Acute Toxicity

Acute toxicity or acute effects tests are rapid (2 to 4 days) procedures used to measure the concentration that will affect the test organisms, that is, make them sick.
 

• screen for toxicity (determine if the compound is toxic)
• rank toxicity to identify the best ingredients to continue investigating for use in a product, and,
• assess the potential for effects in the environment.
  In some cases, one group of organisms will be more sensitive to a compound than another group. For example, insecticides are usually more toxic to invertebrates than to fish or algae.
  When we start a toxicity test program, we may not know which group will be most sensitive to the new compound. So we usually test at least one plant, one invertebrate, and one fish species. It is important that all three groups of organisms are tested because all are important in the environment, and effects on a plant may not tell us anything about effects on an animal and vice versa.
  

• Lethality is the most common endpoint for invertebrates and fish, while growth of a population of cells is used to understand effects on algae. Of course, aquatic ecosystems are composed of hundreds, or even thousands of different species.
• The process we use to protect all these different species is called environmental risk assessment. When acute toxicity data does not provide enough information for us to decide if the compound is safe or not, we conduct chronic toxicity tests.