I don’t think toner has changed much in years (it’s still mostly styrene and carbon black), but there are more inkjet copiers out there these days. Maybe he’s using one of those…
The chemical composition of toner has changed drastically over the past ten years. The newest HP laser printers are actually using polyester toner.
However, if he’s using a specific Xerox machine, the toner he buys for it today should be the same composition as it was the day he bought the machine. Specific chemical compositions of toner are meant for specific machines. Different toners vary by positive or negative charge, particle size and shape, iron content (for magnetism) and actual ingredients to chemically make up the toner.
Until we upgraded our Xerox printer at my work, we had one (still Xerox) that used toner that looked like weird-shaped crayons. You couldn’t write on the copies with anything other than a sharpie pen, because the wax wouldn’t let ballpoint pen ink stick.
That was part of the Tektronix (bought out by Xerox pretty quickly) Phaser line of printers. They didn’t work the way a laser works…it was more like an inkjet but there wasn’t any liquid ink. The machine actually heated the “crayon” and somehow directed it onto the paper. The print quality came out extremely sharp, but God help you if one of the heads got clogged.