Registration Dossier

Administrative data

Description of key information

The repeated dose toxicity of the carboxylic acid component of the registered substance (tosyl salt) to rats was determined in accordance with the OECD Guideline for Testing of Chemicals 422. The NOEL and NOAEL for the test substance is defined as 400 mg/kg bw/day. The LOEL for the test substance is defined as 1600 mg/kg bw/day. No studies were conducted to determine the repeated dose toxicity via inhalation or dermal exposure as, owing to the physical properties and usage of the substance, it was considered unlikely that inhalation or dermal exposure would occur, therefore making it unjustifiable to perform further animal testing.

Key value for chemical safety assessment

Repeated dose toxicity: via oral route - systemic effects

Link to relevant study records
Reference
Endpoint:
short-term repeated dose toxicity: oral
Remarks:
combined repeated dose and reproduction / developmental screening
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Study period:
2012-2013
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Study was conducted by a GLP accredited laboratory using OECD Testing Guideline 422. The study was conducted on 6-[(p-Tosyl)amino]hexanoic acid, which is the carboxylic acid component of the registered substance i.e. tosyl salt.
Reason / purpose for cross-reference:
reference to other study
Qualifier:
according to guideline
Guideline:
OECD Guideline 422 (Combined Repeated Dose Toxicity Study with the Reproduction / Developmental Toxicity Screening Test)
Deviations:
no
Principles of method if other than guideline:
Daily administration by stomach tube for 54 days
GLP compliance:
yes
Limit test:
no
Species:
rat
Strain:
Wistar
Sex:
male
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: Charles River, Germany, D-97633 Sulzfeld
- Age at purchase: 11 weeks
- weight rage at time of grouping: males, 175-200 g
- Fasting period before study: no
- Housing: 2 per cage,
- Cages: TECHNIPLAST filter top cages type 2145 F with an G-Temp (PSU) durable filter cover, 480x265x210 mm³, floor area 940 cm²,
- Source: Techniplast Company, Italy
- Diet: ad libitum, M3, BONAGRO Ltd., reg. CZ 10174, Czech Republic
- Water: ad libitum, tap water
- Acclimation period: 9 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 +/- 2
- Humidity (%): 40 - 70
- Photoperiod (hrs dark / hrs light): 12/12
Route of administration:
oral: gavage
Vehicle:
water
Details on oral exposure:
VEHICLE: Suspension in water

- Amount of vehicle: 10 ml/kg
- single daily adminisration at similar times each day
Analytical verification of doses or concentrations:
no
Duration of treatment / exposure:
54 administrations, (2 weeks before mating, 2 weeks during mating and 26 days after mating)
dissection ca. 24 hours after the last administration
Frequency of treatment:
daily
Remarks:
Doses / Concentrations:
0, 100, 400, 1600 mg/kg body weight (mg/kg bw)
Basis:
actual ingested
No. of animals per sex per dose:
12 males, satelite groups (control and highest dosage): 5 males each
Control animals:
yes
Details on study design:
- Control groups: drinking water
- Dose selection rationale: Results of an acute toxicity study with oral administration to male and female rats
- Result: no effects up to and including 2000 mg/kg bw.
- Rationale for animal assignment: randomly grouped
- Section schedule rationale: all animals were sacrificed
Positive control:
no
Observations and examinations performed and frequency:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: daily

BODY WEIGHT: Yes
- Time schedule for examinations: on administration days 1, 8, 15, 22, 29, 36, 42, 50 and on day of autopsy

FOOD CONSUMPTION : 2 weeks before mating, after 2 week mating period and weekly until the end of the study

HAEMATOLOGY: Yes
- Time schedule for collection of blood: day 14 (before mating) and prior to autopsy from the satelite groups and from the control and highest dose group.

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood:day 14 (before mating) and prior to autopsy from the satelite groups and from the control and high dose group.

URINALYSIS: No
Sacrifice and pathology:
GROSS PATHOLOGY: Yes
- Organ weights: brain, heart, thymus, spleen, liver, testis, epididymis, kidney, adrenal gland

HISTOPATHOLOGY: Yes: high dose and control animals
- Organ: medulla oblongata, brain, heart, pancreas + lymphnode, spleen, liver, lung, small intestine, stomach, kidneys, adrenal gland, testes, prostrate, urinary bladder, bone + bone marrow, thymus, trachea, white + brown fat, muscle, pituitary gland
Statistics:
Statistical evaluation was operated using the software SPPS version 16.0. Group data were represented by mean, standard deviation and median. Statistical analysis in case of data measured once during the study (organ weight, haematology, clinical chemistry) : Mann-Whitney U test for pairwise comparison between control and individual experimental groups on significance level alpha = 0.05.
Statistical analysis in case of repeated data measurement (body weight, food intake): Repeated measures ANOVA (procedure General Linear Model (GLM) for Repeated Measures in SPSS statistical software).
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 after dosages of 1600 mg/kg bw./day
Food consumption and compound intake (if feeding study):
no effects observed
Food efficiency:
not examined
Water consumption and compound intake (if drinking water study):
not examined
Ophthalmological findings:
not examined
Haematological findings:
no effects observed
Clinical biochemistry findings:
no effects observed
Urinalysis findings:
not examined
Behaviour (functional findings):
not examined
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:
no effects observed
Details on results:
CLINICAL SIGNS:
- 100, 400 and 1600 mg/kg bw/day:
no differences to the control animals observable

MORTALITY: no

BODY WEIGHT GAIN: 1600 mg/kg bw: reduced

FOOD CONSUMPTION: no statistical differences

HAEMATOLOGY/ CLINICAL CHEMISTRY:
Haematology and clinical chemistry reveales some statistically significant differences, but these were neither related to dosage not confirmed by the findings in other groups, for example by the results of the satelite groups, or the effects are of biological low relevance i.e..

URINALYSIS: not examined

NEUROBEHAVIOUR: not examined

ORGAN WEIGHTS: no statistical differences

GROSS PATHOLOGY: no dosage related effects

HISTOPATHOLOGY: NON-NEOPLASTIC: no statistical differences

HISTOPATHOLOGY: NEOPLASTIC: no statistical differences

HISTORICAL CONTROL DATA: not given

Dose descriptor:
NOEL
Effect level:
400 mg/kg bw/day (actual dose received)
Based on:
test mat.
Sex:
male
Dose descriptor:
NOAEL
Effect level:
400 mg/kg bw/day (actual dose received)
Based on:
test mat.
Sex:
male
Dose descriptor:
LOEL
Effect level:
1 600 mg/kg bw/day (actual dose received)
Based on:
test mat.
Sex:
male
Basis for effect level:
other: decrease in body weight (not exeeding 10%)
Critical effects observed:
not specified
Conclusions:
Daily dosages of 0, 100, 400, and 1600 mg/kg bw of the test substance were administered by stomach tube to groups of 12 male rats for 54 days. Satellite animals in a control and the highest dose group (1600mg/kg bw) with 5 individual each were also included.The test-article was formulated in drinking water and administered in 10 ml/kg bw..
At dosages of 100 and 400 mg/kg bw. the animals showed no differences to the control animals (NOAEL).
1600 mg ASC plus/kg bw. , considered as the LOEC, may have induced an influence on the body weight gain of the males (and the survival of pups until day 4 after birth).
NOAEL: 400 mg/kg bw.
Executive summary:

The repeated dose toxicity of the test substance to rats was determined in accordance with the OECD Guideline for Testing of Chemicals 422. Doses of 0, 100, 400, and 1600 mg/kg bw/day of the test substance were administered by stomach tube to groups of 12 male rats for 54 days. The test-article was formulated in drinking water and administered in 10 ml/kg bw. At dosages of 100 and 400 mg/kg bw/day the animals showed no differences to the control animals (NOEL). All examined organs and tissues showed a normal histological structure. 1600 mg/kg bw/day may have induced an influence on the body weight gain of the males (and the survival of pups until day 4 after birth). The NOEL and NOAEL for the test substance is defined as 400 mg/kg bw/day. The LOEL for the test substance is defined as 1600 mg/kg bw/day. The test substance was the carboxylic acid component of the tosyl salt. Read-across between the tosyl salt carboxylic acid (6-[(p-Tosyl)amino]hexanoic acid) and the registered substance is considered justified as the registered substance is manufactured directly from 6-[(p-Tosyl)amino]hexanoic acid by simple neutralisation with triethanolamine (TEA). Other than ionization of the carboxylic acid group, the 6-[(p-Tosyl)amino]hexanoic acid remains chemically unchanged upon salt formation. In water, the acid and amine components of 6-[(p-Tosyl)amino]hexanoic acid, compound with 2,2’,2’’-nitrilotriethanol (1:1) dissociate completely and behave essentially as independent substances. Since TEA can be considered non-hazardous, it is the acid component of the salt that will have a more significant impact on the outcome of any (eco)toxicological or environmental tests. The pKa of the carboxylic acid group in 6-[(p-Tosyl)amino]hexanoic acid (pKa = 4.90) is the same in the free acid as it is in the TEA salt. As a result, 6-[(p-Tosyl)amino]hexanoic acid will respond to changes of pH in the same way whether it is in the salt form or as the parent carboxylic acid and hence it’s bioavailability will be the same.

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed
Dose descriptor:
NOAEL
400 mg/kg bw/day
Study duration:
subacute
Species:
rat

Repeated dose toxicity: inhalation - systemic effects

Endpoint conclusion
Endpoint conclusion:
no study available

Repeated dose toxicity: inhalation - local effects

Endpoint conclusion
Endpoint conclusion:
no study available

Repeated dose toxicity: dermal - systemic effects

Endpoint conclusion
Endpoint conclusion:
no study available

Repeated dose toxicity: dermal - local effects

Endpoint conclusion
Endpoint conclusion:
no study available

Additional information

The repeated dose toxicity of the carboxylic acid component of the registered substance (tosyl salt) to rats was determined in accordance with the OECD Guideline for Testing of Chemicals 422. Doses of 0, 100, 400, and 1600 mg/kg bw/day of the test substance were administered by stomach tube to groups of 12 male rats for 54 days. The test-article was formulated in drinking water and administered in 10 ml/kg bw. At dosages of 100 and 400 mg/kg bw/day the animals showed no differences to the control animals (NOEL). All examined organs and tissues showed a normal histological structure. 1600 mg/kg bw/day may have induced an influence on the body weight gain of the males (and the survival of pups until day 4 after birth). The NOEL and NOAEL for the test substance is defined as 400 mg/kg bw/day. The LOEL for the test substance is defined as 1600 mg/kg bw/day.

Read-across between the tosyl salt carboxylic acid (6-[(p-Tosyl)amino]hexanoic acid) and the registered substance is considered justified as the registered substance is manufactured directly from 6-[(p-Tosyl)amino]hexanoic acid by simple neutralisation with triethanolamine (TEA). Other than ionization of the carboxylic acid group, the 6-[(p-Tosyl)amino]hexanoic acid remains chemically unchanged upon salt formation. In water, the acid and amine components of 6-[(p-Tosyl)amino]hexanoic acid, compound with 2,2’,2’’-nitrilotriethanol (1:1) dissociate completely and behave essentially as independent substances. Since TEA can be considered non-hazardous, it is the acid component of the salt that will have a more significant impact on the outcome of any (eco)toxicological or environmental tests. The pKa of the carboxylic acid group in 6-[(p-Tosyl)amino]hexanoic acid (pKa = 4.90) is the same in the free acid as it is in the TEA salt. As a result, 6-[(p-Tosyl)amino]hexanoic acid will respond to changes of pH in the same way whether it is in the salt form or as the parent carboxylic acid and hence it’s bioavailability will be the same. In a chronic two year study on rats using the triethanolamine component of the tosyl salt, the test substance was found to be toxic to the kidneys at a concentration of 1000 mg/kg bw/day. Kidney weights were greatly increased, and major histopathological changes were observed in the kidneys, suggesting a dose-related acceleration of chronic nephropathy, which is common in ageing Fischer 344 rats. A variety of tumors developed in all groups, including the control group, and all tumors observed were histologically similar to spontaneous tumors in this strain of rats. No statistically significant increase of the incidence of any tumor was observed in the treated groups of both sexes by the chi-square test. In this study, however, there was an increase in nephrotoxicity, which appeared to have an adverse effect on the life expectancy of the treated animals, especially of females. These tumors, however, have been observed spontaneously in this strain of rats, and their incidences in the control group of the present study were lower than those of our historical controls. These results may indicate that a positive trend in the occurrence of these tumors is not attributable to triethanolamine administration. The toxicity of the test substance to the rats would appear to be related to an acceleration of normal ageing and tumour formation in this species of rat. In conclusion, the registered substance (tosyl salt) is not considered toxic via repeated oral exposure and does not need to be classified as such according to EU CLP criteria.


Justification for selection of repeated dose toxicity via oral route - systemic effects endpoint:
Study was conducted by a GLP accredited laboratory using OECD Testing Guideline 422. The study was conducted on 6-[(p-Tosyl)amino]hexanoic acid, which is the carboxylic acid component of the registered substance i.e. tosyl salt. The NOEL and NOAEL for the test substance is defined as 400 mg/kg bw/day. The LOEL for the test substance is defined as 1600 mg/kg bw/day.

Justification for selection of repeated dose toxicity inhalation - systemic effects endpoint:
This study is not deemed necessary as the substance does not solidify readily and when it does it is a waxy solid and does not form inhalable particles. The substance has also been estimated to have a very low vapour pressure via modelling using the EPIsuite modelling program. The substance is provided to customers only in formulated products and is not isolated. Therefore, inhalation is not considered to be a significant route of exposure to the registered substance, in accordance with REACH Annex XI, Column 2. The results of a repeated dose oral toxicity study will be provided (section 7.5.1). It is therefore considered unjustified to perform further animal testing.

Justification for selection of repeated dose toxicity inhalation - local effects endpoint:
This study is not deemed necessary as the substance does not solidify readily and when it does it is a waxy solid and does not form inhalable particles. The substance has also been estimated to have a very low vapour pressure via modelling using the EPIsuite modelling program. The substance is provided to customers only in formulated products and is not isolated. Therefore, inhalation is not considered to be a significant route of exposure to the registered substance, in accordance with REACH Annex XI, Column 2. The results of a repeated dose oral toxicity study will be provided (section 7.5.1). It is therefore considered unjustified to perform further animal testing.

Justification for selection of repeated dose toxicity dermal - systemic effects endpoint:
This study is not considered necessary as repeated dose toxicity via the oral route will be provided (section 7.5.1), in accordance with REACH Annex IX, Column 2. Dermal exposure to the substance is not considered likely as the substance is supplied in an aqueous formulation without isolation of the substance. In addition, the substance is directly added to the formulated product without isolation so skin contact is not considered a major exposure route to this substance. Therefore, further animal testing is considered to be unjustified.

Justification for selection of repeated dose toxicity dermal - local effects endpoint:
This study is not considered necessary as repeated dose toxicity via the oral route will be provided (section 7.5.1), in accordance with REACH Annex IX, Column 2. Dermal exposure to the substance is not considered likely as the substance is supplied in an aqueous formulation without isolation of the substance. In addition, the substance is directly added to the formulated product without isolation so skin contact is not considered a major exposure route to this substance. Therefore, further animal testing is considered to be unjustified.

Justification for classification or non-classification

The carboxylic acid component of the registered substance was not found to cause any toxic effects after repeated oral exposure in rats. Kidney toxicity was seen at a dose of 1000 mg/kg bw/day in a study using the triethanolamine component of the registered substance. However, this toxicity was considered an acceleration of the normal ageing process of the tested species of rat. The registered substance was not considered to cause toxicity after repeated oral exposure.