How to tell a colleague that their breath stinks?

Ok. So, let call this colleague "Simon". Simon's breath stinks. Everyday. No days off. The minute Simon says "Good morning", until the minute I wait for everyday "See you tomorrow". How is it possible? I mean, it is not like Simon's breath smells bad because of coffee or only in the morning. No. Simon's breath smells like public toilets. And not those nice public toilets either. I am talking about a hole in the floor kinda toilet. Not good! How do I tell Simon, nicely, that his breath is offending me. And, that, the reason I use a fan at work, is, well, to blow his breath the other way. But, I think I need to invest in a jet fan, since my £9.99 fan just isn't powerful enough. Any advice? Ples help!