Don't confuse particle board with OSB. Particle board is essentially ground up wood dust, glued together. OSB is much larger wood chips glued together. A quality OSB can be used as a subfloor for many things. Particle board is useless as a subfloor as it has no strength and will fall apart. It also swells up like a sponge if it gets wet. Less than quality OSB can swell up and delaminate, too. If yours is OSB, and it is in good condition, you are probably okay. If it is particle board, trash it, replace it with some good plywood, and go for it.
It makes a difference exactly what you are planning to install over it.