Dimethoxymethane

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Methylal concentrations are not specified but can be derived from the graph representing the percentage mortality after 24 hours depending on the methylal concentration. Except their weights and origins, no other details on test animals and environmental conditions are specified.

Cross-reference

Reason / purpose for cross-reference:

reference to other study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1951

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

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:

mouse

Strain:

Swiss

Sex:

male

Administration / exposure

Route of administration:

inhalation: vapour

Type of inhalation exposure:

whole body

Vehicle:

not specified

Details on inhalation exposure:

not specified

Analytical verification of test atmosphere concentrations:

yes

Duration of exposure:

ca. 7 h

Concentrations:

Not specified but approximations can be derived from the graph representing the percentage mortality after 24 hours depending on the methylal concentration: 46, 53, 56, 57, 61, 65, 67 mg/L (see "Illustration" below).

No. of animals per sex per dose:

10 (only males were used)

Control animals:

not specified

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LC50

Effect level:

ca. 57 000 mg/m³ air

Based on:

not specified

Exp. duration:

7 h

Any other information on results incl. tables

When mortality occured, death were recorded during the exposure with 80% of the deaths within the last hour of exposure. With only one exception, allanimals survivng the 7-exposure period continued to live.

Within the first 15 minutes of exposure and at the approximate LC50, signs of respiratory tract irritation occured. Within one hour the mice became excited and progressively more ataxic. In the second hour they were unsteady to the point of being unable to remain upright, the fur was ruffled and theeyeswere irritated. Within the third hour, anaesthesia was reached and maintained until the end of the 7-hour exsposure. During anaesthesia, respiration became progressively more convulsive and irregular. When death did not occured during exposure, the mice almost invariably survied on removal from the chamber. Approximatively 2 hours o f breathing fresh air were required to restore the mice to full consciousness and coordinated control of their extremities.

LC50 value is approximatively 57 mg/L or 18354 ppm (see "Illustration" below).

Applicant's summary and conclusion

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

LC50 value is approximatively 57 mg/L air (57000 mg/m3 air) or 18354 ppm. No classification required.

Executive summary:

Mice in groups of 10 were exposed to different concentrations of methylal during a 7-hour period in three glass chambers (34 L volume). The approximated concentrations derived from the graph representing the percentage mortality after 24 hours depending on the methylal concentration were 46, 53, 56, 57, 61, 65, 67 mg/L. The death rate was recorded for 24 hours following exposure.

When mortality occured, death were recorded during the exposure with 80% of the deaths within the last hour of exposure. With only one exception, allanimals survivng the 7-hour exposure period continued to live.

Within the first 15 minutes of exposure and at the approximate LC50, signs of respiratory tract irritation occured. Within one hour the mice became excited and progressively more ataxic. In the second hour they were unsteady to the point of being unable to remain upright, the fur was ruffled and theeyeswere irritated. Within the third hour, anaesthesia was reached and maintained until the end of the 7-hour exsposure. During anaesthesia, respiration became progressively more convulsive and irregular. When death did not occured during exposure, the mice almost invariably survied on removal from the chamber. Approximatively 2 hours o f breathing fresh air were required to restore the mice to full consciousness and coordinated control of their extremities.

LC50 value is approximatively 57 mg/L air (57000 mg/m3 air) or 18354 ppm.