Iran Occupational Health

Background and aim: For prevention of accidents in chemical processes, the use of multiple layers of protection is essential. In this regard, the analysis of adequacy and use of protective layer resistance is a necessity. In this study the level of protection layers security of Cephalexin Crystals production unit of one the pharmaceutical companies is examined.

Methods: In this descriptive study the existing hazards in Cephalexin Crystals production unit of one the pharmaceutical companies assessed LOPA technique. Therefore, with visiting and inspecting the Cephalexin Crystals production unit which Cephalexin Crystals production occurs in four reactors, using HAZOP technique the risks were identified. Then, using LOPA technique that is an analysis and risk assessment technique, protective layers were analyzed and finally the risk number calculated.

Results: Using this method the 104 scenarios were identified. Of the 104 Scenarios the 102 Scenarios were at acceptable levels and only two scenarios needed to management's judgment to determine whether further reductions are needed or not.

Conclusion: LOPA technique is a useful method for assessing the adequacy of the independent protective layers in the Cephalexin Crystals production unit of the pharmaceutical company. The results showed that calculation of the some initiating event frequency using specific tables is not possible. Therefore, expert judgment and the exchange of experiences are emphasized. Because of the direct involvement of experts in risk assessment, the skill of the team in determining the authenticity and accuracy of the results is very important and hence calibration and evaluation procedures are also important.