Laboratory Regulations and Safety
These regulations regarding safe laboratory practice are intended to help you work safely with chemicals. Safe laboratory practice is based on understanding and respect, not fear. These guidelines cover ordinary hazards and apply to any laboratory experiments you will encounter. Your instructors will discuss specific safety precautions relevant to any one experiment during laboratory lecture. Your laboratory manual will point out specific hazards and precautions. Before beginning an experiment be sure you have this information at hand and that you understand it. Do not hesitate to consult with your instructors if you have questions about any experiment or about these regulations.
When you have read the enclosed material carefully and feel you understand it, please read and sign the attached form, Chemistry Laboratory Safety Regulations Agreement, and turn it in to a TA. Only then will you be permitted to begin laboratory work.
1. Working alone is forbidden. Students may work in instructional laboratories only during regularly scheduled times and then only when supervised by an authorized Teaching Assistant or a member of the faculty. Working alone in the laboratory is strictly forbidden. Students may only perform authorized experiments and then only at the assigned time.
2. Safety glasses must be worn at all times when in a laboratory. Students with prescription glasses must use goggles over the glasses. Contact lens are strictly forbidden!
3. Open flames are allowed only when authorized. Open flames (burners, matches, etc.) are only to be used with permission and then only in specified locations. It is your responsibility to know the location and operation of fire extinguishers, shower and eye wash stations, fire blankets and any other safety equipment provided for your laboratory.
4. No eating, drinking, or smoking in the lab. Use every precaution to keep all chemicals off your skin and clothing, out of your nose, mouth and eyes, and away from flames. It is strictly forbidden to eat or drink anything (including water) in the laboratory.
5. Loose hair and clothing must be restrained. Long hair and billowy clothing must be confined when in the laboratory. Shoes are mandatory (no sandals), aprons are recommended. Sandals or open-toed shoes are not allowed. Shorts are a bad idea, but if they extend to the knee, may be worn in lab.
6. All accidents must be reported to an instructor. ALL accidents, including contact with chemicals, cuts, burns, or inhalation of fumes must be reported to an instructor immediately. Any treatment beyond emergency first aid will be referred to the student infirmary. Severe emergencies will be referred to the Hospital emergency room.
7. It is your responsibility to read and abide by the "Laboratory Safety" section of this manual and to keep it with you in the laboratory. Any other safety handouts or special precautions mentioned during lab lecture must be scrupulously observed.
8. Failure to observe laboratory safety rules and procedures may result in injury to you or to fellow students. For a first violation, you may be asked to leave the laboratory for the day, while for repeated violations, you may be dropped with a grade of E, at the discretion of the instructor.
If you have any questions about the experiment or about safety regulations at any time, please feel free to consult with your instructors. It is in your own best interest to stay alert and to be aware of possible hazards in the laboratory. Do not hesitate to call unsafe practices by your colleagues to the attention of the instructors.
A. EMERGENCY AID PRELIMINARY TO MEDICAL TREATMENT
IMPORTANT: ATTEND TO THE INJURED PERSON WHILE CALLING FOR ASSISTANCE
1. Eyes. GET HELP IMMEDIATELY! Chemicals in the eyes must be removed at once by flooding with copious quantities of water. Help the victim. Use the eye wash station if available. Otherwise, place the victim on the floor, by force if necessary. One person should straddle the victim with knees on the floor, pouring a moderate stream of water from a flask or beaker onto the bridge of the victim's nose so that both eyes are flooded. Another person should squat at the head of the victim and roll back the eyelids of both eyes; use the thumb and forefinger to spread the eyelids open. The victim will not be able to do this voluntarily. Use at least several liters of water. When it is reasonably certain that the excess chemicals have been washed away, take the victim to the Emergency Room for immediate medical attention.
2. Chemicals on the skin. All chemicals which come in contact with the body should be considered toxic and washed off completely with soap and water even if they do not appear to be corrosive. Wash off corrosive substances by flooding with tap water, using the safety shower if necessary, stripping off any clothing and shoes that are soaked with chemicals. Except as follows, do not try to neutralize acids with alkali or alkalis with acid; do not apply ointments or salves.
Acids: After washing thoroughly with water, rub a paste of sodium bicarbonate and water into the skin; don't do this with burns to the eyes.
Alkalis: After washing thoroughly with water, apply a 1% solution of acetic acid (l mL acetic acid in 100 mL water). Better yet, use a 1% boric acid solution if it's readily available.
Bromine: Work fast. Wash the excess bromine from the skin and immediately rub the entire area with a generous amount of glycerol (glycerine).
3. Inhalation of chemicals. Get fresh air. Report to the laboratory instructor all incidents in which more than a smell is inhaled or where prolonged exposure to laboratory fumes has induced faintness or a headache.
4. Ingestion of chemicals. Call the Poison Center ?? for recommended treatment. Vomiting is often dangerous, especially if vomit gets into the lungs; most serious poisoning problems are best treated in the hospital emergency room. If necessary, you can induce vomiting by swallowing as much warm water as possible as rapidly as possible. The addition of one or two teaspoons of table salt per glass of warm water will help. Vomiting should be encouraged by swallowing additional water until the vomited liquid is clear.
5. Cuts. Serious bleeding should be controlled by direct pressure on the wound, preferably with a clean gauze or cloth pad. Minor cuts should be washed with tap water and allowed to bleed briefly. Then press with a clean cotton pad or piece of gauze. Cover with a gauze pad to keep the wound clean. More severe cuts, especially with glass or other foreign objects in the wound, require medical attention.
6. Thermal burns. Wash the burned area gently with cold tap water. If the burn is severe or extensive get immediate medical attention. Wrapping the burned area lightly with a clean wet cloth will help reduce the pain. Do not use ointments or salves unless so instructed by a physician.
7. Faintness. If the victim is conscious, have them sit down and place their head between their knees. Support them to prevent a fall. If they are weak or have fainted, lay them on their back on the floor, raise their feet and legs a little above the level of their head. Call for medical assistance if the victim fails to regain consciousness within a half minute. Insist that they remain quiet, seated or lying down, for a few minutes after recovery unless it is necessary to take them to the hospital for treatment.
8. Clothing fires. Call for help and a blanket. If clothing about the body catches fire, the flame and smoke will rise and be inhaled by the victim. Put the victim prone on the floor, forcibly if necessary, and roll in a blanket, if available. Otherwise, roll him on the floor and beat the flames out with hands or smother the flames with heavy garments. Do not use a fire extinguisher on a person.
B. SAFETY PRECAUTIONS IN THE CHEM LAB
Accidents in the laboratory are the result of carelessness or ignorance either by you or by your neighbors. Stay alert and pay constant attention to your own and to your neighbors' actions. The safety precautions outlined below will be worthless unless you plan every operation, understand every operation, and think through the consequences of every operation before you perform it. The common accidents, which often occur simultaneously, are fire, explosion, chemical and thermal burns, cuts from broken tubing and thermometers, absorption of toxic, but non-corrosive chemicals through the skin, and inhalation of toxic fumes. Less common, but obviously dangerous, is ingestion of a toxic chemical. Each of these types is discussed in a general way below, and more specific reference to certain hazards will be found in the individual experiments.
1. Wear goggles, even over your prescription glasses, at all times in the laboratory. Persons who do not conform to this requirement will be asked to leave the laboratory. It is more the rule than the exception for flying glass and spattered chemicals to hit the face. Even if you are not conducting a reaction or other operation, your neighbors are probably working and they may have an accident which spatters you .
You should understand that most prescription glasses, even with hardened lenses, do not meet stringent OSHA standards for protection against flying debris, and that glasses, compared to goggles, offer only modest splash protection even when fitted with side shields. You should also understand that plastic prescription lenses may be attacked by certain laboratory solvents.
2. Fire. Make it a working rule that water is the only nonflammable liquid you are likely to encounter. Treat all others in the vicinity of a flame as you would gasoline. Specifically, never heat any organic solvent in an open vessel, such as a test tube, Erlenmeyer flask, or beaker with a flame. Such solvents should be heated with a steam bath, not a hot plate, if possible and the flammable vapors drawn off with an aspirator tube or, preferably, by working in a hood. Never keep volatile solvents, such as ether, acetone, or benzene in a beaker or open Erlenmeyer flask. The vapors can and will creep along the bench, ignite, and flash back if they reach a flame.
It is your responsibility to yourself and to your neighbors to know where the nearest shower and fire extinguisher are located and how to operate them. Point an extinguisher at the outer reaches of flames and work inwards. Call for additional extinguishers.
3. Explosion. Never heat a closed system or conduct a reaction in a closed system (unless specifically directed to perform the latter process and then only with frequent venting). Before starting a distillation or a chemical reaction, make sure that the system is vented. The results of an explosion are flying glass and spattered chemicals, usually both hot and corrosive.
4. Chemical and Thermal Burns. Many inorganic chemicals such as the mineral acids and alkalis are corrosive to the skin and eyes. Likewise, many organic chemicals, such as acid halides, phenols, and so forth are corrosive and often toxic. If these are spilled on the desk, in the hood, or on a shelf, you must clean them up before you leave the area of a spill.
5. Cuts. The most common laboratory accident is probably the cut received while attempting to force a cork or rubber stopper onto a piece of glass tubing, a thermometer, or the side-arm of a distilling flask. Be sure to make a proper-sized hole, lubricate the cork or stopper (lubrication is essential with a rubber stopper), and use a gentle pressure with rotation on the glass part. Severed nerves and tendons are common results of injuries caused by improper manipulation of glass tubes and thermometers. Always pull rather than push on the glass when possible.
6. Absorption of Chemicals. Keep chemicals off the skin. Many organic substances are not corrosive, do not burn the skin, or seem to have any serious effects. They are, however, absorbed through the skin, often with dire consequences. Others will give a serious allergic reaction upon repeated exposure, as evidenced by severe dermatitis.
7. Inhalation of Chemicals. Keep your nose away from organic chemicals. Many of the common solvents are extremely toxic if inhaled in any quantity or over a period of time. Do not evaporate excess solvents in the laboratory; use the hood or a suitable distillation apparatus with a condenser. Some compounds, such as acetyl chloride, will severely irritate membranes in your eyes, nose, throat, and lungs, while others, such as benzyl chloride, are severe lachrymators, i.e. they induce eye irritation and tears. When in doubt, use the hood or consult with the laboratory instructor about the use of chemicals required for your work.
8. Ingestion of Chemicals. The common ways of accidently ingesting harmful chemicals are: (1) by pipette, (2) from dirty hands, (3) contaminated food or drink and (4) food use of chemicals taken from the laboratory.
C. EMERGENCY PHONE NUMBERS IN THE CHEM LAB
CAMPUS FIRE STATION 6-2000
MEDICAL EMERGENCY 911
Some Laboratory Policies
Generally, most accidents can be avoided by a thoughtful and alert approach to lab work. The particular hazards of reagents used in different procedures will be pointed out in advance. Common situations which call for special care include the following:
1. Think twice before touching anything during a procedure that involves a Bunsen burner or hot plate. Burns are very common.
2. Do not heat anything other than water or an aqueous solution over an open flame. All other solvents should be assumed to be at least as flammable as gasoline. Many, such as ether, are more flammable.
3. If a piece of glass tubing or a thermometer is to be inserted into a hole in a rubber stopper, lubricate the glass and stopper with glycerin, do not force the tubing, and keep the entire assembly wrapped in a towel while applying gentle pressure. Cuts incurred in this way are probably the most common significant lab injuries. Severed tendons and nerves can result from even relatively minor cuts to the hands.
4. Be careful around concentrated acids. All of them are corrosive to the skin and will cause severe eye damage even on short exposure. Some of them, such as sulfuric acid generate large amounts of heat when diluted. Add a small amount of acid to a large amount of water, slowly and with stirring. If a small dilution factor is desired, external cooling in an ice bath may be necessary.
A Historical Reference
Ira Remsen (1846-1927), a founder of the chemistry department at Johns Hopkins University (more than 100 years ago), a codiscoverer of saccharin (1879) recalled a vivid "learning experience," which led to a heightened interest in laboratory work:
While reading a textbook of chemistry I came upon the statement, "nitric acid acts upon copper." I was getting tired of reading such absurd stuff and I was determined to see what this meant. Copper was more or less familiar to me, for copper cents were then in use. I had seen a bottle marked nitric acid on a table in the doctor's office where I was then "doing time." I did not know its peculiarities, but the spirit of adventure was upon me. Having nitric acid and copper, I had only to learn what the words "act upon" meant. The statement "nitric acid acts upon copper" would be something more than mere words. All was still. In the interest of knowledge I was even willing to sacrifice one of the few copper cents then in my possession. I put one of them on the table, opened the bottle marked nitric acid, poured some of the liquid on the copper and prepared to make an observation. But what was this wonderful thing which I beheld? The cent was already changed and it was no small change either. A green-blue liquid foamed and fumed over the cent and over the table. The air in the neighborhood of the performance became colored dark red. A great colored cloud arose. This was disagreeable and suffocating. How should I stop this? I tried to get rid of the objectionable mess by picking it up and throwing it out of the window. I learned another fact. Nitric acid not only acts upon copper, but it acts upon fingers. The pain led to another unpremeditated experiment. I drew my fingers across my trousers and another fact was discovered. Nitric acid acts upon trousers. Taking everything into consideration, that was the most impressive experiment and relatively probably the most costly experiment I have ever performed. . . . It was a revelation to me. It resulted in a desire on my part to learn more about that remarkable kind of action. Plainly, the only way to learn about it was to see its results, to experiment, to work in a laboratory.
from Journal of Chemical Education: