Final answer:
When handling volatile substances or poisonous vapors, always work in an open and well-ventilated area to ensure safety and reduce the risk of inhaling toxic fumes.
Step-by-step explanation:
When working with volatile substances or poisonous vapors, it is always best to work in an area that is A. Open and well-ventilated. Good ventilation is essential in reducing the risk of inhaling toxic fumes, as it helps disperse them and reduce their concentration in the air. It is also important to follow lab safety rules such as: using a fume hood, never smelling or tasting chemicals, working in a well-ventilated room, properly handling flammable chemicals away from flames or sparks, and ensuring proper cleanup after each experiment.