Total toxic organics definition

Effluent Guidelines and Standards Electroplating - Definitions of Total Toxic Organics >0.01 mg/L 40 CFR 413.02 EPA 1981... 

Definition of Total Toxic Organics (TTO) for Electroplating Point Source Category Yes 40 CFR 413.02 EPA 1981b... 

Metal finishing subcategory-Definition of total toxic organics (TTC)... 

Effluent Guidelines and Standards Metal Finishing--Definition of Total Toxic Organic Applicability Description of the Organic Chemicals Manufacturing Subcategory... 

Effluent Guidelines and Standards Electroplating-- Yes Definition of Total Toxic Organic (2,4-di ni trophenol)... 

Definition of total toxic organic (TTO) (all PAHs, excluding acenaphthene)... 

Electrochemical methods have been used for determinations of species of elements in natural waters. Of the many electrochemical techniques, only a few have proved to be useful for studies of speciation in complex samples, and to possess the sensitivity required for environmental applications. The greatest concern is the measurement of the toxic fraction of a metal in an aqueous sample. The definition of a toxic fraction of a metal is that fraction of the total dissolved metal concentration that is recognised as toxic by an aquatic organism. Toxicity is measured by means of bioassays. Elowever, a universally applicable bioassay procedure cannot be adopted because the responses of different aquatic species to metal species vary. Nevertheless, bioassays should be used as means of evaluation and validation of speciation methods. A condition is that the test species (of the bioassay) should be very sensitive to the metals being studied so as to simulate a worst case situation (Florence, 1992). 

In the definition of Thornton [5] the calculation of the TP refers to wet-only deposition, and thus excludes dry deposition to be potentially toxic. In our opinion, toxicity should be related to the total biological availability of the pollutants, without excluding the contribution of dry deposition. Other authots [9] have already stressed the need and recognized the importance of quantifying the water-soluble fraction of atmospheric deposition. In table 3 the TP is calculated on the basis of the water-soluble fraction of the total deposition. The drinking water standards of the European Community [6] and the aquatic-organism-toxicity values from Gough et al. [7] are used as upper limits in this calculation. 

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