Machine Safety Systems: Categorization Based on International Standards

Introduction and definitions

Abstract

Machine safety systems are crucial for ensuring the protection of operators and equipment in industrial environments. The categorization of these systems based on international standards helps in maintaining consistency, reliability, and effectiveness. This paper provides a detailed overview of the various categories of machine safety systems according to prominent international standards such as ISO, IEC, and ANSI. The paper highlights the significance of each category, the standards governing them, and the practical implications for industries.

Introduction

Machine safety systems are designed to prevent accidents and reduce the risk of injury in industrial settings. These systems are categorized based on international standards, which provide guidelines and requirements for their design, implementation, and maintenance. This paper aims to elucidate the different categories of machine safety systems, focusing on their definitions, standard requirements, and applications.

International Standards Overview

ISO (International Organization for Standardization)

The ISO develops and publishes a wide range of international standards, including those related to machine safety. Key ISO standards relevant to machine safety systems include:

• ISO 12100: Safety of machinery – General principles for design – Risk assessment and risk reduction.
• ISO 13849: Safety of machinery – Safety-related parts of control systems.
• ISO 14119: Safety of machinery – Interlocking devices associated with guards.

IEC (International Electrotechnical Commission)

IEC standards focus on electrical and electronic technologies. Key IEC standards for machine safety systems include:

• IEC 60204-1: Safety of machinery – Electrical equipment of machines – Part 1: General requirements.
• IEC 61508: Functional safety of electrical/electronic/programmable electronic safety-related systems.
• IEC 62061: Safety of machinery – Functional safety of safety-related electrical, electronic, and programmable electronic control systems.

ANSI (American National Standards Institute)

ANSI standards, developed in the United States, provide guidelines for machine safety, including:

• ANSI B11: Safety standards for machine tools.
• ANSI/RIA R15.06: Industrial robots and robot systems – Safety requirements.

Categories of Machine Safety Systems

1. Safety Control Systems

Definition: Systems designed to monitor and control machinery operations to prevent hazardous conditions.

Standards:

• ISO 13849-1: Specifies the safety requirements and guidance on the principles for the design of safety-related parts of control systems.
• IEC 62061: Provides requirements for the design and integration of safety-related control systems.

Applications:

• Emergency stop systems.
• Safety interlock systems.
• Safety-related programmable logic controllers (PLCs).

2. Guarding Systems

Definition: Physical barriers that prevent access to dangerous parts of machinery.

Standards:

• ISO 12100: General principles for risk assessment and risk reduction, including the use of guards.
• ISO 14120: Safety of machinery – Guards – General requirements for the design and construction of fixed and movable guards.

Applications:

• Fixed guards around hazardous machine parts.
• Interlocking guards that disable machine operation when removed.

3. Interlocking Devices

Definition: Devices that prevent machinery from operating under unsafe conditions by ensuring guards are in place.

Standards:

• ISO 14119: Specifies the design and selection of interlocking devices associated with guards.
• IEC 60947-5-1: Low-voltage switchgear and control gear – Part 5-1: Control circuit devices and switching elements – Electromechanical control circuit devices.

Applications:

• Door interlocks on industrial robots.
• Safety switches on access panels.

4. Safety Instrumented Systems (SIS)

Definition: Systems that take automatic action to prevent hazardous events based on specific inputs.

Standards:

• IEC 61508: Functional safety of electrical/electronic/programmable electronic safety-related systems.
• IEC 62061: Functional safety of safety-related control systems.

Applications:

• Emergency shutdown systems in chemical plants.
• Fire and gas detection systems.

5. Personal Protective Equipment (PPE)

Definition: Equipment worn by workers to protect against specific hazards.

Standards:

• ISO 13688: Protective clothing – General requirements.
• ISO 20345: Personal protective equipment – Safety footwear.

Applications:

• Protective gloves and eyewear.
• Safety harnesses and helmets.

Practical Implications

Implementing machine safety systems according to international standards ensures a high level of safety and compliance. Industries benefit from reduced accident rates, improved worker confidence, and adherence to legal and regulatory requirements. Additionally, standardized safety systems facilitate interoperability and consistency across different regions and sectors.

Conclusion

The categorization of machine safety systems based on international standards is essential for ensuring the safety and reliability of industrial operations. Understanding and implementing these categories help organizations mitigate risks and protect their workforce. This paper has outlined the primary categories and standards governing machine safety systems, providing a foundation for further exploration and application in various industrial contexts.

References

1. ISO 12100:2010, "Safety of machinery – General principles for design – Risk assessment and risk reduction."
2. ISO 13849-1:2015, "Safety of machinery – Safety-related parts of control systems – Part 1: General principles for design."
3. ISO 14119:2013, "Safety of machinery – Interlocking devices associated with guards – Principles for design and selection."
4. IEC 60204-1:2016, "Safety of machinery – Electrical equipment of machines – Part 1: General requirements."
5. IEC 61508:2010, "Functional safety of electrical/electronic/programmable electronic safety-related systems."
6. IEC 62061:2021, "Safety of machinery – Functional safety of safety-related electrical, electronic and programmable electronic control systems."
7. ANSI B11.19-2019, "Performance Requirements for Risk Reduction Measures: Safeguarding and other Means of Reducing Risk."
8. ANSI/RIA R15.06-2012, "Industrial Robots and Robot Systems – Safety Requirements."

Mostafa Sayed