Several years ago I defended my first toxic tort case.  A highway patrolman had opened the back of a cargo truck that was owned by my client and was allegedly exposed to PCB dust remnants that blew onto him.  He claimed he later developed an enlarged liver and cysts that he related to the exposure.

I learned that every substance in the world has a dose-repsonse.  That is, any substance, even water, for example, can be toxic in certain levels.  Each substance has a dose level that if consumed or exposed to, can be fatal or injurious.  The key to defending most toxic tort cases is knowing the dose-response principle and proving the TLV - threshold limit value . 

TLV is the threshold level in which humans begin to see the toxic or adverse effects of exposure to a substance.  Toxicologists, through years of research have generally established TLV for substances.  While there may be other defenses available to a product manufactuer, the TLV is key and can be established through experts and their research.  In my case, we were able to prove that the patrolman's exposure was simply transient in nature and the amount of PCB exposure could never have reached the TLV required to cause a toxic effect in humans. 

For example, workers in the electric utility industry routinely put there hands in transformers (not anymore mind you) and were exposed to greater amounts of PCBs with no adverse effects.   By comparison, a one time brief exposure should not cause and adverse reaction with this particular substance.  To be sure, PCBs can have a toxic effect, as all substances, but the TLV is the key to knowing when such effects occur.

After a three week jury trial, the jury came back with a defense verdict on all counts.  TLV was the key to the case.