Need help identifying old gas mask sterling pin

[KumaKuma]

Recently acquired this odd gas mask enameled sterling silver pin with an old style balled end hinge pin safety pin catch. The pin measures about 1 inch across any parallel side. The gas mask has a "US" at the top of it thus eliminating it being foreign. With the old style fastening pin and catch I'm guessing it pre-dates WW2. Y'all always have been helpful to me in the past and I'm hoping I've posted this in the proper forum to receive yet more of your expert opinions on just what I have here.

 

 

[1SG_1st_Cav]

Chemical Corps

[atb]

Chemical Corps Replacement Training Center, a Distinctive Unit Insignia from WW2.

[KumaKuma]

1SG_1st_Cav & atb,

 

Thanks fellows, you hit it right on the nose. I was pondering it being associated with the chemical corp but numerous google searches didn't turn up one. Found it fully ID'd at http://www.nbc-links.com/dui-other.html.

 

Much appreciation for taking the time to help me out!

[KumaKuma]

the previous link doesn't seem to work but lots of great DUI info, including the one just ID'd for me at nbc-links.com