Fire precautions

Fire compartment

A fire compartment is a part of a building separated by fire-rated floors, walls and doors to prevent the spread of smoke and fire between different parts of the building.

Our laboratory premises are not always designed as separate fire compartments, but are often included as one of several premises in a single fire compartment. This means that a fire in one laboratory can spread to neighbouring rooms. It is therefore important to understand the activities and risks in the surrounding area.

Each fire cell has a separate ventilation system, but there may also be a ventilation system in the laboratory that serves only a fume cupboard or a flammable storage cabinet, for example.

Cabinets or storerooms for flammable gases must be separated to fire class EI30 or higher and are then considered as a separate fire cell. Flammable liquids may be stored in ventilated cupboards without fire class, up to 50 litres per fire cell. Therefore, if several companies use the same premises, it is important that they work together to ensure that the 50 litre limit is not exceeded. Read more about this in the section on flammable goods.

Evacuation route

In principle, every building should have at least two independent evacuation route. If one route is blocked by a fire or other event, you should be able to get out via the other route. It is therefore important that an escape route is never blocked.

Extinguishing equipment

Hand-held fire extinguishers should be available in laboratory premises and a guideline is that the distance to the nearest one should not exceed 15 metres. There are several different types of extinguishers, but the most common in the laboratory environment is the carbon dioxide extinguisher. It contains a clean and self-cleaning extinguishing agent that does not destroy sensitive equipment. Extinguishers with some form of additive are also usually present in our premises.

Cabinets or storerooms for flammable gases must be separated in fire protection class EI30 or higher and are then counted as a separate fire cell. In the case of flammable liquids, these can in some cases be stored in ventilated cabinets without a fire class, up to 50 litres per fire cell. Read more about this in the section on flammable goods.

For more specific information about structural fire protection in a particular lab - contact the fire protection coordinator at LiU or the Coordinator Fire Safety at Region Östergötland, see the menu on the right.

Most flammable goods in use give off flammable vapours which may form an explosive atmosphere during normal handling. An explosive atmosphere is a mixture of gas or vapour in air which, in contact with a source of ignition, may ignite, in which case explosion documents (classification plan) and associated classification drawings must be prepared.

These explosion documents indicate where flammable/explosive gas mixtures may arise. Classification drawings show where in the organisation these areas are located. The classification drawings indicating the risk area for explosive atmospheres must be available and known in the organisation. Ignition sources must not be present within these zones. Classified areas must be protected so that nothing that can ignite the explosive atmosphere enters them. Equipment that can be sources of ignition include mobile phones, electrical equipment or tools that can become hot. Electrical equipment to be used or placed in classified areas must be ATEX certified.

Determining which areas may contain explosive atmospheres is called zone classification. The zones are shown on a classification drawing.

• Zone 0 is an area where explosive atmospheres are present continuously, persistently or frequently. Explosive atmospheres can often be expected to be present inside vessels containing flammable liquids.
• Zone 1 is where explosive atmospheres occur occasionally during normal handling. This may, for example, be an area where minor spills, splashes, evaporation and emissions normally occur.
• Zone 2 is an area where explosive atmospheres occur only rarely and then only briefly. This could be if there is a release that is not intended but can still be expected to happen.

To establish a new classification plan or make adjustments to an existing one - contact LiU's fire protection coordinator or Region Östergötland's fire protection controller.

Electrical equipment should always be used safely and according to the supplier's instructions. Equipment used in laboratories may require high currents. It is therefore important to check that the equipment in question, wall sockets and power strips can withstand the load to which they are subjected. Loose electrical installation should be avoided as far as possible.

• Cable reels should not be used but replaced with power strips.
• Power strips should not be placed horizontally on a workbench or on the floor where there is a risk of spillage or where heavy gases can find their way down. Instead, place them on the wall or equivalent.

The electrical equipment used in laboratories should be checked and maintained according to the manufacturer's instructions or according to their own procedures. Damaged equipment should be replaced or repaired.

Electrical equipment in classified zones

In a hazardous area, only ATEX-certified equipment may be present. This applies to equipment with an inherent ignition source (both mechanical and electrical equipment, such as switches, agitators, etc.).

A supplier must be provided with the classification plan that specifies the requirements for the equipment. The following can be used to support the selection of equipment.

After installation, an electrical installation certificate should be provided by the contractor. This document should verify that the equipment and installation fulfil the requirements of the hazardous area. Supervisors should have access to the electrical installation certificate.

Electrical equipment in fume cupboards

In some cases, equipment that is not ATEX classified may be used in fume cupboards. In this case, the fume cupboard must fulfil the following requirements.

• Fume cupboards shall have an air velocity of at least 0,5 m/s in the door opening.
• 2/3 of the exhaust air shall be exhausted at the bottom of the enclosure and the remainder at the top.
• The working surface shall be provided with a low point to minimize evaporation from spills.
• Electrical equipment in the cabinet shall be interlocked over the ventilation, i.e. switched off if the ventilation becomes too low. Only sockets belonging to the cabinet may be used.  Resetting must be done manually.
• The cabinet must be fitted with a spillage edge or an insert with an absorbent surface.

If the fume cupboard meets these requirements, no explosive environment is formed.

Every organisation should have procedures in place that describe what to do in the event of an alarm, fire or gas release.

In addition to the general fire procedure described in the Fire section of Emergency, Accident, Incident, the procedure should include other actions to be taken in the event of a fire or evacuation.

For example, the procedure should cover cases where equipment or gas inputs need to be shut down to prevent release. If doors need to be closed to prevent the spread of smoke and fire, or if other equipment and activities in neighbouring premises would be affected. These are only examples of what a procedure might include. It is up to each individual organisation to determine what additions to the fire and evacuation procedure should be included.

The procedure must be available and communicated to all staff and students working on the premises.