Pyrolysis is one of the three main thermochemical routes to convert biomass into useful primary energy products. Fast pyrolysis has benefited from active research programme since 1980's in order to obtain bio-oils which can be used in engines for the generation of electricity or after refining in transport. Today, several demonstration plants are operating in Europe and North America where significant quantities of bio-oils are produced for research and development purposes and several commercial plants are at an advanced stage of planning. Thus, for a commercial development the question of safety procedures for human health and environment preservation is raised. The aim of this programme supported by the European Union is to comprehensively assess toxicity and biodegradability of a representative bio-oil after preliminary screening of a wide range of bio-oils from different processes and temperatures. In the project, the relation between process parameters on one hand and chemical composition and toxicity for human health and environment on the other hand will be investigated so as to recommend the operating conditions to produce bio-oils with the lowest impacts. Then, the optimised compositions of bio-oils will be submitted to the mandatory tests required by the EU legal authority, the objective being the definition of secure handling and storage procedures, in order to control the risks related to the product for the population and the environment. A MSDS containing safety procedures and a report on transport requirements, will be published in order to obtain the bio-oils inscription in the ELINCS and give authorisation for marketing with the corresponding preventive accompanying measures. An appropriate assessment of the risk involved will contribute to reduce the production costs and make pyrolysis bio oil more competitive. In addition the knowledge of the parameters potentially responsible for higher toxicity will limit production losses. The structure of the