Tetrabutylphosphonium chloride

Endpoint summary

Description of key information

In a reliable acute oral toxicity study performed according to OECD 423 and according to GLP principles on the analogue substance, the LD50 cut-off value was determined to be 500 mg/kg bw

 

In two acute inhalation toxicity tests performed accord to the US EPA OPPTS 870.1300, the LC50 was for 1h > 0.04 mg/L and for 4h < 0.05 mg/L

 

The LD50 for acute dermal exposure with the ethylene carbonate vehicle was 500-600 mg/kg. However, the LD50 by acute dermal exposure of undiluted compound was 225 mg/kg.

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:

September - December 2015

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 423 (Acute Oral toxicity - Acute Toxic Class Method)

Version / remarks:

2001

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.1 tris (Acute Oral Toxicity - Acute Toxic Class Method)

Version / remarks:

2008, inlcuding most recent amendments

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.1100 (Acute Oral Toxicity)

Version / remarks:

2002

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: Japanese Ministry of Agriculture, Forestry and Fisheries (JMAFF), 12 Nousan, Notification No 8147, November 2000, including the most recent partial revisions.

Version / remarks:

2000

Deviations:

no

GLP compliance:

yes

Test type:

acute toxic class method

Limit test:

no

Species:

rat

Strain:

other: Crl:WI (Han)

Sex:

female

Details on test animals or test system and environmental conditions:

- Source: Charles River Deutschland, Sulzfeld, Germany.
- Age at study initiation: Young adult animals (approx. 10-11 weeks old)
- Weight at study initiation: Body weight variation was within +/- 20% of the sex mean (158 - 201 grams).
- Fasting period before study: Animals were deprived of food overnight prior to dosing and until 3-4 hours after administration of the test item.
- Housing: Group housing of 3 animals per cage in labeled Macrolon cages containing sterilized sawdust as bedding material and paper as cage-enrichment.
- Diet: Free access to pelleted rodent diet (SM R/M-Z from SSNIFF® Spezialdiäten GmbH, Soest, Germany).
- Water: Free access to tap water.
- Acclimation period: At least 5 days

ENVIRONMENTAL CONDITIONS
Set to maintain:
- Temperature (°C): 18 – 24
- Humidity (%): 40 - 70
- Air changes (per hr): approx 10
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: 29 September 2015 to 22 October 2015

Route of administration:

oral: gavage

Vehicle:

propylene glycol

Remarks:

specific gravity 1.036

Details on oral exposure:

GAVAGE METHOD: plastic feeding tubes.

Frequency: single dosage, on Day 1.

VEHICLE
- Justification for choice of vehicle: The vehicle was selected based on trial formulations performed at WIL Research Europe and on test substance data supplied by the sponsor.
- Stability for at least 6 hours at room temperature; 8 days in the refrigerator and 3 weeks in the freezer is confirmed over the concentration range 1 to 200 mg/mL

DOSAGE PREPARATION
The preparations (w/w) were dosed within 4 hours after adding the vehicle to the test item. Homogeneity was assessed by visual inspection of the solutions and the formulations were stirred during dosing, which ensures homogeneity sufficient for these kinds of studies. Adjustment was made for specific gravity of the vehicle. No correction was made for purity of the test item. The concentration of the test item in vehicle was varied to allow constant dosage volume in terms of mL/kg body weight.

The toxicity of the test item was assessed by stepwise treatment of groups of 3 females. The first group was treated at a dose level of 300 mg/kg bw. The absence or presence of mortality of animals dosed at one step determined the next step, based on the test procedure defined in the guidelines. The onset, duration and severity of the signs of toxicity were taken into account for determination of the time interval between the dose groups.

Doses:

300 mg/kg (10 mL/kg) bw
2000 mg/kg (10 mL/kg) bw

No. of animals per sex per dose:

300 mg/kg bw: 6 (2 groups of three females in a stepwise manner)
2000 mg/kg bw: 3

Control animals:

no

Details on study design:

Duration of observation period following administration: 14 days

Frequency of observations and weighing:
- Mortality/Viability: Twice daily. The time of death was recorded as precisely as possible.
- Body weights: Days 1 (pre-administration), 8 and 15.
- Clinical signs: At periodic intervals on the day of dosing (Day 1) and once daily thereafter, until Day 15.

Necropsy of survivors performed: The animals surviving to the end of the observation period were sacrificed by oxygen/carbon dioxide procedure. All animals assigned to the study were subjected to necropsy and descriptions of all internal macroscopic abnormalities recorded.

Other examinations performed: none.

Statistics:

No statistical analysis was performed (The method used is not intended to allow the calculation of a precise LD50 value).

Key result

Sex:

female

Dose descriptor:

LD50 cut-off

Effect level:

500 mg/kg bw

Based on:

test mat.

Mortality:

At 2000 mg/kg bw, all animals were found dead on day 1.
At 300 mg/kg bw, no mortality occurred.

Clinical signs:

other: At 2000 mg/kg bw, hunched posture and salivation were noted for all animals on Day 1. At 300 mg/kg bw, lethargy, hunched posture, uncoordinated movements, piloerection and/or ptosis were noted for the animals between Days 1 and 3.

Gross pathology:

No abnormalities were found at macroscopic post mortem examination in any of the animals.

Interpretation of results:

Category 4 based on GHS criteria

Conclusions:

In an acute oral toxicity study with rats, performed according to OECD/EC test guidelines, an oral LD50 value of Tetrabutylphosphonium Bromide; CYPHOS® 442 Phosphonium Salt was established to be within the range of 300-2000 mg/kg bw. According to the OECD 423 test guideline, the LD50 cut-off value was considered to be 500 mg/kg bw. According to GHS criteria (2011) (including all amendments), Tetrabutylphosphonium Bromide; CYPHOS® 442 Phosphonium Salt should be classified as: harmful if swallowed (Category 4) for acute toxicity by the oral route.

Executive summary:

An assessment of acute oral toxicity with Tetrabutylphosphonium Bromide; CYPHOS® 442 Phosphonium Salt in the rat (Acute Toxic Class Method) was performed according to OECD guidelines and in accordance with GLP principles. Initially, Tetrabutylphosphonium Bromide; CYPHOS® 442 Phosphonium Salt was administered by oral gavage to three female Wistar rats at 300 mg/kg bw. In a stepwise procedure two additional groups of three females were dosed at 2000 and 300 mg/kg bw. At 2000 mg/kg, all animals were found dead on day 1. At 300 mg/kg bw, no mortality occurred. At 2000 mg/kg bw, hunched posture and salivation were noted for all animals on Day 1. At 300 mg/kg bw, lethargy, hunched posture, uncoordinated movements, piloerection and/or ptosis were noted for the animals between days 1 and 3. The mean body weight gain shown by the surviving animals over the study period was considered to be similar to that expected for normal untreated animals of the same age and strain. No abnormalities were found at macroscopic post mortem examination in any of the animals.

The oral LD50 value of Tetrabutylphosphonium Bromide; CYPHOS® 442 Phosphonium Salt in Wistar rats was established to be within the range of 300-2000 mg/kg bw.

According to the OECD 423 test guideline, the LD50 cut-off value was considered to be 500 mg/kg bw.

Based on these results:

- according to the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) of the United Nations (2011) (including all amendments), Tetrabutylphosphonium Bromide; CYPHOS® 442 Phosphonium Salt should be classified as: harmful if swallowed (Category 4) for acute toxicity by the oral route;

- according to the Regulation (EC) No 1272/2008 on classification, labelling and packaging of items and mixtures (including all amendments), Tetrabutylphosphonium Bromide; CYPHOS® 442 Phosphonium Salt should be classified as Category 4 and should be labeled as H302: Harmful if swallowed.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LD50

Value:

500 mg/kg bw

Quality of whole database:

Study was performed according to OECD 423 guideline (2001) and in accordance with GLP principles.

Acute toxicity: via inhalation route

Link to relevant study records

Reference

Reference 1

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2012-12-04 - 2013-01-28

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.1300 (Acute inhalation toxicity)

GLP compliance:

yes

Test type:

fixed concentration procedure

Limit test:

no

Specific details on test material used for the study:

Cyphos 3453W Phosphonium salt
Liquid
Purity: 50% in water
Lot: WEC042091
Expiration date: 30 May 2013

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Harlan Laboratorins Inc
- Females nulliparous and non-pregnant
- Age at study initiation: 11-12 weeks
- Weight at study initiation: 310-355g for males and 204-245g for females
- Housing: singly housed in suspended stainless steel caging with mesh floors, size recommendations of the Guide for the Care and Use of laboratory animals, litter paper beneath the cage and changed three times per week
- Diet: Harlan Teklad Global 16% Protein Rodent Diet ad libitum except during the exposure
- Water: Filtered tap water ad libitum by an automatic water dispenser except during exposure
- Acclimation period: 22 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19-23 °C
- Humidity (%): 42-50 %
- Air changes/hour: 12
- Photoperiod (hrs dark / hrs light): 12-hour light/dark cycle

Route of administration:

inhalation: aerosol

Type of inhalation exposure:

nose only

Vehicle:

air

Mass median aerodynamic diameter (MMAD):

1.93 µm

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: Nose Only inhalation chamber, ADG Developments LTD
- Exposure chamber volume: 28 liters
- Method of holding animals in test chamber: Animals were individually housed in polycarbonate holding tubes wich seal to the chamber with an "O" ring during exposure. The base unit terminiates the chamber with 0.5-inch diameter tube for discarged air.
- Source and rate of air: 20.0 liters per minute of filtered air was supplied by an air compressor to the spray atomization nozzle. An additional 10.0 liters per minute of compressed mixing air was supplied using air from the same compressor which was introduced into the chamber to help uniformly distribute the test atmosphere by creating a vortex at the chamber inlet. Chamber airflow was monitored throughout the exposure period and recorded periodically. Total airflow was 30.3 liters per minute. Based on the volume fo the inhalation chamber, this airflow provided approximately 64 air changes per hour during the study.
- System of generating particulates/aerosols: The test atmosphere was generated using a 1/4 inch JCO atomizer, FC3 fluid cap and 70SS air cap. Compressed/mixing air was supplied at 30 psi. The test substance was metered to the atomization nozzle through BPT-Size 13 tubing, using a peristaltic pump.
- Method of particle size determination: An eight-stage ACFM Andersen Ambient Particle Sizing Sampler was used to assess the particle size distribution of the test atmospohere. A sample was withdrawn from the breathing zone of the animals at one interval. The filter paper collection stages were weighed before and after sampling to determine the mass collected upon each stage. The aerodynamic mass median diameter and geometric standard deviation were determined graphically using two-cycle logarithmic probit axes.
- Temperature, humidity, pressure in air chamber: The exposure tube temperature and relative humidity ranges during exposure were 20 °C and 21-26%, respectively. The room temperature and relative humidity ranges during exposure were 21 °C and 22-28%, respectively.

TEST ATMOSPHERE
- Brief description of analytical method used: Gravimetric samples were withdrawn at 2 intervals from the breathing zone of the animals. Samples were collected using 37 mm glass fiber filters in a filter holder attached by 1/4 inch Tygon tubing to a vacuum pump. Filer papers were weighed before and after collection to determine the mass collected. This value was divided by the total volume of air sampled to determine the chamber concentration. The collections were carried out for 5 minutes at airflows of 1 liter per minute. Sample airflows were measured unsing a Mass Flowmeter.
- Samples taken from breathing zone: yes

TEST ATMOSPHERE
- MMAD (Mass median aerodynamic diameter): 1.93 µm

Analytical verification of test atmosphere concentrations:

yes

Duration of exposure:

1 h

Remarks on duration:

1h and 5min: The exposure period was extended beyond 1 hour to allow the chamber to reach equilibrium.

Concentrations:

Gravimetric: 0.04 mg/L

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: Individual body weights were recorded prior to the exposure and again on days 1, 3, 7 and 14. All animals were observed for mortality during the exposure period. They were examined for signs of gross toxicity and behavioral changes upon removal and at least once daily thereafter up to 14 days.
- Necropsy of survivors performed: yes
- Other examinations performed: gross evaluation of skin and fur, eyes and mucous membranes, respiratory, circulatory, autonomic and central nervous systems, somatomotor activity and behavior pattern. Particular attention was directed to observation of tremors, convulsions, salivation, diarrhea and coma.

Key result

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 0.04 mg/L air (analytical)

Exp. duration:

1 h

Mortality:

All animals survived exposure to the test atmosphere.

Clinical signs:

other: Following exposure, all rats exhibited abnormal respiration, hypoactivity and/or ano-genital staining. However, all aniamls recovered from the above symptoms by Day 3 and appeared active and healthy for the remainder of the observation period.

Body weight:

Although all animals lost body weight on Day 1, they showed continued weights gain thereafter and gained weight through Day 14.

Gross pathology:

No gross abnormalities were noted for any of the animals when necropsied at the conclusion of the 14-day observation period.

Interpretation of results:

study cannot be used for classification

Conclusions:

Under the conditions of this study, the single 1h exposure acute inhalation LC50 of Cyphos 3453W Phosphonium salt is more than 0.04 mg/L in male and female rats.

Executive summary:

The acute inhalation toxicity of Tributyltetradecylphosphonium chloride in the rat was investigated according to the US EPA OPPTS 870.1300 guideline and under GLP.

The substance was administered as an aerosol by inhalation for 1 hour to one group of five male and five female rats at 0.04 mg/L (Gravimetric concentration). Animals were subjected to daily observations and determination of body weights on Days 1, 3, 7, 14 and at death. Macroscopic examination was performed. 

The gravimetric chamber concentration was 0.04 mg/L. Based on graphic analysis of the particle size distribution as measured with an ACFM Andersen Ambient Particle Sizing Sampler, the mass median aerodynamic diameter was estimated to be 1.93 µm (GSD 1.95).

All animals survived the exposure.

Based on the above observations, the inhalatory LC50 1h value of Tributyltetradecylphosphonium chloride in rats was established to be > 0.04 mg/L..

Reference 2

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2012-07-06 - 2012-10-18

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.1300 (Acute inhalation toxicity)

GLP compliance:

yes

Test type:

fixed concentration procedure

Limit test:

yes

Specific details on test material used for the study:

Cyphos 3453W Phosphonium salt
Liquid
Purity: 50% in water
Lot: WEC042091
Expiration date: 30 May 2013

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Harlan Laboratorins Inc
- Females nulliparous and non-pregnant
- Age at study initiation: 10 weeks
- Weight at study initiation: 269-295g for males and 201-225g for females
- Housing: singly housed in suspended stainless steel caging with mesh floors, size recommendations of the Guide for the Care and Use of laboratory animals, litter paper beneath the cage and changed three times per week
- Diet: Harlan Teklad Global 16% Protein Rodent Diet ad libitum except during the exposure
- Water: Filtered tap water ad libitum by an automatic water dispenser except during exposure
- Acclimation period: 13 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19-23 °C
- Humidity (%): 56-74 % (Humidity was above the targeted upper limit for five days and a portable dehumidifier was used to lower the humidity levels)
- Photoperiod (hrs dark / hrs light): 12-hour light/dark cycle

Route of administration:

inhalation: aerosol

Type of inhalation exposure:

nose only

Vehicle:

air

Mass median aerodynamic diameter (MMAD):

1.92 µm

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: Nose Only inhalation chamber, ADG Developments LTD
- Exposure chamber volume: 28 liters
- Method of holding animals in test chamber: Animals were individually housed in polycarbonate holding tubes wich seal to the chamber with an "O" ring during exposure. The base unit terminiates the chamber with 0.5-inch diameter tube for discarged air.
- Source and rate of air: 20.0 liters per minute of filtered air was supplied by an air compressor to the spray atomization nozzle. An additional 10.0 liters per minute of compressed mixing air was supplied using air from the same compressor which was introduced into the chamber to help uniformly distribute the test atmosphere by creating a vortex at the chamber inlet. Chamber airflow was monitored throughout the exposure period and recorded periodically. Total airflow was 30.3 liters per minute. Based on the volume fo the inhalation chamber, this airflow provided approximately 64 air changes per hour during the study.
- System of generating particulates/aerosols: The test atmosphere was generated using a 1/4 inch JCO atomizer, FC3 fluid cap and 70SS air cap. Compressed/mixing air was supplied at 30/30 psi. The test substance was metered to the atomization nozzle through BPT-Size 14 tubing, using a Syringe pump.
- Method of particle size determination: An eight-stage ACFM Andersen Ambient Particle Sizing Sampler was used to assess the particle size distribution of the test atmospohere. Samples were withdrawn from the breathing zone of the animals at two intervals. The filter paper collection stages were weighed before and after sampling to determine the mass collected upon each stage. The aerodynamic mass median diameter and geometric standard deviation were determined graphically using two-cycle logarithmic probit axes.
- Temperature, humidity, pressure in air chamber: The exposure tube temperature and relative humidity ranges during exposure were 22-24 °C and 24-34%, respectively. The room temperature and relative humidity ranges during exposure were 21-23 °C and 55-60%, respectively.

TEST ATMOSPHERE
- Brief description of analytical method used: Gravimetric samples were withdrawn at 6 intervals from the breathing zone of the animals. Samples were collected using 37 mm glass fiber filters in a filter holder attached by 1/4 inch Tygon tubing to a vacuum pump. Filer papers were weighed before and after collection to determine the mass collected. This value was divided by the total volume of air sampled to determine the chamber concentration. The collections were carried out for 5 minutes at airflows of 4 liters per minute. Sample airflows were measured unsing a Mass Flowmeter.
- Samples taken from breathing zone: yes

TEST ATMOSPHERE
- MMAD (Mass median aerodynamic diameter): 1.92 µm

Analytical verification of test atmosphere concentrations:

yes

Duration of exposure:

4 h

Remarks on duration:

4h and 10min: The exposure period was extended beyond 4hours to allow the chamber to reach equilibrium.

Concentrations:

Gravimetric: 0.053 +- 0.007 mg/L

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: Individual body weights were recorded prior to the exposure and again on days 1, 3, 7 and 14 or after death. All animals were observed for mortality during the exposure period. They were examined for signs of gross toxicity and behavioral changes upon removal and at least once daily thereafter up to 14 days.
- Necropsy of survivors performed: yes
- Other examinations performed: gross evaluation of skin and fur, eyes and mucous membranes, respiratory, circulatory, autonomic and central nervous systems, somatomotor activity and behavior pattern. Particular attention was directed to observation of tremors, convulsions, salivation, diarrhea and coma.

Key result

Sex:

male/female

Dose descriptor:

LC50

Effect level:

< 0.05 mg/L air (analytical)

Exp. duration:

4 h

Mortality:

Within three days of exposure to the test atmosphere, four males and two females died and one male and two females were euthanized for humane reasons. Prior to death, the animals were hypoactive and exhibited abnormal respiration, gasping, abdominal distention, ano-genital staining, facial staining, nasal discharge, prone position and/or moribund condition.

Clinical signs:

other: Following exposure, the clinical signs noted for the surviving female included hypoactivity, ano-genital staining, abnormal respiration, gasping and abdominal distention.

Body weight:

Although the surviving female lost weight through Day 3, the animal showed a continued weight gain thereafter through Day 14.

Gross pathology:

Gross necropsy of the decedents revealed discolored lungs, distention of stomach and/or intestines and/or mottled liver. No gross abnormalities were noted for the surviving euthanized female when necropsied at the conclusion of the 14-day observation period.

Interpretation of results:

Category 1 based on GHS criteria

Conclusions:

Under the conditions of this study, the single 4h exposure acute inhalation LC50 of Cyphos 3453W Phosphonium salt is less than 0.05 mg/L in male and female rats.

Executive summary:

The acute inhalation toxicity of Tributyltetradecylphosphonium chloride in the rat was investigated according to the US EPA OPPTS 870.1300 guideline and under GLP.

The substance was administered as an aerosol by inhalation for 4 hours to one group of five male and five female rats at 0.05 mg/L. Animals were subjected to daily observations and determination of body weights on Days 1, 3, 7, 14 and at death. Macroscopic examination was performed. 

The gravimetric chamber concentration was 0.053 mg/L. Based on graphic analysis of the particle size distribution as measured with an ACFM Andersen Ambient Particle Sizing Sampler, the mass median aerodynamic diameter was estimated to be 1.92 µm (sample 1: 1.69 µm - GSD 2.24; sample 2: 2.14 µm - GSD 2.35 ).

Within three days of exposure to the test atmosphere, four males and two females died and one male and two females were euthanized for humane reasons. Prior to death, the animals were hypoactive and exhibited abnormal respiration, gasping, abdominal distention, ano-genital staining, facial staining, nasal discharge, prone position and/or moribund condition. 

Based on the above observations, the inhalatory LC50 4h value of Tributyltetradecylphosphonium chloride in rats was established to be < 0.05 mg/L.

Based on these results, the substance should be classified as fatal if inhaled according to the CLP and the UN GHS.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LC50

Value:

50 mg/m³ air

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:

1982

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

test procedure in accordance with generally accepted scientific standards and described in sufficient detail

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

GLP compliance:

not specified

Test type:

standard acute method

Limit test:

no

Specific details on test material used for the study:

Purity > 98%

Species:

rabbit

Strain:

New Zealand White

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Weight at study initiation: 2.3 - 3.2 kg
- Acclimation period: 14 days

Type of coverage:

occlusive

Vehicle:

other: Ethylene carbonate

Remarks:

The substance was tested both with and without vehicle.

Details on dermal exposure:

TEST SITE
- Area of exposure: no less than 10% of the body surface area was available for application
- Type of wrap if used: The trunk of each animal was wrapped with an impermeable plastic film of Saran Wrap

REMOVAL OF TEST SUBSTANCE
- Washing (if done): Yes
- Time after start of exposure: 24h

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 2 ml/kg
- Concentration (if solution): 11.9 to 66.8% w/w
- Constant volume used: yes

Duration of exposure:

24h

Doses:

Tetrabutylphosphonium chloride with Ethylene carbonate: 159, 302, 506, 676, 862 and 1368 mg/kg
Pure Tetrabutylphosphonium chloride: 100, 200, 300 and 400 mg/kg

No. of animals per sex per dose:

4

Control animals:

yes

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Animals were observed for any signs of systemic toxicity and/or death frequently during the day of administration and thereafter, at least twice a day for 14 days. Body weights were recorded just prior to dosing and again on day 7 and day 14.
- Necropsy of survivors performed: yes
- Other examinations performed: Gross necropsy and examination were performed on each animal, whether it died during the study or was killed at the end of the study. The brain with spinal cord, heart, each kidney, spleen, liver and lungs were weighed.

Statistics:

Each LC50 was calculated according to the method of Litchfield and Wilcoxon. The results of the quantitative continuous variables, such as body weight and organ weight changes, were intercompared for the test groups versus the control group by analysis of variance and by a multiple range test. These analyses included all animals alive at the appropriate weighing time. When a significant F value in the analysis of variance was observed, the latter test was employed to determine which group (or groups) differed significantly from which other group (groups).

Key result

Sex:

male

Dose descriptor:

LD50

Effect level:

225 mg/kg bw

Based on:

test mat.

Remarks on result:

other: Pure substance

Sex:

male

Dose descriptor:

LD50

Effect level:

600 mg/kg bw

Based on:

test mat.

Remarks on result:

other: with EC as a vehicle

Sex:

female

Dose descriptor:

LD50

Effect level:

500 mg/kg bw

Based on:

test mat.

Remarks on result:

other: with EC as a vehicle

Mortality:

See tables below for details. Death was preceded by cyanosis and convulsion, and occurred within 24h of dosing.

Clinical signs:

other: Clinical signs of Bu4PCl toxicity included weight loss, ataxia, hypotonia (head and ear droop), and labored breathing. These signs persisted for 2-4 days in surviving males and for 1-9 days in surviving females.

Gross pathology:

The mean male kidney weight/body weight ratios for both kindeys of the 506 and 862 mg/kg test groups were significantly increased as compared to those of the 676, 1368 mg/kg test groups and the control group. The mean male brain with spinal cord weight/body weight ratio of the 862 mg/kg exposure group was significantly higher than those of the 506, 676, 1368 mg/kg test groups and the control group. The mean female brain with spinal cord weight/body weight ratios of the 505, 676 and 862 mg/kg test groups were significantly higher than those of the 158, 302 mg/kg test groups and the control group.
The other mean organ weights (absolute and organ wt/body wt ratios) of rabbits receiving applications of Bu4PCl were comparable to controls.

BU4PCl with EC
Application in mg/kg	Number of dead/Number of dosed
	Male	Female
159	0/4	0/4
302	*	0/4
506	*	2/4
676	3/4	4/4
862	3/4	4/4
1368	4/4	*
LD50	600	500
	mg/kg	mg/kg

* Dose not tested

Pure BU4PCl
Application in mg/kg	Number of dead/Number of dosed
	Male
100	0/5
200	0/5
300	3/5
400	5/5
LD50	600
	mg/kg

Interpretation of results:

Category 3 based on GHS criteria

Conclusions:

The LD50 for acute dermal exposure with the ethylene carbonate vehicle was 500-600 mg/kg. However, the LD50 by acute dermal exposure of undiluted compound was 225 mg/kg.

Executive summary:

The acute dermal toxicity of Tetrabutylphosphonium chloride was tested according to acceptable scientific standards. The product was tested in ethylene carbonate as a vehicle but also as the pure undiluted substance.

Tetrabutylphosphonium chloride was applied to the skin of 4 or 5 rabbits of each sex at 159, 302, 506, 676, 862 and 1368 mg/kg in the vehicle or at 100, 200, 300 and 400 mg/kg as a pure compound for 24 hours. Animals were subjected to daily observations and weekly determination of body weight. Necropsy was performed upon death or after terminal sacrifice at the end of the study period.

The LD50 for acute dermal exposure with the ethylene carbonate vehicle was 500 (female) -600 (male) mg/kg. However, the LD50 by acute dermal exposure of undiluted compound was 225 mg/kg (male).

Based on these results, Tetrabutylphosphonium chloride should be classified as Category 3 for acute dermal toxicity according to the CLP and the UN GHS.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LD50

Value:

225 mg/kg bw