Dioxinas are synthesis contaminants, formed spontaneously in diverse industrial processes. Dioxinas are organoclorades compounds, very stable in the environment, capable of remain on human and animal tissue and therefore capable of producing chronic toxicity, like carcinogenicity and mutagenicity and endocrine disruptor effect. This compounds’ physical and chemical characteristics, its toxicity and adverse effects, are referred in this article, so we will be able to relate this compounds toxicity, to human health and production of innocuous food for human beings.