Amines, C11-C13 (linear and branched) alkyl

Endpoint summary

Description of key information

NOAEL, rat (oral), 3 month; systemic toxicity: 5 mg/kg bw/d (BASF 2003)

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:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes (incl. QA statement)

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River, Sulzfeld, Germany
- Age at study initiation: 35 ± 1 days; age at start of application: 42 ± 1 days
- Housing: single housing in type DK III stainless steel wire mesh cages, floor area about 800 cm² (Becker & Co., Castrop-Rauxel, FRG)
- Diet: ground Kliba maintenance diet rat/mouse/hamster, 343 meal (Provimi Kliba SA, Kaiseraugst, Switzerland) ad libitum
- Water: ad libitum
- Acclimation period: 7 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 - 24
- Humidity (%): 30 - 70
- Photoperiod (hrs dark / hrs light): 12 / 12 (6.00 pm - 6.00 am dark, 6.00 am - 6.00 pm light)

Route of administration:

oral: gavage

Vehicle:

other: doubly distilled water with 0.5% Carboxymethylcellulose and 0.05% Cremophor EL

Details on oral exposure:

PREPARATION OF DOSING SOLUTIONS:
The appropriate amount of test substance was weighed in, depending on the dose group, filled up to the desired volume with the vehicle, and mixed using a magnetic stirrer. The test substance was kept homogeneously by using a magnetic stirrer during the administration. These solutions were prepared in intervals of no longer than 7 days.

ADMINISTRATION VOLUME:
5 ml/kg bw

Analytical verification of doses or concentrations:

yes

Duration of treatment / exposure:

90 days

Frequency of treatment:

7 days per week

Remarks:

Doses / Concentrations:
0, 5, 15, 45 mg/kg bw/d
Basis:

No. of animals per sex per dose:

10

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: Dose levels were selected based on the results of a 4-week range finding study where TS was administered to 5 animals/sex/dose level at 25, 50, and 75 mg/kg bw/d. Toxic effects were noted at the intermediate and the high dose level.
- Post-exposure period: none

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: daily


DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: prior to the start of the administration period and weekly thereafter


BODY WEIGHT: Yes
- Time schedule for examinations: weekly


FOOD CONSUMPTION: Yes
- Time schedule for examinations: weekly


FOOD EFFICIENCY: Yes
- Food efficiency (group means) was calculated based upon individual values for body weight and food consumption


OPHTHALMOSCOPIC EXAMINATION: Yes
- Time schedule for examinations: in all animals before and in control and high dose animals at the end of the administration period


HAEMATOLOGY: Yes
- Time schedule for collection of blood: at the end of the study (study days 92 and 93)
- Anaesthetic used for blood collection: No
- Animals fasted: Yes, fasting period 16 - 20 hours
- How many animals: all animals
- Parameters examined: leukocytes, erythrocytes, hemoglobin, hematocrit, mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, platelets, differential blood count, prothrombin time (Hepato Quick's test)


CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: at the end of the study (study days 92 and 93)
- Animals fasted: Yes, fasting period 16 - 20 hours
- How many animals: all animals
- Parameters examined: alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, serum-γ-glutamyltransferase, sodium, potassium, chloride, inorganic phosphate, calcium, urea, creatinine, glucose, total bilirubin, total protein, albumin, globulins, triglycerides, cholesterol, magnesium


URINALYSIS: Yes
- Time schedule for collection of urine: towards the end of the study (study day 90, over night)
- Metabolism cages used for collection of urine: Yes
- Animals fasted: Yes
- Parameters examined: volume, color, turbidity, pH, protein, glucose, ketones, urobilinogen, bilirubin, blood, specific gravity, sediment


NEUROBEHAVIOURAL EXAMINATION: Yes
- Time schedule for examinations: a functional observational battery (FOB) and measurement of motor activity was carried out to the end of administration
- Dose groups that were examined: all dose groups
- Battery of functions tested: sensory activity, grip strength, motor activity


OTHER:
- effects on reproductive organs were examined in males (sperm parameters tested: motility, morphology, sperm head count in testis and in cauda epididymis) and in females (estrus cycle, examination of vaginal smears). For sperm analyses specimen were sampled in a randomized sequence from
fasted anesthetized males at necropsy. Vaginal smears for estrus cycle determination of all female animals were prepared and evaluated each day during the last 4 weeks of the study.

Sacrifice and pathology:

GROSS PATHOLOGY: Yes
HISTOPATHOLOGY: Yes

Statistics:

Statistical analysis of data included the use of the Kruskal-Wallis test and the Wilcoxon test for clinical pathology data; Fisher's exact test for urinalysis data; Wilcoxon test for sperm count data; and Kruskal-Wallis test and Wilcoxon test for statistics of pathology.

Details on results:

Substance-related findings were as follows:

Test group 1 (5 mg/kg bw/d):
No substance-related findings were seen.

Test group 2 (15 mg/kg bw/d):
Body weight (day 7, -4.7% and day 14, -7.3%) as well as body weight change (day 7, -14.8% and day 14, -17.2%) was statistically significantly reduced in males. Food efficiency was statistically significantly impaired in males on day 7. Reduced general condition in 1 male animal from day 80 until the end of the study. Slight salivation after treatment in 3 males and 7 females on several days from day 32 until day 90 after treatment. Respiration sounds in 1 male animal and 3 females on several days from day 46 until the end of administration period. Labored respiration in 1 male (day 78 till 90) and 1 female animal (day 70 till 93). Piloerection in 1 male animal from day 80 until the end of the study. Extended abdomen in 1 male animal in the last week of the study.

Test group 3 (45 mg/kg bw/d):
Premature death of 1 male (day 90) and 1 female animal (day 77). Several ulcer of the glandular stomach were observed during macroscopy. Body weight (day 70, -13.1%) as well as body weight change (day 7, -13.2%) was statistically significantly decreased in males. Food efficiency was statistically significantly reduced in males on day 7 and on day 42. Terminal body weight was significantly decreased in males. Reduced general condition in 2 males and the 1 female animal on several days from day 42 to day 90. Salivation after treatment in all animals on several days from day 8 until the end of the administration period. Respiration sounds in 8 males and 5 females from day 15 until the end of the study. Labored respiration in 2 males and 1 female animal on several days from day 56 until the end of the study. Piloerection in 3 males and in 2 females on several days from day 28 until the end of the study. Extended abdomen in 2 males and 1 female animal on several days from day 69 to day 90. Anogenital region smeared with urine in 2 males and 1 female animal on several days from day 69 to day 90. Hypothermia in 2 males and 1 female animal on several days from day 70 to day 90.

Further findings were as follows:
Food consumption: no substance related changes seen.
Functional observational battery: landing foot-splay test was significantly reduced in high dose males, probably due to the reduced general condition and therefore substance-related.
Open field observations (piloerection, gasping, hypothermia) are described above.
Sensimotor tests and reflexes were not affected by the treatment.
Motor activity measurements revealed isolated random increases and decreases in females of all treatment groups, therefore this was not regarded as a substance-related effect.
Ophthalmological examinations: no substance-related effects noted.
Estrous cycle: no substance-related effects.
Sperm analysis: no substance-related effects.
Clinical pathology (hematology, clinical chemistry, urinalysis): no substance-related effects.
Pathology: Findings referred to as "significant" in the following section implies that the differences have attained statistical significance (p<0.05) when compared to the control group.
i) Weight parameters:
Absolute terminal body weight: significantly decreased in high dose males, while a significant increase was noted in low dose females.
Testes: mean weight significantly decreased in the intermediate dose group.
Relative liver weight was significantly increased in high dose females.
ii) Gross lesions:
few lesions, without relation to treatment.
iii) Histopathology:
There were no findings in the microscopic examinations that were beyond the normal. In particular, there were no histopathological changes that could explain the decrease in terminal body weights, or the increase in female liver weights. No correlates were found which could explain the reduced terminal body weight in high dose males, nor were changes found in lung which would explain the clinical signs of the respiratory system, like gasping.

Dose descriptor:

NOAEL

Effect level:

5 mg/kg bw/day (nominal)

Sex:

male/female

Basis for effect level:

body weight and weight gain

clinical signs

Critical effects observed:

no

Conclusions:

Signs of toxicity were seen in animals of both sexes at 15 and 45 mg/kg body weight per day. No adverse effects were seen at 5 mg/kg body weight per day. Therefore, this was the NOAEL in this study for both sexes.
Reduced body weights and impaired food efficiency were noted at the intermediate and high dose levels in male rats. Piloerection and labored respiration were observed. Salivation was also seen, but this was attributed to bad taste of the test substance. Sperm quality parameters and estrous cycle were not affected at the high dose level, i.e. 45 mg/kg body weight per day.

Executive summary:

The study was conducted according to OECD Guideline 408 under GLP conditions.

Ten animals per sex and dose group received emulsions of TS in distilled water with 0.5% carboxmethylcellulose and 0.05% Cremophor EL by oral gavage. At the start of the application period the rats were 42 +/- 1 days old. Emulsions were kept homogenously by using a magnetic stirrer. Emulsions were prepared in intervals no longer than 7 days. Stability of TS was proven by analysis. The dose volume was 5 ml/kg. The animals were housed singly.

Examinations were conducted according to and exceeding the OECD 408 test guideline requirements, i.e. clinical, functional, ophthalmological, pathological and histopathological examinations were conducted as required. In addition, effects on reproductive organs were examined in males (sperm parameters tested: motility, morphology, sperm head count in testis and in cauda epididymis) and in females (estrus cycle, examination of vaginal smears).

Concerning Clinical Examinations food efficiency was reduced connected with an impairment in body weight as well as body weight change in male animals of the high and mid dose group . Moreover, abnormal clinical signs such as extended abdomen, reduced general condition and piloerection were seen in few animals. In addition, 2 males and 1 female animal of the high dose group showed anogenital region smeared with urine and hypothermia towards the end of the study. Most likely, this general reduced state of health caused the premature death of 1 male and 1 female animal of the high dose group . However, regarding the clinical signs of the respiratory system, such as respiration sounds and/or labored respiration, no histological changes were seen in the lung. The observed salivation in all animals of the high dose group as well as some males and females of the mid dose group, exclusively obtained after treatment, were rather caused by the physical property of the test compound (bad taste) than a toxicologically relevant finding. Clinical pathology examinations revealed no treatment-related changes . Regarding Pathology, a significant treatment-related weight change could only be noted for the terminal body weight in males of the high dose group. All other weight changes noted were regarded fortuitous . All gross lesions and all other microscopic findings were either single observations, or they were recorded at low or comparable incidence in control and treated males and/or females. Hence, they were all regarded to have been developed unrelated to treatment.

In conclusion, the test article caused the above mentioned signs of general toxicity. The no-observed-adverse-effect level (NOAEL) under the conditions of this study was therefore 5 mg/kg bw/day in both sexes.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

NOAEL

5 mg/kg bw/day

Study duration:

subchronic

Species:

rat

Additional information

The subchronic toxicity of TDA was tested under GLP conditions in a 90 day oral gavage study according to OECD TG 408 in male and female Wistar rats (BASF AG, 2004; Val. 2). Additionally, the effects on the male and female reproductive organs were examined. The tested dose levels of 5, 15, and 45 mg/kg bw/day were selected based on the results of a 4-week range finding study that was conducted with 5 rats per sex and dose at 25, 50, and 75 mg/kg bw/day.

 

No changes were seen in animals at 5 mg/kg bw/day. In the groups at 15 mg/kg bw/day, signs of toxicity included statistically significantly reduced body weights, body weight changes, and reduced food efficiency in males during the first 14 days of treatment, and respiration sounds and labored respiration in 4/10 male and in 4/10 females starting from day 32 until the end of the study. Similar findings, but in higher frequency and severity were seen in the groups at 45 mg/kg bw/day. This dose also led to increased relative liver weights in females and was lethal for one male and one female animal. Sensimotor tests and reflexes were not affected by the treatment in any group except for the landing foot-splay test in high-dose males, probably due to the generally poor condition of these animals. Ophthalmological examinations revealed no substance-related effects. Clinical pathology, i.e. hematology, clinical chemistry, and urinalysis, showed no treatment-related effects as compared to the control animals. Histopathological examinations revealed no changes beyond the normal.

Reduced body weight (gain) might be due to the bad taste and irritation of the stomach. Food consumption was not statistically reduced, but it was below control levels at all time points in the mid and high dose group. Irritation might also have contributed to the bad general state. In the two high dose animals that died, ulcers were observed in the stomach. In all other animals, buffer capacity was sufficient to prevent local damage. Additionally, based on the branched structure, metabolism is expected to be difficult, which might explain the increased liver weight and potentially higher energy demand.

 

Overall, signs of toxicity were seen in groups at 15 and 45 mg/kg bw/day. The NOAEL for systemic toxicity was 5 mg/kg bw/day. Sperm quality parameters and the estrous cycle were not affected at 45 mg/kg bw/day.

Justification for classification or non-classification

No need for classification according to the EU Classification, Labelling and Packaging of Substances and Mixtures (CLP) Regulation (EC) No. 1272/2008.