Care & Maintenance
Joining and Separating glass apparatus
1.
When storing glass stopcocks and joints, insert a thin strip of paper between joint surfaces to prevent sticking.
2.
Never store stopcocks for long periods with lubricant still on the ground surfaces.
3.
Glass stopcocks on Burettes and Separation Funnels should be lubricated frequently to prevent sticking.
4.
If a ground joint sticks, separation can generally be achieved by carefully racking the cone in the socket, or gently tapping of the socket flange on a wooden surface, or by heating the socket and not the cone in a localised flame. The use of penetrating oil will often prove useful in aiding separation.
5.
In using lubricants it is advisable to apply light coat of grease completely around the upper part of the joint. Use only a small amount and avoid greasing that part of the joint which contacts the inner part of apparatus.
6.
Three type of lubricants are commonly use on standard taper joints
(A) Hydrocarbon grease is the most widely used. It can be easily remove by most laboratory solvents, including acetone.
(B) Because hydrocarbon grease is so easily removable, silicon grease is often preferred for higher temperature or high vacuum applications. It can be removed readily with chloroform.
(C) For long term reflux or extraction reactions, a water soluble, organic and insoluble grease, such as glycerin, is suitable. Water will clean glycerin.
There are other type of greases which can be used specifically when certain reagents are used in the Burettes or Separating Funnels.
7.
The use of water, oil or glycerol is recommended on both tubing and rubber bung when inserting glass tubing into a bung. Always wear heavy protective gloves or similar protection when carrying out this operation.
8.
Always fire polish rough ends of glass tubing before attempting to insert into flexible tubing. The lubricants recommended above may also prove useful.
9.
Never attempt to pull a thermometer out of a rubber bung. Always cut the bung away.
 
PERSONAL SAFETY
1.
Use tongs to asbestos gloves to remove all glassware from heat. Hot glass can cause severs burns.
2.
Protective gloves, safety shoes, aprons, and goggles should be worn as safety chemical accidents, spilling or splattering.
3.
Always flush the outside of acid bottle with water before opening. Do not put the stopper on the counter top where someone else may come in contact with acid residue.
4.
Special care is needed when dealing with mercury. Even a small amount of mercury in the bottom of a drawer can poison the room atmosphere. Mercury toxicity is cumulative and the element's ability to amalgamate with a number of metals is well known. After an accident involving mercury, the area should be cleaned carefully until there are no globules remaining. All mercury containers should be kept well-stoppered.
5.
 Never drink from a beaker. A beaker left specifically for drinking is a menace to the laboratory. Do not taste chemicals for identification. Smell chemicals only when necessary and by waiting a small amount of vapour towards the nose.
6.
 Avoid pipeting by mouth, particularly when using concentrated acids, alkalis or potentially biohazardous materials. Use mechanical means such as a rubber bulb or an automatic dispenser.
7.
 Never fill receptacle with material other than that called for by the label. Label all containers before filling. Throw away contents of unlabelled containers.
8.
 To avoid breakage when clamping glassware, do not permit glass-to-metal contact and do not use excessive force to tighten the clamps.
9.
 Do not look down into a test tube being heated or containing chemicals and do not point its open end at another person. A reaction might cause the contents to be ejected, resulting in injury.
10.
 Spattering from acids, caustic materials and strong oxidizing solutions on the skin or clothing should be washed off immediately with large quantities of water.
11.
 When working with chlorine, hydrogen sulphide, carbon monoxide, hydrogen cyanide and other very toxic substances, always use a protective mask or perform these experiments under a fume hood on a well ventilated area.
12.
 In working with volatile materials, remember that heat causes expansion and confinement of expansion results in explosion. Remember also that danger exists even though external heat is not applied.
13.
 Perchloric acid is especially dangerous because it explodes on contact with organic materials. Do not use perchloric acid around wooden benches or tables. Keep perchloric acid, wear protective clothing.
14.
 When using hot plates and other electrical equipments, ensure the wire and plugs are in good condition. Never handle Electrical connection with damp hands.
 
CLEANING
Successful experimental results can only be achieved by using a clean apparatus. In all instances laboratory glassware must be physically clean, in nearly all cases it must be chemically clean and in specific cases it must be bacteriologically clean or sterile. There must be no trace of grease and the safest criteria of cleanliness is the uniform wetting of the glass surface by distilled water-this being of the utmost importance for glassware used for volumetric methods. Any prevention of uniform wetting of the surface will introduce errors such as distortion of the meniscus and accuracy of volume.