Dialkyl C18 and C18-unsaturated phosphonates

Endpoint summary

Description of key information

The available experimental data in animals suggest oral absorption and systemic distribution of the submitted substance since clinical signs were reported in the repeated administration oral toxicity study. No indications on the submitted substance metabolism and excretion were obtained.

Key value for chemical safety assessment

Bioaccumulation potential:

high bioaccumulation potential

Additional information

 No specific toxicocinetic studies are available on Alkenyl phosphonate. A toxicokinetic assessment was done based on the physico-chemical properties of the submitted substance and based on the results of the acute and repeated administration toxicity studies by oral route.

 

Physico-chemical properties of Alkenyl phosphonate:

- Water solubility: < 0.17 µg/ at 20 °C

- Boiling point: 322.1°c ± 0.5°C at 1013.25 hPa

- Partition coefficient in octanol/water: 5.19 at 20°C

- Vapour pressure: < 0.15 mbar at 90°C and < 4.0 mbar at 250 °C

- Density: 0.901 ± 0.001 °C

N.B: Chemical Name was changed after registration toSubstance name:Dialkyl C18 and C18-unsaturated phosphonates;

EC Number:                        701-298-1

 

Absorption:

 

Inhalation:

No data were available for this route of exposure. However, the submitted substance is a liquid with a low volatility, as evidenced by the very low vapour pressure. Therefore it can be considered that the absorption by the inhalation route is limited.

 

Oral:

No mortality was observed after the oral administration of Alkenyl phosphonate to rats at the dose of 2000 mg/kg bw (OECD 423, Kr.1, GLP). There were no systemic clinical signs noted in any animal throughout the study.

In the repeated administration subacute study (OECD 422, Kr.1, GLP), hypersalivation associated or not with abnormal foraging and/or pedalling from Day 18 of treatment up to the end of the dosing period for both sexes in the 250 and 750 mg/kg/day groups were observed. Other incidental findings were observed such as a torn claw, scab or localized hairloss.

Observations made on the repeated administration toxicity study support an absorption of the submitted substance by the oral route.

 

Dermal route:

In the acute toxicity by dermal route (OECD 402, Kr.1, GLP), no mortality occurred following dosing and no clinical signs were observed. Very slight to well-defined erythema in 10/10 animals (Day 1-5 or 1-6), very slight to slight oedema in 9/10 animals (Day 1-6) and crust in 9/10 animals were seen at the treated area after treatment with the test item. The absorption by the dermal route is therefore possible.

 

Distribution:

The clinical signs observed in the repeated administration oral toxicity study suggest a systemic distribution of the submitted substance. 

Metabolism:

In vitro genotoxicity studies were performed on the submitted substance. These studies showed no genotoxic potential but did not provide any information on possible metabolism.

 

Elimination:

There is no information to indicate a route of excretion for the submitted substance. The parent substances could not be eliminated via the lungs in expired air due to its low volatility.