Registration Dossier

Toxicological information

Repeated dose toxicity: inhalation

Currently viewing:

Administrative data

Endpoint:
sub-chronic toxicity: inhalation
Type of information:
experimental study
Adequacy of study:
key study
Study period:
11 November 1991 to 11 November 1992 (date of first exposure to sacrifice)
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Study conducted under GLP conditions

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1992
Report Date:
1992

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 413 (Subchronic Inhalation Toxicity: 90-Day Study)
Deviations:
no
Principles of method if other than guideline:
U.S. Environmental Protection Agency, TSCA, Title 40 Code of Federal Regulations Part 792, Federal Register, 29 November 1983 and subsequent amendment Federal Register 17 August 1989: Japanese Ministry of International Trade and Industry, Directive 31 March 1984 (Kampogyo No. 39 Environmental Agency, Kikyoku No. 85 MITI. Organization for Economic Co-operation and Development, ISBN 92064012367-9, Paris 1982
GLP compliance:
yes
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): T-5333
- Physical state: Colorless liquid
- Analytical purity: Assumed pure
- Composition of test material, percentage of components: Mainly perflurohexane
- Lot/batch no.: 647
- Expiration date of the lot/batch: 16 August 1996
- Stability under test conditions: Stable for at least 5 years
- Storage condition of test material: Ambient in steel drums supplied

Test animals

Species:
rat
Strain:
Sprague-Dawley
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
-CD (SD) BR-Sprauge-Dawley Strain
- Source: Charles River (U.K.). Ltd. Manston Road, margate, Kent, England
- Age at study initiation: Approximately 6 weeks
- Weight at study initiation :146.1 to 147 g (Female) and 136.0 to 136.7 g (Male)
- Housing: 5 of the same sex rats/cage, in suspended cages with stainless steel sides and stainless steel mesh floors. Lx W x H=53 cm x 35 cm x 25 cm. Plastic trays, lined with absorbent paper were placed below each cage to collect animal excreta. The paper was changed daily and clean cages were introduced at intervals throughout the study. The groups of rats were kept in separate ventilated cabinets to prevent a pssible cross-contamination between groups once exposures had commenced.
- Diet (e.g. ad libitum): ad libitum (to weighed amounts of quality controlled food, No. 1 modified diet, Special Diets Service, Witham, Essex, England).
- Water (e.g. ad libitum): ad libutum while in cage
- Acclimation period: at least 7 days.
ENVIRONMENTAL CONDITIONS
- Temperature (°C): 16-23
- Humidity (%): 36-60
- Photoperiod (hrs dark / hrs light): 12/12
IN-LIFE DATES: From 25 November 1991 to 23 march 1992 (Date of first exposure of all animals to sacrifice of satellite groups)

Administration / exposure

Route of administration:
inhalation: vapour
Type of inhalation exposure:
whole body
Vehicle:
other: no vehicle
Details on inhalation exposure:
GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: Vapor generator
- Method of holding animals in test chamber: Individual stainless steel wire mesh cages
- Source and rate of air: 40 L/min test article; 110 L/min diluent air
- Temperature, humidity, pressure in air chamber: each test substance was pressurised with nitrogen to pressures of 20, 40, 60 p.s.i. in the low, intermediate and high does groups, respectively. Temperatures were recorded by measuring the wet and dry bulb temperatures of the termohygrometer in each chamber. The water baths were set at 80 degrees C. The chamber relative humidity was calculated from these data.
- Air flow rate: 40 L/min test article; 110 L/min diluent air
TEST ATMOSPHERE
- Brief description of analytical method used: The concentration of the test substance was monitored throughout exposure by Miran 1A-CVF infra-red gas analysers.
- Samples taken from breathing zone: yes
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
Nominal concentrations were calculated for each group and each exposure from the recorded weight loss from each resevoir.
Duration of treatment / exposure:
6 hours
Frequency of treatment:
5 days a week for 13 weeks
Doses / concentrations
Remarks:
Doses / Concentrations:

Basis:
nominal conc.
No. of animals per sex per dose:
10 rats per sex per group
Control animals:
yes, concurrent vehicle
Details on study design:
Of the 4 groups, group 1 is the control group receiving air only, group 2 is the low dose group, receiving 5000 ppm, group 3 is the intermediate dose group receiving 15000 ppm and group four is the high dose group receiving 50000 ppm of the test compound. The actual mean exposure levels observed were 4987, 15060, and 49821 ppm, respectively.

- Rationale for animal assignment (if not random): Grouped by body weights so that mean bodyweights were equalized.
- Post-exposure recovery period in satellite groups: Blood samples were removed from all Satellite group rats during week 17 of the study. The samples were taken from the orbital sinus, under light ether anesthesia. Samples were stored in heparinized vials, frozen, and shipped to the owning company for future analysis.

Examinations

Observations and examinations performed and frequency:
CAGE SIDE OBSERVATIONS: No data
DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: during exposure, as a group reseponse, all visible animals appeared to be responding similarly or a proportion were affected. Animals were examined twice each day, usually prior to loading and immediately following unloading from chambers on exposure days.
BODY WEIGHT: Yes
- Time schedule for examinations: after group allocation, animals were weighed weekly prior to loading and immediately following unloading from the chambers on exposure days.
FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study):
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: No
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: Yes, but using cumulative cage weekly average intake per group.
FOOD EFFICIENCY:
- Body weight gain in kg/food consumption in kg per unit time X 100 calculated as time-weighted averages from the consumption and body weight gain data: No data
WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): No data
OPHTHALMOSCOPIC EXAMINATION: Yes
- Time schedule for examinations: pre-dose and week 13 findings
- Dose groups that were examined: all dose groups were examined
HAEMATOLOGY: Yes
- Time schedule for collection of blood: week 13 (main group), week 17 (Satellite group)
- Anaesthetic used for blood collection: Yes, under light ether anaesthesia.
- Animals fasted: Yes, overnight
- How many animals: all main group rats and all satellite group rats
- Parameters checked in table No.1 were examined.
CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: week 13 (main group), week 17 (Satellite group)
- Animals fasted: Yes, overnight
- How many animals: all main group rats and all satellite group rats.
- Parameters checked in table No.2 were examined.
URINALYSIS:No
NEUROBEHAVIOURAL EXAMINATION: No
Sacrifice and pathology:
GROSS PATHOLOGY: Yes (see table 3)
HISTOPATHOLOGY: Yes (see table 4)

Results and discussion

Results of examinations

Clinical signs:
no effects observed
Mortality:
no mortality observed
Body weight and weight changes:
no effects observed
Food consumption and compound intake (if feeding study):
no effects observed
Food efficiency:
no effects observed
Water consumption and compound intake (if drinking water study):
not examined
Ophthalmological findings:
no effects observed
Haematological findings:
no effects observed
Clinical biochemistry findings:
no effects observed
Urinalysis findings:
not examined
Behaviour (functional findings):
not examined
Organ weight findings including organ / body weight ratios:
no effects observed
Gross pathological findings:
no effects observed
Histopathological findings: non-neoplastic:
no effects observed
Histopathological findings: neoplastic:
no effects observed
Details on results:
CLINICAL SIGNS AND MORTALITY
Clinical Signs: During exposure and at other times there were no treatment-releated effects.
Mortality: One rat (female number 84) was found dead in the exposure cage. At necrospy a ruptured spleen with the blood in the abdominal cavity were noted. This death of this rat was considered not related to treatment with the test substance and was probaly traumatic in orgin.
BODY WEIGHT AND WEIGHT GAIN
No treatment-related differences between control and exposed groups were seen.
FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study)
Statistically significant differences from control group consumption were seen between weeks 5 and 13 in male rats from Groups 3 (intermediate dose) and 4 (high dose). The differences were small and were not seen in female rats. In the absense of any significant differences in bodyweight gain it is considered that the differences in food consumption are not of toxicological significance.
OPHTHALMOSCOPIC EXAMINATION
Pre-dose findings were consistent with the age of strain of animals examined. At week 13, no abnormalities were detected.
HAEMATOLOGY
mean corpuscular volume: greater in females from group 3 (intermediate dose) and 4 (high dose).
white cells: lower total numbers in males from groups 3 (intermediate dose) and 4 (high dose) and greater total numbers in females from group 4 (high dose). Lower lymphocyte numbers in males from group 4 (high dose) and greater lymphocyte numbers in females from group 4. These differences were small, inconsistent between the sexes and all values were within normal limits. They are considered not to be of toxicological significance.
CLINICAL CHEMISTRY
Alkaline phosphatase: lower activity in males from group 4 (high dose).
Electrolytes: higher inorganic phosphorus concentration in females from groups 3 (intermediate dose) and 4 (high dose). Lower chloride concentration in males from group 3 (intermediate dose) and males and females from Group 4 (high dose).
ORGAN WEIGHTS
There were no treatment-related differences seen at week 14.
GROSS PATHOLOGY
No changes attributable to treatment with the test substance was seen at the terminal or withdrawl kill.
HISTOPATHOLOGY: NON-NEOPLASTIC
No histological changes were seen that were considered to be related to exposure to the test substance. The incidental changes that were seen were within the normally expected spontaneous profile for rats of this strain and age and were considered not to be of toxicological significance.

Effect levels

Dose descriptor:
NOAEL
Effect level:
ca. 49 821 ppm
Sex:
male/female
Basis for effect level:
other: No effects of exposure were observed.

Target system / organ toxicity

Critical effects observed:
not specified

Applicant's summary and conclusion

Conclusions:
No effects of exposure were observed. Therefore, the no observed adverse effect level (NOAEL) for this study was 49821 ppm.
Executive summary:

A 90-day inhalation study on the test article was conducted using Albino CD (SD) BR Sprague-Dawley rats. The animals were whole-body exposed to the test substance for six hours a day, five days a week for 13 weeks.The animals were separated into 4 groups:1-control, 2-low dose, 3-intermediate dose, 4-high dose (administered zero, 5000, 15000 and 50000 ppm of the vaporized test substance). There were no toxicologically significant treatment-related signs of mortality, clinical signs of toxicity, bodyweight, food consumption, ophthalmoscopy, biochemistry, macroscopic pathology, organ weights and microscopic pathology. No effects of exposure were observed. From this study, a no observed adverse effect level (NOAEL) of 49821 ppm (the highest measured dose) was determined.