In order for no one to be harmed when working in lab the following rules apply:

Transcription

1 Lab safety In order for no one to be harmed when working in lab the following rules apply: 1. When working in the lab you must always use protective clothing. Protective clothing consists of a lab coat or a lab apron, safety goggles and gloves. If you normally use contact lenses you should switch to glasses when working in the lab. 2. Do not eat or drink when working in the lab. No food, fruit, candy, snuff or anything else that you put in your mouth is allowed. If you need a snack, contact your lab supervisor and ask if it is OK for you to leave the lab. 3. You must not, under no circumstances, taste any chemicals. Chemicals are chemicals and food is food, and these two are never combined in the lab! In the same way, no beakers (or any other lab material) should be used for drinking. Do not store chemicals in containers you usually store food/drinks in, since you might mix them up later. 4. No running when working in lab. Of course you are allowed to have fun, but remind yourself that this is a working place for you and the other students. 5. You must not come up with your own experiments. Come to the lab well prepared, that is, you should have read all the instructions in advance and understood them. Follow these instructions to the letter. If you have any questions regarding the instructions, check with your lab supervisor. 6. Wipe up any spills on the workbench and in the hood. After you have finished your work in the lab, the workbench and the hood should be clean. 7. Report immediately to your lab supervisor if the equipment you are using does not work. Beaker Made out of borosilicate glass, tolerates heating on a hot plate. The glass should be labeled with Boro, Simax, Duran, or Pyrex. Also available are soda lime glasses, which are softer and less tolerant to heating. Available in volumes ranging from 25 ml to 2 l. 1

2 Erlenmayer Available in the same glass qualities as the beakers and in volumes ranging from 25 ml to 2 l. The lines indicating the volume are quite coarse and can result in errors by up to 10%. Funnels out of plastics, glass or porcelain. The most common funnels used in the lab are, from left to right: the powder funnel, with an opening at the foot; the filter funnel with a narrower opening at the foot; and the Büchner funnel. The Büchner funnel has a plate where you can put the filter paper, and is usually used to wash the final product after a chemical synthesis. The funnels can be made Graduated cylinder Graduated or volumetric cylinders (leftmost) are used for measuring volumes of water or any other liquid chemical. The grading is fairly accurate, but for better accuracy the flask to the right should be used. Flask The flask (rightmost) does not have any grading except for the line showing the volume which it is calibrated for. The flask is used when you are making a solution for which you need to and you want to be sure about the number of grams of a certain chemical you have per liter solution. Both the graduated cylinders and the volumetric flasks are made of borosilicate glass and can withstand heat. Care should be taken when heating them calibrated volumetric material, though, since volume is dependent on temperature (at higher temperatures, the volume increases). 2

3 Pipettes Pipettes are used to extract volumes from solutions or liquid chemicals. The pipette to the left is a volumetric pipette. It has no grading except for a line indicating the volume it is calibrated for. It is often used along with a flask when making solutions with well known contents. The second pipette to the left is a graduated pipette which is graded and, as the graduated cylinder above, is fairly accurate. The third pipette is a dropper, also called Pasteur pipette. It is practical when you need to add small amounts of a liquid. The fourth pipette is a burette, which is used for different chemical analysis of content. The grading is fairly accurate, better than the graduated pipette. The tap makes it easy to control addition of chemicals. Hazard symbols Below you find the most common hazard symbols you can see on chemical containers and vessels containing solutions. If a container lacks hazard marking it does not mean that one can handle it in anyway. All chemicals must be handled with respect. Even if a chemical is not directly hazardous there can still be some nasty consequences if it is handled in an improper way. Highly toxic This marking consists of a black skull on an orange background inside a black frame. The symbol means that the chemical or solution is toxic or highly toxic and/or carcinogenic, mutagenic or can have long term and irreversible effects on reproductive organs. 3

4 Highly flammable This marking consists of a black flame on an orange background inside a black frame. The symbol means that the chemical can easily be ignited both by an open flame or by hot surfaces. Corrosive This marking consists of two black corrosive symbols on an orange background inside a black frame. The symbol means that the chemical or solution causes burns to the skin, eyes and other body tissue. The chemical can also act corrosively on different physical materials, and must therefore be stored in special containers. Harmful/Irritant The marking consists of a black cross on an orange background inside a black frame. The symbol means that the chemical can cause harm or discomfort on skin, eyes, mucosa or internal organs. Oxidizing The marking consists of a flame burning on a black ring on an orange background inside a black frame. The symbol means that the chemical is an oxidizing agent, which means that it can react violently and it can contribute to starting a fire. Explosive The marking consists of an exploding bowl on an orange background inside a black frame. The symbol means that the chemical can explode if handled improperly. 4

5 Harmful to the environment down the sink! The marking consists of a black dead fish and a black defoliated tree on an orange background inside a black frame. The symbol means that the chemical causes long term harm on the environment and must therefore be handled in such a way so that it never comes in contact with the environment. The chemical must not be poured If you want to get more thorough information about a certain chemical you can look in its material safety data sheet (MSDS). Each chemical substance has one. In the MSDS, physical properties, risk information and instructions on how the chemical should be handled can be found. 5