Just received the WSH Alert (Singapore) on a recent laundry fire caused by spontaneous fire (copied below). See my earlier post on a similar topic.
WSH Alert: 26 0ay 2008
Laundry fire caused by spontaneous ignition
A fire broke out in a laundry shop on 2 April 2008 at about 2am. There had been a few cases of such fires. Investigation revealed that these fires were probably caused by spontaneous ignition, a result of poor dissipation of heat generated from chemical reactions of chemical residues in the laundry.
Spontaneous ignition may occur when heat, combustible material and reactive chemicals are present. The ignition can take place over a period of time, ranging from 3 to more than 57 hours (source: Robison, Don. “Laundry Fire, Probable Cause: Spontaneous Ignition” in Industrial Fire World Magazine) This implies that fires caused by spontaneous ignition can occur after working hours when no one is present in the factory.
Laundry factories are exposed to the dangerous combination of heat, combustible material and reactive chemicals due to soiled linens. Here is a Technical Advisory to provide you with information on the spontaneous ignition of laundry and the precautions to undertake:
Technical Advisory For Laundry Factories on the Spontaneous Ignition of Laundry Spontaneous Ignition
Spontaneous ignition is the occurrence of fire without the application of an external heat source. They can occur in the following forms:
• A pile of soiled laundry where the soiling agents are reactive and heat up the fabric as a result of the respective reaction processes until ignition takes place.
• Washed and dried laundries where there are still remains of oil residues which generate heat (from exothermic chemical reactions) that is poorly dissipated.
Heat, combustible material and residual oils increase the possibility of spontaneous ignition. The residual oils such as vegetable oils and massage oils can self-heat to the point of ignition. Improper washing practices such as the lack of proper detergent, low water temperature settings and faster wash cycles may not be able to remove these oils in a normal wash. The storage of washed laundries with residual oils is also a concern as they are often stacked up after the drying process without adequate prior cooling time. Poor dissipation of the inherent heat (from the drying process) and generated heat (from the residual oil reactions) could lead to spontaneous ignition.
Another possible contributing factor is that soiled laundry is often collected and stored in carts. Washed laundry from the dryer or ironer may also be placed in carts for storage or delivery. Some of these carts are made of plastics which are excellent thermal insulators and may hold in the heat generated, an effect similar to that of a large stack or pile of laundry. This increases the likelihood of spontaneous ignition of laundry in the carts. Furthermore, when ignition takes place, most plastics can become fuel which further sustain the fire.
Control and Preventive Measures
Here are some measures that laundry factories should implement:
a. Inform all workers of the hazard of spontaneous ignition.
b. Make sure that all the dryers have a cool down cycle long enough to properly lower the temperature of the dryer load. Check the temperature settings of each dryer on a regular basis.
c. Maintain dryers regularly to ensure that laundry will not be heated to excessively high temperatures.
d. Wash items with oily stains thoroughly and use a proper heavy-duty liquid laundry detergent.
e. Allow enough time for all heat to dissipate before folding or bundling.
f. Never store bundled or folded laundry in boiler rooms, next to hot water heaters, behind dryers, or any areas where the temperature is higher than normal room temperature.
g. Install smoke detectors where bundled or stacked laundry are stored. Ensure effective implementation of other emergency measures like fire extinguishers, evacuation route and fire drills.
h. Never allow large loads to remain in dryers after the drying cycle has ended.
i. When laundry catches fire, normal plastic laundry carts will melt and the flaming liquid plastic can spread the fire. Check with your cart supplier or manufacturer to ensure that the laundry carts are made of noncombustible or highly fire-retardant materials.
This WSH Alert is available free of charge, may be printed or downloaded onto electronic, optical or similar storage media provided that such activities are for private research, study, or in-house use only. If such material is to be copied or reproduced, users are asked to ensure that the material is reproduced accurately and not in a misleading context, that the status of the material is identified and to acknowledge Workplace Safety & Health Council, Singapore as the source of the material.