General Laboratory rules, Laboratory hazards, and Simple First Aid in the Laboratory

by Heba Soffar · Published August 31, 2023 · Updated April 17, 2024

Organic chemicals such as ethers, alcohols, acetone…etc. are easily evaporated at room temperature. Vapors of such chemicals are very inflammable, Therefore, the student must be very careful when using these solvents. In order to minimize the accidents, the following precautions are indicated.

Laboratory hazards

1. Fire and explosion

Inflammable solvents must be stored in a cool room separately, such a storeroom must be quipped ventilating devices and should be ventilated every now & then the inflammable solvents should be taken to the laboratories as needed, and in the smallest amounts required for experiments.

Before opening a bottle containing an inflammable solvent, make sure there is no flame around, Never heat inflammable solvents on an open flame, If a fire does take place, keep calm, do not become confused, and Immediately ask the laboratory instructor for help.

2. Corrosive and Caustic Chemicals

a. Strong Acids: Many acids such as sulfuric, hydrochloric, nitric….etc. are dangerous when in contact with tissues. Thus the following precautions must be followed when handling such chemicals:

Never hold the container from the stopper, hold it with two hands.
When pouring acid from a bottle into another container, prevent splashing by pouring very slowly.
When the dilution of an acid is desired, always the acid should be added to water. If you are using a pipette use suction pumps, hold the pipette against the wall of the container that has water in it. Mix the diluted acid frequently and if heat develops either wait a few minutes before you add more acid or cool the container.
After using the bottles return them back safely to their specific place.

b. Strong Bases: Many bases such as NaOH, KOH, NH₄OH….etc. are highly caustic and may cause severe damage to the body. The following precautions are recommended:

Do not store strong bases in glass-stoppered bottles.
When dissolving NAOH or KOH in water, make sure that the base is added slowly to water since a large amount of heat will be released if large amounts of base is added to water.
When opening a bottle that contains ammonia, be careful not to hold your face above the opening of the bottle, or better open it in a fume-hood.

3. Poisons

There are many compounds such as cyanides, and various alcohols such as methyl alcohol, mercurials…etc. that may not cause skin damage but are highly toxic. When handling such substances, one must be extremely careful and follow meticulously the precautions outlined below:

Whenever possible, place the toxic solvents in the hood.
Never use an ordinary pipette for transferring toxic solvents. An automatic pipette or a pipette equipped with a rubber bulb should be employed.
Make sure that all of the containers are properly labeled so that a poisonous solution will not be mistaken for something else.