BOROSILÂ®Â range of Laboratory Ware includes almost all items required in general lab usage. Our expertise in melting and forming low expansion, chemically inert borosilicate glass for over 50 years has made our products preferred globally. In fact, for a laboratory to get ISO 9001 certification in India, it is recommended that it use BOROSIL certified A-class glassware.
Our apparatus for measurement of volumes rank amongst the most accurate in the world.
Safe Use Of Glassware
When treated with proper care laboratory apparatus will give long and satisfactory service. The following notes have been prepared to assist users in obtaining the maximum life and performance from their apparatus. Our Sales Department will be happy to advice on any aspect concerning the safe use of our products.
Heating And Cooling
Glass may suffer damage in three ways.
It may break under thermal stress in the â€˜steady stateâ€™, that is when a constant thermal gradient is established through the glass.
It may break under the transient stress of a thermal shock, that is sudden heating or cooling.
It may, if heated beyond certain temperature, acquire a permanent stress which on cooling could cause
The following precautions will assist in avoiding failures during heating and cooling procedures. Never leave vessel unattended when evaporation work is being carried out. The vessel may crack or explode as â€˜drynessâ€™ condition approaches and if the heat source is not adjusted correctly. Lower the temperature gradually as the
liquid level drops.
lways use caution when removing glassware from a heat source and avoid placing on a cold or damp surface.
Although the ware can withstand extreme temperatures, sudden temperature changes may cause the vessel to break.
Always cool vessels slowly to prevent thermal breakage. Never apply heat to badly scratched or etched vessel as the thermal strength would have been greatly reduced. Never apply point source heating to a vessel as this will greatly increase the chance of breakage.
Always diffuse the heat source by using a metal gauze or air/water bath. Alternatively ensure even heating of the vessel by slow movement of the vessel in relation to the heat source.
Adjust bunsen burner to get a large soft flame. It will heat slowly but also more uniformly. Uniform heat is a critical factor for some chemical reactions. Ensure that the flame contacts the vessel below the liquid
level. Heating above that level will invite breakage of the vessels.
Always use anti-bumping devices in the vessel, such as powdered pumice or glass wool when rapid heating of the vessel and contents is required. Never use material with sharp edges such as broken porcelain as an antibumping device.This will cause internal abrasions and reduce the mechanical and thermal strength of the vessel.
Thick walled glassware should not be subjected to direct flame or other localised heat source. Vessels of this type are best heated with the use of an electric immersion heater. Avoid heating glassware over electric heaters with open elements. Uneven heat of this type can induce localised stress and increase the chances of breakage. Remember that a hot plate will retain heat long after the appliance has been switched off. Always ensure that the surface of the hot plate is larger in area than the base of the vessel being heated. An undersized plate for the job in hand will invite uneven heating and promote breakage of glassware. Always ensure that manufacturerâ€™s instructions are followed when using electrical heat sources.
Mixing And Stirring
Always use a â€˜policemanâ€™ or similar device on stirring rods to prevent scratching of the inside of a vessel. When using a glass vessel with a magnetic stirrer always use a covered follower to prevent abrasion of the inside of the vessel. When using glass or metal mechanical stirrer in a glass vessel always predetermine the height of the stirrer before use to ensure there is no contact between the stirrer blade and the bottom or sides of the vessel. Never mix sulphuric acid and water inside a glass measuring cylinder. The heat of reaction can break the base of the cylinder
Vacuum And Pressure
Never use a glassware beyond the recommended safe limit. Always use a safety screen when working with glassware
subjected to pressure or vacuum. Never subject glassware to sudden pressure changes. Always apply and release positive and negative pressures gradually
Joining And Separating Glass Apparatus
When storing glass stopcocks and joints, insert a thin strip of paper between joint surfaces to prevent sticking. Never store stopcocks for long periods with lubricants still on the ground surfaces. Glass stopcocks on Burettes and Separating Funnels should be lubricated frequently to prevent sticking. If a ground joint sticks, separations can generally be achieved by carefully rocking the cone in the socket, or gentle tapping 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. In using lubricants it is advisable to apply a 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 the apparatus. Three types of lubricants are commonly used on standard taper joints.
(a) Hydrocarbon grease is the most widely used. It can be easily removed 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 types of greases which can be used specifically when certain reagents are used in the Burettes or Separating Funnels. Details of these can be available from our nearest Regional Sales Offices
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. Always fire polish rough ends of glass tubing before attempting to insert into flexible tubing. The lubricants recommended above may also prove useful. Never attempt to pull a thermometer out of a rubber bung, always cut the bung away.
Use tongs or asbestos gloves to remove all glassware from heat.Hot glass can cause severe burns. Protective gloves, safety shoes, aprons, and goggles should be worn as safety against chemical accidents, spilling or splattering. 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. 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 elementâ€™s ability to amalgamate with a number of metals is well known. After an accident involving mercury, the area should be gone over carefully until there are no globules remaining. All mercury containers should be kept well stoppered. 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 only by wafting a small amount of vapour towards the nose.
Avoid pipeting by mouth, particularly when using concentrated acids, alkalis or potentially biohazardous materials. Use mechanical means such as a rubber bulb or a automatic dispenser. Never fill receptacle with material other than that called for by the label. Label all containers before filling. Throw away contents of unlabelled containers. To avoid breakage when clamping glassware, do not permit glass-to-metal contact, and do no use excessive force to tighten the clamps. 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.
Splattering from acids, caustic materials and strong oxidizing solutions on the skin or clothing should be washed off immediately with large quantities of water. 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 in a well ventilated area. 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. 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 bottles on glass or ceramic trays having enough volume to hold all the acid in case the bottle breaks. When using perchloric acid, always wear protective clothing. When using hot plates and other electrical equipments, ensure the wire and plugs are in good condition.
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 chemicaiiy clean and in specific cases it must be bacreriologically 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 miniscus and accuracy of volume.
Cleaning of glassware which has contained hazardous materials must be solely undertaken by experienced personnel.
Most new glassware is slightly alkaline in reaction.For precision chemical tests,new glassware should be soaked several hours in acid water (1%solution hydrochloric acid or nitric acid) before washing.
Glassware which is contaminated with blood clots,culture media, etc. must be sterilized before cleaning.
If glassware becomes unduly clouded or dirty or contains coagulated organic matter, it must be cleaned with chromic acid cleaning solution.The dichromates,should be handled with extreme care because it is a powerful corrosive.
Wash glassware as quickly as possible after use but if delays are unavoidable, the artcles should be allowed to soak in water.
Grease is removed by weak sodium carbonate solution or acetone or fat solvents.Never use strong alkalis.
Hot water with recommended detergents should be used and if glass is exceptionally dirty, a cleaning powder with a mild abrasive action can be applied provided the surface is not scratched.
During the washing, all parts of the article should be thoroughly scrubbed with a brush selected for the shape and size of the glassware.Brushes should always be in good condition to avoid any abrasion of the glassware.
When chromic acid solution is used, the item may be rinsed with the cleaning solution or it may be filled and allowed to stand-the amount of time depending on amount of contamination on the glassware.
Special types of precipitate material may require removal with nitric acid,aqua regia or fuming sulphuric acid.These are very corrosive substances and should be used only when required.
It is imperative that all soap detergents and other cleaning fluids be removed from glassware before use.
Cleaning Specific Types Of Glassware
Place pipettes tips down, in a cylinder or tall jar of water immediately after use.Do not drop them into the jar, since this may break or chip the tips and render the pipettes useless for accurate measurements. A pad of cotton or glass wool at the bottom of the jar will help to prevent breaking of the tips.Be certain that the water level is high enough to immerse the greater portion or all of each pipette. At a convenient time, the pipettes may then be drained and placed in a cylinder or jar of dissolved detergent or, if exceptionally dirty, in a jar of chromic acid cleaning solution. After soaking for several hours, or overnight, drain the pipettes and run tap water over and through them until all traces of dirt are removed. Soak the pipettes in distilled water for at least one hour. Remove from the distilled water, dry the outside with a cloth, shake out the water and dry. In laboratories where a large number of pipettes are used daily, it is convenient to use an automatic pipette washer. Polyethylene baskets and jars may be used for soaking and rinsing pipettes in chromic acid cleaning solution. Electrically heated metallic pipette driers are also available. After drying, place pipettes in a dust-free drawer. Wrap serological and bacteriological pipettes in paper or place in0 pipette cans and sterilize in the dry air sterilizer at 160 C for two hours. Pipette used for transferring infectious material should have a plug of cotton placed in the mouth end of the pipette before sterilising.
BURETTES (with glass stopcock)
Remove stopcock key and wash the burette with detergent and water. Rinse with tap water until all the dirt is removed. Then rinse with distilled water and dry. Wash the stopcock key separately. Before the stopcock key is replaced in the burette, lubricate the joint with a small amount of lubricant. Remember that burette stopcock keys are not interchangeable. Always cover burettes when not in use.
Culture tubes which have been used previously must be sterilized before cleaning. The best general method for sterilising culture tubes is by autoclaving for 30 minutes at 0 121 C (15 lb pressure). Media which solidify on cooling should be poured out while the tubes are hot. After the tubes are emptied, brush with detergent and water, rinse throughly with tap water, rinse with distilled water, place in a basket and dry. If tubes are to be filled with a medium which is sterilized by autoclaving, do not plug until the medium is added. Both medium and tubes are thus sterilized with one autoclaving. If the tubes are to be filled with a sterile medium or if they are to be sterilized by the fractional method sterilize the tubes in the autoclaves or dry air sterilizer before adding the medium.
Serological Tubes should be chemically clean but need not be sterile. However, specimens of blood which are to be kept for some time at room temperature should be collected in a sterile container. It may be expedient to sterilize all tubes as routine. To clean and sterilize tubes containing blood, discard the clots in a waste container and place the tubes in a large basket. Put the basket with others, in a large bucket or boiler. Cover with water, add a fair quantity of soft soap or detergent and boil for 30 minutes.Rinse the tubes and clean with brush, rinse and dry with the usual precautions. It is imperative when washing serological glassware that all acid, alkali and detergent be completely removed. Both acid and alkali in small amounts destroy complement and in larger amounts produce hemolysis. Detergents interfere with serologic reactions. Serological tubes and glassware should be kept separate from all other glassware and used for nothing except serologic procedures.
Dishes And Culture Bottles
Sterilize and clean as detailed under Culture Tubes. Wrap in heavy paper or place in a petri dish can. Sterilize in the autoclave or dry air sterilizer.
Chemical & Physical Properties Of Low Density Polyethylene
Excellent : 30 days of constant exposure cause no damage. Plastic may even tolerate for years.
Good : Little or no damage after 30 days if constant exposure to the reagent.
Fair : Some effect after 7 days of constant exposure to the reagent. Depending on the plastic, the effect may be crazing, cracking, loss of strength, or discoloration. Solvents may cause softening, swelling and permeation losses which are normally reversible, the part will usually return to its normal conditions after evaporation.
Maximum use temperature : 80 C; Not recommended for autoclaving / dry heat sterilization. Gas and chemical sterilization can be done.
Brittleness temperature :100 C. Currently this material is used on Stoppers for Volumetric Flasks, bases for measuring Cylinders and Plastic Wash Bottles.