Milo is right of course (Respectful bow) but the fact remains that I only once replaced my HP laser carts with OEM ones; the rest of the time (five years and 60,000 pages) I used compatibles - always from the same company based in Channel Isles - and never had real problems with toner spillage. (ok, a few bits of dust, occasionally, but not enought to do damage.)
I've obviously been lucky then, but I will still buy compatibles for my new printer.