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Environmental fate & pathways

Bioaccumulation: terrestrial

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Description of key information

Bioaccumulation is not applicable to the substance pitch, coal tar, high-temp. as such. Provisionally and as information for the chemical safety assessment, a terrestrial BCF for benzo[a]pyrene as marker substance is provided. Based on a log Pow of 6.13 (Pow = 1,350,000), the BCF for earthworm is estimated following the procedure described in the Technical Guidance Document (ECHA guidance on IR&CSA - Chapter R.16) (see under Discussion).

Key value for chemical safety assessment

BCF (terrestrial species):
16 200 L/kg ww

Additional information

According to ECHA Guidance on IR&CSA - Chapter R.16: Environmental exposure assessment (Version 3.0, February 2016) - Appendix A.16-3.3.8, Equation R.16 -66 (p. 134), bioconcentration in earthworm can be described for organic substances as a hydrophobic partitioning between the pore water and the phases inside the organism. This equilibrium partitioning approach can be modelled according to the following equation as described by Jager (1998):

BCFearthworm = (0.84 + 0.012Kow) / ROHearthworm

where for ROHearthworm by default a value of 1 (kg wwt/L) can be assumed.

Kow of BaP used as marker substance for pitch, coal tar, high-temp. is 1,350,000 (log Kow = 6.13 see Chapter 1.3 - Partition coefficient).

BCFearthworm = (0.84 + 0.012 x 1,350,000) / 1

                     = 16200 L/kg wwt


Reference (cited in ECHA Guidance document on IR&CSA - Chapter R.16):

Jager T (1998) Mechanistic approach for estimating bioconcentration of organic chemicals in earthworms (Oligochaeta). Environmental Toxicology and Chemistry 17(10), 2080-2090