Diacetoxyscirpenol (DAS) is a trichothecene mycotoxin produced by various species of fungi. Trichothecenes are known as major contaminants of cereals and cereal-containing foods. DAS has been detected in agricultural products worldwide and persists in products after processing. In human as well as in animals, DAS consumption has been shown to induce haematological disorders (neutropenia, aplastic anemia). Granulo-monocytic progenitors (CFU-GM) from human umbilical cord blood and rat bone marrow have been cultured in the presence of DAS (from 10(-8) M to 5 x 10(-10) M) for 14 days. Study of concentration and effect relationships have shown a sharp effect of DAS on rat CFU-GM between 10(-7) M and 10(-8) M, while human CFU-GM are able to grow in the presence of 10(-8) M of the toxin. IC50 values on day 14 are respectively, 7.6 x 10(-9) M for human CFU-GM and 6.2 x 10(-9) M for rat CFU-GM.