Imidazolium compounds, 2-C17-unsatd.-alkyl-1-(2-C18-unsatd. amidoethyl)-4,5-dihydro-N-methyl, Me sulfates

Endpoint summary

Description of key information

In subchronic repeat dose studies performed in rats by oral feed and in rabbits, exposed dermally, only mild effects have been observed.

Key value for chemical safety assessment

Repeated dose toxicity: via oral route - systemic effects

Link to relevant study records

Reference

Endpoint:

sub-chronic toxicity: oral

Type of information:

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

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 408 (Repeated Dose 90-Day Oral Toxicity Study in Rodents)

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
- Albino rats CD-Crl: (CD (SD) BR
- Age at study initiation: 6 weeks old
- Weight at study initiation: males 218 - 272 g and females 154 - 190 g
- Fasting period before study: no data
- Housing: individually in stainless steel screen bottom cages
- Diet (e.g. ad libitum): basal diet was ground Purina Certified Rodent Chow 95002
- Water (e.g. ad libitum): ad libitum - partially demineralized by reverse osmosis and sterilized by ultraviolet light
- Acclimation period: 26 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 72 °F +/- 3 °
- Humidity (%): 50 % +/- 2 %
- Air changes (per hr): 10 changes per hour
- Photoperiod (hrs dark / hrs light): 12 hour light/dark cycle

Route of administration:

oral: feed

Vehicle:

other: Purina Certified Rodent Chow 95002

Details on oral exposure:

PREPARATION OF DOSING SOLUTIONS:

DIET PREPARATION
- Rate of preparation of diet (frequency): on a basis of 90 % active ingredient all diets were prepared fresh weekly.
- Mixing appropriate amounts with (Type of food): Purina Certified Rodent Chow 95002
- Storage temperature of food: refrigerated in covered polyethylene containers

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

A sample of each diet preparation will be analyzed each week for test compound concentration. If the mean concentration of test compound varied from the theoretical value by more than +/- 20 % the test diets will be prepared again.
The test substance is extracted with methanol/chloroform and passed through a cation exchange column. The analyt is eluted with 5 % HCl in methanol from the column and determined by analyzing by HPLC using a PAC-type column and conductivity detector.

Duration of treatment / exposure:

13 weeks

Frequency of treatment:

The test diet was provided ad libitum, individual food consumption was recorded in g/week

Dose / conc.:

0 mg/kg bw/day (nominal)

Dose / conc.:

10 mg/kg bw/day (nominal)

Dose / conc.:

100 mg/kg bw/day (nominal)

Dose / conc.:

1 000 mg/kg bw/day (nominal)

No. of animals per sex per dose:

20 animals per sex per dose

Control animals:

yes, plain diet

other: no positive control, but not necessarily needed according to OECD 408

Details on study design:

- Dose selection rationale: Not given in study report
- Rationale for animal assignment (if not random): random
- Post-exposure recovery period in satellite groups: no satellite groups for recovery
- Section schedule rationale (if not random): random

Positive control:

no positive control

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: twice daily
- All animals were observed at least twice daily for moribundity, death and obvious indications of a toxic effect. At least once each week each animal was removed from its cage and carefully examined for abnormalities and clinical signs of toxic or pharmacologic effects.

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: at least once a week

BODY WEIGHT: Yes
- Time schedule for examinations: at initiation and weekly through termination of study

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 food consumption and body weight gain data: Yes

FOOD EFFICIENCY:
- Food efficiency was calculated as percentage value.

WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): No

OPHTHALMOSCOPIC EXAMINATION: No

Haematology: Yes
- Time schedule for collection of blood: a blood sample was collected from the vena cava during exsanguination and placed into collection tubes.
- Anaesthetic used for blood collection: no
- Animals fasted: no data
- How many animals: all
- Parameters examined: total erythrocyte count,nucleated erythrocyte count, hemoglobin, hematocrit, mean corpuscular volume (MCV),
mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCCH), total leucocytes,
differential leucocyte count (neutrophil, lymphocyte, eosinophil, monocyte, basophil)
immature neutrophils, mature neutrophils

CLINICAL CHEMISTRY: Yes
- Parameters examined in serum:
glucose, blood urea nitrogen, total protein, total bilirubin, serum glutamic-oxaloacetic transaminase SGOT (also known as serum aspartate aminotransferase), serum glutamic-pyruvic transaminase SGPT (also known as serum alanine aminotransferase)
alkaline phosphatase

URINALYSIS: No

NEUROBEHAVIOURAL EXAMINATION: No

Sacrifice and pathology:

All animals were killed within 3 days after completion of the 91-day dosing period. The animals were weighed on the day of necropsy, anesthetized with ether and killed by exsanguination.

GROSS PATHOLOGY: Yes
All animals were examined macroscopically. Relative and absolute organ weights of liver and kidneys were recorded.

HISTOPATHOLOGY: Yes
All tissues were identified only by a random number. The following tissues and organs were examined and preserved in enough 10 % phosphate-buffered formalin to ensure adequate fixation.

Bone marrow, lung, heart, aorta (thoracic), tongue, trachea, esophagus, thyroid, submandibular lymph nodes, lymph nodes (ileocecocolic and
anterior mesenteric), stomach (fundic, cardiac pyloric regions), liver, duodenum, jejunum, ileum, cecum, colon urinary bladder, kidneys (left kidney
longitudinally, right kidney transversely to show cortex medulla and pelvis)
Reproductive organs males: prostate and seminal vesicle, testis with tunic nicked and epididymis attached.
Reproductive organs females: ovaries cross section of both uterine horns cross section of vagina.
Adrenals, thymus, gluteal plus biceps muscle, spleen, pancreas, distal femur (with marrow), brain (incl. cerebrum, mid-brain, cerebellum and stem),
lumbar spinal cord, sciatic nerve, submandibular salivary glands, pituitary gland, eyes (fixed in Zenker´s solution)

Lesions were collected.

Statistics:

The body weights, body weight gains, organ weights, organ weight to terminal body weight ratio, clinical pathology data, bone marrow smear values, and food consumption and efficiency values were statistically analyzed by sex. The statistical evaluation was by analysis of variance techniques. When Bartlett´s test of homogeneity of variance was not significant, treated groups were compared with the control group using the least significant difference (LSD) criterion. When Bartlett´s test was significant, comparisons with this control group were made by t-test and Wilcoxon´s rank sum test. Regression analysis was performed where significant differences between control and treated groups occurred. This analysis included tests for linear regression and lack of fit. All statistical tests where conducted at a 5 % two-sided risk level. Statistical comparisons were not made between sexes or among treated groups within a sex.

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):

effects observed, treatment-related

Description (incidence and severity):

Values for females treated with 10 mg/kg bw/d were significantly higher than those of controls during weeks 1-6 and 12. Food consumption values for females treated with 100 mg/kg bw/day were significantly higher during weeks 1-8 and 11-12.

Food efficiency:

effects observed, treatment-related

Description (incidence and severity):

Significantly lower mean values were detected during week 1 for male rats treated with 100 mg/kg bw/day and during weeks 1 and 2 for males treated with 1000 mg/kg bw/day.

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

not specified

Ophthalmological findings:

not specified

Haematological findings:

no effects observed

Clinical biochemistry findings:

effects observed, treatment-related

Description (incidence and severity):

Significantly higher mean values for total protein and SGOT in males treated with 10 mg/kg bw/day. A significantly lower value for total protein and significantly higher values for SGOT and SGPT levels were detected in the male 1000 mg/kg bw/day.

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Description (incidence and severity):

Significant lower mean absolute and relative liver weights occurred in males treated with 1000 mg/kg bw/day.

Gross pathological findings:

no effects observed

Histopathological findings: non-neoplastic:

no effects observed

Histopathological findings: neoplastic:

no effects observed

Details on results:

CLINICAL SIGNS AND MORTALITY
There were no treatment related clinical signs observed, no animals died or were sacrificed during the study.

BODY WEIGHT AND WEIGHT GAIN
No significant differences in mean body weights or body weight gains were detected.

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study)
No significant differences were detected for any treated male group when compared with the male control group. Food consumption values for
females treated with 10 mg/kg bw/d were significantly higher than those of controls during weeks 1-6 and 12. Food consumption values for
females treated with 100 mg/kg bw/day were significantly higher during weeks 1-8 and 11-12.

FOOD EFFICIENCY
No significant differences for food efficiencies were detected in female dose groups and the male 10 mg/kg bw/day dose group. Significantly lower mean values were detected during week 1 for male rats treated with 100 mg/kg bw/day and during weeks 1 and 2 for males treated with 1000 mg/kg bw/day.

WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study)
No data

OPHTHALMOSCOPIC EXAMINATION
No data

HAEMATOLOGY
There were no significant differences between treated groups and controls.

CLINICAL CHEMISTRY
There were no significant differences detected for males treated with 100 mg/kg bw/day or females of all dose groups. Significantly higher mean values for total protein and SGOT were detected in males treated with 10 mg/kg bw/day. A significantly lower value for total protein and significantly higher values for SGOT and SGPT levels were detected in the male 1000 mg/kg bw/day group.

URINALYSIS
No data

NEUROBEHAVIOUR
No data

ORGAN WEIGHTS
No significant differences were detected in absolute or relative organ weights for males treated with 10 or 100 mg/kg bw/day and females of all dose groups.
Significant lower mean absolute and relative liver weights occurred in males treated with 1000 mg/kg bw/day.


GROSS PATHOLOGY:
All findings were considered incidential and not treatment related.

HISTOPATHOLOGY: NON-NEOPLASTIC
All observations were considered incidential and not treatment related. Liver lesions in 1000 mg/kg bw/day males, which would correlate with the differences in chemistries and organ weights were not found at the light microscopic level.

HISTOPATHOLOGY: NEOPLASTIC (if applicable)
No neoplastic lesions are described in the study report.

Dose descriptor:

NOEL

Effect level:

100 mg/kg bw/day (nominal)

Based on:

act. ingr.

Sex:

male/female

Basis for effect level:

other: Reduced liver weight and minor serum enzymes changes in males at 1000 mg/kg bw/day

Key result

Dose descriptor:

NOAEL

Effect level:

300 mg/kg bw/day (nominal)

Based on:

other: act. ingr. (recalculated)

Sex:

male/female

Basis for effect level:

other: see 'Remark'

Critical effects observed:

not specified

Conclusions:

Treatment related effects were limited to lower absolute and relative liver weight in the male high dose group with concomitant lower total plasma protein and higher SGPT and SGOT values for this treatment group.

Executive summary:

In a subchronic toxicity study comparable to OECD guideline 408 (1981), the partially unsaturated IQAC, DMS quaternised (tallow fatty acid based; CAS-no. 68122-86-1) was administered to 20 Sprague-Dawley rats/sex/dose by oral feed at dose levels of 0, 10, 100 and 1000 mg/kg bw/day (active ingredient). No satellite group was included to assess the reversibility of any potentially adverse effects.

The active ingredient in diet was analysed in all preparations and actual test material consumption closely resembled theoretical values (males 94 to 95 % and females 86 to 93 %).

There were no treatment related clinical signs observed, no animal died or was sacrificed during the study. Body weights and weight gains were in a normal range. No significant differences in food consumption were detected for any treated male group. Food consumption in the 10 and 100 mg/kg bw/day female groups were significantly increased during some weeks during the study. There were no consistent differences in food efficiencies.

Decreased values of absolute and relative liver weights in the male high dose group were probably treatment related and were accompanied by lower total serum protein and higher SGPT and SGOT concentrations for this treatment level. Correlating microscopic lesions were not detected. A dose dependency for these effects was not found.

No other treatment related effects on organ weights, hematological or clinical chemistry parameters were observed. All macroscopic observations and microscopic lesions were considered incidental and not treatment related. Microscopic examinations revealed no treatment related changes.

The histological examination of the reproductive organs (testes, epididymis, prostate, seminal vesicle, ovary, uterus and vagina) did not reveal any treatment related abnormalities.

A pretest health examination, conducted on 10 animals/sex, showed five animals with positive background endoparasites or viral titers.

The NOEL was 100 mg/kg bw/day.

The study suffers, however, from the excessively wide dose spacing, which would not be the standard for present day testing protocols. Considering the overall toxicological profile, there is no evidence for a potential serious health risk for humans upon ingestion of members of this chemical structure family. As a consequence, the reported NOEL has been recalculated for the derivation of an acceptable DNEL longterm oral, departing from the highest dose as the LOAEL to arrive at a realistic basis for DNEL derivations, resulting in the recalculated NOAEL of 300 mg/kg bw/day.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

NOAEL

300 mg/kg bw/day

Study duration:

subchronic

Species:

rat

Quality of whole database:

The key study is conducted according to modern regulatory standards and is adequately reported.

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

In subchronic repeat dose toxicity studies performed with the read-across substance partially unsaturated IQAC, DMS quaternised (tallow fatty acids) (CAS-no. 68122-86-1) in rats by oral feed and in rabbits, exposed dermally, only mild effects have been observed.

In the 91-day oral study in male rats, absolute and relative liver weight decrease, a slight decrease in serum albumin concentration and higher SGPT and SGOT concentrations were observed in highest dose group (1000 mg/kg bw/day). Correlating histopathological lesions were not detected. A dose dependency for these effects was not found.

For the partially unsaturated IQAC, DMS quaternised (tallow fatty acid based; CAS-no. 68122-86-1) the NOELs reported for short term repeat dose and subchronic oral application are disparate, as the higher NOEL has been determined in the longer term, subchronic, oral feed study.

Furthermore, minor effects on liver enzyme serum levels in both genders and on serum bilirubin levels in female animals at 400 mg/kg bw/day, the highest dose tested, were reported in the 28 days study, while in the subchronic study decreased relative and absolute liver weights, a slight decrease in protein concentration and minor increases in serum enzyme levels (SGOT and SGPT) were reported for the male high dose group (1000 mg/kg bw/day), only. Findings were without histopathological correlate. These observations are in accordance with the mild and obviously not dose related and potentially reversible effects observed, the practically absent acute oral toxicity for this substance class and its low bioavailability upon ingestion as determined in the toxicokinetic studies (cf. 7.1 Summary and discussion of toxicokinetics).

The repeated dose toxicity studies, also reported by NICNAS for the oral route, are significant in showing that in consequence there is no evidence for a potential serious health risk for humans upon ingestion of members of this structure family. The studies suffer, however, from the wide dose spacing, which would not be the standard for present day testing protocols. As a consequence, the reported NOELs have been recalculated for the derivation of an acceptable DNEL longterm oral, departing from the highest dose as the LOAEL to arrive at a realistic basis for DNEL derivations.

Furthermore, no effects on reproductive organs have been reported in the oral sub-chronic study up to the highest dose of 1000 mg/kg bw/day.

In rabbits, up to the highest dose of 27 mg/kg bw/day, only irritating effects were reported without any associated systemic toxicity. Judged on the low dermal uptake rate observed in toxicokineticstudies this is in accordance with the low toxicity of this substance group upon acute exposure.

 

On the basis of the sub-chronic study read-across a DNEL longterm, oral of 7.5 mg/kg bw/d has been calculated for the general population. Considering a body weight of 60 kg, the human exposure to oleic-acid based IQAC, DMS quaternised would have to amount to a daily oral intake of 0.45 g per day before reaching a level of toxicological concern.

In consideration of the use of this substance class in industrial cleaning products an oral exposure of the general population appears highly unlikely. Dermal uptake by inadvertant skin contact is limited by the strong irritative property of this substance class, establishing a significant avoidance barrier and is further regarded as insignificant due to the proven very low cutaneous uptake shown in toxicokinetic studies.

Inhalation uptake of vapours is regarded as insignificant due to the very low vapour pressure of the substance class.

Aerosols which may be generated in car wash booth with a 1: 20,000 fold dilution of the test substance in the final impregnation step in the standard settings of a car wash booth of 50 m³ airspace will lead to an aerosol concentration of approx. 1.14 mg/m³ (calculated for the measured 40 % fraction of inhalable aerosol with a droplet size < 50 µm), yielding a RCR longterm, systemic of approx. 0.09 (DNEL longterm inhalation, systemic, general public: 13 mg/m³.) The margin of safety for this exposure scenario is sufficiently high to make additional animal tests obsolete. With respect to irritation, it has been shown that eye irritation effects have a threshold level at approximately 5 % of the active ingredient. A similar threshold can be expected for other mucous membranes as the respiratory tract tissue. The substance concentration in spray applications is 0.0038 %, three orders of magnitude below the irritation threshold. Therefore, also for irritative effects on the respiratory tract, a sufficient margin of safety is expected for this application. Further, from the absence of a skin sensitisation potential for this substance class, respiratory sensitisation is not expected. 

For workers with a risk to aerosol inhalation with the undiluted test substance, personal protective equipment will be in place to avoid respiratory exposure.

Justification for read-across:

The structural similarities between the source and the target substances are the basis for the read-across hypothesis. Adequate, reliable and available scientific information indicates that the source and target substances have similar physicochemical properties and toxicity profiles and thus support the read-across hypothesis.

Acute oral toxicity for source substance (partially unsaturated IQAC, DMS quaternised) and target substance (oleic-acid based IQAC, DMS quaternised) is comparably low. Also the skin irritation and sensitizing potential is similar. There is no potential for point mutations and chromosome aberrations indicated by data from both substances.

Therefore, based on the considerations above, it can be concluded that the results for endpoints, mediated by systemically available, are likely to predict the properties of the target substance.

Read-across is considered as adequate to fulfil the information requirements Annex IX, 8.7.2 (oral sub-chronic repeated dose toxicity) and the results sub-chronic toxicity study conducted in the rat with the source substance are considered a reliable source to cover the respective endpoints. Beyond, the dose descriptors obtained from these studies performed on the source substance are considered as an appropriate starting point for deriving the respective DNELs.

 

A more detailed justification for read-across is outlined in a separate document:

“Justification for read-across - toxicological information”, is attached to the endpoint summary acute toxicity and provided in chapter 13 of Technical dossier.

 

 

 

 

 

 

 

 

Justification for selection of repeated dose toxicity via oral route - systemic effects endpoint:
Data from a reliable study (RL2), taking into account exposure duration were selected for this endpoint.

Justification for classification or non-classification

The existing read-across data do not indicate a classification for repeated dose toxicity for the oleic-acid based IQAC, DMS quaternised according to Directive 67/548/EEC as well as GHS Regulation EC No 1272/2008 and therefore labelling is not necessary.