Tetrabutylphosphonium chloride

Acute Toxicity: oral

Administrative data

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

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2015

Report date:

2015

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

2001

Deviations:

no

Test guideline 2

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

Test guideline 3

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.1100 (Acute Oral Toxicity)

Version / remarks:

2002

Deviations:

no

Test guideline 4

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

Test material

Test material information

Constituent 1

Reference substance name:

Tetrabutylphosphonium bromide

EC Number:

221-487-8

EC Name:

Tetrabutylphosphonium bromide

Cas Number:

3115-68-2

Molecular formula:

C16H36P.Br

IUPAC Name:

tetrabutylphosphonium bromide

Test material form:

other: crystallized solid

Details on test material:

- Name of test material (as cited in study report): Tetrabutylphosphonium Bromide; CYPHOS® 442 Phosphonium Salt
- Physical state: Light orange crystallized solid
- Storage condition of test material: At room temperature, container flushed with nitrogen
- Other: hygroscopic

Test animals

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

Administration / exposure

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).

Results and discussion

Effect levels

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.

Applicant's summary and conclusion

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.