Airbnb has published a blog post that all hosts will need to confirm by the close of 2014 that they have installed smoke and carbon monoxide detectors. But this does not imply that you will need to go to the market to get these because Airbnb will provide these detectors to each and every US based host with an active listing on Airbnb. However, hosts will need to log a request on their website because these will not be emailed automatically.
Airbnb is also giving away 10,000 first aid kits (similar to 85 piece) to hosts on a first come first served basis. Another effort at improving safety is display of emergency safety card with information about emergency numbers, fire exits and other similar important information. These cards will also be provided free of charge to hosts similar to smoke and carbon monoxide detectors.