5


The flash points are self evidently low. In a single skinned or double skinned cabinet the boiling points would be reached very quickly indeed within the first couple of minutes. A solvent can expand by a factor of tens of thousands when turning into a vapour and the autoignition temperature is reached soon afterwards. Heat enters the cabinet extremely quickly and solvent vapour escapes soon afterwards with potentially catastrophic results.


Several factors in BS EN 14470-1/2 cabinet construction minimise the amount of heat entering a cabinet and minimising the amount of solvent vapour released into the working environment. These are as follows:


1) Main body construction is highly insulating gypsum encased in sheet metal.


2) Every possible air gap is surrounded by intumescent materials which swell up to 20 times their original volume in the event of a fire.


3) Thermal fuses are incorporated so that doors or drawers which are left open automatically shut in the event of a fire.


BS EN 14470-1 requires a furnace test by an independent material testing institute: • The fire resistance must be investigated by tests on a design sample • The fire resistant cabinet is exposed to flames in a suitable furnace


• The doors, walls and ceiling of the cabinet being tested must be exposed to the same heating conditions


Safety storage cabinets according to BS EN 14470-1 in a laboratory at Gießen University • Cabinets must be tested as free-standing single cabinets


• The example being tested must be positioned with its rear wall at least 100 mm from the furnace wall


• The flame exposure is carried out in accordance with the standard temperature curve of BS EN 1363-1 (5.1.1)


• The temperature rise is measured inside the cabinet


• The cabinet must then be classed as type 15, 30, 60 or 90, according to the time that has elapsed before the temperature rose by 180 K.


Apart from the safety aspects, cabinets according to BS EN 14470 can be equipped with many different interior equipment variations, in order to make work most effective and utilise maximum storage space.


Furnance test according to BS EN 14470-1


When it comes to storing flammables in a cabinet it is not only important to shield the flammables from an external fire, but also to avoid fires or explosions inside. This can be achieved by technical ventilation. The Standard also gives clear advice:


BS EN 14470-1 (safety storage cabinets for flammable liquids) • Cabinets shall be equipped with openings for inlet and exhaust air • The openings must close automatically when exposed to a temperature of 70 +/- 10°C


• The entire air volume inside a ventilated cabinet shall be exchanged at a rate of at least 10 times per hour, at a maximum pressure drop of 150 pa


• Ventilation has to be effective directly above the bottom collecting sump


BS EN 14470-2 (safety storage cabinets for pressurised gas cylinders) • Cabinets shall be equipped with openings for inlet and exhaust air • The openings shall close automatically in the event of a fire


• The entire air volume inside a ventilated cabinet shall be exchanged at a rate of at least 10 times per hour for flammable or fire supporting gases; at least 120 times per hour for toxic gases; at a maximum pressure drop of 150 pa


• Air circulation system within the cabinet shall ensure adequate purging from minor leakage Type 90 safety storage cabinets according to BS EN 14470-1 in a laboratory at Sussex University


More than 50 safety storage cabinets connected to a central ventilation system


Clever Combination


Storage space in the workplace is often at a premium but when it comes to hazardous materials, safe storage is essential for protecting lives and the environment.


The 2-in-1 combined safety storage cabinet from asecos protects both – and saves on space. Especially where space is rare and additionally only a small quantaty of hazardous materials is needed this criteria could be of great value.


The unit combines a Type 90 cabinet certified to the high standard of BS EN 14470-1 for storing flammable liquids with a cabinet for storing aggressive acid and alkaline solutions. The latter consists of two separately ventilated and hermetically sealed chambers, so rules governing segregation are met. Only one unit is needed, instead of two. The combined cabinet has the dimension of a normal 120cm wide safety storage cabinet, meaning the cabinet saves space, costs and efforts of maintanance.


The flammable substances cabinet is made from fire-resistant components conforming to BS EN 14470-1, as well as the outer body of the combined cabinet, while the acids and alkalis section is made from highly chemically-resistant melamine. Fully extractable, gliding drawers add to the safety and convenience of this storage solution.


Circle no. 515


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36