Everything you want to know about glassware in the lab
While chemists and researchers are making increased use of plastic in the laboratory, glass is still the choice of many. Obviously, deciding whether glass or plastic is right for the job at hand depends on various elements such as instrument design, material characteristics, and cost. But glass is the choice of many for many good reasons.
The general properties of glass
Glass out-performs plastic with its high chemical resistance against many substances, including acids, alkalis, organic solvents, saline solutions, and water. The only substances that can destroy glass are hydrofluoric acid, strong alkalis used at high temperatures, and concentrated phosphoric acid.
Additional advantages to using glass in the lab include its dimensional stability, even at high temperatures, and its transparency. Other advantages include the fact that many sizes of many pieces of laboratory equipment are available, and glass is easy to clean. It is suitable for reagent and chemical storage, and Pyrex, a type of glass, is resilient to heat.
There are different kinds of technical glass types available, each with different properties, making them useful for differing applications. These are:
Soda-lime glass: eg. AR-Glas is suitable for short exposure to chemicals, and for limited heat stress because of its good physical and chemical properties. Products manufactured from this kind of glass include culture tubes and pipettes.
Borosilicate glass: eg. BORO 3.3, BORO 5.0 Once again, this type of glass has good physical and chemical properties. BORO 3.3 has the ability to withstand a high variety of chemicals and temperatures and has good thermal shock and mechanical stability capabilities.
What is laboratory glassware?
Laboratory glassware is a large variety of equipment used in science that has, up until the advent of some plastic alternatives, been traditionally made from glass. Glass is used in analytical laboratories, as well as in chemistry and biology.
Glass can be formed into many shapes and sizes by molding, cutting, bending, and blowing. Because of the possibility of breakage, many laboratories train first-time staff in how to use glassware in the lab correctly, and about the potential hazards inherent in working with glass.
Tips for working with glass in the laboratories
When you work with glass in the laboratory, it is important to remember its limitations in regard to mechanical stress and thermal shock. Ensure that you take strict safety measures at all times. When inducing an exothermic reaction, such as when you dilute sulphuric acid, make sure you stir and cool, and that the reaction takes place in a suitable vessel.
This could be an Erlenmeyer flask. Avoid using graduated cylinders and volumetric flasks for exothermic reactions. Do not heat volumetric instruments on heating plates or you run the risk of breakage.
Do not expose glass instruments to sudden temperature changes or to sudden pressure changes. For example, do not let air quickly into evacuated glass apparatus, and never evacuate vessels with flat bottoms. They are not designed for vacuum use. Only apply effort (not force) steadily and in a controlled manner on empty glass instruments. Use safety devices such as goggles, gloves, and screens.