Trifluoro(trifluoromethoxy)ethylene

Repeated dose toxicity: inhalation

Administrative data

Endpoint:

short-term repeated dose toxicity: inhalation

Remarks:

combined repeated dose and reproduction / developmental screening

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2007

Report date:

2007

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 422 (Combined Repeated Dose Toxicity Study with the Reproduction / Developmental Toxicity Screening Test)

Deviations:

yes

Remarks:

The animal room accountability sheets from August 28 - September 2006, could not be located at the time the report was prepared. But this deviation does not impact the validity or interpretation of the study.

GLP compliance:

yes

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Trifluoro(trifluoromethoxy)ethylene

EC Number:

214-703-7

EC Name:

Trifluoro(trifluoromethoxy)ethylene

Cas Number:

1187-93-5

Molecular formula:

C3F6O

IUPAC Name:

1,1,2-trifluoro-2-(trifluoromethoxy)ethene

Details on test material:

Substance Tested: Perfluoromethylvinyl Ether, Ether trifluoro(trifluoromethoxy)-, 1187-93-5(CAS Number)
Haskell Number: 27649
- Analytical purity: 99.32%
- Composition of test material, percentage of components:
0.18% Hydro-PMVE
0.292% HFP+C3
0.200% O2+N2+CO
0.02% Others

Test animals

Species:

rat

Strain:

Sprague-Dawley

Details on species / strain selection:

Crl: CD(SD)

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Laboratories, Inc Raleigh, North Carolina Crl: CD(SD) rat
- Age at study initiation: Approximately 60 days
- Weight at study initiation: Males: 199.1-230.6 g Females: 170.6-207.5 g
- Fasting period before study: Animals subjected to clinical pathology evaluation were fasted after 3 p.m. for at least 15 hours.
- Housing:
Pretest/Premating: Individually (except during cohabitation of mating pairs) in stainless steel, wire-mesh cages suspended above cage boards; sexes on separate racks.
Cohabitation: Mating pairs (females placed in males’ cages) on a 1:1 basis in stainless steel, wire-mesh cages suspended above cage boards.
Days 0–19 of gestation: Individually in stainless steel, wire-mesh cages suspended above cage boards; sexes on separate racks.
Day 19 of gestation -
Day 4 of lactation: Females assumed pregnant were housed individually in polycarbonate pans with bedding material. Females presumed nonpregnant were housed in the same manner as pregnant females 7 days after the mating pairs were separated.
- Diet (e.g. ad libitum):PMI® Nutrition International, LLC Certified Rodent LabDiet® 5002 (pelleted) ad libitum except during exposure and when fasted.
- Water (e.g. ad libitum):Tap water from United Water Delaware ad libitum provided by an automatic watering system except during exposure.
- Acclimation period: 18days

ENVIRONMENTAL CONDITIONS
- Temperature (°C):18-26°C
- Humidity (%):30-70%
- Air changes (per hr):at least 10 air changes
- Photoperiod (hrs dark / hrs light):12-hour light/dark cycle, with an artificial fluorescent light.

Administration / exposure

Route of administration:

inhalation: gas

Type of inhalation exposure:

whole body

Vehicle:

clean air

Remarks on MMAD:

MMAD / GSD: 0, 60, 300, and 1500 ppm.

Details on inhalation exposure:

During exposure, animals were individually placed in stainless steel wire-mesh modules (one/module) and exposed,, whole-body,inside the exposure chamber, except during the mating period when animals were housed as mating pairs in stainless steel wire-mesh modules and exposed in the same manner.
Chamber atmospheres were generated by dilution of H-27649 gas in air. The test substance was metered into the test chamber inlets using a Brooks model 0154E or 0154 mass flow controller and mixed with filtered and conditioned air. Chamber concentrations of test substance were controlled by varying the test substance feed rate and the air flow to the chamber. All exposure chambers were constructed of stainless steel and glass (NYU style) with a nominal internal volume of 350 L. A tangential feed at the chamber inlet promoted uniform chamber distribution of the test atmosphere.
Chamber temperature was targeted at 19-25°C and recorded at least 3 times during each exposure. Chamber relative humidity was targeted at 30-70% and recorded at least 3 times during each exposure. Temperature and humidity were measured with a VWR dial-type thermometer/hygrometer. Chamber airflow was set at the beginning of each exposure to achieve at least 10 air changes per hour. The airflow was monitored continually with thermoanemometers and recorded at least 2 times during each exposure. Chamber oxygen concentration was targeted to be at least 19%. The oxygen concentration was measured with a Biosystems model 3100R oxygen analyzer and recorded once during each exposure.

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

During each exposure, the atmospheric concentration of the test substance in the test chambers was determined by gas chromatography (GC) at approximately 30-minute intervals. The control chamber was sampled once per exposure. Known volumes of chamber atmosphere were continually drawn from the breathing zone of the animals and were directly injected into a Hewlett Packard model 6890 gas chromatograph equipped with an automated gas sample valve and a flame ionization detector. All samples were chromatographed isothermally at 35°C on a J&W Scientific, DB-5, 30 M capillary column. The atmospheric concentration of the test substance was determined from a standard curve derived from gas standards. Standards were
prepared prior to each exposure by injecting known volumes of the gaseous test substance into Tedlar® bags containing known volumes of air.

Duration of treatment / exposure:

Animals/Study Phase Duration
Premating 14 Days (Approximate)
Cohabitation Up to 14 days
Postcohabitation
Males Until sacrifice
Females with no evidence of copulation 19 Days (Approximate)
Gestation Day 0-19G

Frequency of treatment:

All exposures were conducted for 6 hours/day, 5 days/week during the premating phase.
Beginning at the start of cohabitation, exposures were conducted for 6 hours/day, 7 days/week.
Lactating dams and offspring were not exposed.

Doses / concentrations

Doses / concentrations 1

Dose / conc.:

0 ppm (analytical)

Doses / concentrations 2

Dose / conc.:

60 ppm (analytical)

Doses / concentrations 3

Dose / conc.:

300 ppm (analytical)

Doses / concentrations 4

Dose / conc.:

1 500 ppm (analytical)

No. of animals per sex per dose:

12/sex/concentration

Control animals:

yes, concurrent no treatment

Details on study design:

Assignment to Groups:
Selection Criteria: Animals without adequate body weight gain and/or with clinical signs of disease or injury were eliminated from consideration for use in the study; weight variation of individual rats did not exceed ± 20% of the mean weight for each sex on test day 0.
Randomization: Computerized, stratified randomization procedure designed to produce a homogeneous distribution of body weights across groups.
Disposition of Remaining Animals: Sacrificed by carbon dioxide asphyxiation.

Positive control:

Procedures and data describing the effects of trimethyltin, acrylamide, carbaryl, and d-amphetamine are presented in 5 separate reports. These positive control studies are the basis of training certification for the people making judgments in the neurobehavioral tests. The data also documents that the equipment and procedures are capable of detecting effects that may be seen in studies of this type.

Examinations

Observations and examinations performed and frequency:

Careful clinical observations were recorded once daily after the initiation of exposures. Detailed clinical observations were recorded once during pretest and weekly thereafter. Body weights and food consumption were recorded weekly for P1 males and females (premating), on days 0, 7, 14, and 21 of gestation; and on days 0 and 4 of lactation. Food consumption was not measured during cohabitation or thereafter for males, or for females with no evidence of copulation. An abbreviated neurobehavioral evaluation consisting of a functional observational battery and motor activity was conducted in P1 rats (12/sex/group) once during pretest and prior to cohabitation. F1 litter examinations (pup viability, individual pup weights, clinical observations) were performed at birth and on lactation day 4.

Sacrifice and pathology:

Clinical pathology parameters were measured in P1 rats (5/sex/group) at the end of the premating period (hematology, clinical chemistry) and at terminal sacrifice (coagulation).
Sacrifice Schedule
Males Test days 29-30
Dams with Litters Day 4L
Females without evidence of mating Test day 54
Gross Pathology All adult animals
Histopathology Control and high-dose groups (kidneys)

Other examinations:

no data

Statistics:

Male and female data were evaluated separately. For litter parameters, the proportion of affected pups per litter or the litter mean were used as the experimental unit for statistical evaluation.The level of significance selected is p < 0.05. Additional statistical tests were used, and other parameters analyzed, if deemed necessary.
The adopted statistical methods are reported in the field "Attached backgroud materials".

Results and discussion

Results of examinations

Clinical signs:

no effects observed

Description (incidence and severity):

There were no test substance-related clinical signs of toxicity observed during the daily exposures to PMVE.

Mortality:

no mortality observed

Description (incidence):

Mortality did not occur at any exposure concentration.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

1. P1 Males Overall body weight gain over test days 0 – 28 was reduced 14% in 1500 ppm males compared to the control value. While not statistically significant (p < 0.05) a similar trend was observed in the range-finding study, and this reduction was considered to be test substance related; although, not biologically adverse. Body weight and overall body weight gain for males exposed to 60 and 300 ppm were within 90% of the control value.

2. P1 Females – Premating Test substance-related, statistically significant (p < 0.05) reduction in body weight gain occurred in during test days 0 – 7 of the premating period for 1500 ppm females. However, since this reduction was transient, and overall weight gain was similar to control values, it was not considered to be biologically adverse. Body weight and overall weight gain for 60 and 300 ppm females were similar to control values.

3. P1 Females – Gestation Test substance-related, statistically significant (p < 0.05) reduction in body weight gain occurred in during test days 0 – 7 of gestation for 1500 ppm females. However, since this reduction was transient, and overall weight gain was similar to control values, it was not considered to be biologically adverse. Body weight and overall weight gain for 60 and 300 ppm females were similar to control values.

4. P1 Females – Lactation There were no test substance-related or statistically significant differences in body weight or weight gain exposed to any concentration of the test substance.

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

1. Male Rats There were no test substance-related or statistically significant differences in food consumption or food efficiency for P1 males exposed to any concentration of the test substance.

2. P1 Females – Premating
Test substance-related, statistically significant reductions in food consumption and food efficiency occurred in 1500 ppm females. During test days 0 – 7, food consumption and food efficiency were decreased 11% and 90%, respectively, compared to the control values. However, these reductions were transient, and recovery occurred during test days 7 – 14 such that food consumption and food efficiency values over the entire premating period (test days 0 - 14) were similar to the control values. There were no test substance-related effects or statistically significant differences on food consumption or food efficiency in females exposed to 60 or 300 ppm.

3. P1 Females – Gestation Test substance-related reductions in food consumption and food efficiency occurred in 1500 ppm females. During test days 0 – 7, food consumption and food efficiency were decreased 8% and 25%, respectively, compared to the control values. However, these reductions were transient, and recovery occurred during gestation days (GD) 7 – 14 such that food consumption and food efficiency values over the entire gestation period (GD 0 – 21) were similar to the control values. There were no test substance-related effects or statistically significant differences on food consumption or food efficiency in females exposed to 60 or 300 ppm.

4. P1 Females – Lactation There were no test substance-related or statistically significant differences on food consumption or food efficiency in females for any exposure concentration.

Food efficiency:

effects observed, treatment-related

Description (incidence and severity):

1. Male Rats There were no test substance-related or statistically significant differences in food consumption or food efficiency for P1 males exposed to any concentration of the test substance.

2. P1 Females – Premating
Test substance-related, statistically significant reductions in food consumption and food efficiency occurred in 1500 ppm females. During test days 0 – 7, food consumption and food efficiency were decreased 11% and 90%, respectively, compared to the control values. However, these reductions were transient, and recovery occurred during test days 7 – 14 such that food consumption and food efficiency values over the entire premating period (test days 0 - 14) were similar to the control values. There were no test substance-related effects or statistically significant differences on food consumption or food efficiency in females exposed to 60 or 300 ppm.

3. P1 Females – Gestation Test substance-related reductions in food consumption and food efficiency occurred in 1500 ppm females. During test days 0 – 7, food consumption and food efficiency were decreased 8% and 25%, respectively, compared to the control values. However, these reductions were transient, and recovery occurred during gestation days (GD) 7 – 14 such that food consumption and food efficiency values over the entire gestation period (GD 0 – 21) were similar to the control values. There were no test substance-related effects or statistically significant differences on food consumption or food efficiency in females exposed to 60 or 300 ppm.

4. P1 Females – Lactation There were no test substance-related or statistically significant differences on food consumption or food efficiency in females for any exposure concentration.

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

not specified

Ophthalmological findings:

not specified

Haematological findings:

effects observed, non-treatment-related

Description (incidence and severity):

There were no adverse changes in hematology parameters in male or female rats.

The following statistically significant change in a mean hematology parameter was not considered to be adverse:
White blood cell count was minimally decreased at test day 14 in female rats exposed to 1500 ppm (mean was 80% of the control group mean). The decrease in white blood cell count was due primarily to a minimal decrease in lymphocyte counts (not statistically significant). Similar findings were not observed in male rats at any dose. Decreased white cell count may have been related to treatment because the consistency in the white counts of the 5 females in this group. However, this change was considered to be non-adverse because of the minimal nature of the change.

Clinical biochemistry findings:

effects observed, non-treatment-related

Description (incidence and severity):

There were no adverse changes in clinical chemistry parameters in male or female rats.

The following statistically significant changes in mean clinical chemistry parameters were not adverse or not related to exposure to the test substance:
- Bilirubin was minimally increased at test day 14 in male rats exposed to 1500 ppm (mean was 122% of control group mean). This change was due to minimally increased bilirubin in one male (animal #403) and was considered to be unrelated to treatment and thus non-adverse.
- Albumin was minimally increased at test day 14 in female rats exposed to 1500 ppm (mean was 111% of the control group mean). This change may have been related to treatment because of the consistency in the albumin concentrations of the 5 females in this group. However, increased albumin was considered to be non-adverse because of the minimal degree of change.
- Alkaline phosphatase was mildly increased at test day 14 in females exposed to 60 ppm (mean was 153% of the control group mean). This change was considered to be unrelated to treatment because it did not occur in a concentration-related pattern.

Urinalysis findings:

not specified

Behaviour (functional findings):

no effects observed

Description (incidence and severity):

Under the conditions of the study, there were no test substance-related effects or any neurobehavioral parameter evaluated (forelimb grip strength, hindlimb grip strenght and open field observations) in either males or females exposed to inhalation concentrations of 1500 ppm and below.

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Description (incidence and severity):

A test substance-related increase (in P 1 adult females, mean absolute and relative (% body weight) kidney weights were increased 9% and 15%, respectively in the 1500 ppm exposure group, as compared to control values) was observed in female rats exposed to 1500 ppm.
There was no test substance-related organ weight effect in male rats.

Gross pathological findings:

no effects observed

Description (incidence and severity):

There were no test substance-related gross observations in any of the P1 adults.`All gross observations, recorded at necropsy, were consistent with normal background lesions that occur in rats of this age and strain.

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Description (incidence and severity):

Daily inhalation exposure of P1 adult rats to 1500 ppm of the test substance, for approximately 28 days (males) or 42 days (females), resulted in minimal regeneration of renal tubular epithelium. Regeneration of the renal tubular epithelium was observed in 10/12 males and 9/12 females exposed to 1500 ppm of the test substance. It was not observed at lower exposures. The regeneration was characterized by an increase in the number of cells in the lining epithelium of the tubules and a decrease in the average cell size. An increase in mitotic figures or associated epithelial degeneration was not observed. The change was confined to the outer medulla, was usually diffuse, and was graded as minimal (grade 1 of 4) in all instances.
A slight increase in kidney weight parameters was observed at the same dose in females only.
There were no test substance-related microscopic or organ weight effects at exposures ≤ 300 ppm in either sex.
There were no test substance-related effects on causes of death, gross pathology, or reproductive failures at any exposure (≤ 1500 ppm).
Under the conditions of this study, the no-observed-effect level (NOEC) for pathology for male and female P1 adult rats was 300 ppm.

Histopathological findings: neoplastic:

not specified

Effect levels

Key result

Dose descriptor:

NOAEC

Remarks:

systemic toxicity

Effect level:

300 ppm (analytical)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

body weight and weight gain

food consumption and compound intake

histopathology: non-neoplastic

organ weights and organ / body weight ratios

Target system / organ toxicity

Key result

Critical effects observed:

yes

Lowest effective dose / conc.:

1 500 ppm (analytical)

System:

urinary

Organ:

kidney

Treatment related:

yes

Dose response relationship:

yes

Any other information on results incl. tables

Incidence of renal tubular regeneration in P1 male and female rats

sex	Males				Females
concentration (ppm)	0	60	300	1500	0	60	300	1500
number of rats	12	12	12	12	12	12	12	12
Kidneys: Regeneration, tubular epithelium	0	0	0	10	0	0	0	9

Applicant's summary and conclusion

Conclusions:

Under the conditions of the study, the No-Observed-Adverse-Effect Concentration (NOAEC) for systemic toxicity was 300 ppm in males and females based on the histopathological effects observed at 1500 ppm.

Executive summary:

A combined repeated exposure toxicity study with reproduction/developmental toxicity screening test was conducted with Perfluoromethylvinyl Ether. Crl:CD(SD) rats (12/sex/concentration) were exposed whole body to 0, 60, 300, or 1500 ppm of perfluoromethylvinyl ether. Exposures for males and females were conducted for 6 hours per day, 5 days per week from the initiation of the study through the 14-day premating period. Exposure to the test substance did not result in adverse clinical signs or mortality. Test substance-related reductions in weight gain, food consumption, and/or food efficiency occurred in 1500 ppm males and females; however, they were transient and did not adversely affect the health of the animals. There were no adverse or test substance-related effects on neurobehavioral parameters, clinical pathology parameters, and no effects on clinical observations, or survival. Test substance-related, minimal regeneration of renal tubular epithelium was observed in 1500 ppm males and females, and was accompanied by increased absolute and relative kidney weights in 1500 ppm females. Based on the results above, the NOEC for systemic toxicity was 300 ppm ( 2037,08 mg/m³).