Science laboratories are potentially dangerous places. The chemicals used in them can damage people and equipment quickly and severely if not handled with care and proper procedure. Almost any lab uses some gases, if only to burn to heat Bunsen burners. Many labs stock a variety of gases that may be hazardous in several distinct ways. Understanding all the potential dangers of gas in the science laboratory is essential for safe work.
Gas Lines and Burners
Most labs (especially in schools) have gas lines that are used to hook up Bunsen burners, small flame sources used to heat up beakers to create chemical reactions. If not shut down properly, these lines could vent flammable natural gas into the room until enough builds up to cause an explosion when a spark is introduced.
Other gases used in the lab may be dangerously reactive. This means that they could explode at room temperature or on contact with other substances. This may happen if a container is shaken or heated while the gas is confined.
Gases such as hydrogen can ignite in the presence of a flame or a spark. This can be dangerous if a valve is left open long enough to fill the room with the gas, or if the flame or spark is placed close to the outlet from the gas cylinder.
Gases can present many health hazards. They may simply irritate the skin or eyes, or be harmful to a person's health when inhaled. Some gases are corrosive or toxic; these will cause immediate and serious damage to the body if they are inhaled or absorbed through the eyes. Some gases may even be fatal when absorbed in this way. Personal protective gear such as goggles, masks and gloves should always be used, and gas hoods should be used to vent the gas away from the lab user in the event of a problem.
Gas is stored in metal cylinders, where it is under pressure. These cylinders can explode if weakened by a sudden impact or long use; knocking them over also risks knocking off the valve assembly and turning the cylinder itself into a projectile that could damage people and equipment. To avoid this, all cylinders should be regularly inspected, labelled and bolted down to the walls of the lab. Flammable gas should be stored away from oxidising gases that it could react with, and all valves should be opened very slowly.