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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:
1995
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Acceptable, well-documented study report equivalent or similar to OECD guideline 403 : GLP.
Justification for type of information:
A discussion and report on the read across strategy is given as an attachment in IUCLID Section 13.
Cross-reference
Reason / purpose for cross-reference:
read-across: supporting information
Reference
Endpoint:
acute toxicity: inhalation
Type of information:
read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Study period:
1995
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Acceptable, well-documented study report equivalent or similar to OECD guideline 403 : GLP.
Justification for type of information:
A discussion and report on the read across strategy is given as an attachment in IUCLID Section 13.
Reason / purpose for cross-reference:
read-across source
Sex:
male/female
Dose descriptor:
LC50
Effect level:
>= 6 100 mg/m³ air (analytical)
Exp. duration:
4 h
Mortality:
None
Clinical signs:
other: other:
Body weight:
Body weight appeared normal throughout experiment. One female lost 2 grams during the Day 7-14 post-exposure observation period.
Gross pathology:
All animals appeared normal.
Other findings:
N/A
Interpretation of results:
other: Not classified
Remarks:
Criteria used for interpretation of results: EU
Conclusions:
The LC50 for acute inhalation exposure to MRD-94-979 vapor is greater than 6100 mg/m3. Classification as an acute inhalation toxicant is not warranted under the new Regulation (EC) 1272/2008 on classification, labeling and packaging of substances and mixtures (CLP) or under Directive 67/518/EEC for dangerous substances and Directive 1999/45/EC for preparations.
Executive summary:

This data is being read across from the source study that tested Hydrocarbons, C9-C11, isoalkanes, cyclics, <2% aromatics based on analogue read across.

MRD-94-979 was administered via individual inhalation chambers for four hours to ten Sprague-Dawley rats (5 males, 5 females) to an average actual vapor concentration of 6100 mg/m3 for four hours to assess acute inhalation toxicity. Animals were observed for fourteen days following exposure.  There were no mortality or gross pathological alterations noted in any of the animals.  Based on the conditions of this study, The LC50 for acute inhalation exposure to MRD-94-979 vapor is greater than 6100 mg/m3.  Classification as an acute inhalation toxicant is not warranted under the new Regulation (EC) 1272/2008 on classification, labeling and packaging of substances and mixtures (CLP) or under Directive 67/518/EEC for dangerous substances and Directive 1999/45/EC for preparations.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1995
Report date:
1995

Materials and methods

Test guideline
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 403 (Acute Inhalation Toxicity)
GLP compliance:
yes
Test type:
standard acute method

Test material

Constituent 1
Reference substance name:
Hydrocarbons, C9-C11, isoalkanes, cyclics, < 2% aromatics
EC Number:
926-952-5
IUPAC Name:
Hydrocarbons, C9-C11, isoalkanes, cyclics, < 2% aromatics
Details on test material:
- Name of test material (as cited in study report): MRD-94-979
- Physical state: Colorless liquid
- Analytical purity:
- Lot/batch No.: 012294
- Storage condition of test material: Room temperature

Test animals

Species:
rat
Strain:
Sprague-Dawley
Sex:
male/female
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: Charles River
- Age at study initiation: 9-11 weeks
- Weight at study initiation: 245-325 g
- Housing:individually
- Diet (e.g. ad libitum): ad libitum during non-exposure, food withheld while in chamber
- Water (e.g. ad libitum): ad libitum
- Acclimation period: 14 days


ENVIRONMENTAL CONDITIONS
- Temperature (°F): 68-76
- Humidity (%): 40-70
- Photoperiod (hrs dark / hrs light): 12/12


Administration / exposure

Route of administration:
inhalation: vapour
Type of inhalation exposure:
whole body
Details on inhalation exposure:
GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
Exposure apparatus: 150 liter stainless steel inhalation chamber
- Exposure chamber volume: 150 liter
- Temperature, humidity, pressure in air chamber: 75° F, 48%, slight negative pressure to the room


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



CLASS METHOD (if applicable)
- Rationale for the selection of the starting concentration:
Analytical verification of test atmosphere concentrations:
yes
Duration of exposure:
4 h
Concentrations:
actual vapor concentration of6100 mg/m3
No. of animals per sex per dose:
10 animals/dose (5 males; 5 females)
Control animals:
no
Details on study design:
- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Day 0, 7, and 14
- Necropsy of survivors performed: yes

Results and discussion

Effect levels
Sex:
male/female
Dose descriptor:
LC50
Effect level:
>= 6 100 mg/m³ air (analytical)
Exp. duration:
4 h
Mortality:
None
Clinical signs:
other: other:
Body weight:
Body weight appeared normal throughout experiment. One female lost 2 grams during the Day 7-14 post-exposure observation period.
Gross pathology:
All animals appeared normal.
Other findings:
N/A

Applicant's summary and conclusion

Interpretation of results:
other: Not classified
Remarks:
Criteria used for interpretation of results: EU
Conclusions:
The LC50 for acute inhalation exposure to MRD-94-979 vapor is greater than 6100 mg/m3. Classification as an acute inhalation toxicant is not warranted under the new Regulation (EC) 1272/2008 on classification, labeling and packaging of substances and mixtures (CLP) or under Directive 67/518/EEC for dangerous substances and Directive 1999/45/EC for preparations.
Executive summary:

MRD-94-979 was administered via individual inhalation chambers for four hours to ten Sprague-Dawley rats (5 males, 5 females) to an average actual vapor concentration of 6100 mg/m3 for four hours to assess acute inhalation toxicity. Animals were observed for fourteen days following exposure.  There were no mortality or gross pathological alterations noted in any of the animals.  Based on the conditions of this study, The LC50 for acute inhalation exposure to MRD-94-979 vapor is greater than 6100 mg/m3.  Classification as an acute inhalation toxicant is not warranted under the new Regulation (EC) 1272/2008 on classification, labeling and packaging of substances and mixtures (CLP) or under Directive 67/518/EEC for dangerous substances and Directive 1999/45/EC for preparations.