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
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.