4-bromo-3,3,4,4-tetrafluorobut-1-ene

Endpoint summary

Description of key information

Acute oral toxicity: Rat LD50 > 2000 mg/kg bw (OECD 423 Acute Toxic Class Method).

Acute inhalation toxicity: Rat LC50 > 84650 mg/m3 (similar to Fixed Concentration Procedure, Reliability =2)

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:

17 March 2020 - 09 April 2020

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)

Deviations:

no

GLP compliance:

yes

Test type:

acute toxic class method

Limit test:

yes

Species:

rat

Strain:

Sprague-Dawley

Remarks:

Crl:CD(SD)

Sex:

male

Details on test animals or test system and environmental conditions:

- Source: Charles River Raleigh, Raleigh, NC
- Age at study initiation: 8 weeks old
- Weight at study initiation: 244 to 302 g
- Fasting period before study: Animals were fasted the day before dosing.
- Housing: Group housing (up to 3 animals per cage) in polycarbonate cages, containing appropriate bedding material and an automatic watering valve. Animals were socially housed for psychological/environmental enrichment and were provided with items such as a chewing object. Edible enrichment treats were also offered throughout the study.
- Diet: Ad libitum (except during designated procedures), Pelleted Lab Diet Certified CR Rodent Diet 5CR4. (Based on analysis provided by the supplier it is considered that there were no known contaminants in the feed that interfered with the objectives of the study)
- Water: Ad libitum (except during designated procedures), Municipal tap water, treated by reverse osmosis and ultraviolet irradiation (Based on periodic analysis of the water it is considered that there were no known contaminants in the water that interfered with the outcome of the study.)
- Acclimation period: At least 6 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20-26 (targeted conditions)
- Humidity (%): 30-70 (targeted conditions)
- Air changes (per hr): 10 or more
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: 23 March 2020 - 09 April 2020

Route of administration:

oral: gavage

Vehicle:

unchanged (no vehicle)

Details on oral exposure:

VEHICLE
No vehicle was used, the substance was administered as received.

DOSE VOLUME APPLIED:
2000 mg/kg bodyweight
The dose volume (1.29 mL/kg) did not exceed 20 mL/kg for aqueous preparations.

CLASS METHOD
Rationale for the selection of the starting dose: Because the test substance was thought to be of low toxicity, a limit test was conducted at a single high-dose level (e.g., 2000 mg/kg).

Doses:

2000 mg/kg bodyweight

No. of animals per sex per dose:

2 groups of 3 males/dose

Control animals:

no

Details on study design:

The test substance was administered using a syringe attached to a gavage cannula. Individual doses were calculated based on the animal’s fasted (Day 0) body weight. The dose formulations were inverted 5 times prior to dosing. Animals were returned to ad libitum feeding after dosing.

Duration of observation period following administration: 14 days
Frequency of observations and weighing:
- Mortality/Viability: twice daily;
- Body weights: on the day of dosing (fasted weight) and on day 0 (pre-administration), 7 and 14;
- Clinical signs: at periodic intervals on the day of dosing (day 0) and once daily thereafter
- Necropsy of survivors performed: yes
- Other examinations performed: no

Statistics:

The LD50 cut-off value was established based on OECD guideline 423. No statistical analysis was performed.

Key result

Sex:

male

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

No mortality occurred during the study.

Clinical signs:

There were no test substance-related clinical observations.

Body weight:

There were no test substance-related effects on body weight. All dosed animals gained weight from Day 0 to Day 14.

Gross pathology:

There were no test substance-related macroscopic pathology findings. Dark discoloration of the thymus (left lobe) in one animal was observed.This macroscopic pathology finding is a common incidental finding in toxicity studies for this age and strain of rat.

Interpretation of results:

GHS criteria not met

Conclusions:

Based on an acute toxicity study performed according to OECD TG 423 and in accordance with GLP principles the acute oral LD50 of BTFB was determined to be > 2000 mg/kg in the male rat.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

> 2 000 mg/kg bw

Quality of whole database:

A GLP compliant OECD 423 acute oral toxicity study was performed on the test substance (Reliability = 1). Applying the acute toxic class method: A group of 3 male Sprague Dawley Crl:CD(SD) rats (Group 1) was dosed via oral gavage with 2000 mg/kg BTFB. All animals from Group 1 survived with no clinical findings; therefore, 3 additional male rats (Group 2) were dosed via oral gavage with 2000 mg/kg BTFB.
No mortality occurred and no significant clinical signs were observed during the study. All animals gained body weight during the test period. No test substance-related gross internal findings were observed at scheduled necropsy.

Under the conditions of this study, the acute oral LD50 of BTFB was determined to be > 2000 mg/kg in the male rat. When applying the OECD test guideline 423 classification criteria, no GHS classification is warranted.

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:

28 January 1980 - 22 February 1980

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

test procedure in accordance with national standard methods with acceptable restrictions

Justification for type of information:

Although a subacute study is not typically used to determine an acute inhalation classification, this study included concentrations 4 times above the current recommended toxicity testing limit. The exposure concentrations were measured, and rats were treated for 6 hours per day. Since no mortality or significant clinical signs beyond narcosis were noted, this study is considered sufficient to support a STOT SE 3 classification. Pathology examinations and clinical chemistry measurements were also included in the study allowing a reliable prediction of no classification for acute toxicity by inhalation.

Qualifier:

no guideline available

Principles of method if other than guideline:

- Principle of test: to observe the effects of the test substance - BTFB on male rats after repeated inhalation exposures over a 2 week period.
- Short description of test conditions: Male Crl:CD rats were exposed to BTFB at 0.10% or 1.03% in air with the control group exposed to air only for 6hrs/day, 5 days/week for 2 weeks. Clinical observations were made throughout the testing period with clinical chemical analyses performed following 10th exposure. Pathological examinations performed following necropsy with body and organ weigh analysis performed.
- Parameters analysed / observed:Clinical observations, pathological analysis, clinical chemistry, body weight

GLP compliance:

no

Limit test:

no

Species:

rat

Strain:

other: Crl:CD

Sex:

male

Route of administration:

inhalation: vapour

Type of inhalation exposure:

whole body

Remarks:

via glass exposure chambers

Vehicle:

air

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: Glass exposure chambers
- Method of holding animals in test chamber: Not stated
- Source and rate of air: Not stated
- Method of conditioning air: Not stated
- System of generating particulates/aerosols: Not stated
- Temperature, humidity, pressure in air chamber: Temperature = less than or equal to 30˚C, Atmosphere = greater than or equal to 19%
- Air flow rate: Not stated
- Air change rate: Not stated
- Method of particle size determination: Not stated
- Treatment of exhaust air: Not stated

TEST ATMOSPHERE
- Brief description of analytical method used: Test item vapours were analysed on a HP 5700A GC with flame ionised detector and an injection splitter.
- Samples taken from breathing zone: yes

VEHICLE (if applicable)
- Justification for use and choice of vehicle: Not stated
- Composition of vehicle: Air
- Type and concentration of dispersant aid (if powder): N/A
- Concentration of test material in vehicle: 0.1% and 1%
- Lot/batch no. of vehicle (if requir

Analytical verification of test atmosphere concentrations:

yes

Remarks:

GC with flame ionisation detector

Duration of exposure:

6 h

Remarks on duration:

5 days a week for 2 weeks

Concentrations:

1% = 84650 mg/m3 = 84.65 mg/L
0.1% = 8465 mg/m3 = 8.465 mg/L

No. of animals per sex per dose:

10

Control animals:

yes

Remarks:

0% concentration

Details on study design:

- Dose selection rationale: Not stated
- Rationale for animal assignment (if not random): Not stated
- Fasting period before blood sampling for clinical biochemistry: Not stated
- Rationale for selecting satellite groups: Not stated
- Post-exposure recovery period in satellite groups: Not stated
- Section schedule rationale (if not random): N/A
- Other: N/A

Sex:

male

Dose descriptor:

LC0

Effect level:

84 650 mg/m³ air

Based on:

test mat.

Exp. duration:

6 h

Mortality:

none

Clinical signs:

other: decreased response to sound and loss of coordination.

Body weight:

The mean body weights of animals exposed to test material at 1.0% were significantly lower than those in the control group from exposure 5 through to the recovery period. Rats showed normal rate of weight gain during the recovery period.

Reference 2

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

documentation insufficient for assessment

Remarks:

Test system pre-GLP and pre international test guidelines. Study was performed by a reputable laboratory having 20 plus years of experience in toxicology testing. Information lacking on materials and methods (test material, animals, environmental conditions, inhalation exposure) and results presented.

Principles of method if other than guideline:

- Principle of test: Test is a pre-guideline and pre-GLP acute inhalation toxicity study.
- Short description of test conditions: A sample of the test material was delivered by syringe drive into a headed stainless steel tube. Air was added at 3L/minute and the fume-air mixture was passed into a 20-litre battery jar containing 6 male rats. The fume concentration was determined nominally from metered air and the amount of sample used.
- Parameters analysed / observed: Acute toxicity via Inhalation. Clinical signs and bodyweight were used to determine toxicity.

GLP compliance:

no

Remarks:

Test was conducted before adoption of GLP

Test type:

traditional method

Limit test:

no

Species:

rat

Strain:

other: Ch-R CD rats

Sex:

male

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Rationale for alternative/additional species to rat (if applicable)
- Source: not specified
- Females (if applicable) nulliparous and non-pregnant: N/A
- Rationale for use of males (if applicable): not provided
- Age at study initiation: not provided
- Weight at study initiation: 251-283 grams
- Fasting period before study: Not specified
- Housing: Not specified
- Historical data: Not specified
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: Not specified
- Microbiological status when known: Not specified
- Method of randomisation in assigning animals to test and control groups: Not specified

ENVIRONMENTAL CONDITIONS
- Temperature (°C): Not specified
- Humidity (%): Not specified
- Air changes (per hr): Not specified
- Photoperiod (hrs dark / hrs light): Not specified

IN-LIFE DATES: Not specified

Route of administration:

inhalation: mixture of gas and vapour

Type of inhalation exposure:

whole body

Vehicle:

air

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: Battery Jar
- Exposure chamber volume: 20 litre
- Method of holding animals in test chamber: not restrained
- Source and rate of air (airflow): 3L/minute, no source provided
- Method of conditioning air: not provided
- System of generating particulates/aerosols: not provided
- Method of particle size determination: N/A
- Treatment of exhaust air: not provided
- Temperature, humidity, pressure in air chamber:

TEST ATMOSPHERE
- Brief description of analytical method and equipment used: Not undertaken (see below)
- Samples taken from breathing zone: yes but attempts to utilise flame ionisation gas chromatography as an analytical method had technical difficulties
- Time needed for equilibrium of exposure concentration before animal exposure: Not provided.

VEHICLE
- Composition of vehicle (if applicable): air
- Concentration of test material in vehicle (if applicable): N/A
- Justification of choice of vehicle: N/A
- Lot/batch no. (if required): N/A
- Purity: N/A

CLASS METHOD (if applicable)
- Rationale for the selection of the starting concentration: Not provided.

Analytical verification of test atmosphere concentrations:

no

Remarks:

Attempts to utilise flame ionisation gas chromatography as an analytical method failed due to technical difficulties

Duration of exposure:

4 h

Concentrations:

Nominal concentrations: 528 ppm, 1,841 ppm, 7,116 ppm & 19,300 ppm (5.1, 15.5, 59.9, 163.9 mg/L). Nominal fume concentrations were determined from metered air flow and amount of sample used.

No. of animals per sex per dose:

Not specified. 6 animals per exposure.

Control animals:

no

Details on study design:

No further details specified.

Statistics:

Not undertaken.

Key result

Sex:

male

Dose descriptor:

other: ALC

Effect level:

> 163 900 mg/m³ air (nominal)

Based on:

test mat.

Exp. duration:

4 h

Mortality:

No

Clinical signs:

other: Increasing lethargy with dose, accompanied by chewing, pawing and motor observations at higher doses.

Remarks:

Chewing, pawing , lethargy and temporary prostration and loss of righting at the highest dose. Clinical observations are summarised within table 1.

Body weight:

No changes to bodyweight reported

Gross pathology:

Not reported

Table 1: Clinical observations

Exposure No.	Temperature	Nominal Concentration	Mortality ratio	Air flow	Sample delivery rate	Clinical signs
						During exposure	After exposure
1	54˚C	528ppm 5.3mg/L	0/6	3L/min	0.0096cc/min	Occasional chewing, pawing, and one animal salivating mildly	Normal weight gain
2	54˚C	1,841ppm 15.5mg/L	0/6	3L/min	0.0282/min	Very mild lethargy, chewing and pawing	Normal weight gain
3	54˚C	7,116ppm 59.9mg/L	0/6	3L/min	0.109cc/min	Chewing, pawing, and mild lethargy	Normal weight gain
4	54˚C	19,300ppm 163.9mg/L	0/6	3L/min	0.299cc/min	Very lethargic, some temporary prostration, loss of righting when attempting to walk, pawing and chewing	Normal weight gain

Interpretation of results:

study cannot be used for classification

Remarks:

Supporting study due to Klimish 4 score.

Conclusions:

The rat 4 hour ALC > 163900 mg/m3.

Executive summary:

In this pre-GLP Acute Inhalation toxicity study, the test substance produced clinical symptoms but no deaths in rats exposed to nominal inhaled levels as high as 163.9 mg/L (19,300ppm by volume) for four hours. Central nervous system effects including lethargy, temporary prostration, and loss of righting reflex, were observed during exposure to 163900 mg/m3.  The rats at all test levels showed no abnormal clinical signs during the 14-day post exposure observation period. 

 

The rat 4 hour ALC > 163900 mg/m³

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

discriminating conc.

Value:

84 650 mg/m³

Physical form:

inhalation: vapour

Quality of whole database:

In a pre GLP and test guideline era subacute inhalation toxicity study (Reliability = 2), groups of 10 male albino Crl:CD rats were exposed via inhalation to either 0, 8465, or 84650 mg/m3 (0, 0.1, or 1.0%) BTFB for 6 hours/day. No mortality occurred. During exposure to 84650 mg/m3 BTFB, rats showed a decreased response to sound and loss of coordination. No other significant clinical signs were observed during the study. No test substance-related gross internal findings were observed at scheduled necropsy and no significant clinical chemistry changes were noted.
In a pre GLP and test guideline era acute lethal concentration inhalation study (Reliability = 4), BTFB showed no mortality or moribundity at concentrations up to 163900 mg/m3. Central nervous system effects including lethargy, temporary prostration, and loss of righting reflex, were observed during exposure to BTFB at 163900 mg/m3.

These studies support a rat acute inhalation LC50 of BTFB > 84650 mg/m3. No classification of acute inhalation is needed. A single exposure specific target organ toxicity of Category 3 for CNS effects is warranted.

Acute toxicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

The oral route is considered the most likely route of exposure.

Supporting study - Oral Acute Toxicity: Finlay (2001):

Under the conditions of the study the oral approximate lethal dose (ALD) of the test substance in rats was determined to be greater than 11,000 mg/kg body weight following a single dose via intragastric intubation.  This data is consistent with the key study.

 

Rational for Use of Inhalation Studies:

Although a subacute study is not typically used to determine an acute inhalation classification, this study (Ferenz, R.L. 1980) included concentrations 4 times above the current recommended toxicity testing limit.  The exposure concentrations were measured, and rats were treated for 6 hours per day.   Since no mortality or significant clinical signs beyond narcosis were noted, this study is considered sufficient to support a STOT SE 3 classification.  Pathology examinations and clinical chemistry measurements were also included in the study allowing a reliable prediction of no classification for acute toxicity by inhalation.

Justification for classification or non-classification

Based on the available information, classification and labelling of the substance for acute oral and inhalation toxicity is not warranted.  STOT SE Cat 3 classification for CNS effects is applied in accordance with EU Classification, Labelling and Packaging of Substances and Mixtures (CLP) Regulation No. 1272/2008 and its amendments.