Bis(2-methylisouronium) sulphate

Endpoint summary

Description of key information

From the mortality figures the LD50 of O-Methylisourea sulphate was calculated to be 3.7 g/kg body weight.

Within one hour after dosing most of the rats showed diarrhoea and decreased activity. In the three highest doses groups some rats had signs of unconsciousness. Deaths occurred within 24 hours. No delayed deaths were observed. At the end of the observation period the surviving animals looked quite healthy again. No treatment-related gross changes were seen at autopsy at day 14.

Exposure to O-Methylisourea sulfate techical at a single chamber concentration of 2.133 mg/L did not cause mortality. Minor signs of toxicity such as changes in clinical condition and a small reduction in body weight gain were considered not to be significant signs of toxicity.

Using standard toxicity assessment criteria the test article can be classified as non-toxic or slightly toxic. As the maximum practical concentration used produced only slight signs of toxicity the test article is of low acute toxicity and should probably be classified as non-toxic.

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records

Reference

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1974

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study without detailed documentation

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

GLP compliance:

not specified

Test type:

standard acute method

Species:

rat

Strain:

Wistar

Sex:

male/female

Route of administration:

oral: unspecified

Vehicle:

water

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

ca. 3 700 mg/kg bw

Based on:

test mat.

Within one hour after dosing most of the rats showed diarrhoea and decreased activity. In the three highest doses groups some rats had signs of unconsciousness. Deaths occurred within 24 hours. No delayed deaths were observed. At the end of the observation period the surviving animals looked quite healthy again. No treatment-related gross changes were seen at autopsy at day 14.

Interpretation of results:

GHS criteria not met

Conclusions:

From the mortality figures the LD50 of O-Methylisourea sulphate was calculated to be 3.7 g/kg body weight.

Executive summary:

From the mortality figures the LD50 of O-Methylisourea sulphate was calculated to be 3.7 g/kg body weight.

Within one hour after dosing most of the rats showed diarrhoea and decreased activity. In the three highest doses groups some rats had signs of unconsciousness. Deaths occurred within 24 hours. No delayed deaths were observed. At the end of the observation period the surviving animals looked quite healthy again. No treatment-related gross changes were seen at autopsy at day 14.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LD50

Value:

3 700 mg/kg bw

Acute toxicity: via inhalation route

Link to relevant study records

Reference

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

March 1991

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

GLP compliance:

yes

Test type:

standard acute method

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Route of administration:

inhalation: mist

Type of inhalation exposure:

head only

Vehicle:

air

Analytical verification of test atmosphere concentrations:

yes

Duration of exposure:

ca. 4 h

Concentrations:

2.13 mg/l

No. of animals per sex per dose:

five

Sex:

male/female

Dose descriptor:

LC0

Effect level:

> 2.133 mg/L air (analytical)

Based on:

test mat.

Exp. duration:

4 h

Key result

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 2.133 mg/L air (analytical)

Based on:

test mat.

Exp. duration:

4 h

Mortality:

none

Exposure to O-Methylisourea sulfate techical at a single chamber concentration of 2.133 mg/L did not cause mortality. Minor signs of toxicity such as changes in clinical condition and a small reduction in body weight gain were considered not to be significant signs of toxicity.

Using standard toxicity assessment criteria the test article can be classified as non-toxic or slightly toxic. As the maximum practical concentration used produced only slight signs of toxicity the test article is of low acute toxicity and should probably be classified as non-toxic.

Interpretation of results:

GHS criteria not met

Remarks:

Migrated information

Conclusions:

At a concentration of 2.133 mg/L no death occured.

Executive summary:

Exposure to O-Methylisourea sulfate techical at a single chamber concentration of 2.133 mg/L did not cause mortality. Minor signs of toxicity such as changes in clinical condition and a small reduction in body weight gain were considered not to be significant signs of toxicity.

Using standard toxicity assessment criteria the test article can be classified as non-toxic or slightly toxic. As the maximum practical concentration used produced only slight signs of toxicity the test article is of low acute toxicity and should probably be classified as non-toxic.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Acute toxicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Justification for selection of acute toxicity – oral endpoint
From the mortality figures the LD50 of O-Methylisourea sulphate was calculated to be 3.7 g/kg body weight.

Justification for selection of acute toxicity – inhalation endpoint
Exposure to O-Methylisourea sulfate techical at a single chamber concentration of 2.133 mg/L did not cause mortality. Minor signs of toxicity such as changes in clinical condition and a small reduction in body weight gain were considered not to be significant signs of toxicity.