Final answer:
A worker should feel a steady draft entering the face of the hood. This ensures that the chemical hood is properly venting toxic fumes away from personnel and preventing them from inhaling hazardous materials. So the correct option is A.
Step-by-step explanation:
The correct statement regarding how a worker should interact with a chemical hood, which is used to protect workers using volatile hazardous materials, is A. A worker should feel a steady draft entering the face of the hood. This indicates that the hood is drawing air into it, which means that vapors from the volatile substances are being captured and removed, thereby protecting the worker from inhaling harmful chemical fumes.
Fume hoods are designed to vent toxic fumes away from the user, not towards them. This is by safety protocols designed to prevent fume inhalation, as fumes from certain chemicals or reactions can present significant health hazards. Workers should never smell or otherwise breathe in chemicals or vapors directly in the lab. In contrast to protective suits in BSL-4 labs that maintain a positive pressure to prevent air from flowing into suits, chemical hoods ensure that harmful fumes are vented out.
When working with flammable chemicals or near an open flame like a Bunsen burner, having proper ventilation is crucial to avoid ignitions caused by accumulated vapors. This underlines the importance of the draft that should be felt at the face of the hood, indicative of effective ventilation.