Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

Soil adsorption

The computer program KOCWIN v2.00 (made available by US-EPA) was used to predict the organic-normalised sorption coefficient for soil (Koc). Two different models are used for this purpose: the Sabljic molecular connectivity (MCI) method and the traditional method which is based on the logPow value of the substance. The MCI method is taken more seriously into account, due to the fact that is includes improved correction factors, resulting in a Koc value of 769.9 L/kg for the chemical compound. The traditional method gives a value of 208.2 L/kg, concerning the experimentally determined LogPow of 3.5 (Frischmann, 2011).

Accordingly the substance has a moderate potential for sorption onto soil organic matter.

Further, the adsorption potential to soil / sewage sludge of tributyl acetylcitrate was investigated in a study conducted according to OECD 121 and EU method C.19 using the HPLC method. A log Koc of 4.271 was determined. It can be assumed that the same applies to tributyl citrate (CAS 77 -94 -1) as it is a near analogue to the test substance acetyl tributyl citrate.

Henry`s Law constant

The Henry's Law Constant was calculated with the computer program HENRYWIN (v3.20) made available by the U.S. Environmental Protection Agency. This program estimates the Henry's Law Constant of organic compounds at 25°C by two separate methods that yield two separate estimates. The first method is the Bond Contribution Method and the second is the Group Contribution Method. Both the Group Method and Bond Method are susceptible to estimates resulting in "Missing Fragments". When a compound is split into groups or bonds, one or more of the resulting groups or bonds may not have a value in the library of available values. The Group Method is much more likely to have a "Missing Fragment" occurrence (meaning an HLC estimate is not possible), as in this case: The Group Method showed an “incomplete Result”, using the Bond Method a Henry´s Law Constant of 3.55 E-004 Pa*m3*mol-1 was calculated for the substance tributyl citrate at 25 °C.