This is a tough decision and probably depends on the type of work you do and the people around you. As a rule I don't think it's a good idea unless its away from work or at lunch and that may depend on the people you are with. So poses a few questions then:
Do you email the people you work with while at work about your business?
Is it better to email from home on your time?
It is more acceptable to present only your product to them at work?
Do you directly ask them for a referral for your XYZ product without directly asking them if they would be interested?