HI there and thanks for using the AIDS Vancouver Helpline as a source for HIV/AIDS related information.
You are correct as far as HIV dying once exposed to the air. HIV is a very weak virus and needs to be in a controlled environment in order to survive. So we can apply the same theory to your question. Once HIV is exposed to the air it dies within an extremely short time. HIV is not transferable once exposed to the air.
I trust I have addressed your concerns however, should further information be required, feel free to contact us again.