Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

Two studies on bioaccumulation were available on TRIGONOX 101.

The first study (Erhardt, 2008) was evaluated as the key study. This study assessed the bioaccumulation of TRIGONOX 101 using thein vitrotrout liver S9 metabolism assay (no guideline followed). The BCF value was determined with and without metabolism being taken into account. The calculation is based on the Arnot Gobas BCF mass balance model run with and without metabolism. When metabolic rate (Kmet) is set to 0, the model calculates a BCF ot 46097. When Kmet is experimentally determined using two methods: arterial hepatic and arterial hepatic and portal, blood flow extrapolation further to a trout hepatocyte in vitro study, BCFs are calculated as 766 and 443 L/Kg respectively. Thein vitrorate of metabolism was determined for this organic peroxide. The substance dissipated rapidly under biologically active conditions. A half- life for metabolism was 210 min or 3.5 hours. These data were used to extrapolate in vivo rate constants of metabolism or Kmet of 0.116 day-1or 0.189 day-1using hepatic portal blood flow or hepatic portal and arterial blood flow, respectively. The use of these kMET values in conjunction with the Gobas model dropped the calculated BCF from 31,819.51(assuming no metabolism) to 521 or 839.

The second study (author unknown, 2004) was evaluated as the weight of evidence. This study assessed the bioconcentration of TRIGONOX 101 on Cyprinus carpio, following "Methods concerning the testing of new chemical substances" (Kanpo n°. 5, Yakuhattsu n°.615, 49th Unit, n°.392, 1974, partially revised in 1998), which is similar to OECD Guideline 305. Results demonstrated that a BCF steady-state of 3690 and 2250 L/Kg (for primary and secondary concentration areas respectively).

As the experimental BCF study was incomplete missing numerous details allowing it to be validated, the BCF and as further experimental data are available from anin vitrostudy which is deamed to be valid, it is concluded that the BCF is between 521 and 839.