字幕列表 影片播放 列印英文字幕 Ben Franklin once said, “By failing to prepare, you are preparing to fail.” It’s vital that you prepare for each lab activity. Before you begin, determine the possible risks, wear the right PPE, and be aware of any protective measures and emergency responses that are pertinent for the chemicals that you’ll be working with. When diluting acids or bases, always add the acid or the base to the solvent, such as water...not the other way around. Pouring the solvent into an acid or base can cause a violent reaction and you may get burned. Never remove chemicals from the lab. Use a break resistant secondary container to transport chemicals between lab spaces. Chemicals must be handled safely in order to avoid skin, eye, or inhalation exposure. First, let’s talk about protecting your eyes. As we mentioned in our lesson about PPE, safety glasses with side shields offer some protection, but they won’t help you when working with a potential splash hazard. Splash goggles are more effective at protecting your eyes. Chemical splash goggles should be marked with the code Z 87.1. This code indicates compliance with American National Standards Institute. Prescription glasses don’t offer adequate eye protection. Wear safety glasses, goggles, or a full face shield over your prescription glasses. Corrosive chemicals will harm you if they splash or come into contact with your skin. A lab coat and gloves will help protect your skin to a degree. But a full-length chemical-resistant lab apron is the best choice when working with splash hazards. If you’re working with an especially corrosive chemical, use full arm-length rubber gloves instead of the typical nitrile gloves. Some chemicals in the lab can harm you without even touching you. That’s why it’s important to be aware of inhalation exposure. Never smell chemicals. Always work with toxic chemicals under a fume hood. And keep containers closed tightly if you’re not using them. If a large chemical spill occurs, evacuate, seal off the lab, and notify the authorities. Large spills can produce excessive vapors; they have to be cleaned by qualified personnel. Don’t re-enter the lab until your supervisor gives you the “all clear”. Flammable chemicals require special handling techniques. First, always know the flammability and explosive potential for each chemical you’re working with. Keep flammables away from all ignition sources, such as bunsen burners or hot plates. Store flammable chemicals in a dedicated and grounded storage cabinet. When you’re finished working in the lab, properly dispose of chemicals and waste according to federal, state, local, and institutional requirements. Use chemical-resistant plastic or metal containers for waste disposal. Solvents should NEVER be evaporated under a fume hood as a means of disposal. Check with your lab supervisor for the best way to evaporate solvents. Any materials used to clean up a chemical spill, such as paper towels, are also considered hazardous waste and must also be disposed of accordingly. Preparation is the key to handling chemicals safely in the lab. Know what you’re working with, how to handle it, and what to do in case of accidental exposure. In our next lesson, we’ll talk about a few other common lab hazards that you need to prepare for.