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NSF/ANSI 391.1 Certification for Professional Services

NSF/ANSI 391.1: General Sustainability Assessment Criteria allows professional service providers (PSPs) to assert and quantify commitments to improve their performance in each of the standard’s four pillars: environmental impact, social equity, economic governance, and supply chain sustainability.

Demonstrate Your Commitment to a Sustainable Future

NSF 391.1 Sustainable Business Practices Leadership Certified

NSF/ANSI 391.1 paves the way for professional service providers (PSPs)* to forge a resilient and responsible business landscape. By embedding transparency ethical standards, and a minimized carbon footprint into your core values.

Using NSF/ANSI 391.1, PSPs can:

  • Gain competitive advantage without modifying corporate structure or bylaws.
  • Attract and retain employees, clients, and investors.
  • Address state and federal procurement guidelines for sustainable services.
  • Align business operations with sustainability objectives.

Certification Levels and Scoring System

NSF/ANSI 391.1 is the only ESG certification specifically designed for the professional services sector. The NSF/ANSI 391.1 standard sets strict initial criteria for all applicants while offering flexibility, allowing you to further highlight your dedication to a sustainable future. It provides two certification tiers, allowing your organization to earn credit for adopting additional policies, actions, and procedures across its four pillars: Positive Environmental Impact, Economic and Corporate Governance, Social Equity for all Stakeholders, and Supply Chain Diversity and Sustainability.

Review the certification levels and points system below:

391.1 Certification Levels and Points System Chart

Required Prerequisites

Within each of the four pillars, all PSPs regardless of size, location or service area must meet all prerequisites to demonstrate compliance to NSF/ANSI 391.1. Some requirements include:


  • Publish publicly available environmental policy
  • Demonstrate a reduction of greenhouse gas emissions caused by company services
  • Increase the use of renewable energy within the corporate footprint


  • Provide documentation of ethical codes of conduct
  • Undertake recurring stakeholder mapping exercises
  • Publicly report sustainability and ESG policies


  • Commit to preventing harassment, discrimination and violence in the workplace
  • Document anti-corruption, labor, anti-discrimination and career path policies
  • Commit to support nonprofits and NGOs or provide pro bono services

Supply Chain

  • Implement supplier diversity programs and increase your spend with diverse suppliers
  • Create a diverse supply chain that supports protected class businesses
  • Establish sustainable procurement policies
  • Undertake recurring stakeholder engagement

Once a PSP has demonstrated compliance with all prerequisites, it can select additional policies and practices to gain points across the four pillars.

* Organizations classified as professional service providers by the U.S. Federal Professional Services Schedule (PSS) or NAICS code 54.

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