Dimethyl methylphosphonate

Acute Toxicity: oral

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: Scientifically acceptable study (similar to guideline)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1976

Report date:

1976

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

Determination of acute toxicity (LD50) after acute oral application of the test substance to rats

GLP compliance:

no

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Dimethyl methylphosphonate

EC Number:

212-052-3

EC Name:

Dimethyl methylphosphonate

Cas Number:

756-79-6

Molecular formula:

C3H9O3P

IUPAC Name:

dimethyl methylphosphonate

Details on test material:

- Name of test material (as cited in study report): 80 021/B
No additional data

Test animals

Species:

rat

Strain:

other: Tif RAIf (SPF)

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: raised on the premises of the testing facility were used for the experiments
- Age at study initiation: no data
- Weight at study initiation: 105 to 235 grams
- Fasting period: animals were fasted overnight before treatment
- Housing: during the treatment and observation period the animals were housed in groups of 5 in Macrolon cages- (type 3)
- Diet (e.g. ad libitum): standard diet of pellets - No. 890, Nafag Gossau SG
- Water (e.g. ad libitum): drinking water
- Acclimation period: a minimum of 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22±1°C
- Humidity (%): 55±5%
- Photoperiod (hrs dark / hrs light): 14 hours light cycle day

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

unchanged (no vehicle)

Details on oral exposure:

The test substance was administered undiluted

Doses:

1000, 3000, 4500, 6000, 8000, 10000 and 15000 mg/kg bw

No. of animals per sex per dose:

5

Control animals:

no

Details on study design:

- Duration of observation period following administration: 15 days
Physical condition and rate of death were monitored throughout the whole observation period.

Statistics:

LD50 including 9 5% confidence limits were calculated by the probit analysis method (Goulden A., Methods of Statistical Analysis, John Wiley and Sons, 1960, 3rd printing, pages 404-408)

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LD50

Effect level:

10 190 mg/kg bw

95% CL:

9 140 - 11 360

Remarks on result:

other: Deaths were observed in the 8000, 10000 and 15000 mg/kg dose groups

Mortality:

One animal (1 female) died in 8000 mg/kg dose group (within 1 day), 5 (1 male and 4 females) in the 10000 mg/kg dose group (within 1-8 days) and all animals of the highest dose group (15000 mg/kg bw).

Clinical signs:

other: - In the 1000, 3000 and 4500 mg/kg bw group: lasting >6 hours, reduction in spontaneous motility, ataxia, muscular hypotonia, ventricumbency, hypoventilation; dyspnoea was additionally observed in the 3000 mg/kg dose group and diarrhea in the 4500 mg/kg d

Gross pathology:

No data

Any other information on results incl. tables

Table 1: Mortality and body weight during the course of the experiment

Dose (mg/kg bw)	Morality and percentage of deaths			Body weight (g)
	Absolute mortality / total tested animals		Percentage (%)	Pretest	On day 15 of test
	Males	Females
1000	0/5	0/5	0	110	197
3000	0/5	0/5	0	135	220
4500	0/5	0/5	0	120	191
6000	0/5	0/5	0	110	186
8000	0/5	1/5	10	120	189
10000	1/5	4/5	50	110	195
15000	5/5	5/5	100	105	180