Coastal Bioanalysts, Inc.

Toxicity Identification


Toxicity Reduction Evaluations (TRE) are often required when an effluent, sediment or other environmental sample is determined to exhibit unacceptable acute or chronic toxicity.  Determining the cause of toxicity can be difficult because 1) multiple potential toxicants may be present, 2) little or no toxicity data exist for many compounds, 3) toxicity is frequently variable, and 4) the sample matrix may greatly modify toxicity. By working closely with site personnel and engineers we have assisted numerous facilities identify the causative toxicant(s) so that appropriate treatment and/or management options could be instituted and toxicity reduced or eliminated.


A Toxicity Identification Evaluation (TIE) is generally performed as part of the TRE to identify causative toxicants.  In the TIE process samples are manipulated in such a way that toxicity is predictably increased or decreased dependent on the causative toxicant(s).  For example, chelator addition is used to reduce metal toxicity, solid-phase extraction is used to remove acid, base and neutral organic compounds and pH control is used to modify toxicity of pH-dependent toxicants such as ammonia and metals.  However, the EPA TRE/TIE procedures do not address all potential toxicants (e.g. ion imbalance, biological pathogens) and additional procedures are constantly being developed and published in the scientific literature.  We can tailor a TIE which incorporates identification methods appropriate for the specific situation and thus provides the most economical and expeditious solution to the toxicity problem.