1. Standards Comparison: USA and Europe

2. Europe and US maintain distinct machine safety standards, but a migration is beginning.
In regions around the globe there exist different legal requirements regarding what has to be proven, and how, when determining whether there’s sufficient safety. Likewise, the assignment of levels of responsibility can vary significantly.
Industrial machine safety standards have been harmonizing over the past 10 to 15 years with greater interest, activity, collaboration, and results from participating countries globally. Standards technical committees are working together to create international standards that meet the needs of global and regional markets and individual countries. This seems to be driven by global companies, economic and competitive issues, and a world economy. Countries still have domestic standards, but even they are trending to reference the international standards more often, such as those from IEC (International Electrotechnical Commission) and ISO (International Organization for Standardization).

3. EU Machinery Directive 2006/42/EC
National laws of the European Union (EU) require that machines meet Essential Health and Safety Requirements (EHSR)
All new machinery must fulfill the same legal requirements when supplied throughout the EU.

4. Role of 2006/42/EC
Defines the Essential Health & Safety Requirements (EHSR)
Ensures that a machine is designed and constructed to be safe so that it can be used, configured, and maintained throughout all phases of its life, causing minimal risk to people and environment

5. Two Standards: ISO and IEC
ISO – International Organization for Standardization
IEC – International Electrotechnical Commission
Historically, international standards (IEC & ISO) have been strongly influenced by the European countries; Conversely, U.S. consensus standards for machine safety tend to be written equally for users and suppliers, especially as it relates to the design, construction, and long-term ownership of machinery. Therefore, we’ve seen a U.S. shift toward additional compliance requirements.

6. ISO 13849-1 Making Machines Safe
Defines How to Determine Performance Level (PL) and How to Verify Achieved PL within a System

7. EN 62061 Designing Electrical Safety Systems
Defines Safety Integrity Level (SIL)

8. Meeting Machine Directive
Achieving and Managing Functional Safety
Safety Plan

9. Steps to Achieve Functional Safety
Assessment and Risk Reduction
Establish Safety Function Requirements
Implement Functional Safety
Verify Functional Safety
Validate Functional Safety
Document Functional Safety
Prove Compliance

10. Enforcement (Law)
The U.S. legal model for enforcement is not very straightforward compared to the European compliance model, as the chart shows.  
In each model, the U.S. Occupational Safety & Health Administration (OSHA) and the European Machinery Directive are the “Law.”
Since the Machinery Directive lists the standards, a single flow with dual purpose is achieved, driving compliance and enforcement to the supplier. However, OSHA uses a list of “regulations”. OSHA cites these “regulations” and openly enforces compliance to the end user of machinery and not the supplier. Furthermore, OSHA reserves the “right to reference” consensus standards for enforcement to the end user.
This practice confuses U.S. compliance because OSHA doesn’t openly require that a supplier build a compliant machine. Also:
- End users pass through machine safety compliance requirements in the purchase order.
- Suppliers understand their liability.
- Suppliers apply due diligence and want to provide safe machines to users.
The U.S. model requires that we acknowledge our compliance and enforcement flow with appropriate measures as we consider adopting international machine safety standards. 
How the U.S. adopts requirements of an international standard, like ISO , is critically important, since OSHA puts the U.S. user first in line for enforcement. Users must consider the business impacts of these changes.

11. References Allen-Bradley: Principles, Standards, & Implementation
Schneider Electric: Safe Machinery Handbook`

12. Discussion