If you’ve every had a bad (contaminated) air fill or are concerned about the possibility, check out the Air Quality Safety Survey at
www.scubaSTARnet.com. These folks (Scuba Safety Tracking and Reporting Network) are an independent group that collect safety data and conduct surveys on diving safety concerns. They work with Divers Alert Network and the survey results get published by DAN. They also maintain an up-to-date listing of dive equipment recalls...