In the earlier article General Guidelines for Laboratory Safety you were provided tips on safe practices for carrying out different laboratory operations and processes. It is equally important to familiarize with safety symbols that you are likely to come across on laboratory walls, solvent and reagent bottles,containers and instruments in the laboratory.
It is not enough to know their meanings but more important is to exercise required precautions when you are using any device or chemical bearing such signs.
Lab Coat : Lab coat is a knee length overcoat that should be worn while working in the lab to protect your clothes and skin from damage of corrosive chemicals and acids.
Face Mask : A facemask provides filtering of poisonous fumes or poisonous powders when performing sample preparation and digestions. These also serve to filter out harmful bacteria in microbiological laboratories and also permit easy breathing comfort.
Safety Gloves : Always wear disposable plastic gloves when working with harmful or corrosive chemicals In microbiology laboratories gloves protect you from harmful bacteria.
Safety Goggles : Safety goggles offer protection to eyes and surrounding areas when working with corrosive and acidic chemicals.
Safety Shower : A safety shower provides quick drenching with fresh water when there has been an accidental spill of acids, bases, corrosive chemicals or materials that are toxic through absorption by skin.
Eye Wash : Laboratory eye wash station provides emergency eye flushing with water streams when corrosive or caustic chemicals enter eyeballs or touch eyelids.
Fire Extinguisher :
A fire extinguisher is a hand held device used to control and extinguish small fires. Fire extinguishers contain extinguishing agents such as water, carbon dioxide, dry chemical or halon and are classified according to the class of fires
Class A : fires due to combustible materials such as wood, paper, plastic material, etc
Class B : fires involving highly flammable liquids and gases
Class C : electrical fires
Class D : fires involving highly combustible metals like sodium, aluminium, magnesium,etc
Bottle Buckets : Hazardous solvents can be conveniently carried in bottle buckets to prevent accidental spillage or damage to material or other persons.
Flammable : Flammable substances are liquids, solids and gases which catch fire easily.
No Flame : when using flammable materials make sure there are no naked flames, sparks or other hot surfaces in the surrounding area.
Hot Surface : Avoid contact with surfaces bearing this symbol. Always use tongs to lift hot glassware and use heatproof mittens to remove dried glassware from hot air ovens.
Poisonous : Poisonous substances can cause extreme harm or even death due to oral ingestion or absorption through skin. All containers of such substances should bear the poisonous material symbol to alert potential users.. Do not let any poisonous chemical to come in contact with your skin and do not inhale its vapours.
Corrosive : Corrosive substances attack surfaces or cause severe burns on contact with skin and eyes. Ingestion of corrosive substances can cause damage to respiratory and gastrointestinal tracts. Handle such materials with great care and do not inhale their vapours.
Explosive : An explosive material has stored potential energy which is capable of being released suddenly. Energy release is accompanied by production of light, heat, sound and pressure waves. The explosion can get triggered by spark, reaction with another material or pressure. Explosive materials require very careful handling.
Radioactive : Radioactive materials contain radio isotopes which decay continuously and in the process emit harmful rays such as alpha, beta and gamma particles. Exposure to such radiations can cause cancers of various types depending on exposure periods. Always ensure protection through use of protective shielding and wearing of radioactivity monitoring badges.
High voltage : Do not touch any surface bearing this sign especially if your hands are wet. After use unplug and coil up cords as these can trip unsuspecting persons.
Biohazard : Bio hazards are hazards associated with exposure to infection causing biological materials such as microorganisms, bacteria, viruses and toxins. Protective clothing must be worn when working with such biologically hazardous materials.
Material safety data sheets should be available and easily accessible in all laboratories for the chemicals being used in the laboratory. These contain details on physical data, toxicity, health effects, first aid, reactivity, storage, disposal and spill handling procedures. It goes without saying that the first aid box should be easily accessible and its contents should be replenished from time to time.
Please do share your experiences on laboratory safety and how accidents can be prevented.