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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
Study period:
1987-11-1987 to 1987-11-20
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: This study is classified as reliable with restrictions because it was conducted according to OECD 403.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1988
Report Date:
1988

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 403 (Acute Inhalation Toxicity)
Deviations:
no
GLP compliance:
not specified
Test type:
standard acute method
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): MRD-87-102
- Substance type: Other Lubricant Base Oil (IP 346 < 3%)
- Physical state: clear, colourless liquid

Test animals

Species:
rat
Strain:
Sprague-Dawley
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Charles River Breeding Laboratories, Inc. Stone Ridge, New York
- Age at study initiation: Males approx. 8 weeks/Females approx 9 weeks
- Weight at study initiation: Males: 300-327 grams/ Females: 219-243 grams
- Fasting period before study: No
- Housing: Paired by sex for approximately one week then individually there after in suspended stainless steel wire mesh.
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: approximately 17 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): Animal Room: 19 to 22 degrees Celsius/ Chamber: 21 to 22 degrees Celsius
- Humidity (%): Animal Room: 45 to 68% relative humidity/Chamber: 27 to 41%
- Air changes (per hr): Not reported
- Photoperiod (hrs dark / hrs light): 12 hrs dark/ 12 hrs light


IN-LIFE DATES: From: 1987-10-20 To:

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: FMI Lab Pump connected to a Spraying Systems Atomizer
- Exposure chamber volume: One cubic meter
- Method of holding animals in test chamber: not reported
- Source and rate of air: room air was dispersed with the aerosolized test material.
- Method of conditioning air: not reported
- System of generating particulates/aerosols: compressed air was delivered to the atomizer at 45 psi which caused the liquid droplet aerosol to be expelled toward the top of the chamber.
- Method of particle size determination: Sierra Model 210 Cascade Impactor was used once during the exposure. The change in weight of the filter for each stage was measured and the cumulative percent of the sample collected on each state was calculated.
- Treatment of exhaust air: exhaust flowrate was 200 LPM, one air change every 5.0 minutes and theoretical equilibration time of 23.0 minutes.
- Temperature, humidity, pressure in air chamber: Not reported. Dry bulb/wet bulb hygrometers were used to monitor chamber and room temperatures and relative humidity at approx 30 min intervals.


TEST ATMOSPHERE
- Brief description of analytical method used: air was drawn from the chamber atleast once every hour of exposure.
- Samples taken from breathing zone: yes
Analytical verification of test atmosphere concentrations:
yes
Duration of exposure:
> 0 - 4 h
Concentrations:
5.53 mg/L (5530 milligrams per cubic meter).
No. of animals per sex per dose:
5 animals per sex per dose
Control animals:
yes
Details on study design:
- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: animals were obscured by the test material aerosol during exposure and therefore could not be observed.
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight,organ weights, histopathology, other:
Statistics:
The mean and standard deviations were calculated for relevant exposure and animal data. Sample t-test was used to evaluate equality of means. A standard F-test was performed to determine if the two groups (control and dosed) have equal variance. If the variance were equal, testing was to be based on the standard t-test. If the variance were not equal, the Smith-Satterthwaite Correction for unequal variances was used.

Results and discussion

Effect levels
Sex:
male/female
Dose descriptor:
LC50
Effect level:
> 5.53 mg/L air
Exp. duration:
4 h
Mortality:
There was no mortality in either control or exposed group during the study.
Clinical signs:
other: After removal from the chamber all of the animals had an extreme amount of test material on their fur. Post exposure the number of animals with material on their fur diminished and was absent by Day 10. Single scattered incidences of dried red nasal di
Body weight:
All control animals and exposed animals increased in body weight at the day 7 observation period. At Day 14 all animals in the control group and nine animals in the exposed group increased in body weight. One exposed female decreased slightly in body weight from the day 7 to Day 14 observation period.
Gross pathology:
In the exposed group: two males were found to have lung discoloration and one female with lung discoloration and enlarged lymph nodes. One male was observed to have enlarged lymph nodes and one male with alopecia on the scapular area. One male and four females were found to have no observable abnormalities. In the control group of animals four males and our females appeared to be free of macroscopic abnormalities. One male was observed with lung discoloration, and one female was found to have lung discoloration and uro-gential abnormalities.
Other findings:
None reported

Applicant's summary and conclusion

Interpretation of results:
not classified
Remarks:
Migrated information LC50 > 5.53 mg/L Criteria used for interpretation of results: EU
Conclusions:
The test material which was deposited on the animal fur during exposure diminished by observation Day 10. No mortality in either the control or exposed group was reported. There were no statistically significant differences in mean body weight between groups. Based on the results of the study, the four hour LC50 for MRD-87-102 in rats by inhalation would appear to be greater than 5.53 mg/L (actual).
Executive summary:

In an acute inhalation toxicity study, five male and five female young adult Sprague- Dawley rats were exposed by inhalation route to MRD-87-102 for four hours to whole body at a concentration of 5.53 mg/L. Animals then were observed for 14 days.

The test material which was deposited on the animal fur during exposure diminished by observation Day 10. No mortality in either the control or exposed group was reported. There were no statistically significant differences in mean body weight between groups. Based on the results of the study, the four hour LC50 for MRD-87-102 in rats by inhalation would appear to be greater than 5.53 mg/L (actual).

This study received a Klimisch score of one and is classified as reliable without restriction because it was conducted according to OECD guideline 403.