SWISS AF CBW TESTED EQUIPMENT
In the late 80's early 90's, Swiss AF evaluated a number of Chemical/ Biological Warfare (CBW) pilot protective systems.
The main evaluation criteria the chem/bio protection effectiveness and the compatibility/ integration with Swiss AF aircrew and aircraft operations.
Because of the test results, most likely also for technical, logistical and financial reasons, none of the evaluated systems was put into service.
Below a list and links to some of the equipment tested.
Although not included in the tests, the MBU-13/P full-face mask - CRU-80 /P filter combo was considered as an "off the shelf" option in order to have comparative parameters.
More on MBU-13/ CRU-80 HERE
SPH-4 helmet;
Tested on Alouette III;
Since on the SPH-4 the microphone is installed on the left, the mask was modified by moving the filter threaded housing, which was standard located on that side of the mask, to the right.

Huber+Suhner (then standard Swiss Army "Schutzmaske 90") protective mask.
SPH-4 helmet;
During evaluations was fitted with microphone and external comm unit (Gentex 6011-5);
Tested simultaneously with CBW protective clothing on Alouette III and Pilatus PC-6 Porter.

SPH-4 helmet;
Tested simultaneously with CBW protective clothing on Alouette III and Pilatus PC-6 Porter.

SPH-4 / HGU-55 both modified in order to be compatible with the GB mask suspension system;
Tested simultaneously with CBW protective clothing on helicopters ( Alouette III and Puma);
with standard/ protective pilot equipment on jet (F-5 E Tiger/ Mirage III)
and Pilatus PC-6 Porter.

HGU-55 helmet;
With standard/ protective pilot equipment on F-5 E Tiger and Mirage III.
More on PIHM/ TAERS HERE