Handbook of Solvents - George Wypych - ChemTech - Ventech!

1104 James L. Botsford
(Calleja et al., 1993; Lilius et al., 1994) using the assay involving the sand flea Daphnia
magna are presented. If two systems give the same results, the correlation coefficient will be
1.00. In the literature there are reports of the toxicity of 50 MEIC chemicals (MEIC,
multicenter evaluation of cytotoxicity) tests used in Europe to evaluate different tests for
toxicity. When these two tests with Daphnia were compared, a correlation coefficient of
0.895 was obtained (Figure 15.2.2.2). This indicates that when a standardized test is run in
two laboratories with different personnel, the results are not identical. This discrepancy is
noted in tests involving animals. Apparently variations in the strains of animals, differences
in care and other factors influence the results of toxicity tests with animals. Often variations
of 10x are observed.
This sort of analysis was carried using the Rhizobium assay. Published values for the
chemicals using Microtox, LD50 reports for rats, IC50 (testing with animal cells), Daphnia
magna, and HLD (Human Lethal Dose determined from autopsy reports) are included (Table
15.2.2.2). These values for the assay with Rhizobium will permit comparisons to be
made (Table 15.2.2.3). It should be noted that the values for rats and HLD are much higher
than with the other methods. With animal tests, the animals are force fed the chemical, it is
injected through a tube into their stomach. Occasionally the toxin is injected
intraperitoneally. It is uncertain what happens to the toxic chemical in the acidic stomach.
This methodology has been criticized because humans are rarely exposed to toxic chemicals
in this fashion. HLD data comes from autopsy reports and it can never be certain how much
of the chemical the victim actually came in contact with, it can only be estimated. And this
method only provides data for chemicals already in the environment, it is not a good method
to predict toxicity.
Table 15.2.2.2. MEIC chemicals tested. Comparison
Chemical tested Rhizobium,
m moles
Microtox,
m moles
Rat,
m moles
IC50,
m moles
Daphnia,
m moles
HLD,
m moles
rat hepat,
m moles
acetomenaphen 1.649 2.19 15.8 1.45 0.269 1.698 10.75
acetylsalicylic acid 1.106 0.145 1.122 1.7 0.932 2.818 2.662
amitriptyline 0.0146 0.078 1.148 0.1 0.02 0.2 0.07
barium chloride 0.109 1.349 0.794 0.47
caffeine 1.02 3.388 1 1.58 3.388 1 1.596
carbon tetrachloride 1.91 4.786 15.1 22.1 126 0.447 3.984
chloroform 5.29 12.9 7.586 2.63 1.738 6.198
chlororamphenicol 4.332 1.122 7.7 0.54 5.248 0.402
copper II sulfate 0.007 0.01 1.86 0.001 0.316 0.048
dichloromethane 4.122 37.1 18.6 10.5 4.17 109.1
digoxin 0.231 0.426 0.12 12.8 0.0014 0.271
ethanol 1643 691 151 158 234 109.6 451
ethylene glycol* 3427 1778 75.8 322 1202 25.7 358