Some years back I tried using tung Oil & while I liked it as a finish every time I used it my hands broke out with a rash, so I discontinued it use. In his book "Gunsmithing" Roy Dunlap mentioned this caveat of using tung oil stating a good number of WWII GI's developed a rash from handling Japanese rifles they had picked up off the battlefield. It5 would seem that most are unaffected by it but some are.

Miller/TN
I Didn't Say Everything I Said, Yogi Berra