NOAEL

Effect level:

1 000 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male

Basis for effect level:

other: no adverse affects observed

Key result

Critical effects observed:

not specified

Individual body weights of females during the pre-mating and lactation period.

Control group	Day(s) relative to start
	1	8	15
11	196	209	212
12	217	228	243
13	210	220	213
14	217	234	244
15	3211	215	232
16	195	208	197
17	205	224	239
18	212	238	233
19	224	236	259
20	200	218	214
Mean	209	223	229
SD	9	10	19

1000 mg/kg bw	Day(s) relative to start
	1	8	15
71	200	210	225
72	210	231	234
73	206	234	247
74	210	222	235
75	194	219	218
76	218	243	223
77	214	230	227
78	222	225	210
79	198	200	201
80	203	223	231
Mean	207	224	225
SD	9	12	13

Control group	Day(s) relative to littering
	1	4
11	286	309
12	323	330
13	325	311
14	331	327
15	311	322
16	282	302
17	309	327
18	312	328
19	315	331
20	300	329
Mean	309	322
SD	16	10

1000 mg/kg bw	Day(s) relative to littering
	1	4
71	270	281
72	339	301
73	289	309
75	289	317
77	253	247
78	280	271
79	290	296
80	293	308
Mean	288	291
SD	24	23

Relative food consumption of females between day 1 and 4 of lactation

Control group		1000 mg/kg bw
11	122	71	115
12	91	72	96
13	105	73	63
14	107	75	110
15	106	77	30
16	121	78	63
17	114	79	98
18	100	80	110
19	101
20	126
Mean	109	Mean	86
SD	11	SD	30

Conclusions:

The experimental data obtained by testing 8-methylnonyl octadec-9-enoate can be reliably extrapolated (by read-across) to 11-methyldodecyl laurate and support the low toxicity of the substance.
Overall, 11-methyldodecyl laurate should not be classified for the STOT RE in accordance with Regulation (EC) n. 1272/2008.
Furthermore, the study allows to suitably identify a NOAEL which can be used in the risk assessment.

Reference 2

Endpoint:

short-term repeated dose toxicity: oral

Remarks:

combined repeated dose and reproduction / developmental screening

Type of information:

experimental study

Adequacy of study:

key study

Study period:

01 Nov - 13 Dec 2012

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

GLP - Guideline study.

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

22 Mar 1996

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

Behoerde fuer Soziales, Familie, Gesundheit und Verbraucherschutz; Hamburg, Germany

Species:

rat

Strain:

Crj: CD(SD)

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Laboratories Research Models and Services Germany GmbH, Sulzfeld, Germany
- Age at study initiation: males: 50 days; females: 60 days
- Mean weight at study initiation: males: 248.8 to 298.7 g; females: 195.2 to 228.1 g
- Fasting period before study: no
- Housing: single housing in MAKROLON cages (type III plus)
- Diet: commercial ssniff R-Z V1324 (ssniff Spezialdiäten GmbH, Soest, Germany); ad libitum
- Water: tap water; ad libitum
(Analyses of diet and water was performed.)
- Acclimation period: 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 3
- Humidity (%): 55 ± 15
- Photoperiod (hrs dark / hrs light): 12/12

Route of administration:

oral: gavage

Vehicle:

corn oil

Details on oral exposure:

VEHICLE
- Concentration in vehicle: 50, 150 and 500 mg/mL
- Amount of vehicle (if gavage): 2 mL/kg

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

For the analysis of the test item-vehicle mixtures samples were taken at the following time points and stored at ≤ -20°C until analysis:
Start of treatment period; immediately after preparation of the test item-vehicle mixtures; 8 and 24 hours after storage of the test item preparations at room temperature; end of treatment period; during treatment with the test item always before administration to the last animal of the dose level group
The following parameters were determined: linearity, accuracy, precision, sensitivity, specificity, stability at +2°C to +8°C or -20°C (0, 24, 72 and 168 hours)

Duration of treatment / exposure:

Males: The daily administration of the test item was started two weeks before mating and lasted until test day 35, which was one day before sacrifice.
Females: The daily administration of the test item was started two weeks before mating and continued to at least day 3 of lactation.
Maximum: 56 days of treatment

Frequency of treatment:

once daily; 7 days/week

Remarks:

Doses / Concentrations:
100, 300 and 1000 mg/kg bw
Basis:
actual ingested

No. of animals per sex per dose:

10

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: based on a 14-day range-finding study (Leuschner, 2012)

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: before and after dosing
- Cage side observations checked: skin/fur, eyes, mucous membranes, respiratory and circulatory systems, somatomotor activity and behaviour patterns

MORTALITY AND CLINICAL SIGNS
- Time schedule: at least once daily (the frequency was increased when signs of toxicity were observed); deaths were recorded twice daily (animals which died or were sacrificed during the study were necropsied as soon as possible after exitus)

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: once before the first exposure (to allow within-subject comparisons) and once a week thereafter
- Paramters: changes in skin, fur, eyes, mucous membranes, occurrence of secretions and excretions and autonomic activity (e.g. lacrimation, pilo-erection, pupil size, and unusual respiratory pattern); changes in gait, posture and response to handling as well as the presence of clonic or tonic movements, stereotypies (e.g. excessive grooming, repetitive circling), difficult or prolonged parturition or bizarre behaviour (e.g. self-mutilation, walking backwards)

BODY WEIGHT: Yes
- Time schedule for examinations: weekly

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study):
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: Yes
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: No data

FOOD EFFICIENCY:
- Body weight gain in kg/food consumption in kg per unit time X 100 calculated as time-weighted averages from the consumption and body weight gain data: No

WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): Yes
- Time schedule for examinations: daily by visual appraisal

OPHTHALMOSCOPIC EXAMINATION: Yes
- Time schedule for examinations:
- Dose groups that were examined: all dose groups

HAEMATOLOGY: Yes
- Time schedule for collection of blood: at the end of the pre-mating period
- Anaesthetic used for blood collection: Yes (ether)
- Animals fasted: Yes, overnight
- How many animals: 5/sex/dose
- Parameters: haemoglobin, erythrocytes, leucocytes, differential blood count (absolute/relative), reticulocytes, platelets, haematocrit, mean corpuscular volume, mean corpuscular haemoglobin, mean corpuscular haemoglobin concentration, thromboplastin time, activated partial thromboplastin time

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: at the end of the pre-mating period
- Animals fasted: Yes, overnight
- How many animals: 5/sex/dose
- Parameters examined: albumin, globulin, albumin/globulin ratio, bile acids, bilirubin, cholesterol (total), creatinine, glucose, urea, total protein, calcium, chlorid, potassium, sodium, alanine aminotransferase (ALAT), alkaline phosphatase (AP), aspartate aminotransferase (ASAT)

URINALYSIS: No

NEUROBEHAVIOURAL EXAMINATION: Yes
- Time schedule for examinations: two hours after dosing shortly before scheduled sacrifice in 5 males per group (day 35); two hours after dosing during lactation, shortly before scheduled sacrifice in 5 females per group (day 39-56)
Screening of assessment were conducted as described on the following pages in five males and five females randomly selected from each group.
- Dose groups that were examined: all dose groups
- Battery of functions tested: sensory reactivity to stimuli of different types (e.g. auditory, visual and proprioceptive stimuli) (based on Gad), as well as the assessment of grip strength (Meyer) and motor activity

OTHER: Qualitative sperm analysis was performed.
(for further reproduction parameters see respective study entry (chapter 7.8.1))
Males were sacrificed on day 36, females were sacrifices on day 4 post-partum or shorty thereafter.

Sacrifice and pathology:

GROSS PATHOLOGY: Yes
- Organ weights: epididymes and testicles (all males); adrenal gland, brain, heart, kidney, liver, spleen, thymus (5/sex/dose)
- Fixation: epididymis, gross lesions, mammary gland, ovary, prostate, seminal vesicle, testicle, uterus (incl. cervix and oviducts), vagina (all animals); adrenal gland, bone marrow (os femoris), brain (cerebrum, cerebellum, brain stem), heart (left and right ventricle, septum), intestine, small (duodenum, jejunum, ileum, incl. Peyer's patches, Swiss roll method), intestine, large (colon, rectum), kidney and ureter, liver, lungs (with mainstem bronchi and bronchioles), preserved by inflation with fixative and then immersion, lymph node (1 cervical, 1 mesenteric), nerve (sciatic), oesophagus, spinal cord (3 sections), spleen, stomach, thyroid (incl. parathyroids), thymus, tissue masses or tumours (incl. regional lymph nodes), tongue (incl. base), trachea (incl. larynx), urinary bladder (5/sex/dose)
HISTOPATHOLOGY: Yes, all organs that were included for fixation (5/sex of control and high dose group)

Statistics:

STUDENT's t-test (p ≤ 0.01): all numerical functional tests
Multiple t-test based on DUNNETT (p≤0.05 and p ≤ 0.01): body weight, food consumption, haematology, clinical chemistry, absolute and relative organ weights
For all numerical values homogeneity of variances was tested by using the BARTLETT chi-square test. If the variances were homogeneous, the DUNNETT test (p ≤ 0.01) was used to compare the experimental groups with the control group. In case of heterogeneity of variances, the STUDENT's t-test was carried out; limit of significance was p ≤ 0.01.

Clinical signs:

no effects observed

Mortality:

no mortality observed

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

statistically significant decrease (-9.4%) in body weight in females during lactation at 1000 mg/kg bw/day

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

In the high dose group (females: gestation/lactation period) a statistically significant reduction in food consumption by 21.7% was noted.

Food efficiency:

not examined

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

no effects observed

Ophthalmological findings:

no effects observed

Haematological findings:

no effects observed

Clinical biochemistry findings:

no effects observed

Urinalysis findings:

not examined

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:

no effects observed

Histopathological findings: neoplastic:

not examined

Details on results:

CLINICAL SIGNS AND MORTALITY
Piloerection was seen in 1 female of the high dose group at on day 2-4 of lactation.

BODY WEIGHT AND WEIGHT GAIN
A reduction in body weight (-9.7%) in high dose females during lactation period.

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study)
Reduction in food intake (-21.7%) in high dose females during gestation/lactation.

WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study)
No effects on water consumption in any treatment group were observed.

OPHTHALMOSCOPIC EXAMINATION
No effects were observend in any treatment group.

HAEMATOLOGY
No effects on water consumption in any treatment group were observed.

CLINICAL CHEMISTRY
An decrease of ASAT activity was seen in high dose females on day 15. This effects was considered to be due to the relative low or high value observed for the control group and not to be test item related.

NEUROBEHAVIOUR
No effects observed.

ORGAN WEIGHTS
All effects observed (slight increase in absolute and relative liver weight in males) were still within the historical control data of the laboratory and thus not of toxicological relevance.

GROSS PATHOLOGY
No effects observed.

HISTOPATHOLOGY:
No effects observed.

OTHER FINDINGS
The qualitative sperm staging revealed no test item-related specific spermatogenic changes in the male animals from the high dose group (1000 mg/kg b.w./day).

Dose descriptor:

NOAEL

Effect level:

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

Based on:

test mat.

Sex:

female

Basis for effect level:

other: adverse effects on body weight and body weight gain and food consumption

Dose descriptor:

NOAEL

Effect level:

1 000 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male

Basis for effect level:

other: no adverse affects observed

Critical effects observed:

not specified

Individual body weights of females during the pre-mating and lactation period.

Control group	Day(s) relative to start
	1	8	15
11	196	209	212
12	217	228	243
13	210	220	213
14	217	234	244
15	3211	215	232
16	195	208	197
17	205	224	239
18	212	238	233
19	224	236	259
20	200	218	214
Mean	209	223	229
SD	9	10	19

1000 mg/kg bw	Day(s) relative to start
	1	8	15
71	200	210	225
72	210	231	234
73	206	234	247
74	210	222	235
75	194	219	218
76	218	243	223
77	214	230	227
78	222	225	210
79	198	200	201
80	203	223	231
Mean	207	224	225
SD	9	12	13

Control group	Day(s) relative to littering
	1	4
11	286	309
12	323	330
13	325	311
14	331	327
15	311	322
16	282	302
17	309	327
18	312	328
19	315	331
20	300	329
Mean	309	322
SD	16	10

1000 mg/kg bw	Day(s) relative to littering
	1	4
71	270	281
72	339	301
73	289	309
75	289	317
77	253	247
78	280	271
79	290	296
80	293	308
Mean	288	291
SD	24	23

Relative food consumption of females between day 1 and 4 of lactation

Control group		1000 mg/kg bw
11	122	71	115
12	91	72	96
13	105	73	63
14	107	75	110
15	106	77	30
16	121	78	63
17	114	79	98
18	100	80	110
19	101
20	126
Mean	109	Mean	86
SD	11	SD	30

Conclusions:

8-methylnonyl octadec-9-enoate should not be classified for the STOT RE in accordance with Regulation (EC) n. 1272/2008.
Furthermore, the study allows to suitably identify a NOAEL which can be used in the risk assessment.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

NOAEL

300 mg/kg bw/day

Study duration:

subacute

Species:

rat

System:

other: general toxicity

Organ:

not specified

other: no specific target organs were identified.