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Toxicological information

Acute Toxicity: oral

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Administrative data

Endpoint:
acute toxicity: oral
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1976-08-23
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Well conducted study similar to OECD 401 protocol. The study was done prior to implementation of GLPs.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1976
Report date:
1976

Materials and methods

Test guideline
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 401 (Acute Oral Toxicity)
Deviations:
yes
Remarks:
includes 28-day observation period
Principles of method if other than guideline:
28 day observation period
GLP compliance:
not specified
Test type:
standard acute method
Limit test:
no

Test material

Constituent 1
Chemical structure
Reference substance name:
2-methylpyridine
EC Number:
203-643-7
EC Name:
2-methylpyridine
Cas Number:
109-06-8
Molecular formula:
C6H7N
IUPAC Name:
2-methylpyridine
Details on test material:
- Physical state:Liquid
- Analytical purity:99.5%
- Impurities (identity and concentrations): Pyridine

Test animals

Species:
rat
Strain:
Sprague-Dawley
Sex:
male
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: Spartan Laboratories
- Age at study initiation: Adult
- Weight at study initiation: 178 g
- Fasting period before study: 16-18 h
- Housing: Individually
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum):
- Acclimation period:

ENVIRONMENTAL CONDITIONS
- Temperature (°C):
- Humidity (%):
- Air changes (per hr):
- Photoperiod (hrs dark / hrs light): 12 hour light/dark

IN-LIFE DATES: From: To:

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
water
Details on oral exposure:
VEHICLE
- Concentration in vehicle: 10%
Doses:
550, 790, 950 mg/kg
No. of animals per sex per dose:
10
Control animals:
yes
Details on study design:
- Duration of observation period following administration: 28 days
- Frequency of observations and weighing: daily observations/once per week weighing
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight,organ weights, histopathology
Statistics:
Body weight - analysis of variance and Dunnett's Test (p<0.05)

Results and discussion

Effect levels
Sex:
male
Dose descriptor:
LD50
Effect level:
> 950 mg/kg bw
Based on:
test mat.
Remarks on result:
other: 950 mg/kg- highest dose tested
Mortality:
550 mg/kg - 0/10
790 mg/kg - 0/10
950 mg/kg - 4/10 (by day 2)
Clinical signs:
other: 550 mg/kg - lethargy 790 mg/kg - lethargy 950 mg/kg - lethargy, loss of muscle coordination (1/10)
Gross pathology:
550 mg/kg - no treatment related effects
790 mg/kg - no treatment related effects
950 mg/kg (animals that died during study) - accumulation of exudate around mouth and eyes, decreased content of fluid in gastrointestinal tract, darkened liver, gastric hemorrhage, moist edematous appearance of tissues
950 mg/kg (surviving animals) - decreased content of adipose tissue (4/6), decreased size of carcass (1/6)
Other findings:
- Organ weights:
- Histopathology: 950 mg/kg (animals that died during study) - focal gastric hemorrhage (1/4); 950 mg/kg (surviving animals) - encephalomalacia
(2/6) including animal with loss of muscle coordination
- Potential target organs: CNS
- Other observations:

Applicant's summary and conclusion

Interpretation of results:
harmful
Remarks:
Migrated information Criteria used for interpretation of results: EU
Conclusions:
The LD50 of alpha-picoline was greater than 950 mg/kg (highest dose tested). The incidence of mortality was 40% at 950 mg/kg. The histopathological examination of surviving animals showed encephalomalacia in two rats suggesting that the CNS was a target organ.