The well known WindJet® nozzles with high efficiency and low noise are now available in a PVDF plastic, which is not only certified according to EC1935/2004 and suitable for food contact. It also has an outstanding metal detectable property:

WindJet 727
WindJet Düse

New PVDF (Kynar) material for Food Contact (EC10/2011, EC1935/2004, FDA) is available. The embedded metal particles offer a huge safety advantage over other plastic materials. Even very small pieces of this plastic material are detectable by metal detectors.

Up to 60% reduction in perceived noise level, depending on
the initial air pressure. At 7 bar, for example, an open pipe
would produce a noise level of 98 dBa while our air nozzle
would produce 85 dBa, a reduction of 13 dBa and a perceived
noise reduction of 60%.

For more details see here.