Well, you need more info. What IRC client are you using? What server/network are you using? Is it a chat request or a DCC file transfer request?

In general, you don't accept anything that you're unaware of: e-mails, chat requests, instant messages, etc. It sounds like your IRC client is setup to ask for approval before granting requests...that's a good thing. You don't need to surf 'those' sites in order to pick up a worm or virus. Alot of worms are self-propagating...basically, once a friend gets it, the worm sends itself out to whoever your friend might have in their address book or it may send itself to random IPs.

If you can figure out what network that channel is on, you can probably just pop in and lurk the room.