Ethyl phenyl(2,4,6-trimethylbenzoyl)phosphinate

Endpoint summary

Additional information

There are no studies available for the determination of toxicokinetics or dermal absorption.

Ehtylphenyl (2,4,6 -trimethylbenzoyl) phophinate is a liquid with a molecular weight of 316 g/mol and a very low vapour pressure of 2x10e-4Pa at 20 °C. In agreement with its logPow of 2.9, only 35mg can be dissolved in one liter of water. Due to its low vapour pressure, exposure to vapor is unlikely. The combination of a molecular weight below 500g/mol and moderate lipophilicity (logPoW between 1 and 4) favor oral as well as dermal uptake. Though acute dermal and oral toxicity tests did not show signs of systemic toxicity, sensitization was observed, hinting to dermal uptake of at least small amounts. From the logPoW below 4 it is expected, that the substance does not bioaccumulate.

No mutagenicity or chromosomal aberration was observed, so no reactivity with macromolecules is expected prior to excretion.

Oral gavage over a period of 4 weeks did not reveal signs of systemic toxicity in male and female Wistar rats up to a dose level of 500 mg/kg bw/d. The oral administration of the test substance by gavage to male and female Wistar rats for 3 months caused test substance-related, adverse signs of systemic toxicity at a dose level of 500 mg/kg bw/d taking impaired body weight development, as well as altered clinical pathology parameters and pathology findings into account. Therefore, under the conditions of the present study the NOAEL was 100 mg/kg bw/d for male and female Wistar rats.

Under the conditions of the prenatal developmental toxicity study, the oral administration of the registered substance to pregnant Wistar rats from implantation to one day prior to the expected day of parturition (GD 6-19) caused adverse effects at the highest tested dose of 300 mg/kg bw/d. Maternal toxicity was determined by a normocytic-normochromic, anemic situation. Increases in absolute and relative liver weights indicated a treatment-related adaptive change. In conclusion, the no observed adverse effect level (NOAEL) for maternal toxicity is 100 mg/kg bw/d. In fetuses, three skeletal variations affecting the skull, ribs and sternebrae were assessed as treatment-related but not as adverse. These minor and reversible effects indicate a developmental delay which is reversible. Thus, the no observed adverse effect level (NOAEL) for prenatal developmental toxicity is 300 mg/kg bw/d while the no observed effect level (NOEL) for prenatal developmental toxicity is 100 mg/kg bw/d.

The results of the studies conducted with repeat exposure indicate that the registered substance is being absorbed, and at higher doses is having a toxicological effect on the model used. The NOAEL for repeat exposure toxicity is set at 100 mg/kg bw/day which is outside the guidance value range for specific target organ toxicity - repeat exposure (oral - rat) Category 2. As such the toxicological effect seen is considered to be insufficient for classification in accordance with the EU Classification, Labelling, and Packaging (CLP) regulation (1272/2008).