Question

A fume hood is to be used:

a) for conducting reactions that may result in an explosion.
b) for disposal of toxic liquids and gases.
c) to control exposure to toxic liquids and gases.
d) with the sash in a maximally open position to allow the greatest air flow.
e) in well-ventilated laboratories.

Answer 1

A fume hood is used in chemistry labs to safeguard against exposure to toxic chemicals and gases, not for the disposal of these substances directly. It is one part of a comprehensive safety strategy, which includes proper ventilation, the safe use of flammable materials, and knowledge of lab safety equipment locations. The sash should be kept low for protection and when using open flames, and extra precautions like protective suits might be necessary in high-risk conditions. a) for conducting reactions that may result in an explosion.

Step-by-step explanation:

A fume hood is an essential safety device in a chemistry laboratory, which is mainly used to control the exposure to toxic chemicals and gases. While a fume hood can technically contain some reactions that might result in an explosion, its primary purpose is not for disposing of toxic liquids and gases directly but rather to protect the user from breathing in harmful fumes (c). When using a fume hood, the sash should be positioned as low as possible to ensure maximum protection, not maximally open, as this can compromise safety and the hood's effectiveness (d). Fume hoods also contribute to laboratory safety by containing potential fires away from users, as they often deal with flammable substances. Indeed, a fume hood should be used in a well-ventilated laboratory (e), as it's vital to disperse any harmful gases that may escape when the fume hood is not being used.

It is equally important to practice general laboratory safety rules such as ensuring proper ventilation, being alert to chemical handling, and observing open flame precautions, such as keeping flammables away from the Bunsen burner and securing loose clothing and hair. Knowing where safety equipment, like fire extinguishers and eyewash stations, are located is also crucial (2). When in doubt about conducting particularly hazardous experiments or handling dangerous substances, using additional protective equipment like protective suits with their own air supply in high-risk environments ensures a higher level of user safety (Figure 13.2).

Answer 2

A fume hood is primarily used to control exposure to toxic liquids and gases (option c) in a laboratory setting. The sash should be correctly positioned for effective containment, and the lab must be well-ventilated for safety and optimal hood performance. Option c is the correct use of a fume hood.

Step-by-step explanation:

A fume hood is an essential piece of safety equipment in any laboratory. Its main purpose is to control exposure to toxic liquids and gases during experiments. This is achieved by providing a localized ventilation area where harmful vapors are contained and then expelled, which minimizes the risk of inhalation by laboratory personnel. While it is true that a fume hood can be used for conducting reactions that might explode, its primary function is not for disposal of materials but protection from exposure. It is important that the fume hood sash is positioned at a level recommended by safety protocols, typically indicated by marked levels on the hood itself, to ensure effective containment of fumes and protection of users.

As per laboratory guidelines, a fume hood should always be operated with the sash at the correct level, not in a maximally open position, as this ensures that users are shielded from potential splashes or reactions. Additionally, all procedures involving flammable substances should be carried out with due care. Flammable chemicals should never be exposed to an open flame without proper precautions. Furthermore, it's crucial to ensure that the laboratory is well-ventilated, not only for general safety but also to enhance the performance of the fume hood.

Therefore, to conclude, while all statements related to safety have their merit, the correct option for the usage of a fume hood is to control exposure to toxic liquids and gases, which makes option c the appropriate choice. It's crucial when using the fume hood to follow all given instructions and safety protocols, which include proper sash positioning and ensuring that the lab is well-ventilated.