Safety in the Chemistry Laboratory
1. Maintain a wholesome, businesslike attitude at all times; for the safety of all, unauthorized experiments are prohibited. Any student exhibiting such behavior will be asked to cease lab activity and to leave the lab area. A zero will be given for that lab.
2. Wear protective goggles or a face shield and apron at all times. If you get a chemical in your eyes, walk immediately to the eyewash station and flush the chemicals from the eyes with water (and continue for 15 min) as instructed. Call your instructor while doing this.
3. Never work alone in the laboratory.
4. On lab days, wear dress appropriately.
- Nylon and polyester fabrics burn more easily, so cotton fabrics are a better choice for lab days.
- Loose fitting garments or long sleeves should be out of the way.
- Long pants are preferable but not required.
- Closed shoes should be worn. No sandals.
- Please remove jewelry such as rings, dangling necklaces, chains, watches, medallions and bracelets.
- Long hair should be tied back or covered.
5. Be prepared to work when you enter the laboratory.
- Familiarize yourself with lab procedures before coming to lab. Read the entire lab beforehand and work through any pre-lab exercises.
- For chemistry and Pre-AP Chemistry ONLY lab notebook may be brought to lab.
- Lab procedures will be written in lab notebooks BEFORE coming to lab.
- College Chemistry may bring lab manual to lab but report will be written in notebook.
6. Follow all directions, both written and oral.
7. Use apparatus described in lab manual or by instructor. Use prescribed instrument for handling chemicals. Any activity involving poisonous vapors or gases should be conducted in a fume hood. If you are not sure, ask your instructor.
8. Read and DOUBLE CHECK LABELS on reagent bottles before removing any reagent. Take only amount necessary and RECAP REAGENTS. Avoid using excessive amounts of reagents.
9. Walk with care in the lab.
- Avoid hurrying and bumping into others in the lab.
- Glass tubing should be carried vertically to minimize the likelihood of breakage and to avoid injury.
- If something is spilled, tell the teacher and let her decide how to clean it up immediately.
10. Food, beverages, chewing gum, cosmetics, and smoking are not allowed in the lab.
- NEVER taste a chemical or solution in the lab.
- NEVER eat or drink anything made in lab.
11. Avoid touching chemicals; use instruments provided. If corrosive liquids touch the skin, flood with water, then consult instructor. BE CAREFUL NOT TO TOUCH YOUR FACE, MOUTH, EYES, OR NOSE WHILE IN LAB. DO NOT CHEW ON A PEN OR PENCIL THAT HAS BEEN IN THE LAB.
12. Use a striker to light a Bunsen burner.
13. Be careful when using any heating device such as a burner, a hotplate, an oven, or a heating mantle. Exercise extreme caution when using a gas burner. Keep head and clothing away from flame.
- Never heat anything without being instructed to do so.
- Never leave a reaction (whether heated or not) unattended. If you must leave your station momentarily with a reaction going, ask your neighbor to watch it.
- Do not heat heavy glassware such as volumetric flasks, graduated cylinders or bottles; they break easily.
- Test tubes may break if heated above the liquid level because cooler liquid may splash over hot glass.
- Only crucibles may be heated red hot.
- Avoid heating any apparatus too suddenly; apply flame intermittently at first.
- Do not bring any substance into contact with a flame unless instructed to do so.
- Do not place hot glassware directly on the workbench. Always use an insulating pad of some sort.
- Beware of hot glass. It appears cool long before it is. Test for excessive heat by placing back of hand near the object.
- Always turn the burner off when not in use.
- Check burner hose periodically for wear.
14. If electrical equipment must be used, please use the proper type of outlet and use equipment away from water.
- Do not use equipment with frayed or twisted wires.
- Be sure hands are dry before using electrical equipment.
- Before plugging an electrical cord into a socket, be sure equipment is turned off.
- Do not let electrical cords dangle from workstations.
15. Know the fire safety devices and practices for the lab in which you will be working. Note location the fire safety devices and information.
- Familiarize yourself with chemical and physical properties as they relate to safe use and storage of chemicals in the laboratory. Check the MSDS to determine this information.
- Combustible materials (alcohol, lighter fluid, ether) must be kept away from open flames.
- In the event of fire, smother flames with sand, cloth towels or fire blankets. If your clothes catch fire, walk to the safety shower, stand under it, and turn it on.
- Know the kinds of fire extinguishers and the kind of fire to which each is suited. Know the location of fire extinguishers in the lab in which you will be working.
- Know how fires start.
- Know all fire safety routes and fire drill procedures for the classroom/laboratory in which you will be working.
16. Clean up spilled chemicals properly. Call the teacher’s attention to the spill and let her decide on the proper clean-up method.
- Solid spills are generally brushed into the solid waste container. Always check the TLV before sweeping.
- Liquid spills are cleaned up according to their identity.
Acid on clothing - use very dilute ammonium hydroxide or bicarbonate solution. Bases on clothing - use dilute acetic acid followed by dilute ammonium hydroxide. Acid on the workbench - use solid sodium bicarbonate followed by water.
Base on the workbench – use solid citric acid followed by water.
- Chemicals on the skin should be flushed with water and then washed away with soap and water.
17. ALL accidents should be reported to the instructor.
18. NEVER take chemicals out of the lab.
19. Maintain an orderly, clean lab desk. Wash glassware when you are finished. Wash and wipe workbench at the end of lab period. WASH YOUR HANDS THOROUGHLY AFTER LAB.
LABORATORY PRACTICES
20. Never point a test tube at your neighbor or yourself when heating a substance. A suddenly formed bubble of vapor may eject the contents violently.
21. Do not hold you face directly over a container when noting an odor. Instead, fan a little vapor toward your nostrils by sweeping your hand over the top of the open container.
22. Glass tubing (including thistle tubes, thermometers, etc.) must be wrapped in toweling when being inserted or removed from rubber stoppers. First lubricate the tube and stopper with a small amount of glycerin. Then, holding the tubing with (toweling in place) near the end to be inserted, insert with a twisting motion. Never force the tubing with your hand or any other flat surface.
23. When diluting concentrated acids, pour acid into water. Never reverse the procedure. So much heat is liberated upon mixing that splattering may occur.
24. Dispose of waste materials as per instruction. Never throw matches, paper, splints, or other insoluble material into sink. Wash liquids down the sink with lots of water, unless instructed otherwise.
25. DO NOT RETURN unused reagent to stock bottles. This contaminates the stock.
26. When transferring reagents from one container to another, hold containers away from body. Be sure to LABEL new containers as to contents.
27. LEAVE REAGENT BOTTLES IN THEIR DESIGNATED AREAS. Bring containers to this area to transfer chemicals and carry container, not reagent bottle, back to work station.
28. DO NOT LAY A STOPPER (or dropper) down when it is removed from a bottle. Impurities may be picked up causing contamination to occur when stopper (or dropper) is replaced.
29. Do not insert your own dropper or other instrument into reagent bottle. Instead pour a little reagent into your container or use instrument provided.
30. DO NOT WEIGH SUBSTANCES DIRECTLY on balance pan. Use filter paper or other means to do so as per instruction.
31. Never handle broken glass with your bare hands. Use a brush and a dustpan to clean up broken glass.
32. Be able to identify all equipment and glassware. Know what the use of each is.
ADDITIONAL RULES
33. You are responsible for all breakage or losses of equipment checked out to you. Breakage fees are due as soon as possible. If fees are not paid, your name will be turned over to the assistant principal.
34. Follow ALL precautions and rules ALL the time whether they are given by the instructor or by the lab manual. They are for your safety.
35. Know how to read and use MSDS. Note the use of acronyms: TLV, LD, and others.
36. Know the color codes for flammability, contact hazard, health hazard, and reactivity.
37. REMEMBER there are four routes of entry into the body for chemicals.
- By inhalation.
- By ingestion.
- Through eyes.
- Through cuts or breaks in the skin.
LAB REPORT PROCEDURES
38. Each lab will be written up unless advised otherwise.
39. A lab report will be done for each experiment. Use blue or black ink only. It is very important that you do your own work on reports. If reports are copied, then grade will be divided equally among all papers that are alike.
40. Write conclusions using only third person pronouns.
41. Be neat and orderly in presentation.
42. Be complete and concise. Use complete sentences.