Laboratory glassware
Laboratory glassware refers to a variety of equipment, traditionally made of glass, used for scientific experiments and other work in science, especially in chemistry and biology laboratories. Some of the equipment is now made of plastic for cost, ruggedness, and convenience reasons, but glass is still used for some applications because it is relatively inert, transparent, more heat-resistant than some plastic up to a point, and relatively easy to customize. Borosilicate glasses-formerly called Pyrex-are often used because they are less subject to thermal stress. For some applications quartz is used for its ability to withstand high temperatures or its transparency in certain parts of the electromagnetic spectrum. In some applications, especially some storage bottles, darkened brown glass is used to keep out much of the outside light so that the effect of light on the contents inside is minimized. Special-purpose materials are also used; for example, hydrofluoric acid is stored and used in polyethylene containers because it attacks glass.

Applications
There are many different kinds of laboratory glassware items, the majority of which are covered in separate articles of their own; see the list further below. Such glassware is used for a wide variety of functions which include volumetric measuring, holding or storing chemicals or samples, mixing or preparing solutions or other mixtures, containing lab processes like chemical reactions, heating, cooling, distillation, separations including chromatography, synthesis, growing biological organisms, spectrophotometery, and containing a full or partial vacuum. When in use, laboratory glassware is often held in place with clamps made for that purpose, which are likewise attached and held in place by stands or racks. This article covers aspects of laboratory glassware which may be common to several kinds of glassware and may briefly describe a few glassware items not covered in other articles.