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Good laboratory practice

General work rules and regulations

  • It is mandatory to wear approved eye protection in all rooms containing chemicals, unless the Head of Department and the responsible VIP have agreed otherwise.
  • It is mandatory to wear lab coat in all experimental laboratories.
  • Never work alone. No syntheses at night.
  • Do not start an experiment before you have gathered the needed equipment (substances and apparatus).
  • Synthesis and preparation work must be kept in fume cupboards as far as possible. All foul-smelling and dusty work must be kept in fume cupboards, including cleaning of the used apparatus.
  • Comply with regulations. Only deviate from regulations in consultation with supervisor or instructor. Be particular cautious about uncritically multiplying the quantities. Mainly work in a small scale.
  • Regularly keep a log of all relevant things about the lab work
  • Synthesis reactions should as far as possible be kept in closed systems. Open systems must be completed with e.g. reflux condenser
  • Heating of organic solvents e.g. by recrystallization must be done under reflux condensation
  • If a gas is generated by a reaction, or if a gas is led through the reaction mixture, the escaping gas must be absorbed (dissolved or chemically converted) or cleaned for co-precipitated substances before it is led into the exhaust.
  • Water aspirators must NOT be used for suction filtration of organic solvents, instead use membrane pumps
  • Filtered out (including suction filtered) preparations must always be air-dried in fume cupboard or dried in desiccator. They must NOT be dried in incubator. Seemingly dry preparations can contain large quantities of solvents and cause air pollution and explosion. The incubator is for drying glass for adsorbed water.
  • An user's guide and a function manual should be placed at each fume cupboard
  • Eating, drinking and smoking is forbidden in the laboratories
  • Storage of food is forbidden in the laboratories
  • Keep the laboratory organized
    • Put apparatus in its place, when it is not used. Do not put any apparatus on the floor
    • Put chemical containers and test-tube bottles in their place after use
    • Tidy up the fume cupboard
    • Containers and bottles with inflammable liquids (solvents) must not be placed on the table nor kept on the floor. They must be kept in special cupboards or cupboards with suction
    • Spilled water must immediately be cleaned up. Risk of falling
    • Spilled chemicals must immediately be captured and removed according to the regulations
    • Clean glasses after use
    • Tidy up the laboratory every day after finishing the work
    • Experimental setup and products must be clearly marked with "Date, content and owner" in order to allow other people to react correctly in case of accidents

Preparation og laboratory work

It is important that laboratory work is prepared carefully for the sake of both safety and a good result. A regularly kept laboratory notebook is an invaluable and indispensable means of ensuring these purposes. In most groups it is imperative to keep laboratory notebook.

Assessment of risk factors and safety regulations is an important step in preparing for a current work. It may be necessary to seek information about the properties of a substance: State, reaction to water, inflammability (flash point, ignition temperature and explosion limits), corrosive properties, smell, toxic properties and especially long-term effects, ability to penetrate rubber and plastic (gloves) and the threshold limit value.

For the vast majority of known chemical compounds and products much of this information does not exist. Only the typical physical and chemical properties are registered. However, many of the unhealthy and environmentally damaging properties are described in different types of literature.  

Each employee should as part of the preparation for laboratory work (experiment or routine operation) consider the risk to which the work gives rise:

  • As a result of physical, chemical and toxic properties of the chemicals, substances and mixtures that are to be used or that can be formed
  • As a result of the special features (e.g. large generation of heat) of the reaction or procedure that is intended to be carried out or followed
  • As a result of the apparatus set-up that is meant to be used

Search the literature for missing information

Note substantial information about risk and precautions in the laboratory notebook:

  • Where alternative procedures are possible, the one associated with the least risk should be used.
  • If a substantial risk cannot be eliminated, it should be considered to abandon the experiment. If this does not happen, the responsible project manager should personally carry out or monitor the carrying out of the experiment
  • The member of academic staff who initiates a project/work (the responsible project manager) should personally be aware of the health and environmental side effects that the project/work may cause. The project manager is also responsible for ensuring that the employees (or students), who are involved, also have this knowledge and act accordingly, prior to the start of the project/work
  • Be prepared to provide first aid to yourself and others if the accident happens after all

Fume hoods and the use of these

Work with substances and reactions that evolve harmful or foul-smelling gasses or vapours must be carried out in fume cupboard. In principle, any chemical work should be carried out in fume cupboard, as far as it is possible.

The safety of the user when working in a fume cupboard depends partly on the technical and the structural conditions, partly on the personal and current conditions:

  • The substances that are used and the quantities
  • How the user is handling the substances and is behaving in front of the fume cupboard
  • Setups or other impediments to air movement within the cupboard
  • The temperature in the fume cupboard

Following rules apply to the use of fume cupboards:

  • After opening the fume cupboard, check that the exhaust device and the control device (the alarm) function. Be aware of any defects.
  • Always work with the smallest possible opening. It is, however, not possible to keep the cupboard completely closed, when heating is carried out within the cupboard, because heat changes the balance. 
  • Always close the cupboard completely, when you leave it
  • Respect the alarm of the fume cupboard, when it sounds; make sure to correct the error. When the alarm sounds, the suction is insufficient for you to work safely
  • Keep your face (the respiratory organ) above the edge of the fume cupboard door
  • Place setups close to the back wall and as far away as possible form the side walls. Raise any larger setups, which interfere with air movement within the cupboard, approximately 5 cm.
  • Avoid fast movements during the work and when opening the door. Avoid the use of open coat. Avoid open windows and passing the fume cupboards rapidly - it involves a risk of emission
  • Comply with elementary safety rules for working with inflammable materials in the fume cupboard. For instance, open fire is not allowed in the fume cupboard
  • Keep the fume cupboard clean and tidy. Tidy up and wipe the bottom of the fume cupboard. Do not use the fume cupboard for storage of e.g. chemicals
  • If you observe errors that cause safety hazards, immediately stop the work. Notify the Facilities Management Department, the safety supervisor or the department's safety group
  • Heating apparatus must always be placed on a lift table so that the heating can be interrupted without major safety risk

The alarm system of the fume cupboards:

The Danish Working Environment Authority requires that fume cupboards must be equipped with an alarm that is activated if the suction is insufficient.

Each fume cupboard has its own alarm system which alert by means of sound and red light as soon as the exhaust (the low pressure) drops below a preset level

When a fume cupboard is closed, a slight exhaust is maintained. When the fume cupboard door  is opened, the exhaust increases. However, an opening of approximately 40 cm will activate the alarm. Even before the cupboard is opened that much, air whirls in the opening can reduce the exhaust efficiency, especially if many fume cupboards in the laboratory are open at the same time, as there are limits to the total exhaust capacity.

Introduction to vacuumtechnology and distillation/rotary evaporator

  • Always wear goggles or face screen when working with vacuum
  • When there is vacuum on the system all work must be carried out behind closed fume cupboard doors
  • Always make sure that the glass is intact and without stars
  • Use vacuum grease if necessary to get a completely sealed system
  • Never use flat-bottomed round flasks when working with vacuum
  • Start the assembly of the distillation setup by attaching tubes on the Liebig condenser to avoid water spill in e.g. hot oil bath
  • Water + very hot oil/PEG = "EXPLOSION" with splashes of hot oil/PEG!!
  • Cooling water tubes must be attached correctly with regard to intake and outlet - they must be fastened with cable ties/copper wire
  • Secure all ground joints with joint clips
  • Remember vacuum boiling chips, capillary tubes or micro magnet (to avoid bumping). If the vacuum has been turned off due to e.g. a leak in the system, you must use a new boiling chip. A boiling chip can only be used once. Never put a boiling chip in a "boiling flask"
  • Wrap the column before the apparatus gets hot (cotton/tin foil)
  • Always put vacuum on the system (check tightness) before oil/water bath is introduced
  • Remove the oil bath (lower the level table) before air is released into the system
  • Always release air into the system before the filter pump/diaphragm pump is turned off in order to avoid backwash
  • Release air slowly into the system when a manometer is connected
  • Never put your head/upper body inside the fume hood to check the temperature
  • Be careful using a heat gun for heating in vacuum distillation. May only be used by experienced people in the laboratory or under the guidance of experienced people.

Outside normal working hours

  • No one who is alone at the department is allowed to carry out experimental work or shop work which may involve a risk. When working alone at the department with non-hazardous work, you should make sure that at least one person outside the department is aware of it
  • When you leave laboratories or other rooms for the night, weekend or the like, windows must be shut and the light turned off. Electrical equipment that is not in use and that is plugged must be shut off by the plug, and all gas and water taps must be turned off (also by the permanent cooling water connections)
  • Fume hood doors must be completely closed when the fume hood is left
  • If it is necessary to let an experimental setup run unattended overnight, cooling water connections and suction lines must be attached securely on pipe connections. Electrical installations must be secured against unintended temperature increases that could cause fire
  • The person who leaves an installation in operation is responsible for ensuring that all relevant safety regulations are followed
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