Off-odors caused by halogenated phenols and anisols

Due to their extremely low sensory threshold levels, chloro- and bromoanisoles have been clearly identified for years as the cause of off-odors. The following case shows how new variations and combinations of unpredictable events can lead to a problem whose solution requires a great amount of work. 

A few years ago there was a series of off-odor problems in packed food over a relatively short time period, occurring in different types of packaging and materials related to one another through the use of a polymer granulate. Even though each problem had a different nature, all of the samples studied had several similar characteristics  

The description of the off-odor matched that for trichloro- (TCA) as well as tri-bromoanisole (TBA). 

The number of samples affected was relatively small which means they came from a relatively small batch. 

Together with the seemingly simultaneous occurrence, these characteristics point to a common cause. Since there was no technical reason to assume formation of TCA or TBA in PE, the study was directed to the PE granulate because it was the simplest matrix. 

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