2850 Hydrides, nitrides, azides, silicides and borides, whether or not chemically defined (excl. compounds which are also carbides of heading 2849, and inorganic or organic compounds of mercury whether or not chemically defined)

2850 (01/1988-..) Hydrides, nitrides, azides, silicides and borides, whether or not chemically defined (excl. compounds which are also carbides of heading 2849, and inorganic or organic compounds of mercury whether or not chemically defined) 28500010 (01/1988-12/1997) Hydrides, whether or not chemically defined (excl. compounds which are also carbides of heading 2849) 28500020 (01/1998-12/2011) Hydrides and nitrides, whether or not chemically defined (excl. compounds which are also carbides of heading 2849) 28500030 (01/1988-12/1997) Nitrides, whether or not chemically defined (excl. compounds which are also carbides of heading 2849) 28500050 (01/1988-12/2008) Azides, whether or not chemically defined (excl. compounds which are also carbides of heading 2849) 28500060 (01/2009-12/2011) Azides, silicides, whether or not chemically defined (excl. compounds which are also carbides of heading 2849) 28500070 (01/1988-12/2008) Silicides, whether or not chemically defined (excl. compounds which are also carbides of heading 2849) 28500090 (01/1988-12/2011) Borides, whether or not chemically defined (excl. compounds which are also carbides of heading 2849)