It is kind of odd, are you 100% sure it is osage? I was scraping on an osage yesterday and kept thinking I was smelling an electrical fire. I would get up search my property and the smell would come back, as soon as I started scraping it would come back, I finaly realized it was my scraper against the osage doing it. My buddy could smell it 6ft away. Very strong synthetic plastic or chemical smell. First time I had experienced this also.