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Laboratory Safety

Anyone taking a chemistry lab course at Wellesley College must complete the "Chemistry Safety Quiz" in the "Tests & Quizzes" section of the CHEM-Safety Quiz Sakai Site.

Please "join" the  Sakai site called, "CHEM-Safety Quiz."  (You join a Sakai site by going to your "My Workspace" tab and selecting the "Membership" tab.  In this tab, you can click on "joinable sites" and a list of open Sakai sites should appear.  Selecting "CHEM-Safety Quiz" will put this Sakai site as a tab on your account.)

Plan to take the Chemistry Safety Quiz AFTER your first lab meeting.

You should also review the Wellesley College Laboratory Safety Manual

Safety Equipment
You are responsible for knowing the location and use of safety equipment and for understanding the material in Mohrig, Technique 1: Safety.


Most organic compounds are flammable! Remember that the only non-flammable liquids you will encounter in organic lab are water, methylene chloride, chloroform and aqueous solutions. Use extreme caution with burners and hot plates at all times.

Waste Disposal

Wastes are divided into four main categories:

  • NON-FLAMMABLE - usually organic compounds that contain halogens. Examples: methylene chloride, bromobutane.
  • FLAMMABLE - usually organic compounds that do not contain halogens. Examples: acetone, ethyl acetate, ethanol, methanol.
  • AQUEOUS: Dilute aqueous solutions with pH no lower than 5.5 and no higher than 10.5 may be poured down the drain in the hood sink. Use large amounts of water to flush aqueous solutions.
  • SPECIAL DISPOSAL - organic or inorganic compounds that require special containers or disposal.

Clearly marked waste containers are available in the solvent hood in each organic lab. If you are in doubt about waste-disposal, re-read your manual and/or ask your Instructor for help. The above categories of waste do not include every possible chemical (for example, some reagents react violently with water or other chemicals) so always come prepared for lab and be attentive to specific instructions given by your instructors or the lab manual for 'special waste containers.'

Saving Products

In lab, you will often make some interesting products. You may save them for future procedures; however, when you leave something in your tote be sure to LABEL it. When you have finished with the product, your instructor will advise you of correct disposal procedures.


Avoid skin contact with chemicals; always wear practical clothing to lab. Disposable lab coats are required; one will be supplied to you at the beginning of the semester, and a storage area will be set aside for your lab coat. It is your responsibility to keep your lab coat for the duration of the semester. Approved safety glasses must be worn in the laboratory and the instrument area at all times.

Lab Safety and Gloves
(written by Thea Sittler '03)
Working with chemicals in the laboratory can expose you to various toxins. While many of the chemicals are not highly toxic, especially in the quantities that we work with, exposure to them should be limited. With several routes of exposure, we need to take multiple precautions. As we rarely work with sharp objects, injection is not likely. Food and drink are not allowed in the lab, so there is no risk of ingestion. We work in the hood to prevent inhalation of vapors or fumes. And finally, we wear gloves and safety goggles to prevent absorption of chemicals through the skin.

Since our hands are the most commonly exposed parts of our bodies through handling and spills, it is essential to protect them adequately. The gloves provided in the laboratories are nitrile rubber gloves made by Best Manufacturing Company. This glove provides protection from most of the chemicals we use in the lab. It is important to remember, however, that these gloves do not provide complete protection and chemicals will eventually permeate the glove. These gloves are meant to be changed anytime something is spilled on them. They were selected for their range of protection over a short period of time, for their thickness so we maintain our dexterity, and for their reasonable price but they are disposable and are intended to be changed often. (For a complete listing of Best gloves and the permeation for each type of glove go to http://www.chemrest.com.)

Please remember to protect yourself! Always wear gloves and change them often!

Outside Lab Time

For Chemistry 211 students, the only experiments that are allowed outside lab time are melting point determinations.

You may do these melting points Monday-Friday between 8 AM and 6 PM. You must have another person with you when doing these experiments. If a lab is in session, please get the permission of the instructor before doing any melting points.