The hazard
Labs use many different chemicals, often in small amounts, and that makes it easy to get comfortable. A splash, a vapor you breathe in or a mislabeled bottle can cause burns, poisoning or a fire. Good habits and working equipment are what keep a small mistake from turning into an injury.
The action
The chemical hygiene plan must require that fume hoods and other protective equipment work properly, with specific steps to make sure they do. Work with volatile or toxic chemicals inside the hood, keep the sash as low as you can, and do not block the airflow with clutter. If a hood alarm sounds or the hood does not seem to pull air, stop and report it. (29 CFR 1910.1450(e)(3)(iii))
ASK THE CREW
Which of our chemicals need the fume hood, and how do we know it is working?
From the talk: Laboratory safety. Read it in full, free, with the questions and the sign-in sheet.