Tetrabutylammonium hydroxide

Endpoint summary

Description of key information

Acute Toxicity: Oral

Based on the available results and applying the weight of evidence approach, the acute oral median lethal dose for the test chemical can be considered to lie between 300-2000 mg/kg. Thus by considering the CLP criteria for acute toxicity rating for the chemicals, the test chemical can be classified under the category “Category 4”.

Acute toxicity: inhalation

The study doesnot need to be conducted due to the low vapor pressure of the chemical and its exposure as aerosols, dusts, mists or vapors of inhalable size during manufacture/use is highly unlikely. The test chemical has very low vapor pressure of 2.61E-10 Pa which is equivalent to 1.96E-12 mm Hg at 25 ° C, so the potential for the generation of inhalable vapour is low. Also the normal conditions of use of this substance will not result in aerosols, particles or droplets of an inhalable size, so exposure to humans via the inhalatory route will be unlikely to occur, and therefore this end point was considered for waiver

Acute toxicity: dermal

The study neednot be conducted as the substance is classified as corrosive to skin. In accordance with ANNEX VII Colum 2 of the REACH regulation, the study need not be conducted if the substance is a strong acid (pH<=2.0) or strong base (pH=> 11.5). The experimental pH of the test chemical was 14. Hence, based on the high pH of the test chemical, the acute dermal toxicity study was considered for waiver.

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records

Reference

Endpoint:

acute toxicity: oral

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Remarks:

Weight of evidence approach based on various test chemicals

Justification for type of information:

Weight of evidence approach based on various test chemicals

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Qualifier:

according to guideline

Guideline:

other: Weight of evidence approach based on various test chemicals

Principles of method if other than guideline:

Weight of evidence approach based on various test chemicals

GLP compliance:

not specified

Test type:

other: not specified

Limit test:

no

Species:

rat

Strain:

Wistar

Sex:

female

Details on test animals or test system and environmental conditions:

2. TEST ANIMALS
- Source: Geniron Biolabs Pvt. Ltd. Bengaluru
- Females (if applicable) nulliparous and non-pregnant: yes
- Age at study initiation: 10 to 12 Weeks
- Weight at study initiation:165.34 g to 210.05 g
- Identification:By rat accession number. Identification of individual rats was by cage card and turmeric colour body markings. The rat accession number was allotted during the course of the study. The temporary body marking during acclimatization period was done with crystal violet.
- Fasting period before study: rats were fasted for approximately 16 to 18 hours
- Housing:Rats were housed individually in standard polysulfone cages (Size: L 425 x B 266 x H 185 mm), with stainless steel top grill
- Diet (e.g. ad libitum): Hypro Rat & Mice pellet feed, ad libitum
- Water (e.g. ad libitum): Deep bore-well water passed through activated charcoal filter and exposed to UV rays in Aquaguard on-line water filter-cum-purifier, Mumbai, ad libitum
- Acclimation period: The animals were acclimatized six days for G1-FTS, eight days for G1-STS and twelve days for G2-FTS before treatment.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21 to 24°C
- Humidity (%): 66 to 68%
- Air changes (per hr): air conditioned with adequate fresh air supply (between 13.1 and13.2 air changes/hour)
- Photoperiod (hrs dark / hrs light): 12 hours light and 12 hours dark cycle.

IN-LIFE DATES: From: 24 July 2018 To: 11 September 2018
3. TEST ANIMALS
- Source:Bharat Serum and Vaccines Limited, India.
- Age at study initiation:8- 11 weeks at the time of dosing.
- Health Status:Healthy young adult animals were used for the study. Females were nulliparous and non pregnant.
- Weight at study initiation:Minimum: 197 g and Maximum: 218 g (Individual body weights were within ± 4% prior to treatment after overnight fasting)
- Fasting period:The animals were fasted for minimum 16-18 hours prior to dosing and for 3-4 hours post dosing.
- Housing:The animals were housed individually in polycarbonate cages.
- Bedding: All cages were provided with corn cobs.
- Room Sanitation:The experimental room floor and work tops were swept and mopped with disinfectant solution every day.
- Cages and water bottle:All the cages and water bottles were changed at least twice every week.
- Diet (e.g. ad libitum):All animals were provided conventional laboratory rodent diet (Nutrivet Life Sciences, Pune) ad libitum.
- Water (e.g. ad libitum):Aqua guard filtered tap water was provided ad libitum via drinking bottles.
- Acclimation period:Animal nos. 1-3 were acclimatized for five days and 4-6 for seven days prior to administration of the test item.

ENVIRONMENTAL CONDITIONS
- Temperature (°C):Minimum: 20.40°C and Maximum: 23.10°C.
- Humidity (%):Minimum: 38.40 % and Maximum: 58.70 %.
- Air changes (per hr):More than 12 changes per hour.
- Photoperiod (hrs dark / hrs light):12:12

IN-LIFE DATES: From: February 05, 2014 To: February 26, 2014

Route of administration:

oral: gavage

Vehicle:

water

Details on oral exposure:

2. VEHICLE
- Concentration in vehicle: 300 & 2000 mg/kg body weight.
- Amount of vehicle (if gavage):dose volume was 10 mL/kg body weight
3. VEHICLE
- Concentration in vehicle: 300 mg/kg and 2000 mg/kg
- Amount of vehicle (if gavage):10 ml

Doses:

2. G1 (FTS) - 300 mg/kg
G1 (STS) - 300 mg/kg
G2 (FTS) - 2000 mg/kg
3. G1 = 300 mg/kg bw
G2 = 2000 mg/kg bw

No. of animals per sex per dose:

2. G1 (FTS) - 300 mg/kg - 3
G1 (STS) - 300 mg/kg - 3
G2 (FTS) - 2000 mg/kg - 3
3. 9 female rats

Control animals:

not specified

Details on study design:

2. - Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Clinical signs and pre-terminal deaths - At each step, the animals were observed five times on test day 1 (day of administration) i.e. at 30 minutes and four times at hourly intervals and once daily during days 2 to 15 post administration. Observations included changes in skin and fur, eyes and mucous membranes, and also respiratory, circulatory, autonomic and central nervous systems and somatomotor activity and behaviour pattern. Attention was directed to the observations of tremors, convulsions, salivation, diarrhoea, lethargy, sleep and coma and all observed clinical signs were recorded. Body weights - The body weights were recorded on test day 1 (pre-administration), day 8 (7 days post administration) and day 15 (14 days post administration).
- Necropsy of survivors performed: yes, the rats surviving to the end of the observation period were euthanised by using isoflurane anaesthesia and subjected to detailed necropsy.
- Other examinations performed: Gross pathological findings were recorded and reported. Microscopic examination was not carried out as no gross pathological changes were observed.
3. - Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Clinical Observation - After test item administration, individual animals were frequently observed at 30 minutes, 1, 2, 3 and 4 hours post dosing on day 0 (day of dosing). Subsequently, all the surviving animals were observed once a day during the 14 day observation period.
Body weight - All surviving rats were weighed on days 0 (prior to dosing), 7 and 14. Animals were weighed immediately after found dead.
Mortality - All surviving animals were observed twice daily (morning and evening) for morbidity and mortality, throughout the acclimatization and study period.
- Necropsy of survivors performed: yes, at the end of 14 day observation period, all the survived rats were euthanised by overdose of CO2 for external and internal observations.

Statistics:

2. not specified
3. not specified

Preliminary study:

2. not specified
3. not specified

Sex:

female

Dose descriptor:

LD50

Effect level:

1 000 mg/kg bw

Based on:

test mat.

Sex:

female

Dose descriptor:

LD50

Effect level:

> 300 - < 2 000 mg/kg bw

Based on:

test mat.

Mortality:

2. G1 - [300 mg/kg body weight - Treatment (FTS and STS)]: There were no mortality/morbidity in FTS and STS till the termination.
G2 - [2000 mg/kg body weight - Treatment (FTS)]: There were two mortalities observed at 0.5 hours post-dose observation.
3. No mortality was observed in the animals treated with 300 mg/kg dose throught out the 14 days observation period, whereas all three animals treated with 2000 mg/kg dose level were found dead on day 0 post dosing.

Clinical signs:

other: 2. G1 - [300 mg/kg body weight - Treatment (FTS and STS)]: There were no clinical signs in FTS and STS till the termination. G2 - [2000 mg/kg body weight - Treatment (FTS)]: There were no clinical signs observed in any of the rats. 3. At 300 mg/kg, all th

Gross pathology:

2. There were no gross pathological changes at necropsy.
3. No external gross pathological changes were seen in all the six animals treated with 300 mg/kg body weight during terminal sacrifice. At 2000 mg/kg, animal no. 7 was observed with no abnormalities, whereas animal nos. 8 and 9 were observed with wet around mouth. No internal gross pathological changes were seen in all the six animals treated with 300 mg/kg body weight during terminal sacrifice. At 2000 mg/kg, all three animals were observed with severe red discoloration of all lobes lungs and test item was observed in stomach and intestine.

Other findings:

2. not specified
3. not specified

Interpretation of results:

Category 4 based on GHS criteria

Conclusions:

According to CLP regulation, the test chemical can be classified in "Category 4" for acute oral toxicity, as the LD50 value is between 300-2000 mg/kg bw.

Executive summary:

Various studies have been reviewed to determine the acute oral toxicological profile of the test chemical. These include in vivo experimental studies performed on rats for the test chemical. The results are mentioned below:

The acute oral toxicity study was conducted to assess the toxicological profile of the test chemical as per OECD Guideline 423 (Acute Oral toxicity - Acute Toxic Class Method) in Wistar rats. The dose formulation was prepared by using Milli-Q water and administered as a single oral gavage to overnight fasted (16 to 18 hours) three female rats (G1-FTS) at the dose of 300 mg/kg body weight. There were no clinical signs of toxicity and pre-terminal deaths observed. As all the rats survived at this step, the test was confirmed with three additional female animals with the same dose of 300 mg/kg body weight (G1-STS). There were no clinical signs of toxicity and pre-terminal deaths observed at this step. Based on the scheme - Annex 2c of the guideline OECD 423, the test was continued at the dose of 2000 mg/kg body weight (G2-FTS). The two rats (Rw314 and Rw315) were found dead at 0.5 hours post dose observations, hence as per the scheme - Annex 2c of the guideline OECD 423, the further dosing was stopped. The rats were observed for mortality and clinical signs for 14 days post treatment. Body weights were recorded prior to dosing on day 1 and again on days 8 and 15. Gross necropsy was performed for all the rats at termination. The body weight growth of all survived rats was unaffected by the test chemical. There were no gross pathological changes at necropsy, hence histopathology was not performed. Based on the results of the present study, the LD50 value of the test chemical was considered to be 1000 mg/kg body weight. Thus, the test chemical was classified in “Category 4 (300 – ≤ 2000)” criteria of CLP.

This result is supported by another similar OECD 423 study carried out for the test chemical in rats. Nine female Wistar rats were selected for acute oral toxicity study. The animals were fasted for minimum 16-18 hours prior to dosing and for 3-4 hours post dosing, with food withheld but drinking water provided ad libitum. The time intervals between dosing were determined by the onset, duration and severity of toxic signs. Three rats of first group were dosed with starting dose of 300 mg/kg body weight and the animals did not show any mortality so another three animals of the same group were dosed with 300 mg/kg body weight and no mortality was observed. Hence three rats of second group were dosed with 2000 mg/kg weight. All the rats at 2000mg/kg were found dead on day 0 post dosing. Hence, further dosing was stopped. Body weights were re­corded on day 0 (prior to dosing), 7 and 14. Body weight gain was observed in all surviving animals treated with 300 mg/kg body weight, during the 14 day observation period, as compared to day 0. At 300 mg/kg, all the six animals were observed normal throughout the experiment period. At 2000 mg/kg, animal no. 7 was observed with mild tremors at 30 minutes, mild to moderate abdominal breathing at 30 minutes and 1 hour and sternal recumbency at 1 hour followed by found dead. Animal nos. 8 and 9 were observed with mild tremors, moderate abdominal breathing, sternal recumbency and moderate salivation at 30 minutes followed by found dead. No external gross pathological changes were seen in all the six animals treated with 300 mg/kg body weight during terminal sacrifice. At 2000 mg/kg, animal no. 7 was observed with no abnormalities, whereas animal nos. 8 and 9 were observed with wet around mouth. No internal gross pathological changes were seen in all the six animals treated with 300 mg/kg body weight during terminal sacrifice. At 2000 mg/kg, all three animals were observed with severe red discoloration of all lobes lungs and test chemical was observed in stomach and intestine. Under the conditions of this study, the acute oral toxicity dose LD50 value of test chemical was considered in between 300-2000 mg/kg body weight. Thus by considering the CLP criteria for acute toxicity rating for the chemicals, it infers that the given test chemical exhibits acute oral toxicity in “Category 4” LD50 >300 to ≤ 2000 mg/kg body weight.

Based on the available results and applying the weight of evidence approach, the acute oral median lethal dose for the test chemical can be considered to lie between 300-2000 mg/kg. Thus by considering the CLP criteria for acute toxicity rating for the chemicals, the test chemical can be classified under the category “Category 4”.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LD50

Value:

1 000 mg/kg bw

Quality of whole database:

Klimisch Rating 1

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

Clinical signs:

other:

Endpoint conclusion

Quality of whole database:

waiver

Acute toxicity: via dermal route

Link to relevant study records

Reference

Endpoint:

acute toxicity: dermal

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

the study does not need to be conducted because the substance is classified as corrosive to the skin

Endpoint conclusion

Quality of whole database:

waiver

Additional information

Acute Toxicity: Oral

Various studies have been reviewed to determine the acute oral toxicological profile of the test chemical. These include in vivo experimental studies performed on rats for the test chemical. The results are mentioned below:

The acute oral toxicity study was conducted to assess the toxicological profile of the test chemical as per OECD Guideline 423 (Acute Oral toxicity - Acute Toxic Class Method) in Wistar rats. The dose formulation was prepared by using Milli-Q water and administered as a single oral gavage to overnight fasted (16 to 18 hours) three female rats (G1-FTS) at the dose of 300 mg/kg body weight. There were no clinical signs of toxicity and pre-terminal deaths observed. As all the rats survived at this step, the test was confirmed with three additional female animals with the same dose of 300 mg/kg body weight (G1-STS). There were no clinical signs of toxicity and pre-terminal deaths observed at this step. Based on the scheme - Annex 2c of the guideline OECD 423, the test was continued at the dose of 2000 mg/kg body weight (G2-FTS). The two rats (Rw314 and Rw315) were found dead at 0.5 hours post dose observations, hence as per the scheme - Annex 2c of the guideline OECD 423, the further dosing was stopped. The rats were observed for mortality and clinical signs for 14 days post treatment. Body weights were recorded prior to dosing on day 1 and again on days 8 and 15. Gross necropsy was performed for all the rats at termination. The body weight growth of all survived rats was unaffected by the test chemical. There were no gross pathological changes at necropsy, hence histopathology was not performed. Based on the results of the present study, the LD50 value of the test chemical was considered to be 1000 mg/kg body weight. Thus, the test chemical was classified in “Category 4 (300 – ≤ 2000)” criteria of CLP.

This is supported by another similar OECD 423 study carried out for the test chemical in rats. Nine female Wistar rats were selected for acute oral toxicity study. The animals were fasted for minimum 16-18 hours prior to dosing and for 3-4 hours post dosing, with food withheld but drinking water provided ad libitum. The time intervals between dosing were determined by the onset, duration and severity of toxic signs. Three rats of first group were dosed with starting dose of 300 mg/kg body weight and the animals did not show any mortality so another three animals of the same group were dosed with 300 mg/kg body weight and no mortality was observed. Hence three rats of second group were dosed with 2000 mg/kg weight. All the rats at 2000mg/kg were found dead on day 0 post dosing. Hence, further dosing was stopped. Body weights were re­corded on day 0 (prior to dosing), 7 and 14. Body weight gain was observed in all surviving animals treated with 300 mg/kg body weight, during the 14 day observation period, as compared to day 0. At 300 mg/kg, all the six animals were observed normal throughout the experiment period. At 2000 mg/kg, animal no. 7 was observed with mild tremors at 30 minutes, mild to moderate abdominal breathing at 30 minutes and 1 hour and sternal recumbency at 1 hour followed by found dead. Animal nos. 8 and 9 were observed with mild tremors, moderate abdominal breathing, sternal recumbency and moderate salivation at 30 minutes followed by found dead. No external gross pathological changes were seen in all the six animals treated with 300 mg/kg body weight during terminal sacrifice. At 2000 mg/kg, animal no. 7 was observed with no abnormalities, whereas animal nos. 8 and 9 were observed with wet around mouth. No internal gross pathological changes were seen in all the six animals treated with 300 mg/kg body weight during terminal sacrifice. At 2000 mg/kg, all three animals were observed with severe red discoloration of all lobes lungs and test chemical was observed in stomach and intestine. Under the conditions of this study, the acute oral toxicity dose LD50 value of test chemical was considered in between 300-2000 mg/kg body weight. Thus by considering the CLP criteria for acute toxicity rating for the chemicals, it infers that the given test chemical exhibits acute oral toxicity in “Category 4” LD50 >300 to ≤ 2000 mg/kg body weight.

Based on the available results and applying the weight of evidence approach, the acute oral median lethal dose for the test chemical can be considered to lie between 300-2000 mg/kg. Thus by considering the CLP criteria for acute toxicity rating for the chemicals, the test chemical can be classified under the category “Category 4”.

Acute toxicity: inhalation

The study doesnot need to be conducted due to the low vapor pressure of the chemical and its exposure as aerosols, dusts, mists or vapors of inhalable size during manufacture/use is highly unlikely. The test chemical has very low vapor pressure of 2.61E-10 Pa which is equivalent to 1.96E-12 mm Hg at 25 ° C, so the potential for the generation of inhalable vapour is low. Also the normal conditions of use of this substance will not result in aerosols, particles or droplets of an inhalable size, so exposure to humans via the inhalatory route will be unlikely to occur, and therefore this end point was considered for waiver

Acute toxicity: dermal

The study neednot be conducted as the substance is classified as corrosive to skin. In accordance with ANNEX VII Colum 2 of the REACH regulation, the study need not be conducted if the substance is a strong acid (pH<=2.0) or strong base (pH=> 11.5). The experimental pH of the test chemical was 14. Hence, based on the high pH of the test chemical, the acute dermal toxicity study was considered for waiver.

Justification for classification or non-classification

Based on the available results and applying the weight of evidence approach, the test chemical can be classified under the category “Category 4” for oral toxicity as per CLP Regulation.