Toner is primarily plastic (usually acrylic or polyester resin), colourants (purified carbon black, iron oxide and pigments), and a smaller amount of special additives (for electrical charge, powder flow control and fusing properties).
Each toner is precisely formulated, specified and controlled to ensure the toner performance characteristics match the specific laser printer, ensuring the highest quality print.
All toners are not alike!
You must match the toner for your printer, you cannot use another printer (or copier, or fax!) toner to refill the cartridge in your printer!