IOSH
Supplier due diligence checklist
Assessing suppliers for quality assurance and safer, more sustainable supply chains
Use this checklist to prepare for supplier selection, carry out effective due diligence and establish clear expectations for ongoing performance management.
How to use this resource
Ensuring the sustainability of supply chains relies on robust procedures
- Preparing to subcontract (before going out to tender)
- Effective due diligence (prohibitive to contracting if evidence cannot be provided)
- Agreeing of clear expectations (prior to and during contracting) and ongoing management (sometimes referred to as compliance or quality assurance).
Accordingly, this checklist and the reflective questions below are separated into three parts. Reflective questions are intended as prompts for internal discussion and planning, with the space provided to make notes. It is not anticipated that all questions will be relevant for all suppliers.
The checklist shows how compliance and continual improvement across supply chains supports achievement of the UN Sustainable Development Goals (SDGs). Some items are explicitly linked to particular SDGs – these are referenced by number in the topic column.
The checklist has three parts:
1. Preparing to subcontract
These are questions that apply to your business (‘the company’).
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- Yes
- No
- Provide evidence or add comments.
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- Yes
- No
- Provide evidence or add comments.
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- Yes
- No
- Provide evidence or add comments.
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- Yes
- No
- Provide evidence or add comments.
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- Yes
- No
- Provide evidence or add comments.
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- Yes
- No
- Provide evidence or add comments.
Point for reflection
How will those responsible for managing supplier quality and performance be trained and supported to ensure they are able to manage aspects relating to health, safety, wellbeing and sustainability?
If they will be responsible for training suppliers to help them comply in these areas, who will ensure they are competent and qualified to do so?
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- Yes
- No
- Provide evidence or add comments.
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- Yes
- No
- Provide evidence or add comments.
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- Yes
- No
- Provide evidence or add comments.
Point for reflection
How will it be ensured that non-compliance with contractual obligations relating to health, safety, wellbeing and sustainability are managed and sanctioned appropriately within the scope of the contract, and that poor practice is not superseded by financial needs?
For example, if a supplier is found to be meeting production and financial targets at the expense of the health, safety and wellbeing of their workers or by using methods which negatively impact their health or safety, how will it be ensured that this is not allowed to continue?
2. Effective due diligence
These are questions to ask suppliers before offering contracts. Should it not be possible to satisfy the requirements of due diligence, organisations should reflect on the sustainability of the supplier and whether it is appropriate to offer them a contract.
Explanatory note: the word ‘policy’ does not necessarily indicate individual documents. For example, item 3 may be comprised of documentation associated with items 4, 5, 6, and 8; and items 11 and 12 may be integrated. In addition to providing evidence of written policies and procedures, suppliers should be asked to explain:
- how policies and procedures work in practice
- how workers are trained on policies and procedures relating to safety, health, wellbeing and sustainability; and how their understanding is confirmed (including for speakers of other languages and those with other barriers to learning) (SDG 4.7.1)
- how compliance with policies and procedures is monitored and assured
Point for reflection
Who will ensure that due diligence is undertaken effectively – that proposed suppliers understand the reasons they are being asked for the evidence and that the decision to offer contracts is not made without robust evidence in place? How will they balance the organisation’s financial needs with the need to operate a sustainable supply chain?
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- Yes
- No
- Provide evidence or add comments.
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- Yes
- No
- Provide evidence or add comments.
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- Yes
- No
- Provide evidence or add comments.
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- Yes
- No
- Provide evidence or add comments.
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- mechanical hazards (e.g. machinery and vehicles)
- physical hazards (e.g. noise, vibration, temperature, lighting)
- chemical hazards (e.g. dyes, acids, cleaning products, toxic gases and dusts)
- biological hazards (e.g. bacteria, viruses, mould and fungi)
- environmental hazards (e.g. slippery or unstable floor/ground, trailing cables, poor air quality)
- psychosocial hazards (e.g. bullying and harassment, discrimination, excessively long working hours, unreasonable deadlines, inadequate training) (SDG 10.3.1, 16.1.3, 16.b.1)
- Yes
- No
- Provide evidence or add comments.
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- mental health challenges (work-related and otherwise) (SDG 3.4.2)
- alcohol and substance misuse (SDG 3.5.2)
- domestic violence (5.2.1)
- Yes
- No
- Provide evidence or add comments.
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Do these take into account:
- occupational road risk? (SDG 3.6.1)
- likelihood of natural disaster (such as flood or wildfire) and extreme temperature/weather (SDG 1.5.1)
- proximity to sources of air pollution and unsafe water (SDG 3.9.1, SDG 3.9.2, SDG 3.9.3)
- proximity to public transport (SDG 11.2.1)
- likelihood of exposure to conflict or its effects (SDG 16.1.2)
- proximity to emergency services/healthcare provision and relevant access barriers such as unsafe roads or high traffic volumes (SDG 3.8.2, SDG 3.d.1, SDG 9.11, SDG 9.1.2)
- Yes
- No
- Provide evidence or add comments.
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Including:
- workers with higher vulnerability to occupational injuries and diseases
- young workers (15-24 years old)
- pregnant workers
- women
- older workers
- persons with disabilities
- migrant workers
- those who are not employed formally (SDG 3.1)
- those at risk of discrimination prohibited under international human rights law 1, including:
- right to privacy
- freedom of religion and belief
- freedom of expression
- right to equality before the law
- minority rights
- right of mothers to special protection before and after birth (SDG 16.b.1)
- Yes
- No
- Provide evidence or add comments.
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- Yes
- No
- Provide evidence or add comments.
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- Yes
- No
- Provide evidence or add comments.
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Do these ensure all workers have access to:
- safe drinking water (SDG 6.1.1)
- safe, clean and lockable toilets (SDG 6.2.1)
- safe and hygienic washing facilities with soap, water, and hand-drying equipment (SDG 6.2.1)
- Yes
- No
- Provide evidence or add comments.
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- Yes
- No
- Provide evidence or add comments.
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- Yes
- No
- Provide evidence or add comments.
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Such as:
- smoking cessation
- nutrition
- stress reduction
- healthy sleep, including caffeine intake
- healthy approach to recreational alcohol use
(SDG 3.4.1, 3.5.2) - Yes
- No
- Provide evidence or add comments.
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Including:
- recycling and reuse of materials where possible
- safe and effective storage of chemicals and other hazardous materials (SDG 12.4.1)
- Yes
- No
- Provide evidence or add comments.
Point for reflection
Are there opportunities for the company to liaise with external bodies on any observations and reports that provide insight on the supplier’s approach to health, safety, wellbeing and sustainability?
3. Agreeing expectations/ongoing management
In addition to the undertaking of due diligence, it is expected that suppliers will also receive clear explanations and about the topics in the following section and have the opportunity to discuss them.
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- Yes
- No
- Provide evidence or add comments.
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- Yes
- No
- Provide evidence or add comments.
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- Yes
- No
- Provide evidence or add comments.
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- Yes
- No
- Provide evidence or add comments.
Point for reflection
Is the company assured that the supplier understands the targets relating to health, safety, wellbeing and sustainability? How will performance be measured (e.g. through monitoring of proactive and reactive indicators?), and is the organisation confident the supplier knows what to expect?
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For example:
- Volume/number of health and safety incidents and the management of incidents in accordance with documented procedure
- Volume/number of occupational ill health reports and the control of associated risks in accordance with documented procedure
- Worker feedback on their health, safety and wellbeing
- The results of any external monitoring (e.g. a poor review from an external agency, including those inspecting health and safety, food hygiene or public health might trigger an audit or visit)
- Yes
- No
- Provide evidence or add comments.
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- Yes
- No
- Provide evidence or add comments.
Point for reflection
In what format and how frequently will performance criteria be audited? (e.g. bi-annual performance meetings, desk-based data reviews, worker surveys)? If site visits are considered necessary, how frequent should these be and who will be responsible?
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- Yes
- No
- Provide evidence or add comments.
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- Yes
- No
- Provide evidence or add comments.
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For example, these could be due to:
- the number of workers
- the nature of work and degree of risk to workers
- the financial size of the contract
- the supplier’s locality and its likelihood of engagement with non-standard business practice such as corruption
- evidence of poor practice or increased risk (e.g. suppliers may face increased monitoring as part of following up a poor report or an incident)
- Yes
- No
- Provide evidence or add comments.
Point for reflection
What measures are in place to enforce adherence to monitoring requirements – for example, what would result in failure to provide evidence of compliance or failure to permit visits?
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- Yes
- No
- Provide evidence or add comments.
Point for reflection
What support measures will be provided to the supplier in order to help them achieve compliance? How will performance relating to health, safety, wellbeing and sustainability be reported at the end of the contract, and how will it affect decisions to renew contracts?
4. Reflection and next steps
Use these prompts to explore challenges, partnerships and continuous improvement.
Identify gaps
Review your responses and identify where improvements may be needed.
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Review your responses.
Look back through the checklist and identify any questions answered "No" or where evidence is incomplete.
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Highlight areas of concern.
Focus on gaps relating to health, safety, wellbeing, sustainability, ethical practices and supplier oversight.
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Prioritise actions.
Identify which gaps could have the greatest impact on workers, compliance, reputation or business performance.
Check supplier assurance
Consider whether your due diligence process provides sufficient confidence in your suppliers.
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Review supplier evidence.
Check that suppliers can demonstrate their approach to health, safety, wellbeing and sustainability.
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Assess the level of risk.
Consider the nature of the work, location, workforce and any known areas of concern.
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Identify additional checks.
Determine whether audits, site visits or further evidence are needed before proceeding.
Strengthen monitoring
Review how supplier performance is measured and managed.
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Check monitoring arrangements.
Ensure contracts clearly define reporting requirements, KPIs and review processes.
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Evaluate performance measures.
Confirm that monitoring provides meaningful insight into supplier performance.
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Address weaknesses.
Identify where stronger oversight, audits or reporting may be required.
Plan improvements
Create actions to strengthen supplier due diligence and quality assurance.
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Record improvement actions.
List the changes needed to address identified gaps.
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Assign ownership.
Allocate responsibility for each action to the appropriate person or team.
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Set timescales.
Agree realistic deadlines and review points for implementation.
Review progress
Make supplier due diligence an ongoing process.
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Monitor outcomes.
Review progress against agreed actions and objectives.
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Reassess supplier risks.
Consider whether circumstances have changed and if additional controls are required.
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Repeat the checklist.
Use the checklist regularly to support continual improvement across your supply chain.
Turn insight, questions and reflection into effective action
Download our practical guide to help you strengthen supplier due diligence, improve quality assurance processes and build a safer, healthier and more sustainable supply chain.