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Toxicological information

Acute Toxicity: inhalation

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Administrative data

Endpoint:
acute toxicity: inhalation
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP-compliant study, available as unpublished report, no restrictions, adequate for assessment.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1985
Report Date:
1985

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 403 (Acute Inhalation Toxicity)
GLP compliance:
yes
Test type:
acute toxic class method
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Substance type: Mixture of hydrogenated terphenyls
- Physical state: Yellow-green liquid
- Vapour pressure of less than 0.1mm at 25°C
- Boiling point of 350°C
- Specific gravity of 1.004 g/l

Test animals

Species:
rat
Strain:
Sprague-Dawley
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Charles River Breeding Laboratories
- Age at study initiation: Approximately 5 weeks
- Weight at study initiation: 127-185 grams (males), 101-141 grams (females)
- Housing: Individually housed (during the exposure)
- Diet (e.g. ad libitum): ad libitum (except during the exposure period)
- Water (e.g. ad libitum): ad libitum (except during the exposure period)
- Acclimation period: Test animals were held and observed in quarantine for 10 days prior to release for study.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 70-74°F
- Humidity (%): 39-70% relative humidity
- Air changes (per hr): 19.2 to 22.2 liters/min
- Photoperiod: 12 hrs dark / 12 hrs light cycle

Administration / exposure

Route of administration:
inhalation: aerosol
Type of inhalation exposure:
whole body
Vehicle:
other: unchanged (no vehicle)
Details on inhalation exposure:
GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: Laskin-type nebulizer
- Exposure chamber volume: 0.3 m³
- Method of holding animals in test chamber: One par cage, positioned in two tiers in the chamber
- Method of particle size determination: Andersen cascade impactor

TEST ATMOSPHERE
- Brief description of analytical method used: Determinated by gas chromatography
- Samples taken from breathing zone: yes

TEST ATMOSPHERE (if not tabulated)
- Particle size distribution: 92.9-95.8% of particles were less than 10um in size
- MMAD (Mass median aerodynamic diameter): 1.82-2.36um
Analytical verification of test atmosphere concentrations:
yes
Remarks:
Gas chromatography
Duration of exposure:
4 h
Remarks on duration:
single exposure
Concentrations:
2.5 mg/L; 3.6 mg/L; 4.4 mg/L; 4.7 mg/L
No. of animals per sex per dose:
6 Males ,6 Females /exposure concentration
Control animals:
yes
Details on study design:
- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: twice daily
- Necropsy of survivors performed: yes
- Other examinations performed: macroscopic examination of the external appearance and of tissues of the thoracic, abdominal and cranial cavities.

Results and discussion

Effect levels
Sex:
male/female
Dose descriptor:
LC50
Effect level:
> 4.7 mg/L air
Exp. duration:
4 h
Mortality:
At 4.7 mg/L: 5 rats died (1 males, 4 females) on a total of 36 animals
Clinical signs:
other: In treated animals immediately after exposure were observed: salivation increase; wet fur on the ventral side (due to salivation); discharge and/or encrustation about the nose and eyes; labored breathing; prostrate condition and fur coated with test mater
Body weight:
At 3.6-4.7 mg/L: decreases in mean body weights.
Gross pathology:
Not test-related
Other findings:
All of the effects noted above were reversible by the end of the study (day 14)

Applicant's summary and conclusion

Interpretation of results:
not classified
Remarks:
Criteria used for interpretation of results: EU
Conclusions:
LC50 > 4.7 mg/L
Executive summary:

Six groups of 6 male and 6 female Sprague-Dawley rats per group were each exposed once for 4 hours to atmospheres of aerosolized hydrogenated terphenyl. Mean exposure concentrations ranged from 2,5 to 4.7 mg of Terphenyl, hydrogenated vapor/aerosol per liter of air. The chamber atmospheres were run at elevated and ambient temperatures. Two groups of rats were exposed to house-conditioned air and served as ambient and heated control groups. Exposures were followed by a 14-day observation period and subsequent necropsy. The LC50 for the material could not be calculated due to the low incidence of mortality (3 out of 12 in a single exposure at 4.7 mg/L). In treated animals immediately after exposure, notable observations included salivation, wet fur on the ventral side (due to salivation), discharges and/or encrustation about the nose and eyes, labored breathing, prostrate condition and fur coated with test material. Post-exposure observations included red encrustation about eyes and nose, fur coated with test material and labored breathing. By post-exposure day 14 all surviving animals were in apparent good health. Decreases in mean body weights were noted by post-exposure day 2 in all groups except in the lowest exposure concentration (ambient) and control groups. By the end of the 14 day post-exposure period all groups had exceeded their pre-exposure weights. There were no terminal necropsy findings which are considered to be related to the test material. Based on the test exposure results, the LC50 value for Terphenyl, hydrogenated administered in the study is considered to be greater than 4.7 mg/L.