the organism’s life cycle, and are considered partial life cycle tests. Acute tests are not valid if mortality in the control sample is greater than 10%. However, this control acceptability criterion is dependent upon the species and the duration of the test. Results are reported in EC50, or concentration that will affect fifty percent of the sample size. Chronic tests are long-term tests (weeks, months years), relative to the test organism’s life span (>10% of life span), and generally use sub-lethal endpoints. In chronic exposures, organisms come into contact with low, continuous doses of a toxicant. Chronic exposures may induce effects to acute exposure, but can also result in effects that develop slowly. Chronic tests are generally considered full life cycle tests and cover an entire generation time or reproductive life cycle (“egg to egg”). Chronic tests are not considered valid if mortality in the control sample is greater than 20%. These results have generally been reported in NOECs (No observed effects level) and LOECs (Lowest observed effects level). However, NOECs and LOECs are becoming less common as endpoints are dependent on the concentration series chosen for the test. These reports are starting to become a topic of debate in the field because of the way it may alter the results of the tests. For example, if the concentration rate of the NOEC is 100, 50, 25, 11.25, 6.25 and the toxicology is reported at 2%, the NOEC would report the concentration as 6.25. Early life stage tests are considered as subchronic exposures that are less than a complete reproductive life cycle and include exposure during early, sensitive life stages of an organism. These exposures are also called critical life stage, embryo-larval, or egg-fry tests. Early life stage tests are not considered valid if mortality in the control sample is greater than 30%. Short-term sublethal tests are used to evaluate the toxicity of effluents to aquatic organisms. These methods are developed by the EPA, and only focus on the most sensitive life stages. Endpoints for these test include changes in growth, reproduction and survival. NOECs, LOECs and EC50s are reported in these tests. Bioaccumulation tests are toxicity tests that can be used for hydrophobic chemicals that may accumulated in the fatty tissue of aquatic organisms. Toxicants with low solubilities in water generally can be stored in the fatty tissue due to the high lipid content in this tissue. The storage