Glassware items such as round bottom flasks, volumetric flasks, conical flasks, beakers, test tubes, vials, pipettes, burettes, measuring cylinders and petri-dishes are a common sight in any laboratory. In earlier times all such items were made of glass. However, over the years plastic ware has made a significant presence and is becoming increasingly popular. The main reason for its noticeable presence is its unbreakable nature and compatibility with common laboratory chemicals.
The article outlines the factors which help in deciding your choice of laboratory ware materials.
Benefits of Glassware
Glassware has long preceded plastic ware in laboratories. The main advantages offered by glassware are:
- High clarity affords visibility of contents and accurate recording of volumes
- Sealed glass containers are impermeable to atmospheric gases which prevents the contents from oxidative degradation
- Glass is inert and does not contribute to leaching contamination except for some ionic species
- Glassware is capable of reuse after prescribed cleaning
- Glass items are easily sterilized in comparison to plastic items
- It is possible to fabricate different glassware items in the laboratory taking the services of the glass blower. Plastic ware cannot be fabricated in laboratories.
- Glass beakers and flasks can be heated using hot plates without risk of breakage
Drawbacks of Glassware
- The biggest drawback of glassware is breakage. Accidental breakage results in loss of valuable samples, harmful spillages, leakages of toxic chemicals, radioactivity, harmful bacteria or injuries to the laboratory chemist
- Contamination of samples stored in glass containers due to leaching of inorganic ions into aqueous solutions or exposure to light in case of light-sensitive materials. In addition to contamination it can result in loss of stability of stored material
- Glass containers cannot be used to handle hydrofluoric acid which readily attacks glass
Advances in polymeric material research have contributed to development of container materials which meet the requirements of handling of different laboratory chemicals. Plastic materials have contributed to convenience of large-scale automation and material handling capabilities of laboratory samples. The coming of plastic ware has not made glassware obsolete but has further contributed to the options available to the laboratory chemist.
Advantages of Plastic Ware
- Non-breakable and shows some degree of flexibility
- Plastic ware is generally light in weight and therefore it is easier to handle items such as large desiccators or graduated cylinders, etc.
- Non-leaching of inorganic species makes plastic containers a preferred choice in trace metal studies. However, plastic containers are not suitable for use with most organic solvents
- Plastic items such as vials and micro pipette tips are usually considered disposable. However, whenever possible, these should be reused after proper cleaning as plastics are non-biodegradable and contribute to the environmental burden. If this is not possible dispose according to prescribe norms. Reuse can further save on recurring costs
- Plastic items are commonly less expensive compared to glass items
Technology improvements have contributed to development of new plastics with wide ranging properties that contribute to special features such as autoclavibility, physical strength, handling of highly corrosive acids such as hydrofluoric acid, heat resistance and improved transparency.
The selection of appropriate lab ware should be made keeping in mind the analysis requirements. Plastic lab ware offers several advantages but there are other applications which require use of glass lab ware. Knowledge of properties of different available plastic materials for use in laboratory will prove to be helpful in deciding on your available options.