Replacement of Hazardous Chemicals and Risk Reduction

The replacement of hazardous chemicals with benign and inherently safer alternatives indicated by green chemistry principles is certainly a valuable measure, because a hazardous chemical that is no longer present can no longer be involved in an accident. However, from industrial point of view there are often alternative solution that reduce the risk to a sustainable level at a much lower cost than that required by completely changing the production. 

Avoiding the use of MIC removes a significant amount of the hazard associated with the process and as a result gives an inherently safer process. However, the alternative process still uses phosgene, which is extremely toxic. A process that avoids phosgene would provide further intrinsic safety. 

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