How do I know if I should use a grease with or without EP (extreme pressure) additives?

EP (extreme pressure) additives are used for high load applications.
Indeed, their uses can allow the reduction of the fatigue of the bearings. IGOL advises you to use greases with EP additives when applications have very high axial or radial loads.

IGOL offers you, for example, the possibility of getting a grease oil from chain saw chains containing anti-wear and antioxidant additives.