The use of phenoxy acids as herbicides and DDT as pesticide was initially concidered risk free in Swedish 1970-ies forestry. Eventually, usage of chemicals was found to be hazardous to forestry workers. Later on, the concept of environmental risk was introduced in the debate and during a time-span of ten years, the issue was fiercely debated among foresters, forest workers and environmentalist, simultaneously as the role of science and of authorities changed from a reassuring one to one of risk management and limitation.