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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Administrative data

Endpoint:
acute toxicity: oral
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Predates GLP and OECD guidelines, but otherwise sufficient for assessment.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1972

Materials and methods

Principles of method if other than guideline:
15 male Wistar rats were administered single doses of isoprene in oil by stomach tube. LD50 was calculated according to Litchfield & Wilcoxon (1949).
GLP compliance:
not specified
Test type:
other: unknown
Limit test:
no

Test material

Constituent 1
Chemical structure
Reference substance name:
Isoprene
EC Number:
201-143-3
EC Name:
Isoprene
Cas Number:
78-79-5
Molecular formula:
C5H8
IUPAC Name:
2-methylbuta-1,3-diene

Test animals

Species:
rat
Strain:
Wistar
Sex:
male
Details on test animals or test system and environmental conditions:
160-210 g

Administration / exposure

Route of administration:
other: by stomach tube
Vehicle:
other: plant oil
Doses:
unknown
No. of animals per sex per dose:
250, 500, 1000, 2000, 2150, 2250 and 2500 mg/kg
Control animals:
not specified

Results and discussion

Effect levels
Sex:
male
Dose descriptor:
LD50
Effect level:
2 125 mg/kg bw
Remarks on result:
other: 2043 - 2210 mg/kg
Mortality:
There were no deaths up to and including 1000 mg/kg.
There were 4, 8, 11 and 15 mortalities at 2000, 2150, 2250 and 2500 mg/kg respectively, with first deaths reported after 1 day of exposure.
Clinical signs:
other: At >= 500 mg/kg animals showed signs of sedation and had breathing difficulties after 1 hour's exposure. These observations were reported up to 7 days.

Applicant's summary and conclusion

Interpretation of results:
Category 5 based on GHS criteria
Conclusions:
15 male Wistar rats were administered single doses of isoprene in oil by stomach tube. LD50 was concluded to be 2043 - 2210 mg/kg bw
Executive summary:

In a Key pre-guideline study, 15 male Wistar rats were administered isoprene in oil by stomach tube at single doses of 250, 500, 1000, 2000, 2150, 2250 and 2500 mg/Kg.

No mortality was observed at doses up to and including 1000 mg/kg. There were 4, 8, 11, and 15 mortalities observed at 2000, 2150, 2250, and 2500 mg/Kg doses, respectively, with first deaths reported post day 1 of exposure. At =500 mg/Kg, animals showed signs of sedation and had breathing difficulties after 1 hour's exposure. These observations were reported up to 7 days.

The acute oral LD50 was concluded to be 2043 - 2210 mg/Kg bw in male Wistar rats.