- OSH in general
- OSH Management and organisation
- Prevention and control strategies
- Dangerous substances (chemical and biological)
- Biological agents
- Carcinogenic, mutagenic, reprotoxic (CMR) substances
- Chemical agents
- Dust and aerosols
- Endocrine Disrupting Chemicals
- Indoor air quality
- Irritants and allergens
- Nanomaterials
- Occupational exposure limit values
- Packaging and labeling
- Process-generated contaminants
- Risk management for dangerous substances
- Vulnerable groups
- Physical agents
- Ergonomics
- Safety
- Psychosocial issues
- Health
- Sectors and occupations
- Groups at risk
Introduction
Modern organisations almost always work together with other (partner) organisations in order to achieve their goals. Tasks get subdivided between companies with each company specialising in a particular expertise. All these companies have to cooperate not only effectively but also safely on a common task and often at the same location. In the relevant EU and national legislation companies have a legal obligation to work together effectively with respect to occupational safety and health.
What is a ‘contractor chain’?
It is common for construction work, cleaning, maintenance, waste disposal or catering to be organised into short-term projects. The short-term nature of these projects implies that workers are only temporarily needed. Therefore, specialised companies (contractors) are hired to perform the tasks better, faster and usually cheaper[1] [2]. This kind of relationship is called ‘outsourcing’. The contractors are external companies, organisations or individuals that have a contractual relationship with the client. The client (or host company) is the party that outsources the task. Not only clients hire contractors, but also contractors can hire sub-contractors[3]. A subcontracting chain emerges, if a principal contractor (client or host company) hires one or more subcontractors, who either contribute by bringing their own employees or by subcontracting another company[4].
The work is mostly executed at the premises of the host company/organisation (for example when contractors are hired to inspect and repair industrial installations) or at a project site (for example during building projects). The contractors’ chain comprises a flow of people and their services (i.e. contracting and sub-contracting). In this chain companies are linked together through information, knowledge, people and capital flows[3].
Figure 1: A contractor chain with some common actors

Source: Overview by the authors
Potential effects of contractor chains on occupational safety and health
There are several potential effects of working with contractor chains on occupational safety and health. It can be argued that task division and contractor specialisation could lead to greater expertise and greater knowledge of specific risks on the work floor. This knowledge however cannot be expected to extend beyond risks that are specific to the contractors’ activities. Risks that differ from one worksite to another or risks that arise from tasks carried out by other (sub-)contractors need to be managed within the contracting chain. Contractors performing their job in the client’s facilities may be exposed to risks that they are unfamiliar with, such as exposure to chemical agents or asbestos. Vice versa the workers of the host company can also be exposed to hazardous situations due to the work performed by contractors[3]. The occupational safety and health (OSH) risks in the contractors’ chains are discussed in a number of EU-OSHA reports [3] [5] [6] [7] [8] [9] [10] [11] [12] [13].
There is evidence that working with contractor chains carries specific (types) of risks for safety and health. Included are two examples of (fictional) accidents explicating ways in which (cooperation within) the contractor chain influenced occupational safety:
Example: A self-employed roofer works primarily for the same contractor. He is also occasionally hired directly by clients or through other contracting companies. On one occasion, he was hired to urgently repair a roof leak. Once on site he is urged by the building’s user (who rents but does not own the building) to repair the leak as quickly as possible. The building’s owner did not fit a permanent fall protection system on the roof. The self-employed worker decides to work without fall protection, slips in the rain and falls from the roof.
Example: An energy production plant is stopped for repair works. Many different contractors have been brought in to carry out all the necessary tasks. The pressure on completing the work is very high. Shareholders have pressured the organisation to improve its business results. In response, management has set an ambitious deadline for completing all maintenance work in order to minimise production standstills. One contractor is using a company crane in a factory hall. A second contractor has placed scaffolding in that same factory hall in order to paint supporting struts. The crane driver employed by the first contractor accidentally steered the crane into the scaffolding that was being used by the second contractor. Plans for cooperation between both contractors were made but were not implemented.
In both examples multiple actors in the contractor chain play a role in protecting safety on the work floor. The energy company for example may not be the direct employer of any of the directly involved workers, but it did hire two companies to work on its premises without making sure they worked together effectively. There are many more examples of situations in which contracting chains contributed to accidents, for example through a lack of coordination and communication or when contractual conditions do not leave enough budget for proper OSH measures to be taken. Determining the extent to which different parties bear (legal) responsibility after an event can be the subject of much discussion and debate. From a safety management point of view however it is much more useful to proactively identify opportunities for companies who work in contracting chains to improve cooperation and coordination on health and safety issues.
Influential actors and their contractor-chains
In some specific cases cooperation within a contractor chain can have a positive effect on the OSH practices of some of the participants. This is the case when influential actors, usually bigger client companies or public bodies pose requirements to their contractors for better OSH performance. For example, in the construction sector, it has been shown that when clients raise OSH requirements in the supply chain, as seen at the London Olympics and in the construction of the bridge between Copenhagen and Malmö, for instance, it can positively impact the overall OSH performance[14].
These influential actors are mainly driven, according to the literature, by requirements set in EU and national legislation, such as the EU Framework Directive 89/391/EEC[15], Construction Sites Directive 92/57/EEC[16], and Procurement Directives for public bodies (Directives 2014/25/EU[17] and 2014/24/EU[18] However, good practice examples show that client companies which voluntarily go beyond legal obligations can significantly influence OSH performance across the contractor chain[14]. Another important driver is reputation-risk, especially for companies working on big projects with high visibility, where OSH problems at their or a contractor’s company can have serious consequences for the company’s reputation[3]. Another trigger can be the company’s sustainability/Corporate social responsibility agendas, and external pressure from NGOs, governments and customer’s demand can also play a role. As a result, some big companies consider it important to work together with contractors and sub-contractors in order to improve OSH practices.
Companies’ approaches to improving OSH in contractor chains
There are numerous approaches to improve OSH in the contractor-chain. The most prominent approach followed, which is used most extensively, is the use of management and certification systems. Other approaches focus more broadly on issues such as long-term cooperation, communication and safety culture. In this section we will first discuss management and certification systems and then some of the other approaches.
Management and certification systems
Certification systems for contractors are private, voluntary, third-party certification regimes developed in a business-to-business environment. Such kinds of schemes allow contractors and sub-contractors to independently demonstrate to their clients that they are working according to the safety and health (and environmental) standards of the industry. Certification systems were partly developed in an attempt to standardise the various requirements imposed by clients on their contractors. This prevents contractors from having to comply with a multitude of different client-specific safety requirements, all of which have similar aims but similar but slightly different specifications. Safety certification schemes have become important instruments with regard to the improvement of OSH practices in the contracting chain. Safety certification schemes are developed for companies, individuals or intermediate organisations (agencies). Some of them are:
- The VCA system ('Veiligheid (Gezondheid Milieu) Checklist Aannemers') or in English SCC or 'Safety (Health Environment) Checklist (or Certificate) Contractors'). The system was first developed in the Netherlands in 1994 and has been introduced in other EU Member States such as Belgium, Germany, Austria and Switzerland. The system allows certification on three levels (basic, advanced, and petrochemical) for both basic building contractors and advanced industrial contractors. The system includes a training requirement for employees. A number of similar certification systems have been developed in other countries and sectors (e.g. MASE, CAPS, SSC).
- There are also certification schemes for individuals – so called safety passport schemes. These are schemes ensuring that only workers with sufficient competence in OSH are allowed to work. This system is especially useful for workers and contractors who work in more than one industry or firm[19]. An example is the Finnish Occupational Safety Card[20].
In some sectors, such as construction, information on OSH training and qualifications is integrated into broader systems of labour or social ID card schemes for individuals, which are aimed at tackling undeclared work[21] [22]. Although research-based knowledge of the OSH-related effects and mechanisms of such schemes is limited, they could potentially have a positive influence on OSH in the construction sector. For example, they may improve compliance with OSH regulations by increasing transparency regarding workers, employers, and employment relations[22].A well–known certification system designed for the certification of the safety management systems of temporary employment agencies and intermediaries is a 'Safety and Health Checklist Temporary Employment Agencies and Intermediaries' (SCT) (in Dutch: Veiligheid en Gezondheid Checklist Uitzendorganisaties or VCU)[23]. The SCT certificate enables temporary employment agencies to demonstrate their commitment to OSH and shows that their OSH management system meets the necessary requirements.
Other approaches to improving OSH practices in the contractor chain
There are also other approaches to improving OSH within the contractor chain. These approaches encompass issues such as contractual clarification of responsibilities and planning, transparent tendering and procurement practices, communication, cooperation and training, joint control procedures and contractor evaluation[24][3].
- Contractual clarification of responsibilities and planning – clear definition of responsibilities from an early stage of the contract is necessary, since all involved parties have legal obligations under health and safety law. Formal contracts help to clarify the roles and responsibilities of contractors, define the desired outcomes, and set out procedures for non-compliance[13] . Also, the contract should contain OSH information on the potential hazards, the measures that have been taken to eliminate or limit them, those precautions that still need to be taken, and a description of safe behaviours[2] [3] [25] [26] . Last, but not least, a committed safety leadership at all levels regarding OSH is important to ensure safety and health performance and respect for the terms of contracts[2] [3].
- Transparent tendering and procurement practices whereby clients select main contractors and subcontractors based on their OSH capabilities, competency and performance including key performance indicators (KPIs) on issues such as safety training, accident statistics and assessment records[13] . Identify potential conflicts between the work planning of different contractors in the planning stage such as activities scheduled at the same time and location. Software tools such as building information models and project management tools can help with this task.
- Draft a contractor-specific and overarching project OSH plan which includes all project activities and potential areas of conflict between contractors.
- Communication, cooperation and training – continued cooperation between client contractor and sub-contractor helps implementing a joint safety and cooperation culture[2] [3]. The client company should inform its workers about the presence of contractors/sub-contractors on their premises, as well as the type of work activities and associated risks. The client company should also inform the (sub-)contractor workers about specific safety procedures that are in place, e.g. emergency procedures. In fact, cooperation between client and (sub-)contractors improves common knowledge, awareness and understanding of activities, responsibilities and risks[2] [3] [25] [26]. Training and education on OSH issues helps align standards and procedures between client and contractors, harmonising safety culture and improving OSH performance[2] [3]. For example, at many large companies, particularly those with high risks, employees and contractors/sub-contractors are obliged to follow a short company-specific safety training and pass a small test before entering the site and start working. These trainings are mostly by means of a short film or e-learning. It can also be considered to set minimum requirements for language spoken for all personnel.
- Establish as far as possible a safety culture which is shared by the different parties within the contractor chain. For example, by fostering a longer-term cooperation with a limited number of companies and measuring and improving safety culture across the chain of cooperating companies using the multitude of tools that are available. A key element in creating a safety culture throughout the contractor chain is placing greater emphasis on bottom-up communication about safety. Involving workers and recognising their expertise and practical knowledge could encourage a more constructive and open approach to safety within joint projects[27].
- Joint control procedures – the adoption of the same standards and procedures among client and contractors/sub-contractors improves OSH performance[1] [2] [3].
- Contractor evaluation – evaluating contractors in a systematic way can lead to better OSH performance. This can be organised in different ways, for example the evaluation can be based on a set of predefined criteria, which don't need to be focused only on OSH matters (it could also include quality of delivered service, etc.). For these criteria a questionnaire (checklist) can be drawn up. The timing and frequency of evaluation depends on the type of contract with the contractor. For example, in long-term contracts a periodical evaluation is necessary. For one-time contracts an evaluation is necessary at the end of the contract. Based on this evaluation contractors can be classified in predefined categories. These categories could be used to incentivise contractors, for example by rewarding them with a higher score for future tenders[3].
References
[1] Goudswaard, A. and J.C. André, New Forms of Contractual Relationships and the Implications for Occupational Safety and Health, European Agency for Safety and Health at Work, 2002.
[2] Zwanikken, A.L.J., Drupsteen, L., Beek, F.A., Kampen, J.N., Jongen, M.J.M., Improving chain management of contractor safety, 4th International Conference Working on Safety, Crete, Greece, 2008.
[3] EU-OSHA – European Agency for Safety and Health at Work. Promoting occupational safety and health through the supply chain. Literature review, 2012. Available at: https://osha.europa.eu/en/publications/literature_reviews/promoting-occupational-safety-and-health-through-the-supply-chain/view
[4] Liability in subcontracting chains – National rules and the need for a European framework, European Parliament, 2017. Available at: https://data.europa.eu/doi/10.2861/68736
[5] EU-OSHA – European Agency for Safety and Health at Work, Occupational safety and health in marketing and procurement, Luxembourg, Office for Official Publications of the European Communities, 2000. Available at: https://osha.europa.eu/en/publications/report-occupational-safety-and-health-marketing-and-procurement
[6] EU-OSHA – European Agency for Safety and Health at Work. Recognition schemes in occupational safety and health. Report, 2002. Available at: https://osha.europa.eu/en/publications/report-recognition-schemes-occupational-safety-and-health
[7] EU-OSHA – European Agency for Safety and Health at Work. Prevention of risks in construction in practice, Report, 2004. Available at: https://osha.europa.eu/en/publications/report-prevention-risks-construction-practice
[8] EU-OSHA – European Agency for Safety and Health at Work. Preventing harm to cleaning workers. Report, 2009. Available at: https://osha.europa.eu/en/publications/preventing-harm-cleaning-workers
[9] EU-OSHA – European Agency for Safety and Health at Work. Safe maintenance in practice. Report, 2010. Available at: https://osha.europa.eu/en/publications/safe-maintenance-practice
[10] EU-OSHA – European Agency for Safety and Health at Work. Improving compliance with occupational safety and health regulations: an overarching review. Report, 2021. Available at: https://osha.europa.eu/en/publications/improving-occupational-safety-and-health-changing-world-work-what-works-and-how
[11] EU-OSHA – European Agency for Safety and Health at Work. Supply chains and their present and future implications for occupational safety and health. Discussion paper, 2020. Available at: https://osha.europa.eu/en/publications/supply-chains-and-their-present-and-future-implications-occupational-safety-and-health
[12] EU-OSHA – European Agency for Safety and Health at Work. Supply chains' role in promoting safety and health in construction and agriculture: the LIFT-OSH Project. Report, 2024. Available at: https://osha.europa.eu/en/publications/supply-chains-role-promoting-safety-and-health-construction-and-agriculture-lift-osh-project
[13] EU-OSHA – European Agency for Safety and Health at Work. Improving OSH through supply chains: market-based initiatives in the agri-food and construction industries. Literature review, 2023. Available at: https://osha.europa.eu/en/publications/improving-osh-through-supply-chains-market-based-initiatives-agri-food-and-construction-industries
[14] EU-OSHA – European Agency for Safety and Health at Work. Supply chain governance in construction: Client led OSH regulation in complex construction projects. Policy brief, 2023. Available at: https://osha.europa.eu/en/publications/supply-chain-governance-construction-client-led-osh-regulation-complex-construction-projects
[15] Council Directive 89/391/EEC of 12 June 1989 on the introduction of measures to encourage improvements in the safety and health of workers at work. Available at: https://osha.europa.eu/en/legislation/directives/the-osh-framework-directive/1
[16] Council Directive 92/57/EEC of 24 June 1992 on the implementation of minimum safety and health requirements at temporary or mobile construction sites (eighth individual Directive within the meaning of Article 16 (1) of Directive 89/391/EEC). Available at: https://osha.europa.eu/en/legislation/directive/directive-9257eec-temporary-or-mobile-construction-sites
[17] Directive 2014/25/EU of the European Parliament and of the Council of 26 February 2014 on procurement by entities operating in the water, energy, transport and postal services sectors and repealing Directive 2004/17/EC Text with EEA relevance. Available at: http://data.europa.eu/eli/dir/2014/25/oj
[18] Directive 2014/24/EU of the European Parliament and of the Council of 26 February 2014 on public procurement and repealing Directive 2004/18/EC Text with EEA relevance. Available at: http://data.europa.eu/eli/dir/2014/24/oj
[19] HSE – Health and Safety Executive, Passport schemes for health, safety and the environment: a good practice guide, HSE, INDG 381, 2003.
[20] Finnish Occupational Safety Card. Available at: https://tyoturvallisuuskortti.fi/en/
[21] European Labour Authority, Construction sector – Issues in information provision, enforcement of labour mobility law, social security coordination regulations, and cooperation between Member States, 2023 ELA Strategic Analysis, Publications Office of the European Union, 2023, Available at: https://data.europa.eu/doi/10.2883/9750
[22] EU-OSHA – European Agency for Safety and Health at Work. Labour identification cards and their use for occupational safety and health. Discussion paper, 2025. Available at: https://osha.europa.eu/en/publications/labour-identification-cards-and-their-use-occupational-safety-and-health
[23] https://www.vca.nl/home/diplomas-certificates/sct
[24] Drupsteen L. Veiligheid in de ketens en netwerken. Van samen werken naar samenwerken. TNO, 2009.
[25] NHS – National Health Service, Working with contractors, Scottish Centre for Healthy Working Lives, 2011.
[26] European Commission. Non-binding guide to good practice for understanding and implementing Directive 92/57/EEC on the implementation of minimum safety and health requirements at temporary or mobile construction sites. Available at: https://osha.europa.eu/en/legislation/guidelines/non-binding-guide-good-practice-understanding-and-implementing-directive-9257eec-implementation-minimum-safety-and-health-requirements-temporary-or-mobile-construction-sites
[27] EU-OSHA – European Agency for Safety and Health at Work. Safety culture in the construction industry as part of supply chain governance. Policy brief, 2024. Available at: https://osha.europa.eu/en/publications/safety-culture-construction-industry-part-supply-chain-governance
Further reading
EU-OSHA – European Agency for Safety and Health at Work. Promoting occupational safety and health through the supply chain. Literature review, 2012. Available at: https://osha.europa.eu/en/publications/literature_reviews/promoting-occupational-safety-and-health-through-the-supply-chain/view
EU-OSHA – European Agency for Safety and Health at Work. Supply chains and their present and future implications for occupational safety and health. Discussion paper, 2020. Available at: https://osha.europa.eu/en/publications/supply-chains-and-their-present-and-future-implications-occupational-safety-and-health
EU-OSHA – European Agency for Safety and Health at Work. Supply chains' role in promoting safety and health in construction and agriculture: the LIFT-OSH Project. Report, 2024. Available at: https://osha.europa.eu/en/publications/supply-chains-role-promoting-safety-and-health-construction-and-agriculture-lift-osh-project
EU-OSHA – European Agency for Safety and Health at Work. Improving OSH through supply chains: market-based initiatives in the agri-food and construction industries. Literature review, 2023. Available at: https://osha.europa.eu/en/publications/improving-osh-through-supply-chains-market-based-initiatives-agri-food-and-construction-industries
EU-OSHA – European Agency for Safety and Health at Work. Labour identification cards and their use for occupational safety and health. Discussion paper, 2025. Available at: https://osha.europa.eu/en/publications/labour-identification-cards-and-their-use-occupational-safety-and-health
EU-OSHA – European Agency for Safety and Health at Work. Safety culture in the construction industry as part of supply chain governance. Policy brief, 2024. Available at: https://osha.europa.eu/en/publications/safety-culture-construction-industry-part-supply-chain-governance
EU-OSHA – European Agency for Safety and Health at Work. Supply chain governance in construction: Client led OSH regulation in complex construction projects. Policy brief, 2023. Available at: https://osha.europa.eu/en/publications/supply-chain-governance-construction-client-led-osh-regulation-complex-construction-projects
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