EU-SICHERHEITSDATENBLATT Dieselkraftstoff ... - Schmierstoffe

dimethylcyclohexane
hexylcyclohexane 12 15.7 1.7 1.3
n-heptylcyclohexane 13 18.3 3.7 2.7
n-octylcyclohexane 14 21.3 2.2 3.0
nonylcyclohexane 15 24.8 2.8
decylcyclohexane 16 28.9 3.4
undecylcyclohexane 17 33.7 3.1
dodecylcyclohexane 18 39.3 3.3
Table 3. Predicted and experimental marine and freshwater half-life values for mononaphthenic
hydrocarbons
100.0
Half-life predicted (days)
10.0
1.0
1.0 10.0 100.0
Half-life observed (days)
Freshwater
P criterion
Marine Water
Figure 6. BioHCwin vs. experimental half-lives for mono-naphthenic hydrocarbons
3.4 Di-Naphthenic hydrocarbons
The BioHCwin model predicts half-lives above 60 days for some di-naphthenic structures
above C12 (Figure 7). Marine and freshwater experimental half-lives for di-naphthenic
hydrocarbons are available up to C16, and range from 7.9 to greater than 191 days (Table
4). In several cases, there are data for multiple hydrocarbons with the same number of
carbons. Structures up to C14 have half-lives below 60 days; the half-life for 2,7-
diisopropyldecalin (C16) is above the persistence criterion. This half-life value is much
higher than values for single isopropyl-branched decalins, showing again the influence of
increased branching on persistence results (Prince and Walters 2007).
In Figure 8, predicted and experimental data are shown. The plot shows that predicted
half-lives are often higher that experimental values. While no experimental half-life data
are available for C15 di-naphthenic hydrocarbons, read across to C15 poly-naphthenic
hydrocarbons (see section 3.5) indicates these structures would not fulfill the persistence
14