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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
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
guideline study with acceptable restrictions
Remarks:
partly limited documentation, e.g. no details about test substance

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1971
Report date:
1971

Materials and methods

Test guideline
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 401 (Acute Oral Toxicity)
Deviations:
no
GLP compliance:
no
Test type:
standard acute method
Limit test:
no

Test material

Constituent 1
Chemical structure
Reference substance name:
N-methylacetamide
EC Number:
201-182-6
EC Name:
N-methylacetamide
Cas Number:
79-16-3
Molecular formula:
C3H7NO
IUPAC Name:
N-methylacetamide
Details on test material:
Purity 99.9%
no further details

Test animals

Species:
rat
Strain:
Sprague-Dawley
Sex:
male/female
Details on test animals or test system and environmental conditions:
Initial body weight: 142-165 g in males and 132-167 g in females
No further details.

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
water
Details on oral exposure:
concentration in test solution 20% at a dose level of 1600 µl/kg bw, 30% at all other dose levels
no data about fasting prior to application

Doses:
1600, 3200, 4000, 5000, and 6400 µl/kg bw
with a density of 0.975 @25°C: 1560, 3120, 3900, 4875, 6240 mg/kg
No. of animals per sex per dose:
5 males and 5 females per dose
Control animals:
no
Details on study design:
- Duration of observation period following administration: 14 days
- Frequency of observations: (presumably) daily
- weighing: no data
- Necropsy of survivors and rats found dead
Statistics:
LD50 estimated; no data about confidence limits

Results and discussion

Effect levels
Sex:
male/female
Dose descriptor:
LD50
Effect level:
ca. 4 200 other: µl/kg bw
Remarks on result:
other: corresponding to 4095 mg/kg bw
Mortality:
Data on mortality are presented in the Table below. At the high dose level rats died within 2 days (at other dose levels within 7 days).
Clinical signs:
at 1600 µl/kg bw: no effects
3200 µl/kg bw: 1/10 rats with alopecia (head)
4000 µl/kg bw: no symptoms (but mortality)
5000 µl/kg bw: ruffled coat, apathy, side position
6400 µl/kg bw: bloody muzzle (day 2), adhered eyes, tremor, apathy
Body weight:
No data available on weight at study termination.
Gross pathology:
Surviving rats: no treatment related effects.
Rats found dead: congestion of liver and lung, degeneration of the heart, liver coloured (dark yellow); loss of weight
Other findings:
no data

Any other information on results incl. tables

Acute toxicity in male (m) and female (f) rats after oral application of monomethylacetamide

Dose in µl/kg bw

Number of rats which died within

1 hour

24 hours

48 hours

7 days

14 days

6400

0/5m
0/5f

0/5m
0/5f

4/5m
5/5f

5/5m
5/5f

5/5m
5/5f

5000

0/5m
0/5f

0/5m
0/5f

0/5m
2/5f

5/5m
5/5f

5/5m
5/5f

4000

0/5m
0/5f

0/5m
0/5f

0/5m
0/5f

1/5m
2/5f

1/5m
2/5f

3200

0/5m
0/5f

0/5m
0/5f

0/5m
0/5f

0/5m
0/5f

0/5m
0/5f

1600

0/5m
0/5f

0/5m
0/5f

0/5m
0/5f

0/5m
0/5f

0/5m
0/5f

Applicant's summary and conclusion

Conclusions:
The oral LD50 is 4200 µl/kg bw in male and female rats combined; corresponding to 4095 mg/kg bw with a density of 0,975 g/cm3.
Executive summary:

The study is comparable to OECD Guideline 401 with acceptable restrictions (partly limited documentation, e.g. no details about test animals).

Groups of 5 male and 5 female rats were gavaged with 20 or 30% aqueous solutions at dose levels of 1600, 3200, 4000, 5000, and 6400 µl/kg bw. The post exposure observation period was 14 days. At the high dose levels rats died within 2 days.Clinical signs like ruffled coat, apathy, side position occurred and in the high dose group also bloody muzzle (day 2), adhered eyes, and tremor; no treatment related effects were seen in survivors. Necropsy revealed also no treatment related effects in survivors; rats found dead showed congestion of liver and lung, degeneration of the heart, coloured liver coloured (dark yellow), and loss of weight.

Conclusion: The oral LD50 is 4200 µl/kg bw corresponding to 4095 mg/kg bw in male and female rats combined.