Benzenamine, N-phenyl-, styrenated

Endpoint summary

Description of key information

Acute toxicity: Acute toxicity study oral (gavage), 10 male Wistar-II rats (similar to OECD 401): LD50 > 5000 mg/kg, LD0 ≥ 5000 mg/kg, no mortalities, no clinical symptoms on any observation day observed

Acute toxicity: Acute toxicity study oral (gavage), 10 male Wistar-II rats, 50% solution (similar to OECD 401): LD50 > 5000 mg/kg, LD0 ≥ 5000 mg/kg, no mortalities, no clinical symptoms on any observation day observed

Acute toxicity: Acute toxicity study dermal (neat, semiocclusive), Wistar rat m/f, 5/sex/dose (OECD 402, GLP): LD50 > 2000 mg/kg, LD0 ≥ 2000 mg/kg, no deaths occurred, no signs of systemic toxicity or dermal irritation were noted during the observation period.

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records

Reference

Reference 1

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Scientifically reasonable study on the registered substance itself with some deficiencies in documentation. However, given data indicate that the study was well-performed similar to OECD 401.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

Deviations:

not applicable

GLP compliance:

no

Remarks:

study performed prior to GLP implementation

Test type:

standard acute method

Limit test:

yes

Species:

rat

Strain:

other: Wistar-II, SPF

Sex:

male

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Breeder Winkelmann
- Weight at study initiation: 160-180g
- Housing: 5 animals / cage

Route of administration:

oral: gavage

Vehicle:

other: Lutrol

Details on oral exposure:

MAXIMUM DOSE VOLUME APPLIED: 2ml/kg

Doses:

5 g/kg bw

No. of animals per sex per dose:

10

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Day 1, 2, 3, 4, 5, 6, 7, 14
- Other examinations performed: clinical signs, bodyweight

Statistics:

Calculation of LD50 according to Fink and Hund, Arzneim.-Forsch. 15, 1965, 624

Key result

Sex:

male

Dose descriptor:

LD50

Effect level:

> 5 000 mg/kg bw

Based on:

test mat.

Remarks on result:

other: no mortalities observed

Sex:

male

Dose descriptor:

LD0

Effect level:

>= 5 000 mg/kg bw

Based on:

test mat.

Remarks on result:

other: no mortalities observed

Mortality:

none

Clinical signs:

other: no symptoms observed on any observation day

Gross pathology:

no data

Interpretation of results:

GHS criteria not met

Conclusions:

The study was conducted with a scientifically reasonable study design similar to OECD 401 on the registered substance itself with acceptable deficiencies in documentation. However, the given data indicate that the study was well performed. Hence, the results can be considered as sufficiently reliable to assess the toxicity of the test item towards rats. No rats died or showed symptoms at a dose of 5 g/kg bw, so the substance can be considered as relatively harmless and no classification as acute toxic according to Regulation 1272/2008 is triggered.

Executive summary:

In an acute oral toxicity study similar to OECD 401, groups of young male Wistar-II-rats (10/dose) were given a single oral dose of the test item in Lutrol at a limit dose of 5000 mg/kg bw and observed for 14 days.

 

Oral LD₅₀Males > 5000 mg/kg bw

Oral LD₀Males ≥ 5000 mg/kg bw

 

No mortalities occurred and no symptoms were observed at this dose. The test item is of low Toxicity based on the LD₅₀ in males. No classification as acute toxic according to Regulation 1272/2008 is triggered.

Reference 2

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Scientifically reasonable study on the registered substance itself as 50% solution with deficiencies in documentation. However, given data indicate that the study was well-performed similar to OECD 401.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

Deviations:

not applicable

GLP compliance:

no

Remarks:

study performed prior to GLP implementation

Test type:

standard acute method

Limit test:

yes

Species:

rat

Strain:

other: Wistar-II, SPF

Sex:

male

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Breeder Winkelmann
- Weight at study initiation: 160-180g
- Housing: 5 animals / cage

Route of administration:

oral: gavage

Vehicle:

unchanged (no vehicle)

Doses:

5 g/kg bw (of a 50% solution)

No. of animals per sex per dose:

10

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Other examinations performed: clinical signs

Sex:

male

Dose descriptor:

LD50

Effect level:

> 5 000 mg/kg bw

Based on:

test mat.

Remarks on result:

other: test material contains 50% of the registered substance

Sex:

male

Dose descriptor:

LD0

Effect level:

>= 5 000 mg/kg bw

Based on:

test mat.

Remarks on result:

other: test material contains 50% of the registered substance

Mortality:

none

Clinical signs:

other: no symptoms observed

Interpretation of results:

GHS criteria not met

Conclusions:

The study was conducted with a scientifically reasonable study design similar to OECD 401 on the registered substance itself (50%) with acceptable deficiencies in documentation. However, the given data indicate that the study was well performed. Hence, the results can be considered as sufficiently reliable to assess the toxicity of the test item towards rats. No rats died or showed symptoms at a dose of 5 g/kg bw of the test item, corresponding to 2500 mg/kg oft he registered substance, so the substance can be considered as relatively harmless and no classification as acute toxic according to Regulation 1272/2008 is triggered.

Executive summary:

In an acute oral toxicity study similar to OECD 401, groups of young male Wistar-II-rats (10/dose) were given a single oral dose of the test item containing 50% of the registered substance at a limit dose of 5000 mg/kg bw and observed for 14days. The results for the test material are

 

Oral LD₅₀Males > 5000 mg/kg bw

Oral LD₀Males ≥ 5000 mg/kg bw

 

No mortalities occurred and no symptoms were observed at this dose. The test item is of low Toxicity based on the LD₅₀ in males. No classification as acute toxic according to Regulation 1272/2008 is triggered.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

discriminating dose

Value:

5 000 mg/kg bw

Quality of whole database:

There are two sufficiently reliable studies available consistently indicating 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:

the study does not need to be conducted because exposure of humans via inhalation is not likely taking into account the vapour pressure of the substance and/or the possibility of exposure to aerosols, particles or droplets of an inhalable size

other:

Justification for type of information:

JUSTIFICATION FOR DATA WAIVING

According to REACH Annex VIII column 2, 8.5.2. Testing by the inhalation route is appropriate if exposure of humans via inhalation is likely taking into account the vapour pressure of the substance and/or the possibility of exposure to aerosols, particles or droplets of an inhalable size.
As the substance is a liquid at all relevant handling temperatures, i.e. minimum between -100°C and 400°C, no potentially inhalable particles need to be regarded.
The vapour pressure of the substance was determined to be 2.1 x 10E-4 Pa (25 °C) (OECD 104). According to the BG Bau [BG Bau 2017; Berufsgenossenschaft der Bauwirtschaft, http://www.bgbau.de/gisbau/lehrgang/a-z/dampfdru.htm, download of 2017-09-08], a vapour pressure of p < 0.01 hPa is very low, p = 1-10 hPa low and p > 10 hPa is high. The 31. BImSchV describes an organic substance as volatile if it has a vapour pressure of 0.01 kPa (i.e. 10 Pa) or more at 293.15 K. Also, according to ECHA’s guidance, substances are not available for inhalation as a gas in a relevant manner with a vapour pressure less than 0.5 kPa (i.e. 500 Pa) (or a boiling point above 150°C) [ECHA, 2008]. With a boiling point of >400°C and a vapour pressure of 2.1 x 10E-4 Pa at 25°, the registered substance has a very low vapour pressure and does not need to be regarded a volatile. Hence, the potential inhalation of the substance as a gas is not given and does not need to be regarded. Further, sufficient precautionary measures exclude the formation of droplets of inhalable size or aerosols. In consequence, exposure of humans via inhalation is not likely.

The registrant concludes further that 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 experimentally determined LogPow is 4.64 at 22°C, lying above that value and so hindering diffusion.
However, any lipophilic compound may be taken up by micellular solubilisation. This mechanism may be of particular importance for highly lipophilic compounds (Log Pow >4), particularly those that are poorly soluble in water (1 mg/L or less) that would otherwise be poorly absorbed. Although water solubility of the registered substance is way less than 1 mg/l, exposure is practically not given.
So, the design of an OECD 403 study (5 mg/l actual concentration of respirable substances) may overestimate the actual exposure, if it would be possible anyway to convert the substance into an inhalable form.
Further, there are no signs of toxicity obvious via the oral or dermal route. There is no study available fulfilling the criteria of an OECD 403 study (and required) for the acute inhalation toxicity of the test item; however, there is other information on acute toxicity in rats available:

Acute toxicity study similar to OECD 401: LD50 > 5000 mg/kg, LD0 ≥ 5000 mg/kg, no mortalities, no clinical symptoms on any observation day observed
Acute toxicity study similar to OECD 401, 50% solution: LD50 > 5000 mg/kg, LD0 ≥ 5000 mg/kg, no mortalities, no clinical symptoms on any observation day observed
Acute toxicity study dermal, acc. OECD 402: LD50 > 2000 mg/kg, LD0 ≥ 2000 mg/kg, no deaths occurred, no signs of systemic toxicity or dermal irritation were noted during the observation period.
Due to the lack of relevant toxicity at the application of 5000 resp. 2000 mg/kg bw test item via both the oral and dermal application route, and the fact that the LD50 values could only be determined as greater than 5000 or 2000 mg/kg, the LD50 > 2000 mg/kg bw will be further taken into account (precautionarily the lower value).
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, although not relevant based on the phys.-chem. properties of the substance, 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 is below the limit dose in oral and dermal tests and also below the actual LD50 via the oral application route, as only the limit dose of 5000 mg/kg (2000 mg/kg via dermal route) was tested and led to no deaths or signs of toxicity in all dosed animals.
Hence, it can be reasonably assumed that an additional acute toxicity test via the inhalation route would reveal an LC50inhalation > 5 mg/l.

So, in summary, it can be reasonably assumed that an additional testing for acute inhalation toxicity would not reveal any further relevant information and consequently, testing can be omitted due to animal welfare.

Endpoint conclusion

Endpoint conclusion:

no study available

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:

2016-03-23 - 2016-04-06 (experimental phase)

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Version / remarks:

OECD Guideline for the Testing of Chemicals No. 402 "Acute Dermal Toxicity" (adopted 24 February 1987)

Deviations:

no

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

Method B3 Acute Toxicity (Dermal) of Commission Regulation (EC) No. 440/2008

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

Issued by the Department of Health of the Government of the United Kingdom

Test type:

standard acute method

Limit test:

yes

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: supplied by Envigo RMS (UK) Limited, Oxon, UK
- Females (if applicable) nulliparous and non-pregnant: yes
- Age at study initiation: 8 to 12 weeks
- Weight at study initiation: At the start of the study the animals weighed at least 200 g, the weight variation did not exceed ±20% of the mean weight for each sex.
- Fasting period before study: no
- Housing: The animals were housed in suspended solid floor polypropylene cages furnished with woodflakes. The animals were housed individually during the 24-Hour exposure period and in groups of five, by sex, for the remainder of the study. The animals were provided with environmental enrichment items which were considered not to contain any contaminant of a level that might have affected the purpose or integrity of the study.
- Diet (e.g. ad libitum): 2014C Teklad Global Rodent diet supplied by Envigo RMS (UK) Limited, Oxon, UK, ad libitum
- Water (e.g. ad libitum): mains tap water, ad libitum
- Acclimation period: at least five days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19 to 25 °C
- Humidity (%): 30 to 70%
- Air changes (per hr): at least 15
- Photoperiod (hrs dark / hrs light): 12 hours continuous light and 12 hours darkness

Type of coverage:

semiocclusive

Vehicle:

unchanged (no vehicle)

Details on dermal exposure:

TEST SITE
- Area of exposure: backs and flanks
- % coverage: approximately 10% of the total body surface area
- Type of wrap if used: A piece of surgical gauze was placed over the treatment area and semi-occluded with a piece of self-adhesive bandage.

REMOVAL OF TEST SUBSTANCE
- Washing (if done): wiped with cotton wool moistened with arachis oil BP to remove any residual test item
- Time after start of exposure: 24h

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 2000 mg/kg resp. 1.86 ml/kg
- Constant volume or concentration used: yes, only single dose

Duration of exposure:

24h

Doses:

2000 mg/kg

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: The animals were observed for deaths or overt signs of toxicity 30 minutes, 1, 2 and 4 hours after dosing and subsequently once daily for 14 days. After removal of the dressings and subsequently once daily for 14 days, the test sites were examined for evidence of primary irritation and scored. Individual body weights were recorded prior to application of the test item on Day 0 and on Days 7 and 14.
- Necropsy of survivors performed: yes, this consisted of an external examination and opening of the abdominal and thoracic cavities. The appearance of any macroscopic abnormalities was recorded.

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Remarks on result:

no indication of skin irritation up to the relevant limit dose level

Sex:

male/female

Dose descriptor:

LD0

Effect level:

>= 2 000 mg/kg bw

Based on:

test mat.

Remarks on result:

no indication of skin irritation up to the relevant limit dose level

Remarks:

at 2000 mg/kg, there were no deaths.

Mortality:

There were no deaths.

Clinical signs:

other: No signs of systemic toxicity were noted during the observation period.

Gross pathology:

No abnormalities were noted at necropsy.

Other findings:

- Other observations: There were no signs of dermal irritation.

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 or any deviations. Hence, the results can be considered as reliable to assess the dermal toxicity of Benzenamine, N-phenyl-, styrenated. The acute dermal median lethal dose (LD50) of the test item in the Wistar strain rat was found to be greater than 2000 mg/kg body weight, so, the substance does not need to be classified as acute toxic via the dermal route.

Executive summary:

The OECD 402 study was performed under GLP to assess the acute dermal toxicity of the test item in the Wistar strain rat.

A group of ten animals (five males and five females) was given a single, 24 hour and 40 minute, semi-occluded dermal application of the undiluted test item to intact skin at a dose level of 2000 mg/kg body weight. Clinical signs and body weight development were monitored during the study. All animals were subjected to gross necropsy.

Results

Mortality. There were no deaths.

Clinical Observations. There were no signs of systemic toxicity.

Dermal Irritation. There were no signs of dermal irritation.

Body Weight. Animals showed expected gains in body weight except for three females which showed body weight loss during the first week with expected gain in body weight during the second week.

Necropsy. No abnormalities were noted at necropsy.

Conclusion: The acute dermal median lethal dose (LD50) of the test item in the Wistar strain rat was found to be greater than 2000 mg/kg body weight.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

discriminating dose

Value:

2 000 mg/kg bw

Quality of whole database:

There is a Klimisch 1 GLP OECD 402 study available, which unambiguously shows that the substance does not need to be classified as acutely toxic. This result is consistent with the ones derived from oral studies. Hence, the database is of high quality.

Justification for classification or non-classification

There are two oral and one dermal toxicity study available, all revealing LD50 and even LD0 values above the limit value for classification as acutely toxic acc. Regulation 1272/2008, i.e. 2000 mg/kg bw. So, the substance does not need to be classified as acutely toxic via both oral and dermal route. The physico-chemical and further parameter give no reason to believe that the non-classification may not be relevant for the inhalative route, too.