Laboratory safety is an area which no laboratory can afford to ignore. As soon as you enter any laboratory you will come across safety gear such as fire extinguishers, fume hoods, biological cabinets, eye wash stations, safety fountains, etc. You will also come across safety instructions and charts decorating the laboratory walls.
Several authoritative texts are available on laboratory safety but an area which is often ignored is spill management which deserves its due attention.
Let me first introduce you to the various common laboratory spills and subsequently you’ll be suggested remedial measures :
- Corrosive liquids such as acids and alkalis
- Highly inflammable liquids
- Poisonous substances
- Biological spills
- Radioactive spills
Spills can pose a grave danger to another worker or an outsider who is not aware of the nature of the spill. First of all the spill area needs to be cordoned off and a warning sign put up. Different spills require different remedial measures which would be suggested subsequently but it is important to keep spill management kit readily available so that at time of need you don’t have to run around looking for items necessary to clean up the spill. Equally important is to keep material safety data sheets on laboratory chemicals which should be easily accessible to all.
Corrosive liquids such as acids and alkalis frequently get spilled due to improper handling and breakage of containers.
Never add water directly to the spill or mop directly as it can cause burns on the skin. Cover acid spill with soda ash or sodium bicarbonate powder and after leaving for sometime use the mop. In case of alkaline spills neutralise with a weak acid such as boric acid before mop up.
The first step is to ensure that there are no naked flames in the laboratory. As most of the flammable liquids are volatile in nature you have to switch of all instruments running on motors which can be potential sources of electric sparks. Cover the spill with sawdust so as to absorb the liquid and then using protective gloves transfer to a waste bag for safe disposal.
It is necessary to evacuate the laboratory and then take remedial action as prescribed by the specific material safety data sheet. It is important that the cleaner is equipped with safety gear such as face mask, gas mask, if necessary , protective clothing and gloves before attempting to clean up the spill
Mercury is found in several laboratory items such as thermometers, barometers, lamps and is used in pure state in: polarographic instruments. It is highly toxic and needs careful handling. Apart from pools mercury can spread on the floor as minute droplets which can get trapped in floor cracks. Do not use a vacuum cleaner as it can increase mercury vapour in the air. Sweeping with a broom will only scatter small droplets further Spot small droplets with a searchlight or pour some zinc or sulphur powder to darken the droplets and use an eye dropper to remove them. Always wear gloves when handling mercury spills. Wipe the spill from outside inwards and collect in a plastic sealed pack. Residual Mercury should be mopped with vinegar swabs followed by peroxide. The swabs should then be disposed off in sealed plastic bags.
The collected mercury should never be poured down the drain and mercury contaminated gloves or clothing should not be disposed in regular garbage because of risk of vapor formation.
Biological spills carry potential risk of exposure to disease causing bacteria and micro- organisms. Such spills can take place inside biosafety cabinets, centrifuges or on the floor. In all cases the spill should be cleaned after wearing disposable gloves and protective clothing.In case of breakage carefully remove broken glass, blades, or other sharp objects in a separate sharps disposable bin. Cover the area with 10% bleach disinfectant for about half an hour and then wipe with paper towels soaked in iso-propyl alcohol. Autoclave the contents before disposal. Remove used gloves and shoe covers and wash hands thoroughly with IPA, soap and finally with water.
Radioactive spills need immediate attention. First and foremost evacuate the spill area and prevent any access till the spill is cleared. This is necessary to prevent spread of radioactive contamination to other areas .Persons inside spill area should be monitored for safe levels of radiation before permitting them to leave. Always report radioactive spillage to the institutional safety officer.
After attending to personal injuries, if any, collect broken glass or other sharps in sharps container and cover the spill with paper towels. Dispose the radioactive waste in radioactive waste bags and after decontamination monitor residual radioactivity before starting of routine activities.
Proper management of spills is necessary for all types of spills and specialised procedures should be prescribed by each and every laboratory depending on its activities and nature of materials handled.
Hope this article has been useful and has opened up another dimension of laboratory safety practices. Please do share your experiences and offer your comments.