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Environmental fate & pathways

Bioaccumulation: aquatic / sediment

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Description of key information

Estimated by calculation the BCF for the constituents of 'Reaction mass of benzyl 2-ethylhexyl adipate and bis(2-ethylhexyl) adipate and dibenzyl adipate' revealed values of 358.4 L/kg wwt for benzyl 2-ethylhexyl adipate, 685.4 L/kg wwt for dibenzyl adipate and 957.1 L/kg wwt for bis(2-ethylhexyl) adipate. 
Additionally, bioaccumulation of one constituent of 'Reaction mass of benzyl 2-ethylhexyl adipate and bis(2-ethylhexyl) adipate and dibenzyl adipate' (bis(2-ethylhexyl) adipate) on Lepomis macrchirus was tested in a flow through test according to American national standard ASTM. For bis(2-ethylhexyl) adipate a whole-fish BCF of 27 was observed, indicating no significant bioaccumulation in fish.
Based on this result, it is assumed that also the other two constituents of 'Reaction mass of benzyl 2-ethylhexyl adipate and bis(2-ethylhexyl) adipate and dibenzyl adipate' (benzyl 2-ethylhexyl adipate and dibenzyl adipate) will not be accumulative.

Key value for chemical safety assessment

BCF (aquatic species):
27 dimensionless

Additional information

The bioconcentration factor (BCF) of 'Reaction mass of benzyl 2-ethylhexyl adipate and bis(2-ethylhexyl) adipate and dibenzyl adipate' was predicted using the Estimation Program Interface (EPI) Suite version 4.1.

'Reaction mass of benzyl 2-ethylhexyl adipate and bis(2-ethylhexyl) adipate and dibenzyl adipate' is a "multi constituent substance" consisting of benzyl 2-ethylhexyl adipate [CAS 58394-64-2], bis(2-ethylhexyl) adipate [CAS 103-23-1] and dibenzyl adipate [CAS 2451-84-5].

Each constituent is identified as a non-ionic substance by the program.

The following internally calculated log Kow values were taken into account:

Constituent A [benzyl 2-ethylhexyl adipate]

log Kow: 6.46

Constituent B [bis(2-ethylhexyl) adipate]

log Kow: 8.12

Constituent C [dibenzyl adipate]

log Kow: 4.80

 

The estimation yielded a BCF of 358.4 L/kg wwt for benzyl 2-ethylhexyl adipate, a BCF of 957.1 L/kg wwt for bis(2-ethylhexyl) adipate and a BCF of 685.4 L/kg wwt for dibenzyl adipate. All values indicate a potential for bioaccumulation.

Each constituent of 'Reaction mass of benzyl 2-ethylhexyl adipate and bis(2-ethylhexyl) adipate and dibenzyl adipate' falls within the applicability domain of the model and the applied estimating rules appear appropriate.

In addition to this, there is one reliable study on bioaccumulation for one constituent of 'Reaction mass of benzyl 2-ethylhexyl adipate and bis(2-ethylhexyl) adipate and dibenzyl adipate' (bis(2-ethylhexyl) adipate) available.

Bioaccumulation of bis(2-ethylhexyl) adipate was tested according to American national standard ASTM E35.

Lepomis macrochirus was exposed to 14C-labelled bis(2-ethylhexyl) adipate at a concentration of 0.25 mg/L under flow-through conditions. The fish were observed initially and every 24 h during the exposure period for mortality and unusual behaviour. Water and fish were sampled during the uptake period at 4 h and 1, 3, 7, 14, 21 and 28 d. Muscle filet and viscera portions of fish were analysed. Bis(2-ethylhexyl) adipate appeared to reach equilibrium in the fish on day 7. On day 28 of the exposure period, the remaining fish were exposed to flowing uncontaminated water for an additional 14 days. During this period, water and fish were sampled on days 29, 31, 35, 38 and 42 and analysed as during the uptake period. A BCF of 27 was calculated from the fresh weight of the whole fish. The measured BCF was far less than the BCF calculated from log Kow. The difference is thought to be due to metabolism of the bis(2-ethylhexyl) adipate by the bluegill. The measured BCF was based on 14C determinations and not on measurement of actual substance concentrations in fish tissue. Some of the 14C activity may have been from the incorporation of metabolites of bis(2-ethylhexyl) adipate, and the actual BCF for bis(2-ethylhexyl) adipate may be less than 27. The depuration half-life for bis(2-ethylhexyl) adipate in bluegills is less than 1 day. These data indicate that bis(2-ethylhexyl) adipate is neither an accumulative nor a persistent substance in fish.

Based on this result, it is assumed that also the other two constituents of 'Reaction mass of benzyl 2-ethylhexyl adipate and bis(2-ethylhexyl) adipate and dibenzyl adipate' (benzyl 2-ethylhexyl adipate and dibenzyl adipate) will not be accumulative.