2-Butenoic acid, 4,4,4-trifluoro-3-(methylamino)-, ethyl ester, (2Z)-

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1999

Report date:

1999

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Deviations:

yes

Remarks:

refer to comments below

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.2 (Acute Toxicity (Inhalation))

Deviations:

yes

Remarks:

refer to comments below

Test guideline 3

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.1300 (Acute inhalation toxicity)

Deviations:

yes

Remarks:

refer to comments below

Principles of method if other than guideline:

- At delivery the female animals used in the present study were nine days older then the upper limit of 10 weeks of age proposed in the protocol.
- As an exception, the animals were briefly (seconds) removed from the exposure tubes during exposure for closer clinical examination. This was to clarify if the animals were still alive when they were found to show decrease in spontaneous activity.

GLP compliance:

yes (incl. QA statement)

Test type:

fixed concentration procedure

Test material

Test material information

Constituent 1

Reference substance name:

ethyl (2Z)-4,4,4-trifluoro-3-(methylamino)but-2-enoate

EC Number:

801-277-8

Cas Number:

507448-65-9

Molecular formula:

C7H10F3NO2

IUPAC Name:

ethyl (2Z)-4,4,4-trifluoro-3-(methylamino)but-2-enoate

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: RCC Ltd. Biotechnology & Animal Breeding Division. CH-4414 Füllinsdorf / Switzerland
- Age at study initiation: Males: 9 weeks Females: 12 weeks
- Weight at study initiation: Males: 283.4 - 295.7 g Females: 200.8 - 235.9 g
- Housing: Groups of 5
- Diet: ad libitum (except during the exposure period)
- Water: ad libitum (except during the exposure period)
- Acclimation period: 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19 - 20 °C
- Humidity (%): 44 - 66 %
- Air changes (per hr): 10 - 15
- Photoperiod (hrs dark / hrs light): 12 / 12

Administration / exposure

Route of administration:

inhalation: vapour

Type of inhalation exposure:

nose only

Remarks:

flow-past exposure

Vehicle:

air

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION

- Inhalation exposure system.
The animals were confined separately in restraint tubes which were positioned radially around the exposure chamber. The design ensures a uniform test item distribution, provides a constant stream of “fresh” test item to each animal, and precludes rebreathing the exhaled air.

- Test atmosphere generation:
The test item was used as supplied and placed in an automatic syringe pump supplying a nebulizer. The polyethylene injector inside the nebulizer was replaced by a stainless steel injector. The test atmosphere was generated in ambient conditions and diluted with compressed filtered air to achieve the target concentration.

- Method of holding animals in test chamber: Restraint tubes

Analytical verification of test atmosphere concentrations:

yes

Duration of exposure:

ca. 4 h

Concentrations:

Nominal: 6.079 mg/l air
Analytical (determined by chemical analysis): 5.604 ± 0.360, n = 4

No. of animals per sex per dose:

5

Control animals:

no

Details on study design:

- Mortality
Mortality was checked at least once daily during the acclimatisation phase, once before exposure on the day of exposure (test day 1), once per hour during exposure, once after exposure on test day 1, and twice daily during the remainder of the observation period.

- Clinical Signs
Clinical signs were recorded once per hour during the 4-hour exposure period. In addition, clinical signs were recorded once after exposure on test day 1, and once daily thereafter. Observations included, but were not limited to: changes in behaviour, somatomotor activity, body position, respiratory and circulatory effects, autonomic effects such as salivation, central nervous system effects, e.g. tremors or convulsions, reactivity to handling or sensory stimuli, altered strength, alteration of the skin, fur, nose and eyes.

- Body weights
Body weights were recorded on acclimatisation day 6 and test days 1 (before exposure), 4, 8 and 15 (day of necropsy).

- Necropsy of survivors performed: yes
- Necropsy
Animals were examined macroscopically and any abnormalities would have been recorded. The lungs, trachea, larynx and the head containing the nasopharyngeal tissues were collected from all animals and fixed in neutral phosphate buffered 4% formaldehyde solution. The lungs were instilled with the fixative at a hydrostatic pressure of 30 cm H2O.

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 5.604 mg/L air (analytical)

Based on:

test mat.

Exp. duration:

4 h

Mortality:

No spontaneous deaths occurred in this study. All animals were sacrificed as scheduled on test day 15.

Clinical signs:

other: The following clinical signs were recorded in all animals during and/or after the inhalation exposure. Bradypnea, a slight to marked decrease in spontaneous activity, hunched posture, slightly to markedly ruffled fur, and half closed eyelids on both eyes

Body weight:

A marginal, transient loss in mean body weight of -0.7 % was evident in male animals, and retardation of mean body weight gain in female animals from test day 1 (prior to exposure) to test day 4 (three days after exposure). During the remainder of the 15-day observation period all male animals gained body weight normally. Marginal body weight losses and/or retardation of body weight gain in three of the female animals from test day 4 to 15 were considered to be within the range of natural background variation for female rats of this strain and age.

The general data did not permit any conclusion to what extent this marginal and transient finding was attributable to slight physical stress which may have occurred during restraint in the exposure tubes and to what extent to the treatment with the test item, especially as there were also marginal, I one incidence slight, weight losses in some male and female animals from acclimatisation day 6 to test day 1 (prior to exposure).

Gross pathology:

Examination of each animals on the scheduled day of necropsy (test day 15) did not reveal any macroscopical findings.

Other findings:

The nominal and chemically determined (mean ± S.D.) test atmosphere concentrations are summarised in Table 1.
The mean test atmosphere concentration determined by chemical analysis compared fairly well (-7.8%) with the nominal concentration. Adherence of some of the test atmosphere to the inner surfaces of the aerosol generation and exposure system may have contributed to the minor difference between the chemically determined and the nominal concentrations.

Any other information on results incl. tables

Table 1

 

	Achieved Concentrations (mg/l air) ± S.D.
Group	Nominal	Chemically Determined
1	6.079	5.604 ± 0.360 (n = 4)

 

Applicant's summary and conclusion

Interpretation of results:

study cannot be used for classification

Remarks:

Migrated information

Conclusions:

In conclusion, the LC 50 of CA 2455 A (Intermediate of CGA 276854) obtained in this study, was estimated to be greater than 5.604 mg/l air (chemically determined mean concentration of undiluted formulated test article in the test atmosphere).

The clinical signs observed in all animals were attributed to treatment with the test item, whereas the cause of the transient effect on body weight development could not be identified.

Executive summary:

The purpose of this acute 4-hour inhalation toxicity study was to assess the acute inhalation toxicity of CA 2455 A (Intermediate of CGA 276854) when administered to rats for a single continuous 4-hour period. 

 

Groups of five male and 5 female Albino Wistar rats were exposed by nose only, flow past inhalation to the test item at a mean concentration of 5.604 mg/L air (s.d. ± 0.360, n = 4. All animals were observed for clinical signs and mortality during and following the inhalation exposure, i.e. over a 15 day observation period. Body weights were recorded on acclimatisation day 6 and prior to exposure on test day 1, and during the observation period on test days 4, 8 and 15 (day of necropsy). All animals underwent necropsy and any gross macroscopical changes were recorded. 

 

The ranges of temperature, oxygen content, relative humidity and airflow measured during exposure were satisfactory for a study of this type. The particle size of the test atmosphere could not be measured because the test atmosphere was a vapour at the concentration tested. 

 

There were no deaths. Clinical signs consisted of bradypnea, a slight to marked decrease in spontaneous activity, hunched posture, slight to markedly ruffled fur and , and half closed eyelids on both eyes in all animals. The clinical signs were seen from approximately 1 hour after the beginning of exposure and disappeared within 3 days after exposure. A transient, marginal loss in mean body weight was evident in male animals and a transient retardation in mean body weight gain in female animals. Necropsy of each animal did not reveal any macroscopical findings. 

 

In conclusion, the LC 50 of CA 2455 A (Intermediate of CGA 276854) obtained in this study, was estimated to be greater than 5.604 mg/l air (chemically determined mean concentration of undiluted formulated test article in the test atmosphere). 

 

The clinical signs observed in all animals were attributed to treatment with the test item, whereas the cause of the transient effect on body weight development could not be identified.