3-cyclohexylaminopropane-1-sulphonic acid

Endpoint summary

Description of key information

Acute toxicity oral: fixed dose procedure, oral (gavage), rat (Wistar), female, 14 days postobservation: LD50 > 2000 mg/kg, LD0 ≥ 2000 mg/kg (OECD 420, GLP)

Acute toxicity dermal: standard acute method, limit test, dermal (occlusive), unchanged, rat (Wistar), m/f, 14 days postobservation: LD50 > 2000 mg/kg, LD0 ≥ 2000 mg/kg, no signs of irritation observed (OECD 402, GLP)

Acute toxicity inhalation: no study available, waiving out of scientific reasons and exposure considerations

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records

Reference

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2014-09-12 to 2014-12-12

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: OECD guideline study under GLP without relevant deviations on the registered substance itself.

Qualifier:

according to guideline

Guideline:

OECD Guideline 420 (Acute Oral Toxicity - Fixed Dose Method)

Version / remarks:

2001

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.1 bis (Acute Oral Toxicity - Fixed Dose Procedure)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

valid from 2014-07-11

Test type:

fixed dose procedure

Limit test:

no

Species:

rat

Strain:

other: Wistar (Crl: WI(Han); outbred)

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Experimental Medicine Centre at the Medical University in Białystok
- Age at study initiation: 9 weeks (sighting study) / 10 weeks (main study)
- Weight at study initiation: 207-228 g
- Fasting period before study: yes, approx. 19h
- Housing: The animals were kept in plastic cages covered with wire bar lids. The dimensions of cages were 58 x 37 x 21 cm (length x width x height). In the sighting study, the animal was caged individually. In the main study, there were four animals in one cage. UV-sterilized wood shavings were used as bedding
- Diet (e.g. ad libitum): “Murigran” standard granulated laboratory fodder produced by Wytwórnia Koncentratów i Mieszanek Paszowych AGROPOL, Motycz (Batch No 3/14 and 4/14) ad libitum
- Water (e.g. ad libitum): tap water ad libitum
- Acclimation period: 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 – 24 °C
- Humidity (%): 40 – 85%
- Air changes (per hr): about 16 times/hour
- Photoperiod (hrs dark / hrs light): 12 hours light/12 hours dark

Route of administration:

oral: gavage

Vehicle:

water

Details on oral exposure:

VEHICLE
- Concentration in vehicle: 60 mg/mL or 400 mg/mL
- Amount of vehicle (if gavage): 0.5 mL / 100 g bw

MAXIMUM DOSE VOLUME APPLIED: 0.5 mL / 100 g bw

Doses:

300 mg/mL or 2000 mg/mL

No. of animals per sex per dose:

1 animal (each for gavage of 300 or 2000 mg/kg bw in sighting study)
4 animals (main study)

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: observation of all animals for morbidity and mortality was conducted twice a day or once a day (on days off). The detailed clinical observations were performed on the day of test item administration (day 0), i.e. 10, 30, and 60 minutes after the administration and then at hourly intervals up to the 5th hour after the administration. From the 1st to the 14th day of the experiment, the detailed clinical observations were performed once a day.
- Necropsy of survivors performed: gross examination comprised an observation of the external body surface, all natural apertures, and the cranial, thoracic, and abdominal cavities with their contents
- Other examinations performed: clinical signs, body weight

Preliminary study:

Following single administration of test item at a dose of 300 mg/kg b.w. to the first animal used in the sighting study, no changes were found in the animal during the entire period of observation. The animal survived the experiment.
Following single administration of test item at a dose of 2000 mg/kg b.w. to the second animal used in the sighting study, no changes were found in the animal during the entire period of observation. The animal survived the experiment.

Key result

Sex:

female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Sex:

female

Dose descriptor:

LD0

Effect level:

>= 2 000 mg/kg bw

Remarks on result:

other: All 5 animals given 2000 mg/kg survived the experiment

Mortality:

Following single administration of test item at a dose of 2000 mg/kg b.w. to all five animals, no changes were found in the animals during the entire period of observation. All animals survived the experiment.

Clinical signs:

Following single administration of test item at a dose of 2000 mg/kg b.w. to all five animals, no changes were found in the animals during the entire period of observation.

Body weight:

During the 14-day experiment, body weight gain was found in all animals.

Gross pathology:

No lesions were found at gross necropsy of all animals.

Interpretation of results:

other: EU GHS criteria not met

Conclusions:

The study was conducted under GLP according to OECD guideline 420 on the registered substance itself. The method is to be considered scientifically reasonable with no deficiencies in documentation. Hence, the results can be considered as reliable to assess the acute oral toxicity in rats.
Following single administration of 3-(Cyclohexylamino)-propane sulfonic acid at a dose of 2000 mg/kg b.w. to five female rats no signs of toxicity were found. All animals survived the period of experiment. After the experiment, body weight gain was found in all animals. Gross examination did not reveal any lesions in animals, which leads in summary to the following results: LD0(oral) ≥ 2000 mg/kg bw; LD50(oral) > 2000 mg/kg bw.
On the grounds of the obtained results, 3-(Cyclohexylamino)-propane sulfonic acid, can be classified to the following categories:
- category 5 / unclassified – according to the Globally Harmonized System (GHS),
- agents which are beyond categorization – according to the Regulation (EC) No. 1272/2008

Executive summary:

In an acute oral toxicity study (OECD 420), fasted, 9-10 week old female Wistar (Crl: WI(Han); outbred) rats were given a single oral dose of 3-(Cyclohexylamino)-propane sulfonic acid in water at doses of 300 mg/kg bw (1 female, sighting study) or 2000 mg/kg bw (1 female, sighting study, 4 females, main study) and observed for 14 days.

 

Following single administration of the test item at a dose of 2000 mg/kg b.w. to all animals used in the main study no signs of toxicity were found. All animals survived the period of experiment. After the experiment, body weight gain was found in all animals. Gross examination did not reveal any lesions in animals. Hence, the following results could be gained:

 

LD₀(oral) ≥ 2000 mg/kg bw

LD₅₀(oral) > 2000 mg/kg bw

 

3-(Cyclohexylamino)-propane sulfonic acid is of low Toxicity based on the LD₅₀ determined. 3-(Cyclohexylamino)-propane sulfonic acid, can be classified to the following categories:

- category 5 / unclassified – according to the Globally Harmonized System (GHS),

- agents which are beyond categorization – according to the Regulation (EC) No. 1272/2008

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

2 000 mg/kg bw

Quality of whole database:

There is an acute oral toxicity study available, performed according to OECD TG 420 under GLP, revealing consistently with the available OECD 402 study that the substance does not need to be classified as acutely toxic. Hence, the database is of high quality.

Acute toxicity: via inhalation route

Link to relevant study records

Reference

Endpoint:

acute toxicity: inhalation

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

other:

Justification for type of information:

JUSTIFICATION FOR DATA WAIVING
The substance decomposes at ca. 327 °C before melting occurs, and consequently a very low vapour pressure (0.17 + 10exp(-6) Pa, calculated). So, the exposure to CAPS via inhalation of vapour can be disregarded as no vapour will be formed during handling. Also, the substance is not distributed as e.g. aqueous solution, so the formation of inhalable droplets or aerosols can furthermore be excluded. The substance, however, has intrinsically a particle size which needs to be regarded. The average particle size of the test substance = 4.848 µm (D10 = 1.15 µm, D50 = 4.10 µm, D90 = 9.64 µm). This results in the following fractions according to the given limit values:~ 100% are <100 µm (inhalable fraction), ~ 90% are <10 µm (thoracic fraction), and ~ 50% are < 4µm (respirable fraction). So theoretically, the inhalative route, which does not allow an assessment of the systemic toxicity as well as via the oral route, may also be relevant for humans. However, it is considered that additional testing by the inhalative route does not reveal any further valuable information. Both test data via the dermal and oral route is available, covering both the substance as such and possibly its metabolized (oral route) form.
Furthermore, testing is scientifically not necessary and would not reveal any additional information which cannot be derived from other available acute toxicity data, so that testing can be omitted due to animal welfare:
According to ECHA’s guidance, Moderate log P values (between -1 and 4) are favourable for absorption directly across the respiratory tract epithelium by passive diffusion. The log Pow of the test item 3-(Cyclohexylamino)-propane sulfonic acid was calculated as -0.778 ± 0.020 (mean ± standard deviation). As the calculated log Pow of the test item lies below the lowest log Pow of the reference items (2-Butanone with log Pow 0.3), the log Pow of the test item is stated as < 0.3. Hence, this value may indicate a certain potential for absorption. However, with a water solubility of 184 g/L at 20°C, absorption here is hindered. Further, there are no signs of toxicity obvious via the oral or dermal route.
There is no study available (and required) for the acute inhalation toxicity of CAPS; however, there are LD50 values via other application routes available:
Oral: LD50 > 2000 mg/kg, LD0 ≥ 2000 mg/kg (OECD 420, GLP)
Dermal LD50 > 2000 mg/kg, LD0 ≥ 2000 mg/kg (OECD 402, GLP)
The obtained values are consistent and can be hence considered as reliable, and may be so used for further considerations:
According to OECD guideline 403 (Acute inhalation toxicity), the concentration of respirable particles for limit testing is 5 mg/L over 4 h. Taking into account for rats a standard respiratory volume of 0.2 l/min and average body weight of 250 g (Guidance on information and requirements and chemical safety assessment, chapter R.8: Characterisation of dose [concentration]-response for human health, Version 2.1, November 2012, ECHA, http://echa.europa.eu/web/guest/guidance-documents/guidance-on-information-requirements-and-chemical-safety-assessment), a total respiratory volume of 48 litre over 4 h can be assumed. This would result in a total dose of 240 mg per rat, which is equivalent to 960 mg/kg bw.
Assuming in a worst-case scenario that this total dose will be absorbed to 100%, and assuming furthermore that the orally applied amount is only absorbed to 50%, this dose would correspond to an oral dose of 1920 mg/kg bw. This value is below the relevant determined LD50 and even LD0 via the oral and dermal route, i.e. 2000 mg/kg bw. Hence, it can be reasonably assumed that an additional acute toxicity test via the inhalation route would reveal an LC50inhalation >5 mg/L, most likely even a LC0inhalation ≥5 mg/L. This is supported by the reasonably assumable at least partially hindered absorption via the inhalatory route compared to the oral one.
Furthermore, during the investigation of the acute dermal toxicity, no alterations of the skin were detected, and CAPS is neither a skin nor eye irritant nor a dermal sensitizer. So it can be additionally concluded, that no local effects during inhalation toxicity testing are likely occur and need to be regarded.
In consequence, the available oral and dermal acute toxicity studies are sufficient to cover this endpoint, no acute toxicity testing via inhalation route needs to be performed and can consequently be waived due to animal welfare.

Endpoint conclusion

Endpoint conclusion:

no study available

Quality of whole database:

The available oral and dermal acute toxicity studies are sufficient to consistently cover this endpoint, waiving criteria (exposure considerations and scientific justifications) are met, no acute toxicity testing via inhalation route needs to be performed and can consequently be waived due to animal welfare. Hence, despite the fact that no study via the inhalation route is available, the database is of sufficient quality.

Acute toxicity: via dermal route

Link to relevant study records

Reference

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2014-09-12 - 2014-12-17

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: OECD guideline study under GLP without relevant deviations on the registered substance itself.

Reason / purpose for cross-reference:

data waiving: supporting information

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.3 (Acute Toxicity (Dermal))

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

valid from 2014-07-11

Test type:

standard acute method

Limit test:

yes

Species:

rat

Strain:

other: Wistar (Crl: WI(Han); outbred)

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Experimental Medicine Centre at the Medical University in Białystok
- Age at study initiation: 9 weeks (males), 8 weeks (females)
- Weight at study initiation: average 280 g (males), 213 g (females)
- Fasting period before study: no
- Housing: The animals were housed in plastic cages covered with wire bar lids. The dimensions of cages were 58 x 37 x 21 cm (length x width x height). After application of the test item, each animal was housed individually. After the removal of the test item from the animals’ skin, there were five rats per cage. Each sex was kept separately. UV-sterilized wood shavings were used as bedding.
- Diet (e.g. ad libitum): “Murigran” standard granulated laboratory fodder produced by Wytwórnia Koncentratów i Mieszanek Paszowych AGROPOL, Motycz (Batch No 3/14 and 4/14) ad libitum
- Water (e.g. ad libitum): tap water ad libitum
- Acclimation period: 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20-24°C
- Humidity (%): 40-85%
- Air changes (per hr): about 16 times/hour
- Photoperiod (hrs dark / hrs light): 12 hours light/12 hours dark

Type of coverage:

occlusive

Vehicle:

unchanged (no vehicle)

Details on dermal exposure:

TEST SITE
- Area of exposure: dorsal area of the trunks
- % coverage: 10% of the body surface area
- Type of wrap if used: The test item was applied to gauze patches. The patches were laid on the prepared skin and covered with PVC foil. An elastic bandage and a sticking plaster were used to make a circular protecting band.

REMOVAL OF TEST SUBSTANCE
- Washing (if done): with water
- Time after start of exposure: 24 hours

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 2000 mg/kg bw
- For solids, paste formed: no

Duration of exposure:

24 hours

Doses:

2000 mg/kg bw

No. of animals per sex per dose:

5/sex/dose

Control animals:

not required

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Observation of all animals for mortality and morbidity was conducted twice a day or once a day (on days off). The detailed clinical observations were made on the application day (day 0) at hourly intervals up to 5 hours. From the 1st to the 14th day of the experiment, the detailed clinical observations were performed once a day.
- Necropsy of survivors performed: The detailed gross examination comprised the observation of the external body surface, all natural apertures, and the cranial, thoracic, and abdominal cavities with their contents.
- Other examinations performed: clinical signs, body weight

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Sex:

male/female

Dose descriptor:

LD0

Effect level:

>= 2 000 mg/kg bw

Based on:

test mat.

Remarks on result:

other: All animals survived the single application of 2000 mg/kg bw.

Mortality:

All animals survived the experiment.

Clinical signs:

Following single application of the test item, the animals did not show any general clinical signs. No pathological changes on the treated skin were found in males and females.

Body weight:

During the 14-day experiment, body weight gain was found in all animals.

Gross pathology:

The gross examination did not reveal any pathological changes in the examined animals.

Interpretation of results:

other: EU GHS criteria not met

Conclusions:

The study was conducted under GLP according to OECD guideline 402 on the registered substance itself. The method is to be considered scientifically reasonable with no deficiencies in documentation. Hence, the results can be considered as reliable to assess the acute oral toxicity in rats.
Following single application of 3-(Cyclohexylamino)-propane sulfonic acid at a dose of 2000 mg/kg bw, the animals did not show any general clinical signs. No pathological changes on the treated skin of males and females were found. All animals survived the experiment. During the 14-day experiment, body weight gain was found in all animals. Gross examination did not reveal any pathological changes in the examined animals. So it may be stated that the median lethal dose (LD50) of 3-(Cyclohexylamino)-propane sulfonic acid is greater than 2000 mg/kg b.w. Since no animal showed at no observation time any pathological changes on the treated skin or other signs of irritation, it may be concluded that, under the conditions of this test, 3-(Cyclohexylamino)-propane sulfonic acid, does not need to be considered as irritating to rat skin.
According to the Regulation (EC) No. 1272/2008, it may be concluded that 3-(Cyclohexylamino)-propane sulfonic acid is beyond categorization.

Executive summary:

In an acute dermal toxicity study (OECD 402), groups of 8-9 weeks old Wistar (Crl: WI(Han); outbred) rats (5/sex) were dermally exposed to unchanged 3-(Cyclohexylamino)-propane sulfonic acid for 24 hours on 10% of body surface area at a dose of 2000 mg/kg bw under occlusive coverage. Animals then were observed for 14 days.

 

Following single application of the test item, the animals did not show any general clinical signs. No pathological changes on the treated skin of males and females were found. All animals survived the experiment. During the 14-day experiment, body weight gain was found in all animals. Gross examination did not reveal any pathological changes in the examined animals. Hence, the following results could be gained:

 

LD0(dermal) ≥ 2000 mg/kg bw

LD50(dermal) > 2000 mg/kg bw

 

3-(Cyclohexylamino)-propane sulfonic acid is of lowToxicity based on the LD50 determined. Since no animal showed at no observation time any pathological changes on the treated skin or other signs of irritation, it may be concluded that, under the conditions of this test, 3-(Cyclohexylamino)-propane sulfonic acid does not need to be considered as irritating to rat skin.

According to Regulation (EC) No. 1272/2008, it may be concluded that 3-(Cyclohexylamino)-propane sulfonic acid is beyond categorization.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

2 000 mg/kg bw

Quality of whole database:

There is an acute dermal toxicity study available, performed according to OECD TG 402 under GLP, revealing consistently with the available OECD 420 study that the substance does not need to be classified as acutely toxic. Hence, the database is of high quality.

Justification for classification or non-classification

There are both an acute oral and dermal toxicity study available, revealing consistently values of LD50 > 2000 mg/kg, and LD0 ≥ 2000 mg/kg. So both LD50 values are above the limit value (2000 mg/kg) for classification as acute toxic Cat. 4 according to Regulation (EC) 1272/2008, the EU GHS criteria are not met and the substance does not need to be classified.