The Norwegian Work Environment Act, which came into force in 1977, was built upon a revision of the total strategy of work environment legislation. The classical strategy for workers' protection derived from the ''rule of law'' approach. Legislation favoring workers had to be framed in the form of norms which: 1. applied equally to everyone, 2. stated clearly what is allowed and what is not, and 3. were based on a demonstrable need. These constraints restricted the areas in which safety and health work was possible, required solid documentation of advances in the work environment, and turned work environment issues into problems of measurement. The traditional system also failed to recognize the interaction between harmful influences in the work environment.Development of the strategy for the Norwegian work environment reform included a study of safety and health activities in a number of enterprises. Major factors contributing to a positive work environment were found to be: 1. employee involvement in work environment issues, 2. a management commitment toward improving the work environment, and 3. freedom of choice of production methods for the enterprise. The new legislation established: 1. priority for the work environment, 2. minimum standards, 3. new concepts of causality, 4. a holistic approach, and 5. burden of proof upon the employer.