Supply Chain Management

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IRPC is committed to managing our integrated supply chain responsibly and efficiently, embedding environmental, social, and governance (ESG) considerations to support our long-term sustainability objectives.

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Supply chain management is a cornerstone of IRPC’s operations and long-term sustainability, as activities across our value chain may generate both actual and potential impacts on the economy, environment, and society, particularly in relation to resource utilization , emissions, labor practices, and business conduct within our supplier network. These impacts may occur directly from our operations or indirectly through our suppliers and other business partners, making effective oversight essential. IRPC therefore embeds environmental, social, and governance (ESG) considerations into procurement and supplier management processes through a structured and risk-based approach, supported by policies, codes of conduct, and due diligence mechanisms. Through this approach, we aim to prevent and mitigate adverse impacts, strengthen supply chain resilience, and support sustainable growth for the Company and our stakeholders.

Management Approach

IRPC adopts a strategic and sustainable supply chain management approach that prioritizes product and service quality while integrating environmental, social, and governance (ESG) considerations through a risk-based approach. We implement a comprehensive risk management framework covering compliance with labor laws, environmental regulations, and quality standards to mitigate risks that may affect product quality, delivery reliability, and stakeholder trust.

To support consistent implementation, IRPC establishes clear expectations for suppliers and employees through governance tools such as the Supplier Sustainable Code of Conduct and the Purchaser Code of Conduct, which are integrated into procurement processes and business practices. These frameworks guide responsible sourcing and ethical conduct, while enabling effective oversight and continuous improvement across the supply chain. In addition, IRPC provides training and capacity-building programs for procurement personnel to support the consistent implementation of supplier ESG programs, including topics such as sustainable supply chain management.

Oversight of supply chain ESG management is led by executive management, with defined roles across the Procurement Department and Internal Audit Office to ensure effective implementation, monitoring, and independent review of supplier ESG performance. Key risks, including high-risk suppliers and corrective action progress, are reported to executive management on an annual basis.

Supplier Code of Conduct

To operationalize our expectations for responsible supply chain practices, IRPC has established the Supplier Sustainable Code of Conduct (SSCOC), which defines the standards all suppliers are required to uphold. Aligned with applicable laws, regulations, and principles of good corporate governance, the SSCOC is structured across four key topics: (1) business ethics, (2) corporate social responsibility, (3) safety, and (4) environmental management. These topics collectively set expectations for suppliers to operate responsibly across ethical, social, safety, and environmental dimensions throughout the supply chain.

1) Business Ethics

Emphasizes fair operating practices with high integrity, transparency, and compliance with laws.
Covers conflict of interest disclosure, intellectual property protection, data privacy, and financial integrity.
Require suppliers to operate ethically and uphold strong corporate governance standards

2) Corporate Social Responsibility (CSR)

Requires respect for human rights, non-discrimination, fair wages, working conditions, and prohibition of forced or child labor.
Encourages contributions to local communities and positive social impacts.
Promotes ethical labor practices and employee well-being throughout the supply chain

3) Safety

Requires occupational health and safety management that meets legal and industry standards.
Includes risk communication, emergency preparedness, and accident prevention.
Focuses on ensuring safe operations for employees, contractors, and surrounding communities

4) Environmental Management

Promotes compliance with environmental laws and standards while minimizing pollution, waste, and emissions.
Requires monitoring and improving environmental performance and preventing hazardous releases.
Encourages resource efficiency, climate change mitigation, and responsible sourcing

IRPC requires suppliers to comply with the SSCOC as a condition of doing business and communicates these requirements to suppliers across our operations. In cases of non-compliance, the Company reserves the right to take appropriate action based on the level of impact and associated risks. In addition, IRPC encourages suppliers to adopt similar standards within their own supply chains, promoting responsible practices beyond tier-one suppliers and fostering sustainability throughout the value chain.

Supplier Sustainable Code of Conduct (SSCOC)Download

Supplier Screening and Selection

To be included in and remain on IRPC’s Approved Vendor List (AVL) and Approved Contractor List (ACL), all suppliers, both new and existing, are required to undergo a comprehensive evaluation process. This process is based on fair and transparent criteria and includes a pre-qualification questionnaire to assess supplier readiness, production capacity, logistics, safety, occupational health, and environmental compliance. In addition, Environmental, social, and governance (ESG) considerations are integrated into supplier screening and selection. The ESG evaluation is structured around five key objectives:

1. Building awareness and understanding of IRPC’s Sustainability Policy, including the Supplier Code of Conduct
2. Ensuring that suppliers and contractors comply with IRPC’s Way of Conduct
3. Developing and strengthening sustainability management among suppliers and contractors
4. Promoting transparent and accountable business relationships
5. Mitigating risks and improving supplier and contractor performance

ESG criteria account for 25% of the total supplier evaluation score, and suppliers are required to achieve at least 70% of this ESG component to qualify for inclusion on IRPC’s approved vendor list. Moreover, IRPC incorporates relevant requirements into procurement processes and contractual conditions, including the Terms of Reference (TOR), to ensure compliance with applicable laws and contractual obligations, particularly for activities associated with safety, occupational health, and environmental risks. The Company also implements a Contractor SSHE Management Program to assess contractor risks and ensure that only qualified contractors meeting defined criteria are selected.

New Suppliers Screening (%)

2022

2023

2024

2025

New suppliers that were screened using Environmental criteria

100

New suppliers that were screened using Social criteria (labor practices, human rights, impacts on society)

100

To support effective supplier identification and prioritization, IRPC leverages spend analysis together with critical assessment to identify suppliers that are most important to business operations. The Company conducts spend analysis separately for initial feedstock procurement for the petroleum and petrochemical businesses and for general procurement of additives, chemicals, spare parts, and other related components. Currently, two functions are responsible for overseeing business spending: the procurement function, which tracks spending on chemicals, spare parts, and related components, and the feedstock function, which tracks spending on refinery and petrochemical feedstock. IRPC utilizes spend analysis to scrutinize expenditure data to reduce procurement costs, enhance efficiency, and monitor compliance, while providing visibility into supplier expenditure and supporting procurement planning.

Building on these insights, IRPC conducts critical analysis to identify suppliers that are crucial to business operations. All suppliers are assessed and classified as Tier 1 Significant and Tier 1 Non-Significant suppliers This classification enables IRPC to prioritize suppliers that are essential to operations and may pose higher operational or supply chain risks.

Significant Tier-1 Suppliers are those that have high expenditure, significant risk, non-substitutable products, and provide critical parts or components essential to operations.
Significant non-Tier 1 Suppliers are those that supply goods or services to Tier-1 suppliers, assessed based on high expenditure, their critical role in the supply chain, non-substitutability, and potential risks to supply chain stability.

Type of Suppliers (number)

2022

2023

2024

2025

Total tier-1 suppliers

1,844

1,814

1,816

1,638

Significant tier 1 suppliers

% of total spending on significant suppliers in Tier-1

–

6 %

5 %

Significant non-tier 1 suppliers

Suppliers with SCOC signed

156

121

Suppliers with ESG training

Sustainability Performance Summary 2025Download

Supplier Assessment and Development

IRPC conducts ESG risk assessments of suppliers and contractors to identify and manage potential sustainability risks arising from procurement activities. The assessment covers Environmental, Social, and Governance (ESG) risks, including human rights violations, unsafe working conditions, and the use of prohibited substances. These risks are evaluated based on likelihood and potential impact to determine their significance to the Company and stakeholders.

The ESG assessment is integrated into the procurement process and is mandatory for all suppliers that are strategically significant to the company, based on criteria such as procurement value, supply risk, and their significance to product quality and cost. This approach supports IRPC’s commitment to sustainable organizational development through responsible and transparent supply chain management. The assessment framework is aligned with IRPC’s Supplier Code of Conduct and requires suppliers to complete a structured questionnaire to evaluate performance against the Company’s sustainability expectations, including business ethics, human rights and labor practices, occupational health and safety, and environmental management. The assessment includes both desk-based evaluations supported by documentation review and, where applicable, on-site assessments to verify supplier practices.

IRPC identifies suppliers with high sustainability risks based on defined risk criteria. Suppliers classified as High-Risk Tier 1 are subject to annual audits, including on-site visits and employee interviews. These assessments are conducted by appointed internal ESG Auditors to ensure structured, consistent, and objective evaluation process. These suppliers are required to establish mitigation plans and operational guidelines in alignment with IRPC’s supplier procurement management requirements to reduce potential impacts.

IRPC ESG Internal Auditor 2024-2026Download

IRPC ESG Assessment Plan 2025Download

IRPC works closely with high-risk suppliers to conduct root cause analysis and develop Corrective Action Plans. The Procurement Department monitors implementation of these plans to ensure effectiveness in reducing risk levels in line with defined risk appetite, supported by periodic reviews from the Internal Audit Office. The results of monitoring and control plans are reported to the executive management on a quarterly basis.

In cases of non-conformance, IRPC formally notifies suppliers and requires corrective actions within defined timelines to prevent recurrence and drive improvement. All identified non-conformities are addressed through agreed corrective action plans, with ongoing support from IRPC in the form of guidance and follow-up engagement. Additionally, IRPC provides recommendations to all assessed suppliers to enhance ESG practices across the supply chain.

ESG Assessment & Development

Unit

2022

2023

2024

2025

Total number of unique suppliers (Tier-1 & non-Tier-1)

number

1,844

1,814

1,816

1,638

Total number of unique significant suppliers (Tier-1 & non-Tier-1)

number

Unique significant suppliers with development measures

number

–

Unique significant suppliers assessed via desk assessments/on-site assessments

number

–

Unique significant suppliers assessed with substantial actual/potential negative impacts

number

–

Unique significant suppliers with substantial actual/potential negative impacts that were terminated

number

–

Unique significant suppliers with substantial actual/potential negative impacts with agreed corrective action/improvement plan

number

–

Supplier ESG Program

IRPC engages with external partners and industry platforms to strengthen supplier capabilities and promote responsible practices across the supply chain. This includes participation in collaborative initiatives, knowledge-sharing platforms, and supplier development programs, such as training, workshops, and technical support initiatives, that support continuous improvement in ESG performance.

Training and capacity-building workshop on ESG practices for PTT Group companies

The program, organized by PTT Group and MASCI (Management System Certification Institute), was held on 12 June 2568 (2025) at ENCO B building, PTT Headquarters. The objectives were to:

Enhance participants’ understanding of ESG and its importance in business operations.
Share PTT Group’s ESG strategies, self-assessment tools, and questionnaires (PTT Group ESG Questionnaires).
Conduct a hands-on workshop for participants to practice self-assessment using the PTT Group ESG Self-Assessment Tool.

The event included keynote speeches, knowledge-sharing sessions on sustainability excellence, and group workshops, with active participation from employees across the PTT Group.

Supplier on-site visit

IRPC conducted site visits to Pornampol Transport Limited Partnership and Protectfield Co., Ltd. to strengthen strategic supplier relationships and comprehensively review the quality of their operations. The visits covered discussions on operational issues and challenges, as well as the joint identification of improvement opportunities to enhance supply chain efficiency and sustainability.

In addition, the Company conducted on-site ESG assessments to evaluate suppliers’ practices against internationally recognized sustainability standards. The assessments focused on environmental management, labor practices and human rights, and good corporate governance. The assessment results will be used as supporting information for supplier risk evaluation and as part of DJSI reporting, demonstrating the Company’s commitment to responsible, transparent, and sustainable supply chain management.

Supplier Training & Capacity Building – IRPC Cubic Academy 2025

To strengthen the capabilities of business partners and suppliers in conducting responsible business, IRPC integrates ESG principles into supplier development activities.

IRPC organized the IRPC Cubic Academy Season 11, inviting a total of 1,335 business partners and suppliers to participate.
The program consisted of six training courses covering key topics related to innovation, technology, environmental and social risks, health, and anti-corruption.
The training courses included lectures, knowledge-sharing sessions, and practical workshops, with active participation from both business partners and IRPC employees.

Outcome:

114 participants attended the training program in 2025.
Enhanced suppliers’ knowledge and practical guidance on ESG awareness and responsible business conduct.
Supported long-term supplier capability development and contributed to IRPC’s sustainable supply chain management

Supply Chain Management

Supplier Code of Conduct

Supplier Screening and Selection

New Suppliers Screening (%)

2022

2023

2024

2025

Type of Suppliers (number)

2022

2023

2024

2025

Supplier Assessment and Development

ESG Assessment & Development

Unit

2022

2023

2024

2025

Supplier ESG Program

Supplier Satisfaction (%)

2022

2023

2024

2025