EU-SICHERHEITSDATENBLATT Dieselkraftstoff ... - Schmierstoffe

1000.0
Half-life predicted (days)
100.0
10.0
Freshwater
P criterion
Marine Water
1.0
1.0 10.0 100.0
Half-life observed (days)
Figure 10. BioHCwin (Y-axis) vs. experimental half-lives (X-axis) for poly-naphthenic
hydrocarbons
3.6 Mono-Aromatics
The BioHCwin model predicts that half-lives for mono-aromatics above C22 will be
higher than 60 days (Figure 11). Experimental freshwater and marine half-lives for
mono-aromatics up to C18 range from 1.7 to above 182 days (Table 6). In several cases,
there are data for multiple hydrocarbons with the same number of carbons. Most of the
mono-aromatic hydrocarbons across the whole range of carbon chain lengths have halflives
below 5 days, but there is one exception in the dataset with half-life of 50 days: 1,1'-
(1,1,2,2-tetramethyl-1,2-ethanediyl)bis-benzene (Table 6, Figure 12). While
experimental half-life data are available for this compound, this is not a typical structure
found in petroleum substances. Although the BioHCwin model may be overly
conservative, it can be concluded that mono-aromatics at or above C22 may have halflives
above 60 days.
bioHCwin half-life (days)
1000.0
100.0
10.0
1.0
0 5 10 15 20 25 30 35 40
Carbon number
60 d half-life
Figure 11. Half-life predictions for mono-aromatic hydrocarbons using the US EPA
model BioHCwin
18