I have many years of experience on Reproductive toxicity of chemicals in the environment and food. I am the research leader of the group on reproductive toxicology at the department of Toxicology and Risk assessment. Currently I am project manager for several large projects with focus on effects of endocrine disruptors on development of the reproductive system and the brain, e.g. the EU project CONTAMED with special focus on mixture effects of environmental endocrine disruptors. Ulla Hass is also involved in studies on neurobehavioural teratology of food supplements and participates in development of new or enhanced OECD test guidelines.