Friday, December 4, 2009



1.1 Never start an experiment on a bench already crowded with apparatus.

1.2 Avoid leaving a laboratory experiment unattended.

1.3 In case an experiment should be left overnight, involved, the scale of the experiment and the level of the supervision available.

Regular supervision by a competent person who has been fully briefed on possible hazards

should be arranged. (Danger periods are during initial heating, when approaching boiling points

or reaction temperatures, and during additions of further reactants or catalysts).

1.4 Before starting an experiment familiarize yourself and your assistants with all the known

hazards of the starting materials and end products. Decide on appropriate safeguard and


Great care must be taken with unknown combinations of chemical reagents. Anything

unexpected occurs during your experiment, consult your immediate supervisor.

2.0 Machinery :

2.1 Always treat moving machinery with the greates care. Observe necessary safety precautions stipulated by the safety manual.

2.2 Never remove the guards or safety-devices from a machine.


3.1 Use lubricant and a cloth for protection when inserting glass tubing, rods or thermometers into bungs or tubing.

3.2 The safest way to carry lengths of glass rod/tubing is in the upright position. Cut ends of glass rods / tubings should be fire polished before use. Take care in handling glass capillaries.

3.3 Glassware used under vacuum presents a hazard because of the possibility of implosion and should be always inspected before use.

Vacuum desiccators should be protected with a framework of wire or nylon. Air admittance

should be carried out gradually.


1.1 Experiments using hazardous chemicals should be carried out in fume cupboards so as not to endanger co-workers.

Suitable respiratory protection should be always on hand.

1.2 Observe special precautions when handling new organic substances of which the toxic hazards are unknown.

1.3 Wear Eye protection (safety glasses), and where considered necessary use face shield and protective gloves.

1.4 Operations involving grinding of glass vials, ampoules – for glass alkalinity test – grinding of materials, sieving of powders or working with aerosol sprays require wearing of protective wears such as face-shield, rubber gloves etc.

1.5 Always use an approved pipette filter. Never fill pipette using your mouth.

1.6 When boiling a solution in a test tube, keep the mouth of the test tube away from co-worker working next to you or own self.

2.0 Fume Cupboards / Portable Safety Screens :

2.1 Fume cupboards and portable safety screens afford additional protection. Make proper use of them for hazardous operations particularly involving exothermic reactions. Always carry out chemicals reactions and distillations in fume cupboards where there is any possibility of a hazard.

3.0 Flammable Solvents :

3.1 Use a water bath, steam bath or electric heating mantle when using large amounts of flammable solvents. Isolate such experiments. Ensurre that adequate fire extinguishers are available

3.2 Get to know the position of the main laboratory controls for electricity, gas and water and see that they are not in anyway obstructed.

Remember that :-

-Catch-trays may be used to localise possible solvent fibres.

-Electrostatic discharge can ignite flammable vapour /air mixture.

-Water-immiscible solvents must not be poured down drains.

-Always use the approved facilities for disposing of flammable solvents.

--Neveer mix waste solvents in a common bottle or a carboy. Use separate containers, clearly

marked – WASTE FOR DISPOSAL, and name of solvents.

1.0 Condenser :-

1.1 Check the condition of flexible condenser tubing and ensure that it does not become trapped. Check that all connections to a condenser are well secured with clips and be extremely careful with tap settings. The water flow may vary as the conditions change.

2.0 Glassware :-

2.1 Examine all glassware before use for damage, star crack or even a scratch as these defects can cause failure under vacuum.

2.2 Never store broken glassware in cupboards. Either send it for repair or ensure its proper disposal.

2.3 Support all large glass adequately. Do not clamp a large glass vessel solely by the neck. Additional support at the base will improve stability. Never carry a winchester bottle by the neck. Use an approved carrier. Never handle large pieces of glass-ware with wet hands.

3.0 Pressurised Gas Cylinders :-

3.1 Compressed gas cylinders should be always in the upright position and properly supported with stand and chain.

3.2 Use only the permitted valves and regulators. Regulators must be free from oil and grease.

3.3 Before connecting up a gas cylinder, always ensure that the correct gas is being used by carefully checking the printed name of the gas on the cylinder.

(Do not rely on colour codes as these may vary according to the supplier and country of origin).

3.4 Always provide a surge vessel and a system of taps between a gas cylinder and reaction vessel.

1.1 Always turn off, a gas cylinder at the main valve after use and release any excess pressure in the regulator.

1.2 Use approved cylinder trolley for transfer of gas cylinders.

Never handle or lift a cylinder by holding its valve.

1.3 Store pressurised gas cylinders n a cool, ventilated place.

2.0 Electricity :-

2.1 Remember that electricity is dangerous. Death could occur at 60 volts AC.

2.2 See that all wires are properly insulated.

2.3 Ensure that no water points or rubber connections carrying water are allowed to leak on to electrical plugs and switches.

2.4 Worn or damaged cables, sockets and plugs are all dangerous.

Report all electrical faults to your laboratory head/ Maintenance section. Get them replaced.

2.5 All electrical repairs including the replacement of fuses, should always be carried out by an electrician.

3.0 Store –room / Refrigerators :

3.1 Laboratory store-rooms and refrigerators should be inspected regularly.

Hazardous chemicals should not be stored indefinitely but safety disposed of after a project is



3.2 All samples should be properly labelled. Lquid samples should be in closed vessels and be placed on metal drip trays.

3.3 Electrical controls and switches inside refrigerators and freezers may cause sparks which could be a source of ignition for flammable vapours. DO NOT STORE FLAMMABLE SOLVENTS IN THE REFRIGERATOR. Refrigerators should be defrosted rregularly. Do not store food items in the refrigerators.

1.0 Biological / Radiation Hazard :-

1.1 Ensure that special precautions are observed when work on pathogenic micro-organisms or radioactive isotopes is carried out in the laboratory.

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