Is It Really an Independent Protection Layer?

Global Congress on Process Safety
2010 Global Congress on Process Safety
Global Congress on Process Safety
March 21, 2010 - 8:00pm
Layer of Protection Analysis (LOPA) is a simplified chemical process risk assessment tool that is used to determine if sufficient independent protection layers are in place to meet an organization's risk tolerance criteria for a particular hazardous scenario. LOPA can determine how much additional risk reduction is needed for the scenario and can help in specifying the additional protection layers.

The CCPS books, Layer of Protection Analysis – Simplified Process Risk Assessment (2001), and Guidelines for Safe and Reliable Instrumented Protective Systems Center for Chemical Process Safety (2007) identify required attributes of independent protective layers. In more than 15 years experience working with LOPA, we have frequently observed confusion about these attributes among LOPA analysts, protection layer implementers, and operations personnel.

Therefore, this paper discusses the characteristics of independent protection layers, gives examples to avoid confusion and misapplication of the characteristics, gives an easily remembered phrase to screen candidate IPLs, and provides sample tools to confirm IPL compliance with the characteristics. The paper discusses the importance of a Safety Requirements Specification for SIFs (Safety Instrumented Functions) and proposes analogous documentation for other IPLs. The paper gives guidance to determine when protection layers or scenarios require more detailed analysis such as event tree analysis or fault tree analysis.
Professional Development Hours
0.5 PDHs
You will be able to download and print a certificate for these PDH credits once the content has been viewed. If you have already viewed this content, please click here to login.

Would you like to access this content?

No problem. You just have to complete the following steps.

You have completed 0 of 2 steps.

  1. Log in

    You must be logged in to view this content. Log in now.

  2. Purchase Technical Presentation

    You must purchase this technical presentation using one of the options below.
    If you already purchased this content recently, please click here to refresh the system's record of ownerships.


Credits 0.5 Use credits
List Price $25.00 Buy now
AIChE Members $15.00 Buy now
AIChE Undergraduate Student Members Free Free access
AIChE Graduate Student Members Free Free access