[2-Chloro-1,2,2-trifluoro-1-(trifluoromethyl)ethoxy] difluoroacetyl fluoride

Endpoint summary

Description of key information

LD50 oral, rat = 79.5 mg/kg bw

LC50 inhalation, rat > 2.66 - < 5.37 mg/L

LD50 dermal, rat ≥ 250 - ≤ 1000 mg/kg bw

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:

05-MAY-1997 to 11-JUL-1997

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

Deviations:

no

GLP compliance:

yes

Test type:

standard acute method

Limit test:

no

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Rats derived from the Sprague-Dawley strain (Crl: CD(SD)BR)
- Source: Charles River Italia S.p.A. / Via Indipendenza, 11 - 22050 CALCO (Lecco) / ITALY
- Age at study initiation: < 3 months for both sexes
- Weight at study initiation: 347 to 350 g for males and 225 to 300 g for females
- Fasting period before study: yes, about 16 h
- Housing: 5 animals/sex/cage in air-conditioned room (grill cages 40.5 x 38.5 x 18h cm with stainless steel feeder)
- Diet: ad libitum (GLP 4RF21 top certificate pelleted diet produced by Charles River italia’s feed licencee Mucedola S.r.L., Settimo Milanese)
- Water: ad libitum (filtered municipal water)
- Acclimation period: at least 5 days before the start of the test

ENVIRONMENTAL CONDITIONS
- Temperature: 22 ± 2°C
- Humidity: 55 ± 10%
- Air changes: about 20 per hr filtered on HEPA 99.97%
- Photoperiod: 12 hrs dark / 12 hrs light (7 am. - 7 p.m.)

IN-LIFE DATES:
From 08-MAY-1997 to 22-MAY-1997 for females treated with doses of 83 and 58 mg/kg;
from 14-MAY-1997 to 14-MAY-1997 for females treated with a dose of 120 mg/kg;
from 30-MAY-1997 to 13-JUN-1997 for females treated with a dose of 69 mg/kg;
from 20-MAY-1997 to 03-JUN-1997 for males treated with a dose of 58 mg/kg.

Route of administration:

oral: gavage

Vehicle:

unchanged (no vehicle)

Details on oral exposure:

MAXIMUM DOSE VOLUME APPLIED: doses were defined based on a preliminary study (not reported).
0.073, 0.05, 0.041 and 0.035 mL/kg corresponding to 120, 83, 69 and 58 mg/kg, respectively (based on density of 1.65)

Doses:

120, 83, and 69 mg/kg for females only
58 mg/kg for both sexes

No. of animals per sex per dose:

5 per sex and per group

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: observations of clinical signs and mortality were performed at 30 min, 2, 4 and 6 h on the first day after administration (day 1) and then twice a day up to termination of the observation period. Bodyweight was monitored twice pre-trial (at randomization and on day 1 just before administration) and on days 3, 8 and 14. On day 1, the animals were weighed after a 16-h fasting period.
- Necropsy of survivors performed: yes, on all animals which died during the observation period and on animals killed (fasted overnight) by excision of the femoral arteries, after i.p. overdosage anaesthesia with 5% sodium pentobarbital, at the end of the observation period. Portions of any abnormal entities found in any of the necropsied animals were collected. The tissue samples were fixed and preserved in 10% buffered formalin. Histologic examination was not performed.

Statistics:

LD50 was calculated by the method of the Probit.

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

79.5 mg/kg bw

Based on:

test mat.

95% CL:

>= 70.9 - <= 89.2

Mortality:

5/5 female rats at 120 mg/kg, 3/5 females at 83 mg/kg and 1/5 females at 69 mg/kg died before the end of the observation period. The mortalities were observed within 2 h of dosing at 120 mg/kg and during the first week at 83 mg/kg and 69 mg/kg. No deaths occurred in males and females treated at 58 mg/kg (see in Table 1).

Clinical signs:

Piloerection, hunched posture and increased salivation were observed in animals treated with the various doses, starting 30 min to 2 h after dosing. For animals treated with the higher doses (83 and 120 mg/kg), sedation or hypoactivity and gasping or shallow breathing were seen starting 30 min (120 mg/kg) or 2 h to day 3 after dosing (83 mg/kg). One rat of the group treated with 69 mg/kg also showed transient shallow breathing.
Recovery was achieved on day 8 for the group treated with 83 mg/kg, on day 2 for the group treated with 69 mg/kg and within 6 h for animals from the group treated with 58 mg/kg.

Body weight:

Decrease in bodyweight was observed at day 3 in animals treated with 83 mg/kg. Bodyweight gain had returned to normal by day 8. Normal bodyweight growth was found in animals of the lower dose groups.

Gross pathology:

In animals which died before the end of the observation period, the main macroscopic findings were erosion and congestion of stomach and congestion, catarrhal content and thinning walls of intestine. In single animals, these changes were accompanied by paleness of liver, spleen, kidneys or heart. In addition, cases of congestion of lungs and kidney medulla were seen. These changes were mainly confined to the animals treated with the highest dose (120 mg/kg).
At the final killing, no appreciable post-mortem changes were noted in animals.

Table 1: Mortality

Doses (mg/kg)	58	69	83	120
Number of treated animals	10 (males and females)	5 (females)	5 (females)	5 (females)
Day 1	0	1	0	5
Day 4	0	0	1	0
Day 5	0	0	1	0
Day 7	0	0	1	0
Total (day 14)	0	1	3	5
Total (%)	0	20	60	100

Interpretation of results:

Category 3 based on GHS criteria

Conclusions:

In conclusion, the LD50 of the test article, when administered to rats as a single dose by oral route, was estimated to be 79.5 mg/kg bodyweight. The compound mainly induced irritation in the gastrointestinal system in the treated rats, especially at the highest dose.

Executive summary:

The purpose of the study was to evaluate the oral acute toxicity of the test article in Sprague-Dawley Crl: CD(SD) BR rats according to OECD guideline 401 and EU method B.1 and in compliance with good laboratory practices (GLP).

The test item was tested undiluted at the doses of 69, 83 and 120 mg/kg administered by gavage to groups of 5 females per dose and at the dose of 58 mg/kg administered by gavage to 5 males and 5 females. All rats were treated after a 16-h fasting period. The day of treatment was considered as day 1 of the study. Animals were clinically observed for 14 days following the treatment. Moreover, rats were weighed twice before treatment and on days 3, 8 and 14. On day 15, the surviving rats were killed and subjected to a thorough autopsy.

Death occurred in 5/5 female rats at 120 mg/kg, in 3/5 females at 83 mg/kg and in 1/5 females at 69 mg/kg. The mortality occurred within 2 h of dosing at 120 mg/kg and within one week at 83 and 69 mg/kg. No deaths occurred in males and females treated with the dose of 58 mg/kg.

Piloerection, hunched posture and increased salivation were observed in animals treated with the various doses, starting 30 min to 2 h after dosing. For animals treated with the higher doses (83 and 120 mg/kg), sedation or hypoactivity and gasping or shallow breathing were seen starting 30 min (120 mg/kg) or 2 h to day 3 after dosing (83 mg/kg). Recovery was achieved on day 8 for the group treated with 83 mg/kg, on day 2 for the group treated with 69 mg/kg and within 6 h for animals from the group treated with 58 mg/kg.

Decrease in bodyweight was observed at day 3 in animals treated with 83 mg/kg. Bodyweight gain returned to normal by day 8. Normal bodyweight growth was found in animals of the lower dose groups.

In animals which died before the end of the observation period, the main macroscopic findings were erosion and congestion of stomach and congestion, catarrhal content and thinning walls of intestine. In single animals, these changes were accompanied by paleness of liver, spleen, kidneys or heart. In addition, cases of congestion of lungs and kidney medulla were seen. These changes were mainly confined to the animals treated with the highest dose (120 mg/kg).

At the final killing, no appreciable post-mortem changes were noted in animals.

In conclusion, the LD50 of the test article, when administered to rats as a single dose by oral route, was estimated to be 79.5 mg/kg bodyweight. The compound mainly induced irritation in the gastrointestinal system in the treated rats, especially at the highest dose. Therefore, the test substance is classified as Acute Toxicity Category 3 (H301) according to the classification criteria of Regulation (EC) No. 1272/2008 (CLP / EU GHS) and UN GHS.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LD50

Value:

79.5 mg/kg bw

Quality of whole database:

One study with the test item was available. This study was considered sufficient for the assessment of acute toxicity via oral route, therefore the overall quality of the dataset is considered to be good.

Acute toxicity: via inhalation route

Link to relevant study records

Reference

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

26-MAR-1999 to 30-OCT-2000

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Remarks:

The concentrations of substance in the atmosphere were not determined (nominal concentrations).

Qualifier:

no guideline followed

Principles of method if other than guideline:

The study was not designed to be in compliance with any particular guideline. The data were initially generated for internal use. However the method is consistent with standardised methods.

GLP compliance:

yes

Test type:

traditional method

Limit test:

no

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River (UK) Limited (Margate, Kent / ENGLAND)
- Age at study initiation: 7 and 8 weeks old for males and females, respectively
- Weight at study initiation, fasting period before study: no data available
- Housing: by sex in groups of 5, in holding cages (size 35 cm x 53 cm x 25 cm height)
- Diet: ad libitum (except during the 4-h exposure), excess amount of SDS rat and mouse diet (RM1)
- Water: ad libitum (except during the 4-h exposure), tap water
- Acclimation period: at least 5 days before the day of exposure

ENVIRONMENTAL CONDITIONS
- Temperature: 20 to 26°C
- Humidity: 45 to 63%
- Air changes: 12 to 15 per hr
- Photoperiod: 12 hrs dark / 12 hrs light (artificial light between 07:30 - 19:30 daily)

IN-LIFE DATES: from 15-APR-1999 to 22-Jul-1999

Route of administration:

inhalation: vapour

Type of inhalation exposure:

nose only

Vehicle:

air

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: the vapour generator was designed to produce an atmosphere containing vapour by evaporation of the test substance from a fritted glass disc with a countercurrent of air. All parts of the generator in contact with the test substance were made of glass. The test substance was delivered to the generator at a constant flow rate from a syringe driven by a syringe pump and the air supplied to the generator was dried, filtered and oil free. The snout-only exposure chamber used for the exposures was of cylindrical form (30 cm i.d., 45 cm height) and made of aluminium alloy. The rats were held for exposure in (separate) moulded polycarbonate restraining tubes which were attached at evenly spaced ports in the cylindrical section of the chamber. The conditioned test atmosphere entered through a port at the top centre of the chamber and passed out through a port at the base section below the level of the rats.
- Exposure chamber volume: the chambers have an enclosed volume of approximately 30 litres.
- Method of holding animals in test chamber: each rat was restrained in a forward position by an adjustable foamed plastic stopper.
- Source and rate of air: clean dried air at a flow rate of 20 L/min
- Method of conditioning air: no data available
- System of generating test atmosphere: a syringe filled with the test substance was fitted to the syringe pump and connected to the generator with Teflon tubing. The syringe was switched on and the exposure timed for 4 h, following a 5-min equilibration period. The syringe was replaced with a filled syringe as required during the exposure. After 4 h, the syringe pump was switched off and the exposure chamber allowed to clear before rats were removed for examination.
- Treatment of exhaust air: no data available
- Temperature in air chamber: 19.6 to 20.8°C
- Humidity, pressure in air chamber: no data available

TEST ATMOSPHERE
The nominal concentration of the test substance was calculated from the amount of test item delivered to the vapouriser and the total volume of air flowing through the exposure system during the period of generation.

VEHICLE
Not applicable

Analytical verification of test atmosphere concentrations:

no

Duration of exposure:

4 h

Concentrations:

Target concentrations: 1, 5, and 2.5 mg/L for groups 1, 2 and 3, respectively

No. of animals per sex per dose:

5 per sex and per group

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: rats were observed continuously fir signs of reaction to the test substance during exposure and at least twice daily throughout the observation period. The clinical signs were recorded prior to the end of the chamber equilibration period, 0.25, 0.5 and 1 h into exposure, then at hourly intervals during the remainder of the exposure. Signs were also recorded immediately after exposure and at 1 and 2 h after exposure. During the 14-d observation period, the clinical signs were recorded once in the morning and then as necessary following later check for clinical signs. All rats were weighed twice during the week prior to exposure, at time 0 (immediately before exposure) and weekly during the observation period.
- Necropsy of survivors performed: yes; all rats were subjected to a detailed macroscopic examination. The lungs (including the larynx and trachea), liver and kidneys were dissected free of surrounding tissue, weighed and the weights recorded. The heads from group 2 rats and one decedent group 3 rat were preserved in neutral buffered formalin. The remaining tissues were then discarded.
- Other examinations performed: the amount of food consumed by each cage of rats was measured from weighday to weighday throughout the study. Moreover, a visual inspection of water bottles was conducted daily.

Statistics:

LD50 was not calculated.

Preliminary study:

Prior to the exposure of group 1, single rats were exposed to nominal concentrations of 0.088, 0.62 and 1.17 mg/L in order to confirm the survivability of rats up to concentrations of approximately 1 mg/L which is the LC50 for hydrofluoric acid.

Key result

Sex:

male/female

Dose descriptor:

LC0

Effect level:

1.17 mg/L air (nominal)

Based on:

test mat.

Exp. duration:

4 h

Key result

Sex:

male/female

Dose descriptor:

other: approximate LC50

Effect level:

> 2.66 - < 5.37 mg/L air (nominal)

Based on:

test mat.

Exp. duration:

4 h

Mortality:

Four males and one female from group 2 were found dead in the cage on day 1 of the observation period. Two further females from group 2 were found dead in the holding cage, one each on days 2 and 3 of the observation period. Severe lung congestion was seen in all of these animals. One male of group 3 was found in a moribund condition on day 4 of the observation period (see in Table 2).

Clinical signs:

other: During the exposure, exaggerated breathing was seen in all groups. During the observation period, treatment-related observations included signs of respiratory distress in all groups, lethargy, hunched posture and staggering in rats of groups 2 and 3 and p

Body weight:

A treatment-related reduction in bodyweight gain was seen in surviving rats over the observation period (see in Table 3).

Gross pathology:

At the end of the 14-d observation period, pale areas and minimal or moderate congestion was seen in the lungs from surviving rats.

Other findings:

- Organ weights: at the end of the 14-d observation period, no treatment-related effect was seen in surviving rats.
- Food and water consumption: food consumption was reduced concomitant with reduced weight gain. Measurement of water consumption by group 2 was commenced on the day after exposure following gross observation of low consumption. From day 3 of the observation period, water consumption was considered to be normal.

Table 2: Mortality

Group (nominal concentration - mg/L)	Mortality
	Males	Females	Total
1 (1.17)	0/5	0/5	0/10
2 (5.37)	4/5	3/5	7/10
3 (2.66)	1/5	0/5	1/10

 

Table 3: Group mean bodyweights (g)

Group (nominal concentration - mg/L)	Day of observation
	-6	-5	-3	-2	0	7	14
1 (1.17) Males Females	228 198		255 204		273 209	300 228	338 242
2 (5.37) Males Females		230 198		256 209	274 212	285 195	Death 236
3 (2.66) Males Females	278 213		293 216		310 224	306 229	354 244

Interpretation of results:

Category 3 based on GHS criteria

Conclusions:

In this study, the non-lethal exposure level was a nominal concentration of 1.17 mg/L.

Executive summary:

The acute inhalation toxicity of the test item was investigated in compliance with GLP.

Groups of 5 male and 5 female albino rats (Sprague-Dawley in origin) were exposed by nose-only inhalation to a vapour of the test substance in clean dried air at the (calculated) nominal concentrations of 1.17, 2.66 and 5.37 mg/L for a single 4-hour period. Concentrations of test substance in the test atmospheres were not determined. The exposure levels were estimated from test substance usage and were nominal concentrations only. Following exposure, animals were retained without treatment for 14 days. Clinical observations and body weights were recorded throughout the study and at the end of the 14-d observation period. Animals were then killed and given a gross examination post-mortem.

Four males and one female from group 2 (i.e., 5.37 mg/L) were found dead in the cage on day 1 of the observation period. Two further females from group 2 were found dead in the holding cage, one each on days 2 and 3 of the observation period. Severe lung congestion was seen in all of these animals. One male of group 3 (i.e., 2.66 mg/L) was found in a moribund condition on day 4 of the observation period. No death occurred in the group 1 (i.e., 1.17 mg/L).

During the exposure, exaggerated breathing was seen in all groups. During the observation period, treatment-related observations included signs of respiratory distress in all groups, lethargy, hunched posture and staggering in rats of groups 2 and 3 and partially closed eyes and whole-body tremors in group 2 only.

Moreover, a treatment-related reduction in bodyweight gain was seen in surviving rats over the observation period.

At the end of the 14-d observation period, pale areas and minimal or moderate congestion was seen in the lungs from surviving rats but no treatment-related effect on organ weight was seen in surviving rats.

Under the conditions of this study, the non-lethal exposure level (LC0) was a nominal concentration of 1.17 mg/L for male and female rats. Given the number of deaths observed at the concentrations tested (from 1/10 to 7/10), the LC50 of the test substance should be between 2.66 and 5.37 mg/L and therefore the test substance is classified as Acute Toxicity Category 3 (H331) according to the classification criteria of Regulation (EC) No. 1272/2008 (CLP / EU GHS) and UN GHS.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Quality of whole database:

One study with the test item was available. This study was considered sufficient for the assessment of acute toxicity via inhalation route, therefore the overall quality of the dataset is considered to be good.

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:

22-APR-1997 to 28-MAY-1997

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study without detailed documentation

Remarks:

Methods is similar to guideline method, but all the individual animal data are not available in the report.

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Deviations:

yes

Remarks:

reduced number of animals per group as only the preliminary study was performed.

Qualifier:

according to guideline

Guideline:

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

Deviations:

yes

Remarks:

reduced number of animals per group as only the preliminary study was performed.

GLP compliance:

yes

Test type:

standard acute method

Limit test:

no

Species:

rat

Strain:

Sprague-Dawley

Sex:

male

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Rats derived from the Sprague-Dawley strain (Crl: CD(SD)BR)
- Source: Charles River Italia S.p.A. / Via Indipendenza, 11 - 22050 CALCO (Lecco) / ITALY
- Age at study initiation: no more than 3 months old
- Weight at study initiation: 330 to 339 g
- Fasting period before study: no data available
- Housing: 3 animals/cage in an air-conditioned room (grill cages 40.5 x 38.5 x 18h cm with stainless steel feeder)
- Diet: ad libitum (GLP 4RF21 top certificate pelleted diet produced by Charles River italia’s feed licencee Mucedola S.r.L., Settimo Milanese)
- Water: ad libitum (filtered municipal water)
- Acclimation period: > 5 days before the start of the test

ENVIRONMENTAL CONDITIONS
- Temperature: 22 ± 2°C
- Humidity: 55 ± 10%
- Air changes: about 20 per hr filtered on HEPA 99.97%
- Photoperiod: 12 hrs dark / 12 hrs light (7 am. - 7 p.m.)

IN-LIFE DATES: From 21-FEB-1997 to 07-MAY-1997

Type of coverage:

semiocclusive

Vehicle:

unchanged (no vehicle)

Details on dermal exposure:

TEST SITE
- Preparation of animals skin: approximately 24 hours before the test, fur was clipped from the dorsal and ventral area
- Area of exposure: about 6 x 5 cm of the body dorsal surface (about 10% of the total body surface)
- Type of wrap: the treated area was covered with a porous gauze dressing fixed to the skin with hypoallergenic non-irritating tape. The test site was further covered in a suitable manner in order to ensure that the animals could not ingest the test substance.

REMOVAL OF TEST SUBSTANCE
- At the end of the 24-h exposure period, the residual test substance was not washed, but it was wiped off.

TEST MATERIAL
- Amount(s) applied (volume): 0.15, 0.30 and 0.60 mL/kg of undiluted test material were applied, in order to obtain the doses of 250, 500 and 1000 mg/kg respectively (density 1.6-1.7 g/mL).

Duration of exposure:

About 24 h

Doses:

250, 500 and 1000 mg/kg

No. of animals per sex per dose:

1 per dose

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations (clinical signs and mortality): at 30 minutes, 2, 4 and 6 hours on the first day after the administration (day 1) and then twice a day up to termination of the observation period.
- Frequency of body weighing: twice pre-trial (at randomization and on day 1 just before administration) and on days 8 and 15
- Necropsy of survivors performed: gross pathology on animals died before the end of the 14-day observation period and on animals killed at the end of the study
- No histopathology

Statistics:

LD50 was not calculated

Key result

Sex:

male

Dose descriptor:

approximate LD50

Effect level:

>= 250 - <= 1 000 mg/kg bw

Based on:

test mat.

Mortality:

Deaths occurred in the male (on day 3) treated with 1000 mg/kg and in the male (on day 4) given the test article at 500 mg/kg. The male treated with 250 mg/kg survived until the end of the 14-d observation period.

Clinical signs:

Sedation/hypoactivity and piloerection were observed in all treated animals (starting 2-6 hours after treatment for animals given 500 and 1000 mg/kg, and on day 2 at the dose level of 250 mg/kg). In addition, hunched posture, hypothermia and skin/mucous pallor were noted in animals at the two higher doses.
All these clinical signs were achieved on day 4 in the rat given 250 mg/kg (at the two higher doses, animals died before day 5).
After removal of the dressing, local skin oedema and cyanosis were observed in all animals. Skin crust was noted in the animal given 250 mg/kg from day 6 up to the end of the observation period.

Body weight:

Body weight of the rat given 250 mg/kg was not affected by the treatment.

Gross pathology:

For the animals which died, lung congestion was noted at the highest dose (1000 mg/kg), and oedema and cyanosis were observed at the treatment site at the two higher doses (500 and 1000 mg/kg).
At the autopsy performed at the end of the observation period, the rat treated with 250 mg/kg displayed focal scab at the application site.

Interpretation of results:

Category 3 based on GHS criteria

Conclusions:

In conclusion, the test article administered by dermal route induced mortality from 500 mg/kg. No mortality was observed at the dose level of 250 mg/kg.

Executive summary:

The purpose of the study was to evaluate the acute dermal toxicity of the test item in Sprague-Dawley Crl: CD(SD) BR rats according to OECD guideline 402 and EU method B.3 and in compliance with good laboratory practices (GLP).

The test item was tested undiluted at the doses of 250, 500 and 1000 mg/kg (at various volumes) administered by dermal route (semi-occlusive) on the body dorsal surface (ca. 6 x 5 cm) of groups of 1 male/dose. The day of treatment was considered as day 1 of the study. At the end of the 24-h exposure period, the residual test article was wiped off. Animals were clinically observed for 14 days following the treatment. Moreover, rats were weighed twice before treatment and on days 8 and 15. Gross pathology evaluation was performed on animals which died before the end of the 14-day observation period and as well as on animals killed on day 15 at the end of the study.

Only the rat given 250 mg/kg survived until the end of the 14-day observation period; rats given higher doses died on days 3-4 after dosing.

Sedation/hypoactivity and piloerection were observed in all animals; hunched posture, hypothermia and skin/mucous pallor were only seen in animals at the two higher doses.

After removal of the dressing, skin oedema and cyanosis were observed at all 3 doses. Skin crust was then noted in the rat given 250 mg/kg from day 6 up to the end of the observation period.

Lung congestion was observed at the autopsy of the animal given 1000 mg/kg; oedema and cyanosis were noted at the treatment site in animals given 500 and 1000 mg/kg.

At the end of the observation period, skin focal scab was seen in the animal given 250 mg/kg.

In this preliminary study, the test article, when administered to rats as a single dose by dermal route, induced mortality at the doses of 500 and 1000 mg/kg. No mortality was observed at 250 mg/kg. Since corrosive effect was noted at the administration site during this preliminary study, no further animal was treated. The test substance is thus classified as Acute Toxicity Category 3 (H311) according to the classification criteria of Regulation (EC) No. 1272/2008 (CLP / EU GHS) and UN GHS.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Quality of whole database:

One study with the test item was available. This study was considered sufficient for the assessment of acute toxicity via dermal route, therefore the overall quality of the dataset is considered to be good.

Additional information

The acute toxicity of the test item was tested in rats using the three usual routes of administration: oral, inhalation and dermal. Two studies of reliability 1 according to Klimisch criteria were available for oral and dermal routes and both were selected as key studies. One study of reliability 2 (Klimisch, 1997) and selected as key study was available for inhalation route.

The potential acute toxicity of the test substance was investigated following a single oral administration to rats according to OECD guideline 401 and EU method B.1, and in compliance with good laboratory practices (GLP) (Yu P., 1997). The test item was tested undiluted at the doses of 69, 83 and 120 mg/kg body weight administered by gavage to groups of 5 females per dose and at the dose of 58 mg/kg administered by gavage to 5 males and 5 females. Animals were clinically observed for 14 days following the treatment.

Death occurred in all female rats at 120 mg/kg, in 3/5 females at 83 mg/kg and in 1/5 females at 69 mg/kg. The mortality occurred within 2 h of dosing at 120 mg/kg and within one week at 83 and 69 mg/ kg. No deaths occurred in males and females treated with the dose of 58 mg/kg. Transient clinical signs were observed in animals treated with the various doses: e.g. piloerection, hunched posture, increased salivation, sedation or hypoactivity and gasping or shallow breathing. Transient decrease in bodyweight was observed in animals treated with 83 mg/kg. In rats which died before the end of the observation period, the main macroscopic findings were erosion and congestion of stomach, and congestion, catarrhal content and thinning walls of intestine. In single animals, these changes were accompanied by paleness of liver, spleen, kidneys or heart. In addition, cases of congestion of lungs and kidney medulla were seen. These changes were mainly confined to animals treated with the highest dose (120 mg/kg). At the final killing, no appreciable post-mortem changes were noted in animals. The compound mainly induced irritation in the gastrointestinal system of treated rats, especially at the highest dose.

In conclusion, the LD50 of the test article, when administered to rats as a single dose by oral route, was estimated to be 79.5 mg/kg bodyweight (bw), therefore warranting a classification as Acute Toxicity Category 3 (H301) according to the classification criteria of Regulation (EC) No. 1272/2008 (CLP / EU GHS) and UN GHS.

The acute inhalation toxicity of the test item was investigated in compliance with GLP but without any mention of a specific guideline (Kenny T.J., 2000), although the methodology was consistent with standardised methods. Groups of 5 male and 5 female albino rats (Sprague-Dawley in origin) were exposed by nose-only inhalation to a vapour of the test substance in clean dried air at the (calculated) nominal concentrations of 1.17, 2.66 and 5.37 mg/L for a single 4-hour period. Following exposure, animals were retained without treatment for a 14-day observation period.

Death occurred in 4/5 male and 3/5 female rats at 5.37 mg/L. Severe lung congestion was seen in all of these animals. One male of group 3 was found in a moribund condition at 2.66 mg/L on day 4 of the observation period. No death occurred in males and females treated with the concentration of 1.17 mg/L. During the exposure, exaggerated breathing was seen in all groups. During the observation period, treatment-related observations included signs of respiratory distress in all groups, lethargy, hunched posture and staggering in rats of groups 2 and 3 and partially closed eyes and whole-body tremors in group 2 only. Moreover, a treatment-related reduction in bodyweight gain was seen in surviving rats over the observation period. At the end of the 14-day observation period, pale areas and minimal or moderate congestion were seen in the lungs from surviving rats but no treatment-related effect on organ weight was seen in surviving rats.

In conclusion, the non-lethal exposure level (LC0) was a nominal concentration of 1.17 mg/L for male and female rats. Given the number of deaths observed at the concentrations tested (from 1/10 to 7/10), the LC50 of the test substance should be between 2.66 and 5.37 mg/L, therefore warranting a classification as Acute Toxicity Category 3 (H331) according to the classification criteria of Regulation (EC) No. 1272/2008 (CLP / EU GHS) and UN GHS.

An acute dermal study was conducted in Sprague-Dawley Crl: CD(SD) BR rats to assess the toxicity potential of the test item, in accordance with the standardised OECD guideline 402 and EU method B.3, and in compliance with GLP (Yu P., 1997). The test item was tested undiluted at the doses of 250, 500 and 1000 mg/kg body weight (at various dose volumes) administered by dermal route (semi-occlusive) on the body dorsal surface (ca. 6 x 5 cm) of groups of 1 male per dose. At the end of the 24-h exposure period, the residual test article was wiped off. Animals were clinically observed for 14 days following the treatment.

Only the rat given 250 mg/kg survived until the end of the 14-day observation period; rats given higher doses died on days 3-4 after dosing. Sedation/hypoactivity and piloerection were observed in all animals; hunched posture, hypothermia and skin/mucous pallor were only seen in animals from groups treated with the two higher doses. After removal of the dressing, skin oedema and cyanosis were observed in all animals. Skin crust was noted in the rat given 250 mg/kg from day 6 up to the end of the observation period. Lung congestion was observed at the autopsy of the animal given 1000 mg/kg; oedema and cyanosis were noted at the treatment site in animals given 500 and 1000 mg/kg. At the end of the observation period, skin focal scab was seen in the animal given 250 mg/kg.

The test article, when administered to rats as a single dose by dermal route, induced mortality at the doses of 500 and 1000 mg/kg. No mortality was observed at 250 mg/kg. Since corrosive effect was noted at the administration site during the preliminary study, no further animal was treated. The test substance is thus classified as Acute Toxicity Category 3 (H311) according to the classification criteria of Regulation (EC) No. 1272/2008 (CLP / EU GHS) and UN GHS.

Physical-chemistry and toxicological data available on the test substance suggest that the mode of toxic action might be related to a release of hydrogen fluoride which could locally induce a corrosion of tissues. Based on the skin corrosion effects observed following dermal application, and as the test substance may be inhaled, a hazard of respiratory tract corrosion may thus exist. As a consequence, the test item is labelled with EUH071 on the basis of suspected corrosive effects to the respiratory tract. Since no such corrosive effect has been reported so far in humans and as a EUH071 labelling is applied for the test substance, a specific target organ toxicity - single exposure (STOT SE) 3 classification for respiratory tract irritation is not necessary in accordance with ECHA guidance on labelling and packaging according to Regulation (EC) No. 1272/2008.

Justification for classification or non-classification

The available data on the test item showed that mortality occurred in rats after exposure by oral, inhalation and dermal routes, with a median lethal concentration ranging between 2.66 and 5.37 mg/L for inhalation route, and median lethal doses equivalent to 79.5 mg/kg for oral route and ranging between 250 and 1000 mg/kg for dermal route. Thus, the test substance is classified as toxic if swallowed (Acute Tox. 3; H301), inhaled (Acute Tox. 3; H331) and in contact with skin (Acute Tox 3; H311) according to the classification criteria of Regulation (EC) No. 1272/2008 (CLP / EU GHS) and UN GHS.

Moreover, as the mode of toxic action of test substance is suspected to be related to a local release of hydrogen fluoride and its corrosion properties, and considering effects observed during the acute dermal toxicity study, a hazard of respiratory tract corrosion may exist and the test item is thus labelled with EUH071. As corrosion of respiratory tract is suspected but not demonstrated, notably in humans, and given the EUH071 labelling, a STOT SE 3 classification for respiratory tract irritation is not necessary in accordance with ECHA guidance on labelling and packaging according to Regulation (EC) No. 1272/2008.