Ecologically important parameters are dispersion tendency, persistence,
the conversion products resulting from the decomposition, combinatorial effects
with other substances and their toxicological aspects. The category
‘Ecotoxicology’ regarded in EATOS mainly concentrates on the last-mentioned
parameters, namely the toxicology. In EATOS we used WGK (Wassergefährdungsklasse,
i.e. Water Endangerment Class), LC50-, EC50-, and IC50-values
for the determination of weighting factor Q and assigned to the values 1 to 10 (Table
7). The parameters for the water endangerment class (harmless for water;
1, 2, or 3) are acute oral toxicity for mammals (LD50, rat), acute
toxicity for bacteria (cell reproduction-inhibition test, Pseudomonas putida,
threshold of toxicity EC0), acute toxicity for fish (LC0
Goldorfe 48 h), and behavior of biodegradation (OECD screening test). In the
case that an examination is necessary, further points of view as carcinogenicity
or mutagenicity, high bio-accumulation or toxicity compared to, e.g., algae or
daphnia , are considered in the assessment of value. Therefore, the WGK-value
makes a more complete statement concerning the ecotoxicology of a substance as
an LC50-value may do it. If the WGK-value as well as another
toxicity-value is indicated, EATOS prefers to use the WGK-value (1st
priority). The fixing of the (x,y)-pairs (Q =
/ XC50 = 1 mg/l) and (Q = 2 / XC50 = 100 mg/l)
(with X = L, E., or I for fish, daphnia , or alga) defines the exponential
function XC50 = 464.16 × e0.7675×Q, which,
with a value a little bit modified – XC50 = 464 × e0.7675×Q is
used – leads to value ranges in Table
7, so that the function, with which Q is determined by use of toxicity
values, reads:
with w = LC50, EC50,
or IC50.
Table 7 Assignment of WGK and LC50-, EC50-, or IC50-value ranges to the weighting factor QEcotoxicology
Q |
WGK |
|
LC50 (fish, 96 h), EC50 (daphnia, 48 h), IC50
(alga, 72 h) [mg/l] |
|
R-phrase |
||
1 |
|
215.38 |
to |
99.97 |
|
|
|
2 |
|
99.97 |
to |
46.40 |
|
52 |
|
3 |
|
46.40 |
to |
21.54 |
|
52 |
|
4 |
1 |
21.54 |
to |
10.00 |
|
52 |
|
5 |
|
10.00 |
to |
4.64 |
|
51 |
|
6 |
|
4.64 |
to |
2.15 |
|
51 |
|
7 |
2 |
2.15 |
to |
1.00 |
|
51 |
|
8 |
|
1.00 |
to |
0.46 |
|
50 |
|
9 |
|
0.46 |
to |
0.22 |
|
50 |
|
10 |
3 |
0.22 |
to |
0.00 |
|
50 |
|
The modification was made for obtaining an optimal distribution of the classification limits 1 mg/l, 10 mg/l, and 100 mg/l of the so called Gefahrstoffverordnung (GefstV, German act, engl. Hazardous Materials Act)) Appendix I 1.3.2 according to Table 8 to the value range 1 to 10. As you can reconstruct as exemplified in the column ‘R- phrase’ in Table 7, we achieved this by assigning the R-phrases to the value ranges in accordance with Table 8.
Table 8 Classification limits of the GefstV Appendix I 1.3.2 for the assignment of R-phrases*
R
53 & # & § |
|
acute
toxicity |
|
||||||||||||
# |
fish
(96 h) [mg/l] |
daphnia
(48 h) [mg/l] |
alga(72
h) [mg/l] |
||||||||||||
R
50 |
|
|
LC50 |
< |
1 |
|
|
EC50 |
< |
1 |
|
|
IC50 |
< |
1 |
R 51 |
1 |
< |
LC50 |
< |
10 |
1 |
< |
EC50 |
< |
10 |
1 |
< |
IC50 |
< |
10 |
R 52 |
10 |
< |
LC50 |
< |
100 |
10 |
< |
EC50 |
< |
100 |
10 |
< |
IC50 |
< |
100 |
* R 50 Very toxic to aquatic organisms, R 51 Toxic to aquatic organisms, R 52 Harmful to aquatic organisms; § and the substance is easily degradable or logKow < 3 (except for the fact, that the BCF, being experimental determined, < 100)
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