Occupational safety and health in Europe - state and trends 2023 
European Agency for Safety and Health at Work – EU-OSHA 134 
tackling undeclared work’ provides fact sheets of the type and quantity of undeclared work in all EU 
Member States;464 Eurofound published several reports on platform work ,465 and the FRA had a series 
of publications and fact sheets on severe cases of exploitation, particularly of migrant workforces. 466 
Also, the creation of the European Labour Authority (ELA)467 is partly a consequence of the often 
irregular working conditions of mobile, posted, contracted or seasonal workers who leave their 
country to work in the EU or in another European country. ELA particularly aims to mitigate such critical 
issues related to labour mobility and social security coordination between countries.  
In this report, the quantitative data and the interpretation of the developments will cover — in an ideal 
case — the period  2005 to 2020. In 2004,  a major extension of the EU took place, from 15 to 25 
Member States. If it is not possible to cover the whole period, the analysis is limited to the maximum 
possible period. If comparability is high, for a very few selected data a further look back to the 1990s 
was taken.  
Moreover, there can be major comparability difficulties  caused by the change of methodological 
approaches, geographical coverage an d other context factors during the last 10 to 30 years. Major 
challenges for comparative assessments of EU -wide harmonised data collections from different years 
were:  
• The EU went through several enlargement processes, expanded from EU-12 to EU-15 in 
1994, expanded from EU-15 to EU-25 in 2004, to EU27 in 2007 and to EU28 in 2013, and 
from 2020 on — due to the departure of the United Kingdom — the EU consists of 27 Member 
States. In statistical publications the identifier EU27_2020 is often used to dist inguish this 
period from the EU27 phase between 2008 and 2012, before Croatia joined and the EU27 
became EU28.  
• Methodologies of data collection changed, questions in surveys were abandoned or 
changed, and sample sizes or structures changed, for example, the given period in survey 
questions changed. One example is from the EWCS: the time categories for health-related 
absence from work changed from ‘between 10 and 20 days’ to absence of ‘more than 15 
days’.  
• Important structural decisions were taken in the sector of economic statistics , like the 
change of the statistical composition and the coding of economic sectors, NACE Code 1, 
Revision 1 (NACE 1.1) was applied until 2007, and from 2008 NACE Code 2 is applied.  
• The survey providers use(d) for occupation and educational attainment different 
categories and aggregations levels, for example, ESEG, ISCED or ISCO. 
• Some important categories and definitions are not fully harmonised in statistics, for example, 
the definition of ‘manual worker’ or of ‘migration status’. 468  
 
7.3 Qualitative data and research 
Quantitative data gain importance by a comprehensive description of the reasons behind these 
data and their development, by interpretation and analysis . Such analytical explanations are 
elaborated by (roughly categorised): the providers of the quantitative data themselves, in addition by 
scientists at universities and governmental institutions, by European, national or regional governmental 
organisations, by business federations and trade unions, by professional associations and by 
international organisations.  
This analytical work covers a large variety of topics like detailed studies and reports on risks, exposures 
and outcomes , on the development and application of effective technical and organisational 
preventive measures, on preventive OSH systems and infrastructures, for example, evaluations and 
assessments of the level of implementation of OSH directives, and finally on the societal, economic 
and legal frame and context of OSH.