Methylphosphonic acid, compound with amidinourea (1:1)

Endpoint summary

Description of key information

LD50, oral > 2500 mg/kg bw
acute Tox. dermal: test waived (scientifically not justified: not hazardous)
acute Tox. inhalation: test waived (limited exposure)

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:

supporting study

Study period:

from 1983-06-20 till 1983-09-01

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Guideline study without GLP and without deviations.

Qualifier:

according to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

Deviations:

no

GLP compliance:

not specified

Test type:

acute toxic class method

Limit test:

yes

Species:

rat

Strain:

other: Tif:RAIf(SPF), F3-crosses of RII 1/Tif x RII 2/Tif

Sex:

male/female

Route of administration:

oral: gavage

Vehicle:

water

Doses:

one single dose, per os

No. of animals per sex per dose:

5 animals per sex per dose

Control animals:

no

Statistics:

not necessary

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 5 000 mg/kg bw

Based on:

test mat.

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 500 mg/kg bw

Based on:

act. ingr.

Mortality:

one femal rat, 3 hours after treatment.

Clinical signs:

other: The surviving animals recovered within 9 days.

Gross pathology:

Besides one case of spotted lung no gross lesions were found at necropsy.

Interpretation of results:

practically nontoxic

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

The test material has practically no acute toxicity when administered orally to the albino rat up to 5000 mg/kg bw.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

2 500 mg/kg bw

Quality of whole database:

All three available studies are guideline studies and with Klimisch score 1 or 2.

Acute toxicity: via inhalation route

Link to relevant study records

Reference

Endpoint:

acute toxicity: inhalation

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

the study does not need to be conducted because exposure of humans via inhalation is not likely taking into account the vapour pressure of the substance and/or the possibility of exposure to aerosols, particles or droplets of an inhalable size

Endpoint conclusion

Endpoint conclusion:

no study available

Quality of whole database:

No acute inhalation toxicity study available.

Acute toxicity: via dermal route

Link to relevant study records

Reference

Endpoint:

acute toxicity: dermal

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

the study does not need to be conducted because the physicochemical and toxicological properties suggest no potential for a significant rate of absorption through the skin

Endpoint conclusion

Endpoint conclusion:

no study available

Quality of whole database:

No acute dermal toxicity study but a skin penetration test is available.

Additional information

Three acute oral studies with different technical products (ca. 50% MPAAU in water) showed no oral toxicity to rats up to 5000 mg/kg bw. The oral LD50 of MPAAU was >2500 mg/kg bw. This is further supported by the results of a 7 day dose range-finding study in female rats, which showed no clinical signs up to and including 2000 mg MPAAU/kg bw/day (see IUCLID Chapter 7.5.1).

Based on weight of evidence the substance is deemed to be not hazardous for acute systemic toxicity by the dermal route.

A skin penetration test (see IUCLID Chapter 7.1.2) shows very low penetration of the test material (5% in 24 hours) through the skin of porcine ears. The substance did not show adverse effects in two in vivo 4h skin irritation/corrosion tests (see IUCLID Chapter 7.3.1). In view of the oral LD50>2500 mg/kg and the low skin penetration of the substance no acute systemic hazard can be expected for the dermal route.

Based on weight of evidence (no acute oral toxicity, assumption of similar absorption both by oral and inhalation route, no irritating potential to skin or eye) the substance is considered not hazardous with regard to acute systemic and acute local endpoint toxicity by the inhalation route. In addition, inhalation exposure is unlikely to occure under intended conditions of use (limited exposure).

Justification for selection of acute toxicity – oral endpoint
All three acute oral toxicity studies show no toxicity or adverse effects of the substance. The study with the highest dose tested was chosen to report the (theoretical) limit value.

Justification for selection of acute toxicity – inhalation endpoint
No significant inhalation exposure is expected.

Justification for selection of acute toxicity – dermal endpoint
Based on weight of evidence the substance is deemed to be not hazardous for acute systemic toxicity by the dermal route.

Justification for classification or non-classification

According to the GHS criteria, listed in Annex I, the substance does not have to be classified as a hazardous substance regarding acute toxicity to mammals.

Based on the above stated assessment of the acute toxic potential of MPAAU (oral LD50 > 2500 mg/kg, weight of evidence for absence of acute dermal or inhalation systemic toxicity) the substance is deemed non-toxic for acute systemic endpoints and accordingly does not need to be classified according to Council Directive 2001/59/EC (28th ATP of Directive 67/548/EEC) and according to CLP (REGULATION (EC) No 1272/2008 OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL) as implementation of UN-GHS in the EU.