(E)-4-Ethoxy-1,1,1-trifluoro-3-buten-2-one (stabilized with BHT)

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

19 Sept.-06 Oct. 2006

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

The study was conducted according to an internationally recognised method, and under GLP. The substance is adequately characterised with its purity. Therefore full validation applies.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2006

Report date:

2006

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

17 December 2001

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

Certificate from 2004-08-19

Test type:

acute toxic class method

Limit test:

no

Test material

Reference

Name:

Unnamed

Type:

Constituent

Test material form:

liquid

Details on test material:

N.B. This batch BWG 60000 was used in several studies with some descriptive information diverging slightly between the reports (for further details, see below in this field and in the following field).

- Appearance:
* Clear yellowish liquid was mentioned in the 2007 and 2008 Notox reports dealing with physico-chemical properties and in the in 2007 Solvay Pharma report dealing with ASRI test.
* Yellow liquid was mentioned in the 2006 and 2007 TNO reports dealing with toxicological endpoints.
- Storage conditions:
* Storage in freezer (=< -15°C) in the dark under nitrogen was mentioned in the 2007 and 2008 Notox reports dealing with physico-chemical properties.
* Storage in freezer (< -10°C) was mentioned in the 2007 Solvay Pharma report dealing with ASRI test.
* Storage at < -18°C (with or without the mention "protected from light") was mentioned in the 2006 and 2007 TNO reports dealing with toxicological endpoints.
- Stability under storage conditions: Stable.

Test animals

Species:

rat

Strain:

Wistar

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Wistar outbred rat; Crl:(WI) WU BR obtained from Charles River, Germany.
- Females nulliparous and non-pregnant: Not specified in the report.
- Age at arrival: 7-8 weeks.
- Weight at study initiation: 154-172 g.
- Fasting period before study: Prior to dosing, the animals has fasted overnight. Approximately 4 hours after dosing, they had access to food again.
- Housing: A maximum of 6 animals per macrolon cage.
- Diet: Standard laboratory diet ad libitum. Each batch of this diet was analysed by the supplier (SDS Special Diets Services, Whitham, England) for the nutrients and contaminants and the results were kept available in the archives.
- Water: Tap water (N.V. Hydron Midden-Nederland) ad libitum .
- Acclimation period: 6 days.

ENVIRONMENTAL CONDITIONS
- Temperature: 22 +/- 3 °C
- Humidity: 40-70%. Upper limit occasionally up to 100%, because of wet cleaning of the animal room.
- Air changes: ca. 10 air changes/hour.
- Photoperiod: 12 hours light / 12 hours dark cycle.

IN-LIFE DATES:
- Start of study: 19/09/2006 (first group at 300 mg/kg and group at 2000 mg/kg) and 22/09/2006 (second group at 300 mg/kg).
- Termination of study: 06/10/2006.

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

maize oil

Details on oral exposure:

DOSING
The animals were dosed with a 10 mL/kg body weight of a 30 or 200 mg/mL dilution of the test substance in maize oil in order to obtain the 300 and 2000 mg/kg bwt. The exact amount of the test substance to be dosed was calculated for each animal individually and administered by means of a syringe, equipped with an oral gavage.

CLASS METHOD
Rationale for the selection of the starting dose: The study was started with a dose level of 300 mg/kg body weight; which is the starting dose recommended in OECD 423 guideline when there is no information on the test substance.

Doses:

300 and 2000 mg/kg bwt.

No. of animals per sex per dose:

300 mg/kg bwt: 2 groups of 3 females; one being tested at the start of the study and the other being tested after having observed mortality in the 2000 mg/kg bwt dose level group.
2000 mg/kg bwt: 1 group of 3 females.

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days.
- Frequency of observations and weighing: All visible reactions to treatment were recorded, including type, severity, onset and duration. Observations were made within 1 hour and within 4 hours after dosing, and subsequently in surviving animals at least once daily throughout an observation period of 14 days. The body weight of each animal was recorded immediately before dosing on day 0, and on days 3, 7 and 14 of the study for the surviving animals.
- Necropsy of survivors performed: at the end of the observation period (on day 14), all surviving animals were killed with carbon dioxide and examined for external changes. Next, the abdominal and the thorax of each animal was opened and examined for gross pathological changes.

Statistics:

No

Results and discussion

Effect levels

Key result

Sex:

female

Dose descriptor:

LD50

Effect level:

> 300 - < 2 000 mg/kg bw

Based on:

test mat.

Mortality:

300 mg/kg bwt: All animals survived.
2000 mg/kg bwt: All animals died.

Clinical signs:

300 mg/kg bwt: No clinical signs, other than transient piloerection in the first three animals dosed, were observed during the 14-day study period.
2000 mg/kg bwt: The animals generally showed sluggishness, blepharospasm, stretching, piloerection and increased respiratory frequency prior to their death.

Body weight:

300 mg/kg bwt: All animals gained weight during the 14-day study:
* Day 0: mean weight = 163 and 161 g for the first and second groups, respectively.
* Day 3: mean weight = 179 and 178 g for the first and second groups, respectively.
* Day 7: mean weight = 184 and 191 g for the first and second groups, respectively.
* Day 14: mean weight = 197 g for both groups.
2000 mg/kg bwt: All animals died within 24 hours after dosing:
* Day 0: mean weight = 160 g.

Gross pathology:

Examination at necropsy of the animals did not reveal distinct treatment-related gross alterations, other than one animal of the 2000 mg/kg bwt dose level which showed a stomach filled with liquid.

Any other information on results incl. tables

Body weight, mortality and clinical signs:

	Body weight (g)				Mortality	Clinical signs
	Day 0	Day 3	Day 7	Day 14
300 mg/kg bwt – 1^stgroup
1^stanimal	160	177	182	193	Alive	Transient piloerection (1h) in the three animals
2^ndanimal	158	174	178	192	Alive
3^rdanimal	172	187	191	207	Alive
300 mg/kg bwt – 2^ndgroup
1^stanimal	155	175	185	195	Alive	No clinical sign
2^ndanimal	163	180	197	202	Alive
3^rdanimal	165	180	190	193	Alive
2000 mg/kg bwt
1^stanimal	166	Found dead on day 1; terminal weight = 162			Dead	Sluggishness, stretched body position, blepharospasm, piloerection, increased respiratory frequency in 3 animals Coldness in 1 animal
2^ndanimal	161	Found dead on day 0; terminal weight = 160			Dead
3^rdanimal	154	Found dead on day 1; terminal weight = 166			Dead

Applicant's summary and conclusion

Interpretation of results:

Category 4 based on GHS criteria

Conclusions:

The acute oral LD50 of ETFBO was determined to be between 300 and 2000 mg/kg bwt in female Wistar rats.

Executive summary:

The acute oral toxicity to female Wistar rats was investigated in a GPL-compliant study performed according to OECD test guideline 423 (acute toxic class method).

Two ETFBO dose levels were tested: 300 and 2000 mg/kg bwt. Two groups of three females were treated with the dose level of 300 mg/kg bwt, and one group of 3 females was treated with the dose level of 2000 mg/kg bwt. Route of administration was oral gavage using maize oil as vehicle. The observation period lasted 14 days following administration. All visible reactions to treatment were recorded, including type, severity, onset and duration. Observations were made within 1 hour and within 4 hours after dosing, and subsequently in surviving animals at least once daily throughout an observation period of 14 days. The body weight of each animal was recorded immediately before dosing on day 0, and on days 3, 7 and 14 of the study for the surviving animals. At the end of the observation period (on day 14), all surviving animals were killed with carbon dioxide and examined for external changes. Next, the abdominal and the thorax of each animal was opened and examined for gross pathological changes.

At the dose level of 300 mg/kg bwt, all animals survived, gained weight during the 14-day study and no clinical signs, other than transient piloerection in the first three animals dosed, were observed. At the dose level of 2000 mg/kg bwt, all animals died within 24 hours after dosing and generally showed the following clinical signs prior to their death: sluggishness, blepharospasm, stretching, piloerection and increased respiratory frequency. Examination at necropsy of the animals did not reveal distinct treatment-related gross alterations, other than one animal of the 2000 mg/kg bwt dose level which showed a stomach filled with liquid.

Under the conditions of this study, the acute oral LD50 value of ETFBO was thus determined to be between 300 and 2000 mg/kg bwt. According to the GHS criteria, ETFBO has to be considered as harmful if swallowed and has to be classified in category 4 for acute oral toxicity.