GULFTENE C16-18 ISOMERISED OLEFINS - NICNAS

are appropriate for the C16-C18 congener, and indicate significant potential for bioconcentration.
The BCF for a compound may also be estimated from Log Pow using Quantitative Structure
Activity Relationships (QSARs). (Lyman 1982) give a number of QSARs for this purpose
but equation 5-2 is recommended for general estimation of the BCF from Log Pow. This
equation is –
Log BCF = 0.76 x Log Pow – 0.23,
and assuming a Log Pow of 7, estimates Log BCF at 5.1 (BCF = 125 900), which agrees well
with the experimental data above.
(Connell 1990) indicates that compounds with a molecular weight around 350 and a Log Pow
around 6 may have high potential for bioaccumulation. In the present case the molecular
weight is 190-280, while Log Pow appears to be between 6 and 8. Connell (1990) also
remarks that the potential for bioaccumulation peaks when water solubility is around 2 x 10 -6
mole/L, and drops off on either side of this value. The water solubility of Gulftene 16-18 is
estimated to be less than 18 µg/L (less than 10 -7 mole/L) and consequently while the modest
molecular weight and large value for Log Pow indicate large potential for bioaccumulation,
this may be mitigated by the low water solubility.
It should be remarked here that the extent of bioaccumulation is also dependent on the rate of
biodegradation, and while it is probable that after release into marine sediments the new
material will be susceptible to anaerobic degradation, the rate of these processes is uncertain.
Consequently, it must be concluded that the probability for bioaccumulation in marine
organisms may be high.
FULL PUBLIC REPORT 26 April 2000
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