Together with our suppliers for more sustainability

We work with around 4,000 suppliers worldwide, with 6% of our suppliers already accounting for around 90% of our purchasing volume. Half of this volume is divided between Asia and the other half between Europe and North America. The most important procurement areas relate to capital goods, the raw material polysilicon, auxiliary and operating materials for our production processes, energy, information technology and logistics services.

Expectations of our suppliers

Since 2019, Siltronic has been a member of the Responsible Business Alliance, the world's largest industry association with the aim of driving and anchoring social responsibility in global supply chains further, better and in a more structured way.

In our contracts, we agree with our suppliers to comply with our own Code of Conduct and the Code of Conduct of the Responsible Business Alliance. These set out our basic expectations on points such as the avoidance of forced labor and child labor, maximum weekly working hours, fair wages, responsible treatment of the environment and impeccable business ethics.

We communicate our goals and measures in the areas of sustainability and corporate responsibility to our suppliers at regular supplier days.


Measures to increase sustainable action in our supply chain are implemented holistically and globally in close coordination with the Head of Corporate Responsibility.

We regularly monitor and report on the progress of the evaluation of our supplier portfolio both in the purchasing management circle and at Management Board level and reflect this against our targets.  

Management system

Siltronic has implemented a comprehensive supplier management system for many years. The system is designed to ensure that suppliers continuously improve in the areas of quality, service, delivery risks and costs and act responsibly in the area of sustainability with regard to working conditions, ethical standards, safety standards and the use of local resources.

Ratings of our suppliers

We continuously evaluate and assess the performance of over 100 suppliers worldwide. These suppliers represent our global procurement volume. We have various rating systems at our disposal for this purpose, which we use to assess the risk potential and performance of our partners.

Analysis of risks in the supply chain

In addition, we regularly carry out comprehensive assessments of the ESG risks of our supplier base. In doing so, we take into account the geographical location, the type of business activity and the volume of business we conduct with suppliers. The risks considered are divided into categories. Employment practices, health & safety, environmental aspects, business ethics and the maturity of management systems are taken into account. Based on the results of this risk analysis, we select focus suppliers for a more detailed investigation. In addition to suppliers with a high procurement volume or high risk potential, service providers whose employees work in our global production facilities together with our own staff are particularly important to us. We use the extensive self-assessments of the Responsible Business Alliance to precisely assess the risks of these focus suppliers.

In addition to our own risk analyses of our supplier portfolio, we take reports of human rights violations and changes in the law as an opportunity to specifically examine our supply chain and check compliance.

On-site inspections: Audits

We conduct ESG audits of our suppliers with our own qualified auditors. We distinguish between dedicated ESG audits based on a complete list of criteria and an ESG assessment as part of supplier audits, in which compliance with the most important requirements of our own Code of Conduct and the Responsible Business Alliance Code is checked.

We also use the expertise of independent third parties in audits conducted by the Responsible Business Alliance. Additionally, we participate in the Responsible Business Alliance's Audit Cooperation Program, in which various customers join forces and initiate audits together.

Improvement and remedial measures

In the event of indications of deviations and deficiencies with regard to sustainability requirements, we follow these up with the suppliers and check the implementation of appropriate corrective measures.

Reporting of suspected cases

Siltronic's Human Rights Officer is also available to our suppliers' employees as a point of contact for reporting actual or expected violations of human rights. Initial contact can also be made via our local compliance officers.

We have also installed a publicly accessible digital whistleblower system that also enables people to report violations that have occurred as a result of the company's business activities or those of a direct supplier.


We attach great importance to our suppliers acquiring certificates with which they have the suitability of their management systems externally confirmed, including for social and environmental aspects. These also have a relevant influence on the evaluation of our suppliers. We take into account certificates for standards such as ISO 14001, ISO 45001 and ISO 50001,as well as participation in or membership of the Responsible Business Alliance and comparable industry initiatives as well as certifications in the area of diversity. We conclude contracts with important suppliers in which we agree to obtain and maintain these certificates and can evaluate the coverage of our supplier portfolio by these standards in our supplier portal at any time.

Polysilicon and human rights

We have analyzed the raw material polysilicon as our most important supply chain in detail. Our aim was to achieve complete transparency across all stages of polysilicon production and to ensure that none of our subcontractors are involved in publicly known human rights violations. As a result of the extensive analysis, we have succeeded in doing so.

Diversity in the supply chain

We are also committed to promoting equality and diversity in our supply chain. Our goal of further increasing procurement from and with diverse companies is communicated on our website. This provides a direct contact and quotation channel for diverse companies to offer their products or services.

Continuous improvement

Our goal in the coming years remains to use these supplier management processes and measures to further promote sustainable action in our supply chain and to reduce and continuously improve risks in this regard together with our suppliers and partners.

Annual report

Audited information and key figures on sustainability at Siltronic can be found in our current annual report.

Whistleblower system

Violations of legal requirements or Siltronic guidelines can be reported here – anonymously if necessary.

Relevant downloads

Conflict minerals

Siltronic wants to ensure that conflict minerals do not play a role in the value chain of its products.

  • What are conflict minerals?

  • Relevance for Siltronic

  • Approach to exclude conflict minerals

  • Detecting and dealing with violations

more information