Safe By Design - Part 2

Summary

This video walks through the process of conducting a risk assessment for industrial machinery, focusing on evaluating hazards, defining safety controls, and ensuring compliance with industry standards. The discussion includes evaluating injury severity, exposure levels, and the importance of implementing protective measures such as light curtains and safety controllers. Emphasis is placed on a team-based approach to risk assessment, involving diverse perspectives to ensure thorough hazard identification. The video also highlights the role of documentation and software tools in streamlining the assessment process, ensuring machine safety, and meeting performance level requirements.

Takeaways

• 😀 Risk assessments should be performed using a team-based approach, involving multiple departments to ensure comprehensive hazard identification.
• 😀 Exposure to the hazard is evaluated based on the frequency of interaction with the machine or system, and the risk level is adjusted accordingly.
• 😀 Protective measures are prioritized from most preferred (engineering controls) to least preferred (administrative controls and PPE).
• 😀 The use of light curtains and safety sensors is recommended to prevent access to hazardous areas and ensure machine safety.
• 😀 The system automatically calculates the required performance level (PL) for safety, which can range from D to E based on the identified risk.
• 😀 When designing safety systems, it is essential to select components that meet the required safety performance levels (e.g., PL D).
• 😀 In order to assess the risk after applying safety measures, the system recalculates the risk to ensure it falls within acceptable limits.
• 😀 Safety control systems, such as safety controllers or safety relays, are used to monitor and control the safety logic and interlocking of devices.
• 😀 The configuration of safety devices, including input and output devices, ensures correct system operation and documentation for risk assessment.
• 😀 It’s crucial to document the safety requirements and risk assessments in a comprehensive report, which can be shared for review and further refinement.
• 😀 The safety system design can be evaluated through software tools that assess both the device and system-level safety, generating detailed documentation to prove compliance.

Q & A

What is the primary purpose of the risk assessment process discussed in the video?

The primary purpose of the risk assessment process is to evaluate potential hazards and risks associated with a machine or process, and to determine appropriate safety measures, ensuring the safety of operators and others who may interact with the machine.

How does the software assist in the risk assessment process?

The software helps by guiding users through the risk assessment matrix, assisting in the evaluation of severity, exposure, and avoidance of hazards. It automates certain calculations based on predefined safety standards and provides recommendations for the necessary performance levels of safety devices.

What are the factors considered when determining the severity of an injury in a risk assessment?

The severity of an injury is typically categorized as fatal, severe, moderate, or minimal based on the nature of the injury. Factors like broken bones, amputations, or lacerations are considered, and the appropriate severity level is assigned accordingly.

What does the term 'performance level' mean in the context of the risk assessment?

The 'performance level' refers to the required safety performance for a given system or device. It is determined based on the identified risks and is expressed as a level (e.g., D or E), with higher levels indicating more stringent safety requirements.

What are the preferred protective measures for reducing risks according to the video?

The preferred protective measures are designed-out solutions, such as eliminating the hazard or designing the machine to be inherently safe. If that’s not feasible, engineering controls like light curtains, guarding, or access detection devices are recommended. Administrative controls like training and PPE are considered the least preferred option.

What role do light curtains play in the safety solutions discussed?

Light curtains are used as a present sensing safety device to detect the presence of an operator or other personnel at a hazardous location. When the curtain is blocked, it prevents the machine from operating, thereby preventing injuries. They can be applied to multiple hazards if they protect both areas.

How does the risk assessment change after implementing safety measures like light curtains?

After implementing safety measures like light curtains, the risk assessment is reevaluated, and the risk level typically decreases. For example, by preventing access to the hazard zone, the exposure risk may be reduced to an acceptable level, leading to a lower overall risk rating.

What is meant by 'span of control' in the context of safety systems?

The 'span of control' refers to the extent and way in which safety functions and devices are controlled within the system. It involves defining the components and their interactions, such as input devices, safety controllers, and output devices, to ensure that the system meets the necessary safety requirements.

What is the difference between a point of operation light curtain and a perimeter access control curtain?

A point of operation light curtain is used to monitor a specific hazard zone, providing higher resolution and more precise detection (e.g., 14 mm or 30 mm). A perimeter access control curtain is typically used for broader safety purposes, like creating a virtual fence around a machine, but has less resolution (e.g., 3 beam or 2 beam).

Why is it important to involve multiple team members in a risk assessment?

Involving multiple team members from different backgrounds, such as controls engineers, mechanical engineers, and even administrative staff like HR, ensures a more comprehensive risk assessment. This diversity helps identify hazards that might otherwise be overlooked and ensures that no single individual is solely responsible for the process.