Dimethoxymethane

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1982

Report date:

1982

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 423 (Acute Oral toxicity - Acute Toxic Class Method)

GLP compliance:

no

Test type:

acute toxic class method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Methylal

IUPAC Name:

Methylal

Details on test material:

- Name of test material (as cited in study report): Methylal

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Weight at study initiation: 200-300g
- Fasting period before study: yes (overnight before dosing)
- Diet (e.g. ad libitum): commercial diet ad libitum
- Water (e.g. ad libitum): municipal water ad libitum

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

not specified

Details on oral exposure:

Rats received the test material by stomach intubation with a ball-end stainless steel needle. The test material was injected through the needle with a syringe and doses concentrations were varied by adjusting the volume of the test material or its dilution.

Doses:

1.0, 2.0, 4.0, 8.0, 16.0 mL/kg bw

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: Individual bodyweight recorded at Days 0 (before dosing), 7 and 14.
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs and gross pathology

Statistics:

LD50 are calculated by the moving average method (Thompson, 1947) and are based on a 14-day observation period.

Results and discussion

Effect levels

Effect levels 1

Sex:

male/female

Dose descriptor:

LD50

Effect level:

7.46 mL/kg bw

Based on:

test mat.

95% CL:

5.16 - 10.8

Effect levels 2

Sex:

male/female

Dose descriptor:

LD50

Effect level:

6 423 mg/kg bw

Based on:

test mat.

Mortality:

Deaths occurred for 5/5 males and 5/5 females at concentration of 16.0 mL/kg bw and for 3/5 males and 3/5 females at concentration of 8.0 mL/kg bw.

Clinical signs:

other: Sluggishness, unstendy gait was recorded for both males and females at all concentrations. Prostration, slow or rapid and shallow respiration occured for both male and female rats at concentrations of 4.0, 8.0 and 16.0 ml/kg bw.

Gross pathology:

Dark red lungs, livers with tan patches, liquid-filled stomach, red and yellow intestines, black spleens with tan patches and kidney with tan patch were observed among male and female rats from 16.0 mL/kg bw group.
Dark red lungs were observed among dead animals of 8.0 mL/kg bw female rats group.
Lungs with deep red patches were observed among one female rat survivor of dosed 8.0 ml/kg bw group and 2 female rats of dosed 4.0 ml/kg bw group.

Applicant's summary and conclusion

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

The LD50 of the test item Methylal is 7.46 ml/kg bw (6453 mg/kg bw) by oral route (gavage) for both male and female rats. Methylal was classified as slighty toxic following single peroral intubation. But non toxic following CLP regulation.

Executive summary:

Albino Wistar rats were used for this oral acute toxicity test. Animals were fasted overnight before dosing. Municipal water and commercial diet (Agway Prolab Rabbit Ration) were supplied ad libitum.

Rats received the test material by stomach intubation with a ball-end stainless steel needle. The test material was injected through the needle with a syringe and doses concentrations were varied by adjusting the volume of the test material or its dilution.

The test item was applied at levels of 1.0, 2.0, 4.0, 8.0, 16.0 mL/kg bw with 5 animals per sex per dose.

The animals were observed for duration of 14 days following administration. Individual bodyweight was recorded at Days 0 (before dosing), 7 and 14. Signs of toxicity and mortality were recorded. Necropsy of survivors was performed.

Mean body weight increased for survivors of 16.0 ml/ kg bw group and for members of 1.0, 2.0 and 4.0 mL/ kg bw group. Sluggishness, unsteady gait were noted at all concentrations in male and female rats. Prostration, slow or rapid and shallow respiration occurred for both male and female rats at concentrations of 4.0, 8.0 and 16.0 mL/kg bw. Deaths occurred for 5/5 males and 5/5 females at concentration of 16.0 mL/kg bw and for 3/5 males and 3/5 females at concentration of 8.0 mL/kg bw. Dark red lungs, livers with tan patches, liquid-filled stomach, red and yellow intestines, black spleens with tan patches and kidney with tan patch were observed among male and female rats from 16.0 mL/kg bw group. Dark red lungs were observed among victims of dosed 8.0 mL/kg bw female rats group.

The LD50 of the test item Methylal is 7.46 mL/kg bw (6453 mg/kg bw) by oral route (gavage) for both male and female rats. Methylal was classified as slightly toxic following single peroral intubation.