I received a request for one of my books and there is a member condition that states "no books from a smoking environment". I bought this book used and don't know if there was a smoking environment, so what do I do? I wanted to PM the requestor, but there is no button available to PM the person. Do I mark it that it can be sent and then a PM button will show or what? Thanks!! 

If you mark that you can send the book yes you can then PM the person.  The problem is if they don't want your book and you then hit to cancel the transaction you have just lost your place in line.  You will have to repost your book to your shelf and will be at the end of the line.  I once received the same type of condition and I said that it didn't meet requester conditions.  Then in the little box I put that I had received it as a used book and couldn't say what type of envrionment it had been in.

I'd take a look at the book and also smell it.  If it doesn't smell smoky, and you aren't a smoker, and no one smokes in your home, you are good to go.

Doesn't a smoking environment cause premature yellowing of the pages? I agree with Lisa...take a whiff...if it smells ok and the pages aren't dark yellow, I'd send it.  The smell test will give it away quickly. Most smokers I know (including their possessions) stink like burning tires at a junk yard fire

ditto to Lisa, they usually mean currently in a non-smoking home because they know these are all used books and we have no control over the past.  If it smells smoky, say you can't honor their RC.  but if it doesn't, then send it on.

but if you don't want to take the chance, click that you can't meet and it will move the book to the next person

I agree with everyone...I have a similar condition on books I receive and I went back and changed this after I heard a similar discussion...I added currently in a smoking environment.  I think that is actually what most people mean because we have no control or knowledge of what went on before we actually received the book.

If you don't smoke and can't smell it, send the book. If someone wants a book that has never been exposed to smoke, I think they would word the condition much more strictly.

I find it funny that so many people run into this RC when it is the wording that R&R uses in the help section as what NOT to use because it is too vague.

The two I get a lot are "no books that have been in a smoking environment" and "no books currently in a smoking environment."

If I bought the book used, I won't send it to people with the first condition, regardless of whether I can smell it or not.  There are plenty of substances that are too faint to be smelled, but are still strong enough to cause an allergic reaction.