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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other: GLP, guideline study, available as unpublished report, no restrictions, fully adequate for assessment
Cross-referenceopen allclose all
Reason / purpose:
reference to same study
Reason / purpose:
reference to other study

Data source

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

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 403 (Acute Inhalation Toxicity)
Deviations:
no
Principles of method if other than guideline:
not applicable
GLP compliance:
yes (incl. certificate)
Test type:
standard acute method
Limit test:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): butene-2
- Physical state: gas
- Analytical purity: ≥ 95% cis and trans-2-butene
- Composition of test material, percentage of components: n-butane (1.11 vol%), 1-butene (0.935 vol%), isobutylene (+/- 200 vol ppm),
ethylacetylene (< 20 vol ppm), 1,3 butadiene (240 vol ppm), unknown C4 (0.218 vol% as C4H10), trans-2-butene 55.3 vol%), cis-2-butene (42.4 vol%).
- Storage condition of test material: ambient temperature

Test animals

Species:
rat
Strain:
other: Crl:WI (WU) BR
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Charles River, Wiga, Sulzfeld, FRG
- Age at study initiation: 9-10 weeks
- Weight at study initiation: mean weight males 277g, mean weight females 171 g
- Housing: 5/cage
- Diet: TNO Institute stock diet ad libitum):
- Water: ad libitum
- Acclimation period: 27 days

ENVIRONMENTAL CONDITIONS
- Temperature: 21.5-23.0°C
- Humidity: 38-67% (up to 87% for short periods during cleaning)
- Air changes: 10 per hr
- Photoperiod: 12hrs dark / 12hrs light

IN-LIFE DATES: From: 30 March 1992 To: 13 April 1992

Administration / exposure

Route of administration:
inhalation
Type of inhalation exposure:
whole body
Vehicle:
other: air
Details on inhalation exposure:
GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: modified H 1000 multi-tiered inhalation chamber with pyramidal top and bottom, constructed of stainless steel with 2 glass doors.
- Exposure chamber volume: 1.2 m3
- Method of holding animals in test chamber: Individually held in wire mesh stainless steel cages
- Rate of air-flow: 21.4 ± 0.6 m3 per hour
- Treatment of exhaust air:
- Temperature, humidity, pressure in air chamber: Mean temp = 23.1±0.1°C, mean RH = 49±2%, negative pressure = 1-4mm water column.

TEST ATMOSPHERE
- Brief description of analytical method used: total carbon analyser
- Samples taken from breathing zone: yes
Analytical verification of test atmosphere concentrations:
yes
Remarks:
10,057 ± 276 ppm
Duration of exposure:
4 h
Concentrations:
Target concentration of 10,000 ppm (23 g/m3), analytical concentration 10,057 ± 276 ppm
No. of animals per sex per dose:
5
Control animals:
no
Details on study design:
- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: observed just before, during and immediately after exposure and once daily thereafter. Bodyweights recorded just prior to exposure and on days 7 and 14.
- Necropsy of survivors performed: yes
Statistics:
none

Results and discussion

Preliminary study:
none
Effect levels
Sex:
male/female
Dose descriptor:
LC50
Effect level:
10 000 other: ppm (22,948 mg/m3, 23 mg/L) nominal
Exp. duration:
4 h
Remarks on result:
other: no effects were observed at the highest dose
Mortality:
none
Clinical signs:
Restless during 1st hour of exposure. No abnormalities during 14 day observation period.
Body weight:
Normal bodyweight gain except for two females that showed reduced bodyweight gain.
Gross pathology:
no abnormalities
Other findings:
none

Any other information on results incl. tables

none

Applicant's summary and conclusion

Interpretation of results:
not classified
Remarks:
Migrated information Criteria used for interpretation of results: EU
Conclusions:
From the results of this study, it was concluded that the 4-hour acute inhalation LC50value of butene-2 was greater than 10,057 ppm ( 22,948 mg/m3, 23mg/L).
Executive summary:

Rats were exposed for 4 hrs to 2-butene at a nominal concentration of 10,000 ppm ( 22,948 mg/m3). No clinical signs were seen and normal growth occurred over the 14d observation period. No abnormalities were observed at gross necropsy. Only one concentration was tested. This concentration was at the explosive limit and therefore higher concentrations could not be tested.