General Guidelines for Laboratory Safety

 General Guidelines for Laboratory Safety

Your prime concern the moment you start work in the laboratory should be to protect yourself and your fellow co-workers from exposure to harmful toxic substances and hazardous chemicals. Remember you are as much responsible for your own safety as safety of others around you. A majority of laboratory accidents are caused by overconfidence and non-adherence to safety guidelines.

Laboratory accidents often lead to cuts and bruises, severe burns, poisoning, corrosive damage from hazardous chemicals, diseases and long-term genetic disorders due to exposure to harmful microbes and radioactive radiations. Such situations are avoidable through adherence to safety guidelines. While it is not possible to cover the entire subject on the laboratory safety in a short article such as this one an attempt is made to provide some useful guidelines when carrying out different laboratory operations and processes.

 Safety Symbols

Flammable	Radio Active
Corrosive	Explosive

General Operations

• Familiarise yourself with safety symbols and signs.
• Follow laboratory discipline such as non-consumption of eatables or drinks, non-smoking, distracting others and following prescribed dress code.
• Familiarize with SDS (Safety data sheet) on chemicals you are likely to use
• Do not use mobile phase phones while working in the laboratory
• Wear protective clothing, safety glasses, gloves and facemasks when performing hazardous operations
• Avoid working alone in the lab
• Always keep your laboratory bench clean and keep reagents and chemicals at the designated places after use
• Immediately wash acid or alkali spills on your body with water before seeking medical attention
• Check validity of articles in the first aid kit from time to time and replace them accordingly
• Familiarize with the use of fire extinguishers, first aid kits and other safety gear
• Do not use cracked or partially broken glassware
• Ensure proper earthing of electrical instruments and do not overload electrical points
• Storage and handling of hazardous and flammable chemicals
• Corrosive chemicals, acids, alkalis, pesticides, etc should be stored separately in special storage cabinets made of all plastic, polypropylene or painted steel to prevent rusting or delamination of wood core materials.
• Cabinets should bear appropriate safety symbols
• Transfer large solvent bottles and carboys using special trays. Never hold such containers by the neck
• Always wear gloves when handling such containers
• Use liquid dispensing pumps fitted to mouth of bottles when transferring contents to other containers
• Use of hot ovens, muffle furnaces and digestions chambers
• Use fume hoods for sample preparation when digesting samples involving strong acids to prevent exposure to corrosive fumes
• Ensure that the exhaust system of fume hood is switched on during digestions
• Avoid naked flames and use heating mantles and and hotplates for digestions
• Add glass or ceramic beads to prevent bumping during boiling
• Handle muffle furnaces and items inside carefully using heat-proof mittens
• Do not place volumetric flasks with lids intact when drying in hot air ovens

Sample Dilutions

• Use micro pipettes of appropriate glass pipettes.When using pipettes never mouth pipetting. Always use rubber bulb for the purpose.
• Always add strong acid to water and not water to acid when making dilutions
• Bring chemical/solvent to room temperature before opening the bottle specially if volatile or hazardous contents are at a higher temperature.
• After drying glassware ensure that it reaches room temperature before using for dilutions activities
• It is convenient and safe to carry dilutions volumetric flasks in a tray when serial dilutions are required
• Handling of laboratory gases
• Always use handheld trolleys for moving cylinders from one location to another
• Cylinder heads should be capped when gases are not in use
• Flammable gases such as hydrogen should be kept outside the laboratory
• Cylinders should be kept chained to laboratory workbench or wall to prevent accidents
• Make use of makeshift stable ramps in stairway when cylinders are to be moved from one floor to another

Handling of Spills

Spills can happen in any laboratory and can lead to harmful exposure to personal or pose a risk of fire and explosion. Special procedures are prescribed for handling spills of solids, liquids, mercury, radioactive and biological materials

Spill management kits with absorbent materials such as mops and neutralising agents should be readily available. In time of need scurrying around for such items can be prevented if kits are readily available

Acid spills – do not attempt to mop directly. First cover spill with sodium carbonate or sodium bicarbonate to neutralise the strong acid and subsequently mop with water

Alkalis – cover with weak acids such as boric or citric acid and mop subsequently with wet mops

Organic solvents – use protective gloves for mopping. Cover oily spills with sawdust before mopping. Collect sawdust into waste bag and subsequently mop the floor

This article provides some basic guidelines and this topic is exhaustively covered in standard texts. Please do leave your comments.