2,2,2-trifluoroethanol

Acute Toxicity: other routes

Administrative data

Endpoint:

acute toxicity: other routes

Remarks:

intraperitoneal

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

no data

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

documentation insufficient for assessment

Justification for type of information:

Other information : Study well conducted but focused on Testes and Liver histopathology

Cross-reference

Cross-reference 1

Reason / purpose for cross-reference:

reference to same study

Reference

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

documentation insufficient for assessment

Remarks:

The method looks like the OECD 107 shake flask guideline, but few experimental details are provided, testing was not conducted with several volume ratio of solvents, and the analytical method is not specific.

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 107 (Partition Coefficient (n-octanol / water), Shake Flask Method)

Deviations:

yes

Remarks:

determination with a single volume ratio of n-octanol to water

Type of method:

shake-flask method to: flask method

Partition coefficient type:

octanol-water

Analytical method:

other: scintillation counting

Type:

Pow

Partition coefficient:

2.15

Temp.:

20 °C

Remarks on result:

other: mean of n=5, SD +/- 0.07

pH was not specified.

Conclusions:

The substance TFE should have low potential for bioconcentration.

Executive summary:

Partition coefficient of trifluoroethanol was measured according to a method similar to the (OECD) shake flask guideline, but with a single volume ratio. The concentrations in both phases was determined using scintillation counting of radiolabelled substance. A good repeatability was obtained, with a mean value of Kow = 2.15 (+/-0.07), corresponding to log Kow = 0.33.

Cross-reference 2

Reason / purpose for cross-reference:

reference to same study

Reference

Endpoint:

basic toxicokinetics in vivo

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

no data

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

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

Justification for type of information:

Acceptable, well documented publication which meets basic scientific principles.

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Objective of study:

absorption

distribution

excretion

metabolism

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 417 (Toxicokinetics)

Deviations:

no

Principles of method if other than guideline:

Radiolabelled Trifluoroethanol is injected by intraperitoneal route to male Whistar rats. At different time points after the injection, the radioactivity is quantified in different tissues and fluids.

GLP compliance:

not specified

Radiolabelling:

yes

Remarks:

14C

Species:

rat

Strain:

Sprague-Dawley

Sex:

male

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Blue Spruce Farms, Inc
- Age at study initiation: no data
- Weight at study initiation: 250-350g
- Fasting period before study: no data
- Housing: stainless steel metabolism cages (Lab products, Inc.)
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: at least one week

ENVIRONMENTAL CONDITIONS
- Temperature (°C): no data
- Humidity (%): no data
- Air changes (per hr): no data
- Photoperiod (hrs dark / hrs light): no data

IN-LIFE DATES: From: To: no data

Route of administration:

intraperitoneal

Vehicle:

water

Details on exposure:

not applicable

Duration and frequency of treatment / exposure:

single injection

Dose / conc.:

5 mg/kg bw/day (nominal)

Remarks:

12-15 µCi/kg

Dose / conc.:

100 mg/kg bw/day (nominal)

Remarks:

12-15 µCi/kg

No. of animals per sex per dose / concentration:

4 or 5 animals/dose/time point of sacrifice

Control animals:

no

Positive control reference chemical:

no data

Details on study design:

- Dose selection rationale: no data
- Rationale for animal assignment (if not random): no data

Details on dosing and sampling:

PHARMACOKINETIC STUDY (Absorption, distribution, excretion)
- Tissues and body fluids sampled: plasma, urine, expired air, liver, lungs, kidneys and testes.
- Time and frequency of sampling: 15 min to 48 hours after intraperitoneal injection (at the moment of the sacrifice of the animal). Presence of TFE in expired air was measured during the 48h period of experiment.
- Other:
Plasma was obtained from heparinized blood collected during decapitation.
The liver, lungs, kidneys and testes of each animal were removed, rinsed with distilled water, blotted and weighed prior to counting.
Urine samples were collected in plastic containers under mineral oil. The mineral oil-water partition ratio was measured and found to be 0.004 +/- 0.001 at 20°C. Thus extraction of labelled TFE from urine by mineral oil is not of concern.
In order to measure the amount of radioactivity in expired air, several animals were placed individually into a 2.3 L glass chamber. Airflow through the chamber was 500 mL/min. The chamber exhaust passed through 2 glass impingers containing 20 mL of ice water to collect TFE and its derivatives, and then through an impinger containing 20 mL of ice cold 1N NaOH to collect CO2. Recovery by this trapping system of 1.2 µCi injections of 14C-TFE into the chamber was 72 (+/- 2) %. All expired radioactivity calculations were adjusted for this trapping inefficiency.

METABOLITE CHARACTERISATION STUDIES
- Tissues and body fluids sampled (delete / add / specify): Liver and testes
- Time and frequency of sampling: after the sacrifice of the animal 1 hour postinjection.
- From how many animals: 5
- Method type(s) for identification: Fractions of homogenates of Liver and testes were saved for scintillation counting, and for protein analysis using a modification of the Lowry method (1951).
- Limits of detection and quantification: no data
- Other: In order to study the binding of TFE to cellular proteins, rats were also pretreated by the addition of 0.2 % (w/v) sodium phenobarbital to their drinking water for 3 days in order to induce mixed function oxidase activity in their tissues. The animals were given tap water for 24 hrs before use. Control animals received tap water for all 4 days prior to use. Animals were then injected by intraperitoneal route with 100 mg TFE/kg (13.8 µCi/kg), and 1 hr later sacrificed using ether. The liver and testes were removed, rinsed with distilled water and then blotted. The tunica albuginea of the testis was removed, and both tissues were homogenized with 2 volumes of cold saline. Fractions of these homogenates were saved for scintillation counting, and for protein analysis using a modification of the Lowry method (1951).

TREATMENT FOR CLEAVAGE OF CONJUGATES (if applicable): not applicable

Statistics:

no data

Preliminary studies:

Not applicable

Type:

absorption

Results:

TFE was rapidly absorbed following ip administration. The disappearance of 14C activity from the plasma could be described by a biphasic curve, with half times of 2 hrs and 48 hrs.

Type:

distribution

Results:

The octanol-water partition ratio was determined to be Kow = 2.15 (+/- 0.07) at 20°C corresponding to a Log Kow of 0.33. TFE, therefore, is mildly lipophilic and may tend to concentrate in fatty tissue.

Type:

distribution

Results:

15 min following the administration of 14C-TFE (100 mg/kg bw) the percentage of the initial dose appearing in each organ was: 5.6 % for the liver, 1.4 % for the testes, 1.1 % for the kidneys, and 0.6 % for the lung.

Type:

distribution

Results:

No evidence for testicular concentration of TFE was obtained in the present study as the levels of radioactivity at all timepoints postinjection were found to be comparable to those in the liver, kidney, and lung.

Type:

excretion

Results:

Urinary excretion was the major route of elimination accounting for 60 percent of the initial dose after 2 days. Expired air samples were collected for only 6 hours, but accounted for 9% of the initial dose. Excretion of 14CO2 was not detected.

Details on absorption:

The disappearance of 14C activity from the plasma could be described by a biphasic curve, with half times of 2 hrs and 48 hrs. From the plasma data, an initial apparent volume of distribution was calculated to be 318 mL.
Initially, red blood cells and plasma were found to contain similar levels of Carbon-14 activity (v/v comparison following the centrifugation of whole blood at 600*g for 15 min). By 24 hrs postadministration, the concentration of 14C in the red blood cells was twice that in the plasma. At 48 hrs postinjection the concentration of 14C in the red blood cells had decreased only to 1.5 times that in the plasma.

Details on distribution in tissues:

The octanol-water partition ratio was determined to be Kow = 2.15 (+/- 0.07) at 20°C corresponding to a Log Kow of 0.33. TFE, therefore, is mildly lipophilic and may tend to concentrate in fatty tissue. Since this preference towards lipid materials is very small in magnitude, it is suggested that bioconcentration of TFE in food-chains probably will not occur to any significant degree. The method used to determine the Log Kow did not meet the actual required criteria of standard methods.
Relative tissue concentrations 15 min following the ip injection of 5 or 100 mg/kg 14C-TFE were lung > liver >kidneys > testes. Tissue concentrations 15 min after a 100 mg/kg dose were estimated to be 1.5 mM in the liver and 1.2 mM in the testes.
The proportional amount of 14C-TFE reaching the organs closely resembled the relative tissue masses. 15 min following the administration of 14C-TFE (100 mg/kg) the percentage of the initial dose appearing in each organ was: 5.6 % for the liver, 1.4 % for the testes, 1.1 % for the kidneys, and 0.6 % for the lung. After 48 hours a similar ranking was observed, with each organ containing: 0.77 % in the liver, 0.14 % in the testes, and 0.12 % in both the kidneys and the lung.
One hour following the administration of 14C-trifluoroethanol to control rats, 3% of the radioactivity in the testis (on a milligram protein basis) was bound to proteins, while 5% of the radioactivity in the liver was associated with proteins (see details in Table 7.1.1/2). Pretreatment of animals with Phenobarbital did not significantly increase the levels of apparent binding in either organ. A repeat of this experiment with control animals (i.e., no Phenobarbital pretreatment) gave similar results, with only 1% of the radioactivity in the testis, and 3% of the radioactivity in the liver bound to cellular proteins. The radioactivity found in the final pellet and wash supernates accounted for 90% (+/- 15%) (Mean of 20 animals) of the organ counts. On the average, 74% of the radioactivity in both liver and testes was removed during the initial protein precipitation step. The 3 subsequent washes removed 7%, 2% and 0-1% of the initial organ activity, respectively.

No evidence for testicular concentration of TFE was obtained in the present study as the levels of radioactivity at all timepoints postinjection were found to be comparable to those in the liver, kidney, and lung. Thus, the fact that this organ (ie. testes) can be severely damaged by the compound reflects a genuine sensitivity of the testes to TFE. It should be noted however, that these experiments tell us nothing about the distribution of14C-TFE within the structural components of the organ, or among the different cells of the germinal epithelium. It is important to note that in the current study only the carbon-14 label of the trifluoroethanol molecule was monitored. Thus the compound with which the label is associated at any particular moment is unknown.

Details on excretion:

The excretion of radioactivity as percentage of the injected dose in rats following the administration of 14C-trifluoroethanol (100 mg/kg bw) is shown in Table 7.1.1/1.
Urinary excretion was the major route of elimination accounting for 60 percent of the initial dose after 2 days.
Expired air samples were collected for only 6 hours, but accounted for 9% of the initial dose. Excretion of 14CO2 was not detected, as measured by radioactivity in the sodium hydroxide trap. This would suggest that in vivo defluorination of trifluoroethanol did not occur.
Fecal excretion of radioactivity was minor, accounting for about 2% of the initial dose after 48 hrs. Due to the design of the metabolism cages, the feces were occasionally sprayed with urine. Thus it is possible that the true fecal excretion of radioactivity is less than that shown in table 7.1.1/1. The pattern of 14C excretion was: urine>>expired air>>feces.

Metabolites identified:

not measured

Table 7.1.1/1: Excretion of ¹⁴C-Trifluoroethanol when the animals are treated with 100 mg/kg by intraperitoneal injection.

 

Hours postadministration	Cumulative percentage of initial dose excreted
	Urine (n=4)	Feces (n=4)	Expired Air (n=5)
1	-	-	1.7 +/- 0.3
3	1.9 +/- 0.4	-	5.0 +/- 0.4
6	18.7 +/- 0.3	-	9.1 +/- 0.2
12	34.3 +/- 0.8	0.8 +/- 0.3	-
24	50.1 +/- 2.5	0.9 +/- 0.1	-
48	59.9 +/- 1.0	1.8 +/- 0.5	-

 n: number of animals

Table 7.1.1/2: Binding of 2-¹⁴C-Trifluoroethanol to liver and testis protein (100 mg/kg, 13.8 µCi/kg) (All values: mean +/- SD for n=5)

 

Tissue	Pretreatment	Whole homogenate activity (DPM/mg protein)	Pellet activity
			DPM/mg Dry weight	DPM/mg protein
Liver	-	556 +/- 20	19 +/- 0.6	30.2 +/- 1.0
	Phenobarbital	542 +/- 27	19 +/- 1.0	32.7 +/- 1.8
Testis	-	858 +/- 26	16.7 +/- 1.8	25.5 +/- 1.4
	Phenobarbital	899 +/- 28	17.6 +/- 1.3	28.0 +/- 2.1

 

DPM: Desintegration Per Minute

Conclusions:

Under the study conditions, it can be concluded that TFE is rapidly absorbed following ip administration.
Previous studies had shown that the volatile solvent 2,2,2-trifluoroethanol rapidly produces testicular damage following intraperitoneal administration or inhalation. Here, no evidence for testicular concentration of TFE was obtained in the present study as the levels of radioactivity at all timepoints postinjection were found to be comparable to those in the liver, kidney, and lung. Thus, the fact that this organ (ie. testes) can be severely damaged by the compound reflects a genuine sensitivity of the testes to TFE. It should be noted however, that these experiments tell us nothing about the distribution of 14C-TFE within the structural components of the organ, or among the different cells of the germinal epithelium. It is important to note that in the present study only the carbon-14 label of the trifluoroethanol molecule was monitored. Thus the compound with which the label is associated at any particular moment is unknown.
One consequence of the blood-testis barrier is that a permeant substance could be transformed inside the seminiferous tubules to a nonpermeant toxic metabolite. Because this metabolite could not escape from the tubules, it would tend to accumulate there in concentrations much higher than if the toxic metabolite itself were given to the animal. Toxic effects may thereby result at comparatively low doses of the precursor. The production of unique TFE metabolites by the testis may explain the high sensitivity of this organ to TFE.
The levels of protein binding observed in these experiments are so low as to be of questionable significance. Although care was taken to break up the protein pellets during each washing, it is possible that the radiolabel remained in the pellets due to physical entrapment.
The failure of Phenobarbital pretreatment to influence the levels of protein binding in either organ suggests that the metabolism of 14C-TFE by the mixed function oxidase system is not required for binding to occur.

Executive summary:

In this study, performed similarly to the OECD Guideline No. 417, 2,2,2-Trifluoroethanol (TFE) labelled with carbon 14 (TFE) was administered to male Srague-Dawley rats. The substance was administrated by a single intraperitoneal injection at dose levels of 5 or 100 mg/kg bw (4 or 5 animals per dose).

At different time points after the treatment (15 min, 1, 3, 6, 12, 24 and 48 hours postinjection), animals were sacrificed and the tissues and the body fluids were collected (plasma, urine, expired air, liver, lungs, kidneys and testes) to determine the absorption, distribution and excretion of TFE. Rats were also sodium phenobarbital pretreated via the drinking water for 3 days in order to induce mixed function oxidase activity in their tissue. Animals were then i.p. injected with 100 mg TFE/kg bw (13.8 µCi/kg bw), and 1 hr later sacrificed using ether. The liver and testes were removed and fractions of their homogenates were saved for scintillation counting, and for protein analysis using a modification of the Lowry method (1951).

Under the study conditions, it can be concluded that TFE is rapidly absorbed following ip administration.

Previous studies (75-89-8, Acute toxicity: inhalation, Wilkenfeld, 1981, W; 75-89-8, Acute toxicity:other route, intraperitoneal, Wilkenfeld, 1981; 75-89-8, Toxicity to reproduction, Wilkenfeld, 1981, W) showed that the volatile solvent 2,2,2-trifluoroethanol rapidly produced testicular damage following intraperitoneal administration or inhalation. Here, no evidence for testicular concentration of TFE was obtained in the present study as the levels of radioactivity at all timepoints postinjection were found to be comparable to those in the liver, kidney, and lung. Thus, the fact that this organ (ie. testes) can be severely damaged by the compound reflects a genuine sensitivity of the testes to TFE. It should be noted however, that these experiments tell us nothing about the distribution of¹⁴C-TFE within the structural components of the organ, or among the different cells of the germinal epithelium. It is important to note that in the current study only the carbon-14 label of the trifluoroethanol molecule was monitored. Thus the compound with which the label is associated at any particular moment is unknown.

Cross-reference 3

Reason / purpose for cross-reference:

reference to same study

Reference

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

no data

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

documentation insufficient for assessment

Justification for type of information:

Other information : Few informations are available on the study design and on the results. However the study is performed according to scientific principles for acute toxicity by inhalation.

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Qualifier:

no guideline followed

Principles of method if other than guideline:

Male rats inhaled TFE for 2 hours. Animals were sacrificed 24 hours post-exposure for histologic examinations of lungs, liver, testis and kidney.

GLP compliance:

no

Remarks:

Study performed before GLP compliance

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
- Source: Ble Spruce Farms, Inc
- Age at study initiation: no data
- Weight at study initiation: 150-300g
- Fasting period before study: no data
- Housing: no data
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: at least one week

ENVIRONMENTAL CONDITIONS
- Temperature (°C): no data
- Humidity (%): no data
- Air changes (per hr): no data
- Photoperiod (hrs dark / hrs light): no data

IN-LIFE DATES: From: To: no data

Route of administration:

inhalation: vapour

Type of inhalation exposure:

other: supposed whole body

Vehicle:

air

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: no data
- Exposure chamber volume: 28 L
- Method of holding animals in test chamber: no data
- Source and rate of air: no data
- Method of conditioning air: no data
- System of generating particulates/aerosols: no data
- Method of particle size determination: no data
- Treatment of exhaust air: no data
- Temperature, humidity, pressure in air chamber: no data

TEST ATMOSPHERE
- Brief description of analytical method used: no data
- Samples taken from breathing zone: no data

VEHICLE: not applicable

TEST ATMOSPHERE (if not tabulated): no data
- Particle size distribution:
- MMAD (Mass median aerodynamic diameter) / GSD (Geometric st. dev.):

CLASS METHOD (if applicable): not applicable

Analytical verification of test atmosphere concentrations:

not specified

Duration of exposure:

2 h

Concentrations:

0, 400, 1200, 2450, 3450, 3600, 5150, 9500, 14650 ppm (nominal concentration)

No. of animals per sex per dose:

10 male rats/dose

Control animals:

yes

Details on study design:

- Duration of observation period following administration: 24 hours
- Frequency of observations and weighing: no data
- Necropsy of survivors performed: yes
- Other examinations performed: histologic examination of liver, lungs, kidney and testes. Liver triglycerides measurement using a modified method from Biggs (1975).
See details below

Statistics:

Litchfield and Wilcoxon Method (1949) was used to determine the LC50.

Preliminary study:

not applicable

Key result

Sex:

male

Dose descriptor:

LC50

Effect level:

4 850 ppm

95% CL:

>= 2 490 - <= 9 325

Exp. duration:

2 h

Key result

Sex:

male

Dose descriptor:

LC50

Effect level:

2 425 ppm

Based on:

other: extrapolation

95% CL:

>= 5.2 - <= 19

Exp. duration:

4 h

Remarks on result:

other: Corresponding to 10 mg/L

Mortality:

No death was observed prior to 12 hours post-exposure. See details in Table 7.2.3/1. The cause of death following trifluoroethanol exposure is unclear. Although pathological changes in the liver and lungs were observed in the present study, they did not appear to be severe enough to result in death. At the higher levels of TFE exposure, most of the rats died prior to regaining consciousness. However, many of the animals dying following exposure to lower concentrations of TFE did regain consciousness prior to death. Thus, unlike ethanol it does not appear that TFE producs death by direct CNS depression.

Clinical signs:

other: During exposure to TFE flushing of the ears, paws, and scrotum (maybe due to skin irritation) was readily apparent. The state of consciousness varied from drowsy to comatose, depending on the TFE concentration. At 24 hours post-exposure surviving animals

Body weight:

no data

Gross pathology:

no data

Other findings:

- Organ weights: see details in Table 7.3.2/1 :
LUNG: a statistically significant increase (compared to control) in the relative lung weight was observed from the concentration of 3600 ppm of TFE. This increase in relative lung weight may be due to edema, however, wet-to-dry lung weight ratios were not made to confirm this possibility.
LIVER, KIDNEY and TESTIS: no abnormalities observed in the organ weight/body weight ratio.

- Histopathology:
LUNGS, KIDNEY: no histologic abnormalities were seen.
LIVER: Liver sections of exposed animals revealed a loss of normal glycogen stores, and occasional centralobular as well as diffuse fatty accumulation.
TESTIS: significant changes in the seminiferous tubular epithelium. Increase cytoplasmic eosinophilia and frank necrosis of premieotic cells, ie., the spermatogonia and spermatocytes, were noted at all exposure levels used. No changes were noted in the apperance of either the spermatids or spermatozoa, or in the interstitial regions which contains Leydig cells and capillaries. These histologic changes in the testis persisted for at least 86 hours following exposure.

- Other observations: see details in Table 7.3.2/1: Liver triglyceride analyses revealed an inverse relationship between the liver triglyceride levels and the exposure concentration of TFE. Animals surviving for at least 24 hours following TFE exposure (ie. 1200 and 3450 ppm) had elevated levels of triglycerides in the liver.

- Potential target organs: Testis and liver (see above).

Table 7.3.2/1: Mortality 24h post-exposure, organ weight (Liver, Lungs, Kidneys, Testis) and liver triglycerides level

Nominal concentration (ppm)	Mortality 24 h post-exposure	Lung weight (% of body weight)	Liver weight (% of body weight)	Kidney weight (% of body weight)	Testis weight (% of body weight)	Liver triglyceride (mg/g)
0	0/8	0.42 +/- 0.02	4.11 +/- 0.17	0.82 +/- 0.03	1.07 +/- 0.05	18.9 +/- 1.3
400	0/10	0.48 +/- 0.11	4.40 +/- 0.11	0.88 +/- 0.01	0.98 +/- 0.09	-
1200	0/10	0.42 +/- 0.01	3.88 +/- 0.10	0.84 +/- 0.02	1.12 +/- 0.03	29.5 +/- 1.8**
2450	1/10	0.43 +/- 0.03	3.26 +/- 0.06	0.75 +/- 0.02	0.99 +/- 0.04	-
3450	0/10	0.45 +/- 0.02	3.43 +/- 0.08	0.76 +/- 0.02	0.97 +/- 0.04	26.0 +/- 3.1*
3600	5/10	0.66 +/- 0.07**	4.05 +/- 0.11	0.96 +/- 0.02	1.06 +/- 0.03	10.9 +/- 0.7**
5150	9/10	0.93 +/- 0.09**	4.21 +/- 0.08	0.99 +/- 0.02	1.03 +/- 0.04	10.2 +/- 0.7**
9500	9/10	0.75 +/- 0.07**	4.07 +/- 0.07	1.11 +/- 0.02	1.13 +/- 0.02	12.8 +/- 0.8**
14650	10/10	0.99 +/- 0.08**	4.11 +/- 0.16	1.10 +/- 0.03	1.03 +/- 0.03	-

 

*: p< 0.05

**: p< 0.001

Interpretation of results:

Category 3 based on GHS criteria

Conclusions:

With a 4h LC50 between 2 and 10 mg/L (vapour), under the test conditions, 2,2,2 Trifluoroethanol is classified in category 3 (Toxic by inhalation, H331) according to the CLP Regulation (EC) N° 1272-2008, and as harmful (Xn, R20) by inhalation according to the criteria of Annex VI to the Directive 67/548/EEC.

TFE induced a frank necrosis of the premeiotic cells (spermatocytes and spermatogonia) in the testis at all exposure levels. Histologic examinations of liver sections of exposed animals revealed a loss of normal glycogen stores, and occasional centralobular as well as diffuse fatty accumulation. The liver triglyceride were also changed in treated animals.

Executive summary:

In an acute inhalation toxicity study, groups of male adult Sprague-Dawley rats were exposed by inhalation route to vapors of trifluoroethanol (99%) in air for 2 hours (probably by a whole body exposure method) at concentrations of  0, 400, 1200, 2450, 3450, 3600, 5150, 9500 and 14650 ppm.  Animals then were observed for 24 hours.

Inhalation LC₅₀ in male rats = 4850 ppm for an exposure of 2 hours. By calculation, the LC50 in male rats was extrapolated to 2425 ppm for an exposure of 4 hours which corresponded to about 10 mg/L.

 

Histologic examinations revealed effects on testicular functions as necrosis of premeiotic cells from the concentration 400 ppm. Disfunctions were also noted in the liver of treated animals.

 

Therefore, 2,2,2 Trifluoroethanol is classified in category 3 (Toxic by inhalation, H331) according to the CLP Regulation (EC) N° 1272-2008.

Cross-reference 4

Reason / purpose for cross-reference:

reference to same study

Reference

Endpoint:

fertility, other

Remarks:

Evaluation of TFE effects on the testis of rats and impact on the fertility

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

no data

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

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

Remarks:

The study is not conducted according to guidelines for toxicity to reproduction and GLP. However, the study is focused on the male reproductive system. Details on the protocol and the results were available.

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to other study

Qualifier:

no guideline followed

Principles of method if other than guideline:

Male rats were exposed to the 2,2,2-Trifluoroethanol (TFE) by inhalation route at various concentrations for 2 weeks. Serial mating was used to assess fertility: exposed male rats were paired to normal female (ie. non exposed to the test item).

GLP compliance:

not specified

Limit test:

no

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Blue Spruce Farms, Inc.
- Age at study initiation: male rats were 70 days old at the start of the exposure period
- Weight at study initiation: the vasocystotomized (male) rats weighed 300-500 g, all other males rats weighed 250-350 g. Virgin females weighed 250-300 g
- Fasting period before study: no data
- Housing: no data
- Use of restrainers for preventing ingestion (if dermal): not applicable
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: at least one week

ENVIRONMENTAL CONDITIONS
- Temperature (°C): no data
- Humidity (%): no data
- Air changes (per hr): no data
- Photoperiod (hrs dark / hrs light): no data

IN-LIFE DATES: From: To: no data

Route of administration:

inhalation

Type of inhalation exposure (if applicable):

whole body

Vehicle:

unchanged (no vehicle)

Details on exposure:

PREPARATION OF DOSING SOLUTIONS: no data

DIET PREPARATION: not applicable
- Rate of preparation of diet (frequency):
- Mixing appropriate amounts with (Type of food):
- Storage temperature of food:

VEHICLE: no data
- Justification for use and choice of vehicle (if other than water):
- Concentration in vehicle:
- Amount of vehicle (if gavage):
- Lot/batch no. (if required):
- Purity:

Details on mating procedure:

- M/F ratio per cage: trifluoroethanol exposed males were housed individually in wire mesh cages. Each week, for 13 weeks, each male was presented with a different pair of virgin females. Mating was evaluated daily, by checking for the presence of vaginal plugs in the cage excrement pans.
- Length of cohabitation: one week
- Proof of pregnancy: Throughout the thirteen week mating period, a sufficient number of seminal plugs were found under each cage to indicate that every male had mated with both of his females. Females were sacrificed 17 days following the first day of pairing with the males. The uterine horns and ovaries were removed and cheked for implantation sites, resorption sites, live fetuses, and corpora lutea. From these data, male fertility as well as preimplantation and postimplantation losses were evaluated.
- After ... days of unsuccessful pairing replacement of first male by another male with proven fertility: no data
- Further matings after two unsuccessful attempts: no data
- After successful mating each pregnant female was caged (how): no data
- Any other deviations from standard protocol: not applicable

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Airborne concentrations of TFE in the exposure chambers were monitored using a Miran IA Infrared Analyser (Wilks Scientific). The cell pathlength was one meter, the slit width 1mm, and a response time of 10 s was used. The analysis wavelength of 8.6 µm corresponded to a sharp IR absorption peak of TFE, while being free of interfering infrared absorption by water, CO2 and ammonia. The exhaust air from the small 28 L chambers was piped directly through the analyser for determination of the airborne TFE concentration.

Duration of treatment / exposure:

6 hours/day, 5 days/week, for 2 weeks.

Frequency of treatment:

daily

Details on study schedule:

- F1 parental animals not mated until [...] weeks after selected from the F1 litters: no data
- Selection of parents from F1 generation when pups were [...] days of age: no data
- Age at mating of the mated animals in the study: [...] weeks: no data

Dose / conc.:

0 ppm (nominal)

Remarks:

Corresponding to 0 mg/m3

Dose / conc.:

100 ppm (nominal)

Remarks:

Corresponding to 415 mg/m3

Dose / conc.:

200 ppm (nominal)

Remarks:

Corresponding to 830 mg/m3

Dose / conc.:

0 ppm (analytical)

Remarks:

Corresponding to 0 mg/m3

Dose / conc.:

99 ppm (analytical)

Remarks:

Corresponding to 410 mg/m3

Dose / conc.:

202 ppm (analytical)

Remarks:

Corresponding to 840 mg/m3

No. of animals per sex per dose:

4 male rats /concentation for the mating study.
50 male rats / concentration in other analyses.
It is not clear how many animals are present in each group.

Control animals:

yes

Details on study design:

no details

Positive control:

no data

Parental animals: Observations and examinations:

CAGE SIDE OBSERVATIONS: No data


DETAILED CLINICAL OBSERVATIONS: No data


BODY WEIGHT: Yes
- Time schedule for examinations: no data

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): no data


WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): No data

OTHER: sperm production, testicular histology, specific activities of testicular enzymes, testis weight

Oestrous cyclicity (parental animals):

not applicable. Only male rats were treated with TFE

Sperm parameters (parental animals):

Parameters examined in [P] male parental generations:
testis weight, sperm production, other: testicular histology, specific activities of testicular enzymes (sorbital dehydrogenase, malate dehydrogenase).

Litter observations:

Female were sacrificed 17 days following the first day of mating with the males. No birth occurred. The uterine horns and the ovaries were removed and checked for implantation sites, resorption sites, live fetuses and corpora lutea.

Postmortem examinations (parental animals):

SACRIFICE
- Male animals: animals were sacrificed using an overdose of sodium pentobarbital given intraperitoneally. Four of six animals from each exposure group were sacrificed at the end of the first and second week of exposure, and then at 1, 3, 5, 7, 9 and 13 weeks postexposure.
- Maternal animals: Females were sacrificed 17 days following the first day of pairing with the males.

GROSS NECROPSY: no data
- Gross necropsy consisted of [external and internal examinations including the cervical, thoracic, and abdominal viscera.]

HISTOPATHOLOGY / ORGAN WEIGHTS
Sections of lung, liver and kidney were fixed in 10% buffered formalin for histologic examination. Testes and epididymal sections were fixed with Bouin's solution. All sections were stained using a standard heamotoxylin-eosin stain.
Testis weight was determined.
Sperm production was evaluated using surgical vasocystotomy (bilateral diversion of the vasa diferentia to the urinary bladder). The surgical treatment was performed at least 2 weeks before the start of the dosing and allowed the quantification of sperm production in the collected rat urine. Sperm counts were done twice weekly on each animal using 24 hr urine samples.

Postmortem examinations (offspring):

Not applicable as no birth occured. The females were sacrificed prior post-partum.

Statistics:

no data

Reproductive indices:

no data

Offspring viability indices:

no data

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

CLINICAL SIGNS (PARENTAL ANIMALS): During the two weeks exposure to airborne trifluoroethanol many animals in both exposure groups displayed increased levels of piloerection and sneezing, and a few animals exhibited dark mucous secretions at the nostrils.

Dermal irritation (if dermal study):

not specified

Mortality:

not specified

Description (incidence):

MORTALITY (PARENTAL ANIMALS): 2 deaths occured among the vasocystotomized rats during the second week of exposure to 200 ppm TFE.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

BODY WEIGHT (PARENTAL ANIMALS): Animal growth was temporarily depressed by exposure to TFE, but by the seventh week postexposure body weights were again comparable to those of the control group.

Food consumption and compound intake (if feeding study):

not specified

Food efficiency:

not specified

Water consumption and compound intake (if drinking water study):

not specified

Ophthalmological findings:

not specified

Haematological findings:

not specified

Clinical biochemistry findings:

effects observed, treatment-related

Description (incidence and severity):

PARENTAL ANIMALS: blood urea nitrogen was not significantly altered from control values.
Triglyceride analyses revealed a significant depression in the liver triglyceride levels of animals exposed to 200 ppm TFE for 2 weeks. The liver triglyceride levels had not returned to control values by the end of the first week postexposure.

Urinalysis findings:

not specified

Behaviour (functional findings):

not specified

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Description (incidence and severity):

HISTOPATHOLOGY (PARENTAL ANIMALS):
Lung: a background of low grade pneumonitis was seen in both control and exposed rats. This was characterized by mild to moderate interstitial inflammatory cell infiltrates, perivascular mononuclear cell infiltrates and focal to multifocal areas of alveolar histocytosis. The incidence of these changes was not significantly different between animals exposed for 2 weeks and non-exposed animals. Two animals exposed to 200 ppm for 2 weeks and then sacrificed had evidence of pulmonary fibrosis, but it is questionable as to whether this fibrotic reaction could have developed within a two week period.
Liver: no effect
Kidneys: no effect
Brain: no effect
Testes: After one week exposure to 100 ppm TFE necrosis of spermatocytes and some spermatogonia was observed. Necrosis of all tubular cells but Sertoli cells, late stage (attached) spermatids, and spermatozoa was apparent in those animals exposed to 200 ppm TFE for one week. Occasional spermatidal giant cells were seen in the testes of both exposure groups. After one week postexposure early signs of testicular regeneration were observed in animals at both exposure concentrations. Generalized tubular atrophy and degenerating giant cells were still present, but most tubules now contained spermatogonia. By 3 weeks postexposure many of the seminiferous tubules of animals from both exposure groups had regenerated to the point where young spermatids were present. Regeneration of the seminiferous tubules of animals exposed to 100 ppm TFE was almost complete by 5 weeks postexposure. The tubules of animals exposed to 200 ppm TFE had recovered as far as intermediate stage spermatids by 5 weeks postexposure. By the seventh week postexposure approximately 80 to 95% of the seminiferous tubules of animals in the 100 ppm group had fully recovered. Only 50 to 90% of the tubules of animals exposed to 200 ppm TFE had fully recovered by this time. At the final sacrifice thirteen weeks postexposure, approximately 5 to 10% of the seminiferous tubules of animals in both TFE exposure groups were still atrophic. TFE did not damage Leydig cells or testicular capillaries.

Histopathological findings: neoplastic:

not specified

Reproductive function: oestrous cycle:

not examined

Reproductive function: sperm measures:

effects observed, treatment-related

Description (incidence and severity):

REPRODUCTIVE FUNCTION: SPERM MEASURES (PARENTAL ANIMALS): oligospermia was noted 2 to 12 weeks postexposure in both groups of rats exposed to TFE. The 100 ppm group exhibited azoospermia during week 5 post-exposure, while the 200 pmm group had no detectable sperm in the urine between weeks 5 and 7 postexposure.

Reproductive performance:

effects observed, treatment-related

Description (incidence and severity):

REPRODUCTIVE PERFORMANCE (PARENTAL ANIMALS): Males in the 100 ppm TFE exposure group were found to be infertile between weeks 4 and 5 postexposure. Animals in the 200 ppm TFE exposure group were infertile from 4 to 7 weeks postexposure. Decreased fertility, compared to the control group, was observed between 2 and 9 weeks postexposure in the 100 ppm, while the 200 ppm group displayed lowered fertility from the first week postexposure until 12 weeks postexposure.
During weeks 2 and 10 postexposure, decreased corpora lutea counts per pregnant females were correspondingly lower during these intervals, except for normal corpora lutea counts in the females paired with males in the 200 ppm group during the second week postexposure. Postimplantation losses in the 100 ppm group were greater than that in the control group during weeks 3 and 6 postexposure. Preimplantation losses (number of corpora lutea minus number of implantations per pregnancy) were significantly higher compared to the control group during week 3 postexposure in the 200 ppm group and during week 6 postexposure in the 100 ppm group. These increases in preimplantation loss may be attributes to the marked hypospermatogenesis produced by TFE exposure.

Key result

Dose descriptor:

LOAEC

Effect level:

415 mg/m³ air (nominal)

Based on:

test mat.

Sex:

male

Basis for effect level:

reproductive function (sperm measures)

reproductive performance

Key result

Critical effects observed:

yes

Lowest effective dose / conc.:

415 other: mg/m3 air

System:

male reproductive system

Organ:

germ cells

seminiferous tubules

testes

Treatment related:

yes

Dose response relationship:

yes

Clinical signs:

not examined

Description (incidence and severity):

not applicable

Mortality / viability:

not examined

Description (incidence and severity):

not applicable as the fetuses were collected after 17 days of gestation.

Body weight and weight changes:

not examined

Description (incidence and severity):

not applicable

Sexual maturation:

not examined

Description (incidence and severity):

not applicable

Organ weight findings including organ / body weight ratios:

not examined

Description (incidence and severity):

not applicable

Gross pathological findings:

not examined

Description (incidence and severity):

not applicable

Histopathological findings:

not examined

Description (incidence and severity):

not applicable

not applicable as no birth occured. Only Fetal observations (See detail below)

Key result

Remarks on result:

not measured/tested

Remarks:

fetuses were collected after 17 days of gestation.

Reproductive effects observed:

not specified

Observations of the fetuses: The average litter size (mean number of implantation sites) and the mean number of live fetuses per pregnancy of those females mated with males in the 100 ppm group were significantly less than that of females paried with control males during weeks 3 and 6 post-exposure. During weeks 2 and 10 post-exposure there was a similar decrease in litter size and the number of live fetuses for females paired with males in the 100 ppm group.

Testicular enzyme activities: The depletion of germ cells following TFE exposure was accompanied by concomitant changes in the specific activities of both sorbitol and malate dehydrogenase. The specific activity of sorbitol dehydrogenase was temporarily reduced by 72% in rats exposed to 100 ppm TFE, and by 86% in those animals exposed to 200 ppm. In contrast, the specific activity of malate dehydrogenase increased above control levels by 59% in the 100 ppm group and 108% in the 200 ppm group. The activity of both testicular enzymes had returned to control levels by the ninth week postexposure. Testicular protein content did not differ among the treatment groups over the course of the experiment.

Conclusions:

Under the test conditions, 2,2,2 trifluoroethanol produced necrosis of the testicular seminiferous tubules inducing a severe decrease of fertility in males rats exposed by whole-body inhalation at 100 ppm (420 mg/m3) for two weeks 6 hours/day, 5 days/week. TFE affected predominantly the premeiotic germ cells of the testis.

Executive summary:

In a fertility study 2,2,2 trifluoroethanol (TFE; 99% purity) was administered to male Sprague-Dawley rats by inhalation route for 6 hours per day, 5 days/week for 2 weeks at dose levels of 0, 100 and 200 ppm (nominal concentrations) coresponding to 415 mg/m3 and 830 mg/m3 respectively. The animals were exposed to TFE by whole-body inhalation.

After the exposure period, each week during 13 weeks, a serial mating was performed: each male was paired with a virgin female rat to examine the male fertility. Some male rats were sacrificed at the end of each exposure week and then at the end of the 1st, 3rd, 5th, 7th, 9th and 13th week post-exposure. Sperm production was evaluated by sperm counts in the 24 -hour urines twice weekly collected from animals subjected to surgical vasocystotomy. The testicular sorbitol (SDH) and malate deshydrogenase (MDH) activities were also measured.

Pregnant female rats were sacrificed prior post-partum corresponding to 17 days following mating. The uterine horns and the ovaries were removed and checked for implantation sites, resorption sites, live fetuses and corpora lutea.

Some organ weights were measured including kidney, lung, liver and testis.

Oligospermia was noted 2 to 12 weeks postexposure in both groups of rats exposed to TFE. The 100 ppm male group exhibited azoospermia during week 5 post-exposure, while the 200 pmm group had no detectable sperm in the urine between weeks 5 and 7 post-exposure.

Males in the 100 ppm TFE exposure group were found to be infertile between weeks 4 and 5 post-exposure. Animals in the 200 ppm TFE exposure group were infertile from 4 to 7 weeks post-exposure. Decreased fertility, compared to the control group, was observed between 2 and 9 weeks post-exposure in the 100 ppm, while the 200 ppm group displayed lowered fertility from the first week post-exposure until 12 weeks post-exposure.

During weeks 2 and 10 post-exposure, decreased corpora lutea counts per pregnant females were correspondingly lower during these intervals, except for normal corpora lutea counts in the females paired with males in the 200 ppm group during the second week post-exposure. Post-implantation losses in the 100 ppm group were greater than that in the control group during weeks 3 and 6 post-exposure. Pre-implantation losses (number of corpora lutea minus number of implantations per pregnancy) were significantly higher compared to the control group during the week 3 post-exposure in the 200 ppm group and during the week 6 post-exposure in the 100 ppm group. These increases in pre-implantation loss may be attributed to the marked hypospermatogenesis produced by TFE exposure.

Exposure to TFE at concentrations of 100 and 200 ppm did not produce pulmonary edema. Kidney and lung weights, lung wet-to-dry weight ratio were not significantly altered from control values following the two-week exposure to TFE. Liver weights were depressed during the first and second weeks of TFE exposure, but returned to the control levels by the end of the first week post-exposure. Three weeks following exposure to TFE, the relative testes weight was maximally depressed to 44% of control values in the 100 ppm group, and to 33% in the 200 ppm group. The relative testes weight had returned to control levels by the seventh week post-exposure for animals in the 100 ppm group, and by the thirteenth week post-exposure for animals in the 200 ppm group.

A background of low grade pneumonitis was seen in the lung of both control and exposed rats. This was characterized by mild to moderate interstitial inflammatory cell infiltrates, perivascular mononuclear cell infiltrates and focal to multifocal areas of alveolar histocytosis. The incidence of these changes was not significantly different between animals exposed for 2 weeks and non-exposed animals. Two animals exposed to 200 ppm for 2 weeks and then sacrificed had evidence of pulmonary fibrosis, but it is questionable as to whether this fibrotic reaction could have developed within a two week period.

No other effect was observed in the liver and kidney histopathological analysis.

Histophatology of the testes showed necrosis of spermatocytes and some spermatogonia after one week exposure to 100 ppm TFE. Necrosis of all tubular cells but not Sertoli cells, late stage (attached) spermatids, and spermatozoa was apparent in the animals exposed to 200 ppm TFE for one week. Occasional spermatidal giant cells were seen in the testes of both exposure groups. After one week post-exposure, early signs of testicular regeneration were observed in animals at both exposure concentrations. Generalized tubular atrophy and degenerating giant cells were still present, but most tubules now contained spermatogonia. By 3 weeks post-exposure many of the seminiferous tubules of animals from both exposure groups had regenerated to the point where young spermatids were present. Regeneration of the seminiferous tubules of animals exposed to 100 ppm TFE was almost complete by 5 weeks post-exposure. The tubules of animals exposed to 200 ppm TFE had recovered as far as intermediate stage spermatids by 5 weeks post-exposure. By the seventh week post-exposure approximately 80 to 95% of the seminiferous tubules of animals in the 100 ppm group had fully recovered. Only 50 to 90% of the tubules of animals exposed to 200 ppm TFE had fully recovered by this time. At the final sacrifice thirteen weeks post-exposure, approximately 5 to 10% of the seminiferous tubules of animals in both TFE exposure groups were still atrophic. TFE did not damage Leydig cells or testicular capillaries.

Under the test conditions, repeated exposure to 2,2,2 trifluoroethanol by inhalation produced damages on the male reproductive system as necrosis of seminiferous tubules inducing a severe decrease in the fertility without a lack of libido or physical inabilities of male rats after the exposure to TFE. Indeed, the copulatory behaviors were normal. It appeared that TFE affected predominantly the premeiotic germ cells of the testis.

No NOAEC was identified as effects were observed at the both tested concentrations of inhalation. However, the lowest observed adversed effect is determined at 100 ppm corresponding to 415 mg/m3.

Data source

Reference

Reference Type:

other: Thesis

Title:

Unnamed

Year:

1981

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

The test item is administered to rats by intraperitoneal injection and the mortality is then observed for 72 hours. Histologic examinations were performed on the liver and on the testes.

GLP compliance:

no

Remarks:

Study performed before GLP compliance

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

2,2,2-trifluoroethanol

EC Number:

200-913-6

EC Name:

2,2,2-trifluoroethanol

Cas Number:

75-89-8

Molecular formula:

C2H3F3O

IUPAC Name:

2,2,2-trifluoroethan-1-ol

Details on test material:

- Name of test material (as cited in study report): trifluoroethanol (TFE)
- Physical state: no data
- Lot/batch No.: no data
- Expiration date of the lot/batch: no data
- Stability under test conditions: assumed to be stable during the test (sponsor responsibility)
- Storage condition of test material: no data
- Other: source: Aldrich Chemical Company

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Ble Spruce Farms, Inc
- Age at study initiation: no data
- Weight at study initiation: 250-350g
- Fasting period before study: no data
- Housing: no data
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: at least one week

ENVIRONMENTAL CONDITIONS
- Temperature (°C): no data
- Humidity (%): no data
- Air changes (per hr): no data
- Photoperiod (hrs dark / hrs light): no data

IN-LIFE DATES: From: To: no data

Administration / exposure

Route of administration:

intraperitoneal

Vehicle:

water

Details on exposure:

All dosing solutions were made in concentrations such that the volume injected was 1.0 mL/kg bw.

Doses:

0, 200, 250, 300, 400, 450, 500 and 600 mg/kg

No. of animals per sex per dose:

between 6 and 8 animals/dose (see details in Table 7.2.4/1)

Control animals:

yes

Details on study design:

- Duration of observation period following administration: 3 days
- Frequency of observations and weighing: no data
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight,organ weights, histopathology

Statistics:

no data

Results and discussion

Effect levels

Key result

Sex:

male

Dose descriptor:

LD50

Effect level:

>= 300 - <= 400 mg/kg bw

Based on:

not specified

Mortality:

No deaths were observed prior to 12 hours postadministration. See details in Table 7.2.4/2.

Clinical signs:

Within minutes of receiving doses greater than 300 mg/kg of TFE, animals displayed signs of inebriation.

Body weight:

no data

Gross pathology:

no data

Other findings:

- Organ weights: Doses of TFE as low as 200 mg/kg produced a significant reduction of the testes:body weight ratio.

- Histopathology:
LIVER: Histological examination of the livers revealed occasional centrobular cloudy swelling, but necrosis was not observed.
TESTES: the histological effects were identical to that observed following inhalation exposure, ie. significant changes in the seminiferous tubular epithelium. Increase cytoplasmic eosinophilia and frank necrosis of premieotic cells, ie., the spermatogonia and spermatocytes, were noted at all exposure levels used. No changes were noted in the apperance of either the spermatids or spermatozoa, or in the interstitial regions which contains Leydig cells and capillaries. Testicular damage following IP (intraperitoneal) administration occurs relatively rapidly. 8 hrs after 100 mg/kg dose, increased eosinophilia and nuclear condensation can be seen in the premeiotic cells. At only 4 hrs following this dose the testis is histologically normal.
Doses as low as 25 mg/kg were found capable of producing testicular damage. Three to nine days following a single IP injection of 100 mg/kg, maturation depletion of spermatids was observed, with early spermatogonial regeneration being noted around day 9.

- Potential target organs: Testis

- Other observations: no data

Any other information on results incl. tables

Table 7.2.4/2: Mortality 72 hours postinjection and testes weight

 

Dose (mg/kg)	Number of died rats (72 hrs post-injection)	Mean time of death (hr)	Testes weight (% of body weight)
0	0/8	-	1.11 +/- 0.1
200	0/6	-	0.88 +/- 0.2**
250	0/7	-	0.84 +/- 0.07**
300	3/6	29	1.06 +/- 0.09
400	3/6	44	1.01 +/- 0.03*
450	5/6	-	-
500	6/6	26	1.00 +/- 0.02**
600	6/6	27	1.11 +/- 0.02

 

*: p<0.01

**: p<0.001

Applicant's summary and conclusion

Conclusions:

Under the test conditions, 2,2,2-trifluoroethanol administered by intraperitoneal injection induced death of male rats with a LD50 between 300 and 400 mg/kg bw. Furthermore, a single peritoneal injection of TFE produced adverse testicular effects.

Executive summary:

In an acute toxicity study, groups of male Sprague-Dawley rats were exposed once by intraperitoneal route to trifluoroethanol (99%) at level doses of 0, 200, 250, 300, 400, 450, 500 and 600 mg/kg bw.  Then, animals were observed for 72 hours. Mortality and histological changes in liver and testes were evaluated.

Intraperitoneal LD₅₀in male rats was comprised between 300 and 400 mg/kg bw.

Furthermore, a single intraperitoneal injection of TFE produced adverse testicular effects (effects on premeiotic cells).