Non-specific acting modes of toxic action result in narcosis; therefore, narcosis is a mode of toxic action. Narcosis is defined as a generalized depression in biological activity due to the presence of toxicant molecules in the organism. The target site and mechanism of toxic action through which narcosis affects organisms are still unclear, but there are hypotheses that support that it occurs through alterations in the cell membranes at specific sites of the membranes, such as the lipid layers or the proteins bound to the membranes. Even though continuous exposure to a narcotic toxicant can produce death, if the exposure to the toxicant is stopped, narcosis can be reversible.