Effect of Migrant Compounds on Taste and Odour

Some of the tertiary amines used for PU can be replaced by using catal)U ically active polyols, which can replace up to half of some tertiary amine catalysts and can thus result in reduced odours. 

Phenol stabilisers used with PVC are replaced by less odourous, zinc-based heat stabilisers. Octyltin heat stabilisers, with their reduced odour and reduced fogging properties, are used favourably with PVC in automotive applications. 

PPA slip-agents of certain reduced odour amides e.g., erucic and oleic acid-based vegetable-derived amides, are used in polyolefin and styrenic food-packaging materials. 

Since the traces of some remaining monomers can give off unpleasant odours in many plastics and rubbers e.g., monomers of PVC, PS, polyvinyl alcohol and acrylics, they can be eliminated or kept to a minimum by using special inherently monomer-free polymers. 

Small amounts of synthetic zeolites (based on metal aluminosilicates) can be added to the system to adsorb unwanted organic odour-producing molecules and/or to remove the moisture that contributes to odours (by trapping them in their highly porous crystal structures). This technique is successfully used in extruded polyolefin pipes, injection and extrusion blow-moulded containers, barrier packaging materials, extrusion coatings, and sealant polymers. 

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