3. Things Every Chemistry Student Should Know
This section contains information that all chemistry students need to know, whether they are beginning lab work for the first time or working on a senior thesis. It is required reading for all students. If you have questions about any of this material, ask your instructor for more information.
3.1 Basic Building and Safety Info
Before you begin lab work, visit the chemistry building and your lab. Familiarize yourself with the following:
Also, before you begin lab work, obtain the following safety information:
3.2 Self-Protection in the Lab
The first principle of lab safety is to protect yourself from potential hazards. Some of these hazards exist apart from any action by the chemist. For example:
The best way to protect yourself from these hazards is, first, to recognize that they exist (and, unless you know the lab extremely well, you should assume they exist in every lab), and second, to use protective clothing and equipment that will minimize your exposure to unpleasant compounds and flying shards of glass.
The first step in protecting yourself from accidents is to do everything you can to prevent them from occurring in the first place. This means avoiding behavior that might cause an accident. It also means using appropriate equipment in appropriate ways, and means paying attention to the properties of the substances with which you work. Always ask if the material is, for example, flammable, corrosive (base or acid), reactive, an oxidizer, a mutagen, a poison, a biohazard, water reactive, or radioactive.
Once an accident occurs, you must hope that your protective clothing and equipment will work as advertised. You also need to know and follow emergency procedures that will limit injuries and damage (these are covered in the next section).
One especially common, and potentially tragic, student mistake is to assume that “self-protection” means protecting yourself from your own experiments only. This approach is flawed because it fails to recognize dangers created by other students. If 20 students are working in a lab simultaneously, the potential for danger is increased 20 times (and maybe more). You should view all laboratories as potentially hazardous workplaces and protect yourself accordingly. This rule applies even when no one else is present and/or you are not performing an experiment.
Eye protection - Goggles: Goggles, or other approved protective eyewear, must be worn at all times. Normal eyeglasses do not count as safety goggles. If you do not like the goggles provided, you can buy your own from Randie in the chemistry stockroom.
Skin protection - Shoes: Closed-toe shoes that are fastened to your feet must be worn at all times. Sandals, flip-flops, and clogs are not allowed (these shoes provide poor protection and they may slide off your foot). If you forget to wear suitable shoes, your lab instructor may allow you to wear “Booties of Shame” (obtain from Randie in the chemistry stockroom).
Skin protection - Gloves: Your instructor may require you to wear gloves when you handle dangerous compounds or dangerously hot or cold objects (consult the manual for your lab course). Otherwise, gloves are not required. (However, consider this: lab surfaces are often coated with residues from chemical spills, so if you do not wear gloves, be extra careful where you set your hands.)
It is important to select gloves carefully and inspect them. Different glove materials offer different types of chemical and temperature protection. Also, older gloves often contain small holes.
It is also important not to contaminate yourself, doorknobs, and other surfaces outside the lab. Always remove your gloves and wash your hands before leaving the lab.
Skin protection & accident prevention - Clothes and Hair: Safe, protective clothing is required. Wear inexpensive clothing that will cover everything from the tops of your shoulders to your knees. A short-sleeved t-shirt is acceptable, but a tank top is not (bare shoulders). Shirts that leave your mid-section exposed are unacceptable. Since spilled chemicals and broken glass naturally seek their lowest level, we strongly recommend that you cover your legs by wearing long pants.
If your instructor decides that your clothing is unsafe, you will be asked to put on a lab coat or apron, or you will be sent home for more appropriate clothing. The instructor’s opinion is final, so plan ahead on lab days (especially during the warm days of September and April) and wear or bring safe clothing to school.
Internal organ protection - Food and Drink: Do not bring food or drink into any lab. Do not store food in a lab or use lab equipment to prepare food. Never eat or taste a laboratory reagent, or even a compound that you have made (many seemingly safe compounds contain dangerous impurities).
General protection - Fume Hoods: Fume hoods prevent toxic and flammable vapors from entering the lab. In addition, their windows (or “sashes”) block splashes and flying debris. Any experiment that involves a volatile toxic compound, a flammable compound, or a potentially exothermic reaction, or that requires heating, should be performed in a fume hood with the window positioned as low as possible.
3.3 Dealing with Accidents
Accidents are listed by their frequency, most frequent first. The accidents near the end of the list are relatively rare, but it is still important to know how to deal with them, so please review this information from time to time throughout the semester.
Acid Spill: First, rinse off any acid that spills on you (see section 2.4). Second, deal with any acid that spills on the floor or other lab surface by neutralizing the spill with baking soda and notifying your lab instructor. Pour baking soda directly on the spill. Once the bubbling and fizzing stop, wipe up the spill with a sponge (wear gloves!) and wash all of the material down the sink. If you need to leave the immediate area of the spill to get baking soda, make sure someone stays with the spill to keep people from walking through it or accidentally spreading it around.
Base Spill: First, rinse off any base that spills on you (see section 2.4). Second, deal with any base that spills on the floor or other lab surface, neutralizing the spill with a dilute acid (such as vinegar or 3M HCl) and notifying your lab instructor or TA. Periodically test the spill’s pH with pH paper (a pH between 5-9 can be considered “neutral”). Once the spill has been neutralized, wipe up the spill with a sponge (wear gloves!) and wash all of the material down the sink. As with an acid spill, if you need to leave the spill zone, make sure someone stays with the spill to keep people away from it.
Other chemical spills: As with acid and base spills, first deal with material that lands on you (see section 2.4). Then, notify your instructor to get information on how to clean up the spilled material. As with acid and base spills, if you need to leave the spill zone, make sure someone stays with the spill to keep people away from it.
Mercury Spill (example: broken thermometer): This is one spill that you cannot clean up yourself. Mercury is a toxic liquid. Mercury spills generate an enormous number of tiny droplets that are easily dispersed, and special vacuum equipment must be used to clean up these spills.
Do not touch or attempt to wipe up spilled mercury. Make sure someone stays near (but not in) the spill zone to keep people away. Notify your lab instructor immediately and notify the stockroom manager (Randie). Depending on the circumstances, they may clean up the spill for you, or they will provide you with the special clean-up equipment that is needed.
Injury (example: cut, burn, etc.): Begin first-aid treatment and immediately tell your lab instructor (see section 2.4).
Fires: The appropriate response to a fire depends on the size, type, and location of the fire (see section 2.4).
3.4 Waste Disposal
All compounds left over after an experiment must be disposed of in a safe and legal manner in order to protect the “downstream” community (other lab workers, housekeeping staff, EHS staff, wildlife, and so on). Before you begin any experiment, you should identify the type of waste compounds that will be generated and write appropriate disposal procedures for each compound in your lab notebook.
Acid or Base Waste: Inorganic acids and bases should be “neutralized” to bring their pH between 5-9 (check with pH paper). As with acid and base spills, neutralize acid with baking soda, and base with dilute acid. If the neutralized material does not contain one of the metals listed in the next section, rinse the material down the drain. Otherwise, treat the material as a “listed metal waste.”
Listed Metal Wastes: Solutions containing the following metals cannot go down the sink under any circumstances: arsenic (As), barium (Ba), cadmium (Cd), chromium (Cr), copper (Cu), lead (Pb), mercury (Hg), molybdenum (Mo), nickel (Ni), selenium (Se), silver (Ag), and zinc (Zn). Special waste containers will be placed in the lab to collect each type of metal for subsequent disposal by environmental health and safety personnel.
Glass Disposal: In every lab there is a roughly waist-high cardboard box that says Glass Waste. All broken glassware, including disposable pipettes, should go in this glass waste box.
3.5 What Should You Read Next?
Chem 101/102 students can stop reading this manual at this point and may sign the safety statement. After doing that, students should consult their lab course manual for additional safety instructions. We also encourage students to quickly scan Chapters 6 and 7 in this manual just to get acquainted with the rest of this manual’s contents.
Students in Chem 201/202/212 must also read Chapter 4.
All other chemistry students must also read Chapter 5 (they may skip Chapter 4).