text: ***7.4.1 Variety of OSH systems***
  
  In the EU Member States there exists a considerable**variety of working conditions**and related 
  prevention and monitoring systems, as well as a variety of OSH traditions, OSH cultures regarding risk 
  awareness and preventive safety measures, different types of responsibilities of state institutions, and 
  a variety of social dialogue schemes between employers’ and workers’ associations. 
  
  Moreover, practically all EU OSH legislation is**issued as European Directive, not as European**
  **Regulation**. These directives set minimum standards that allow Member States to specify many details 
  related to their national situation. In addition, in many fields already existing national legislation was 
  aligned in different ways with EU OSH directives. 
  
  Consequently, the understanding and assessment of OSH at an EU level causes methodological 
  problems, for example, regarding the**methods of data collection, the application of indicators,**
  **harmonisation of monitoring approaches, and of terminology, recognition of work-related**
  **diseases, comparison of different infrastructures, and even the technical measurement**
  **standards.**
  
  It is not easy to apply data and research generation methodologies that are on one side well harmonised 
  and on the other side give room to understand the functioning and value of different systems and 
  infrastructures. Some trends seem to be general and obvious, and some Member States or some 
  sectors or enterprises can experience no trend at all in this direction, or even the contrary development. 
  Structural developments can differ significantly between countries. Of relevance seems to be the intra- 
  EU exchange of workforce, based on ongoing changes in production chains. The main flow of the 
  workforce takes place — roughly described — from eastern and southern Europe to central, western 
  and northern Europe.483 