2,6-di-tert-butyl-4-nonylphenol

Endpoint summary

Description of key information

In a key acute oral toxicity test according to OECD Guideline 401 a group of ten fasted Sprague-Dawley CD strain rats (five males and five females) was given a single oral dose of undiluted test material at a dose level of 2000 mg/kg bodyweight by gavage. The acute oral median lethal dose (LD50) of the test material in the Sprague-Dawley CD-strain rat was found to be greater than 2000 mg/kg body weight.

Acute inhalation toxicity testing was waived based on low vapour pressure.

In a key acute dermal toxicity study 5 male and 5 female WISTAR Crl: WI(Han) rats were tested according to OECD Guideline 402. The test item was applied semi-occlusive to the dorsal area of the trunk for a 24 -hour exposure period. Under the conditions of the present study, single dermal application of the test item 2,6-Di-tert-butyl-4-nonylphenol to rats at a dose of 2000 mg/kg body weight was not associated with mortality and there were no signs of toxicity but slight signs of irritation. The dermal LD50 was determined to be >2000 mg 2,6-Di-tert-butyl-4-nonylphenol /kg body weight.

 

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:

The study was performed between 9 May 1995 and 1 June 1995.

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

Version / remarks:

adopted 24 February 1987

Qualifier:

according to guideline

Guideline:

EU Method B.1 (Acute Toxicity (Oral))

Version / remarks:

of Commission Directive 92169/EEC (which constitutes Annex V of Council Directive 67/548/EEC)

GLP compliance:

yes (incl. QA statement)

Test type:

standard acute method

Limit test:

yes

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: 99/26.12.94

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: room temperature under nitrogen

FORM AS APPLIED IN THE TEST (if different from that of starting material): clear colourless liquid

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River (UK) Ltd., Margate, Kent, UK.
- Age at study initiation: At the start of the main study the males and the females were five to eight weeks of age.
- Weight at study initiation: At the start of the main study the males weighed 150 to 170g, and the females 145 to 155g.
- Fasting period before study: an overnight fast immediately before dosing and for approximately two hours after dosing,
- Housing: The animals were housed in groups of up to five by sex in solid-floor polypropylene cages furnished with woodflakes
- Diet (e.g. ad libitum): With the exception of an overnight fast immediately before dosing and for approximately two hours after dosing, free access to food (Rat and Mouse Expanded Diet No. 1, Special Diets Services Limited, Witham, Essex, UK) was allowed throughout the study.
- Water (e.g. ad libitum):With the exception of an overnight fast immediately before dosing and for approximately two hours after dosing, free access to mains drinking water was allowed throughout the study.
- Acclimation period: acclimatisation period of at least five days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19 to 23 °C
- Humidity (%): 45 to 58%
- Air changes (per hr): approximately 15 changes per hour
- Photoperiod (hrs dark / hrs light): 12/12

Route of administration:

oral: gavage

Vehicle:

unchanged (no vehicle)

Details on oral exposure:

MAXIMUM DOSE VOLUME APPLIED: 2.24 mL/kg calculated according to its fasted bodyweight at the time of dosing.

Doses:

2000 mg/kg bw

No. of animals per sex per dose:

Range-finding study: 1
Main study: 5

Control animals:

no

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 1/2, 1, 2 and 4 hours after dosing and subsequently once daily for 14 days.
Individual bodyweights were recorded prior to dosing on Day 0 and on Days 7 and 14.
- Necropsy of survivors performed: yes. At the end of the study the animals were killed by cervical dislocation and subjected to gross pathological examination. This consisted of an external examination and opening of the abdominal and thoracic cavities for examination of major organs. The appearance of any macroscopic abnormalities was recorded. No tissues were retained.

Statistics:

Data evaluations included the relationship, if any, between the animals' exposure to the test material and the incidence and severity of all abnormalities including behavioural and clinical observations, gross lesions, bodyweight changes, mortality and any other toxicological effects.
Using the mortality data obtained, an estimate of the acute oral median lethal dose (LD50) of the test material was made.

Preliminary study:

There were no deaths or clinical signs of toxicity.
Based on this information, a dose level of 2000 mg/kg bodyweight was selected for the main study.

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mL/kg bw

Based on:

test mat.

Mortality:

There were no deaths.

Clinical signs:

No signs of systemic toxicity were noted during the study.

Body weight:

Animals showed expected gain in bodyweight during the study.

Gross pathology:

No abnormalities were noted at necropsy.

Interpretation of results:

GHS criteria not met

Conclusions:

The acute oral median lethal dose (LD50) of the test material, ISONOX 232, in the Sprague-Dawley CD strain rat was found to be greater than 2000 mg/kg bodyweight. No symbol and risk phrase are required according to EU labelling regulations.

Executive summary:

A study was performed to assess the acute oral toxicity of the test material in the Sprague-Dawley CD strain rat. The method followed that in the OECD Guideline for Testing Chemicals No. 401 "Acute Oral Toxicity" (adopted 24 February 1987) and Method B1 of Commission Directive 92169/EEC (which vonstitutes Annex V of Council Directive 67/548/EEC).

The results may be used as a basis for classification and labelling under Annex VI of Council Directive 67/548/EEC (as adapted to technical progress by Commission Directive 93/21/EEC) relating to the classification, packaging and labelling of dangerous substances.

Following a range-finding study, a group of ten fasted animals (five males and five females) was given a single oral dose of undiluted test material at a dose level of 2000 mg/kg bodyweight. The animals were observed for fourteen days after the day of dosing and were then killed and subjected to gross pathological examination. There were no deaths. No signs of systemic toxicity were noted during the study.

Animals showed expected bodyweight gain during the study. No abnormalities were noted at necropsy.

The acute oral median lethal dose (LD50) of the test material in the Sprague-Dawley CD-strain rat was found to be greater than 2000 mg/kg bodyweight. No symbol and risk phrase are required according to EU labelling regulations.

Endpoint conclusion

Dose descriptor:

LD50

Value:

2 000 mg/kg bw

Acute toxicity: via inhalation route

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:

2016-2017

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:

1987

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

30 May 2008

GLP compliance:

yes (incl. QA statement)

Test type:

standard acute method

Limit test:

yes

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No. of test material: Delivered by the sponsor; Batch: 222375101
- Expiration date of the lot/batch: 02 May 2018
- Purity test date: 02 September 2016
-Arrival of the Test item: 13 September 2016

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: at room temperature
- Stability under test conditions:

Species:

rat

Strain:

other: WISTAR Crl: WI(Han)

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River, 97633 Sulzfeld, Germany. The animals were derived from a control full-barrier maintained breeding system (SPF).
- Females (if applicable) nulliparous and non-pregnant: yes
- Age at study initiation:
Males: 7-8 weeks old
Females: 8-9 weeks old
- Weight on the day of administration:
Males: 246 – 253 g
Females: 214 – 219 g
- Fasting period before study: No
- Housing: The animals were kept individually in IVC cages, type III H, polysulphone cages on Altromin saw fibre bedding.
- Diet (e.g. ad libitum): Free access to Altromin 1342 maintenance diet for rats and mice.
- Water (e.g. ad libitum): Free access to tap water, sulphur acidified to a pH value of approximately 2.8 (drinking water, municipal residue control, microbiological controls at regular intervals).
- Acclimation period: at least five days under laboratory conditions

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 3 °C
- Humidity (%): 55 ± 10%
- Air changes (per hr): 10x/hour
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES:
From: Experimental starting date: 18 January 2017
To: Experimental Completion Date: 02 February 2017

Type of coverage:

semiocclusive

Vehicle:

unchanged (no vehicle)

Details on dermal exposure:

TEST SITE
- Area of exposure: dorsal area of the trunk
- % coverage: No less than 10% of the body surface
- Type of wrap if used: . Thie dressing consisted of a semi-occlusive dressing made of a porous gauze and non-irritating tape and was fixed with an additional dressing in a suitable manner.

REMOVAL OF TEST SUBSTANCE
- Washing (if done): At the end of the exposure period the residual test item was removed using aqua ad injectionem.
- Time after start of exposure: 24 hours

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 2000 mg/kg body weight

Duration of exposure:

24 hours

Doses:

2000 mg/kg body weight

No. of animals per sex per dose:

5

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing:
The animals were weighed on day 1 (prior to application) and on days 8 and 15.
A careful clinical examination was made several times on the day of dosing (at least once during the first 30 minutes and with special attention given during the first 4 hours post-dose). As soon as symptoms were noticed they were recorded. Thereafter, the animals were observed for clinical signs once daily until the end of the observation period. All abnormalities were recorded.
Cageside observations included changes in the skin and fur, eyes and mucous membranes. Also respiratory, circulatory, autonomic and central nervous systems and somatomotor activity and behaviour pattern were examined. Attention was directed to observations of tremors, convulsions, salivation, diarrhea, lethargy, sleep and coma.
- Necropsy of survivors performed: yes. At the end of the observation period the animals were sacrificed with an overdosage of pentobarbital injected intraperitoneally at a dosage of 250 – 400 mg/kg bw.
All animals were subjected to gross necropsy and examined macroscopically for gross pathological changes. In absence of gross pathological changes no tissues were preserved for a possible histopathological evaluation.

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

No deaths.

Clinical signs:

No treatment-related effects were observed.
No erythema or oedema was observed. Scratches were observed in 1 of 5 male and 2 of 5 female animals.
All signs of irritation were reversible within the observation period.

Body weight:

The body weight development of all male and female animals was within the expected range.

Gross pathology:

No specific gross pathological changes were recorded for any animal.

Interpretation of results:

GHS criteria not met

Conclusions:

Under the conditions of the present study, single dermal application of the test item 2,6-Di-tert-butyl-4-nonylphenol to rats at a dose of 2000 mg/kg body weight was not associated with mortality and there were no signs of toxicity but slight signs of irritation.The dermal LD50 was determined to be >2000 mg 2,6-Di-tert-butyl-4-nonylphenol /kg body weight

Executive summary:

5 Male and 5 female WISTAR Crl: WI(Han) rats were tested for acute dermal toxicity according to OECD TG 402.

Approximately 24 hours before the test, the fur was removed from the dorsal area of the trunk using an electric clipper. Care was taken to avoid abrading the skin, and only animals with healthy intact skin were used. No less than 10% of the body surface was cleared for the application. Prior to application a detailed clinical observation was made of all animals. Only healthy animals were used.

The test item was applied at a single dose, uniformly over an area which was approximately 10% of the total body surface.

The test item was held in contact with the skin by a dressing throughout a 24-hour period. This consisted of a semi-occlusive dressing made of a porous gauze and non-irritating tape and was fixed with an additional dressing in a suitable manner. The test item was applied undiluted at a single dose of 2000 mg/kg body weight to each animal. The test item was held in contact with the skin throughout a 24-hour period. At the end of the exposure period the residual test item was removed using aqua ad injectionem.

All animals were observed for 14 days after dosing. Signs of erythema and oedema were assessed using the scoring system laid down in OECD 404. The animals were weighed on day 1 (prior to application) and on days 8 and 15. A careful clinical examination was made several times on the day of dosing (at least once during the first 30 minutes and with special attention given during the first 4 hours post-dose). As soon as symptoms were noticed they were recorded. Thereafter, the animals were observed for clinical signs once daily until the end of the observation period. All abnormalities were recorded. Cageside observations included changes in the skin and fur, eyes and mucous membranes. Also respiratory, circulatory, autonomic and central nervous systems and somatomotor activity and behaviour pattern were examined. Attention was directed to observations of tremors, convulsions, salivation, diarrhea, lethargy, sleep and coma.

At the end of the observation period the animals were sacrificed with an overdosage of pentobarbital injected intraperitoneally at a dosage of 250 – 400 mg/kg bw. All animals were subjected to gross necropsy and examined macroscopically for gross pathological changes. In absence of gross pathological changes no tissues were preserved for a possible histopathological evaluation.

The test item showed no mortality, no signs of acute dermal toxicity but slight signs of dermal irritation after a single dose application.

The body weight development of all male and female animals was within the expected range.

No specific gross pathological changes were recorded for any animal.

Under the conditions of the present study, single dermal application of the test item 2,6-Di-tert-butyl-4-nonylphenol to rats at a dose of 2000 mg/kg body weight was not associated with mortality and there were no signs of toxicity but slight signs of irritation. The dermal LD50 was determined to be >2000 mg 2,6-Di-tert-butyl-4-nonylphenol /kg body weight.

 

Endpoint conclusion

Dose descriptor:

LD50

Value:

2 000 mg/kg bw

Additional information

A key acute oral toxicity study was performed with the registered substance in the Sprague-Dawley CD strain rat. (Snell, 1995). The method followed that in the OECD Guideline for Testing Chemicals No. 401 "Acute Oral Toxicity" (adopted 24 February 1987) and Method B1 of Commission Directive 92169/EEC (which constitutes Annex V of Council Directive 67/548/EEC). Following a range-finding study, a group of ten fasted animals (five males and five females) was given a single oral dose of undiluted test material at a dose level of 2000 mg/kg bodyweight. The animals were observed for fourteen days after the day of dosing and were then killed and subjected to gross pathological examination. There were no deaths. No signs of systemic toxicity were noted during the study. Animals showed expected bodyweight gain during the study. No abnormalities were noted at necropsy. The acute oral median lethal dose (LD50) of the test material in the Sprague-Dawley CD-strain rat was found to be greater than 2000 mg/kg bodyweight. No symbol and risk phrase are required according to EU labelling regulations.

Acute inhalation toxicity testing was waived based on low vapour pressure.

A key dermal toxicity study was performed in 5 Male and 5 female WISTAR Crl: WI(Han) rats according to OECD TG 402 (Holalagoudar, 2017). The registered substance was applied at a single dose, uniformly over an area which was approximately 10% of the total body surface and was held in contact with the skin by a dressing throughout a 24-hour period, applied undiluted at a single dose of 2000 mg/kg body weight. All animals were observed for 14 days after dosing. The test item showed no mortality, no signs of acute dermal toxicity but slight signs of dermal irritation after a single dose application.

The body weight development of all male and female animals was within the expected range. No specific gross pathological changes were recorded for any animal. Under the conditions of the present study, single dermal application of the test item 2,6-Di-tert-butyl-4-nonylphenol to rats at a dose of 2000 mg/kg body weight was not associated with mortality and there were no signs of toxicity but slight signs of irritation. The dermal LD50 was determined to be >2000 mg 2,6-Di-tert-butyl-4-nonylphenol /kg body weight.

 

Justification for classification or non-classification

No classification and labelling is needed for acute toxicity (oral, dermal) of 2,6-di-tert-butyl-4-nonylphenol according to Regulation No. 1272/2008 (CLP).