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Description of key information

No studies on toxicokinetics are available. However, toxicokinetic information could be derived from acute oral and dermal toxicity studies. We can conclude that 44PD and/or its metabolites will be absorbed by the oral and dermal route. Although inconclusive data are available for the inhalation route, due to the systemic bioavailability via the oral route, it is likely that 44PD will also be absorbed by the inhalation route.

Key value for chemical safety assessment

Additional information

No studies on toxicokinetics are available. However, considering physicochemical properties and taking into account the results of 44PD in acute and repeated dose toxicity studies and skin irritation/corrosion tests, a characterization of 44PD toxicokinetics can be conducted.

44PD is a liquid with a calculated vapour pressure of 0.207 Pa at 25°C. Its molecular mass is 220.35 g/mol and it has a predicted log Kowof 3.5. The water solubility was estimated to be 33 mg/L.

 

Absorption resulting from oral exposure

In general, a log Kowvalue between -1 and 4 indicates that a molecule is favourable for absorption from the gastro-intestinal tract. Furthermore, a molecular weight <500 g/mol is believed to enhance the oral absorption. It can thus be concluded that 44PD will likely be absorbed from the gastro-intestinal tract upon oral intake.

 

Absorption resulting from dermal exposure

For compounds that are water soluble between 1 and 100 mg/L – which is the case for 44PD – dermal absorption is anticipated to be low to moderate. However, it has to be taken in account that the test substance is corrosive to the skin (Parent 1983). Damage to the skin surface may enhance penetration.

 

An abnormal coloration of the urine was observed in acute oral (rat) and dermal (rabbit) toxicity studies. This finding confirms a systemic bioavailability of 44PD or its metabolites.

 

We can conclude that 44PD and/or its metabolites will be absorbed by the oral and dermal route. Although inconclusive data are available for the inhalation route, due to the systemic bioavailability via the oral route, it is likely that 44PD will also be absorbed by the inhalation route.