Spontaneous Ignition – the hidden danger when doing laundry

Vero received a claim for a fire that caused extensive damage to a small business. Upon investigation, we discovered that the cause of the fire was the spontaneous ignition of towels, rags and napkins in the tumble dryer. 

After being washed, the linen was dried in the tumble dryer and left overnight. In the early hours of the following morning the towels, rags and napkins spontaneously ignited. 

It might surprise businesses to know that fires caused by spontaneous ignition involving laundry are relatively common. 

It’s possible for fires to start by spontaneous ignition in any business that does laundry, which can range from day cares, creches, beauty salons and massage parlours to cafes, restaurants, hospitals and aged care facilities – and of course, commercial and self-service laundries.

But there are a few simple steps you can take to reduce the risk of spontaneous ignition causing a fire that could damage your premises and put a halt to your trading for an extended period of time.

What causes spontaneous ignition? 

Spontaneous ignition is caused by a chemical process called oxidation which occurs when a substance combines with oxygen. Oxidation creates heat, and if the heat can’t be removed (for example, by air flow) the temperature of the substance continues to increase until it reaches its ignition temperature and catches fire. 

Oxidation can occur naturally among warm or damp fabrics during the laundering process. There are a few common factors that can increase the chance of spontaneous ignition.

- Cotton fabrics that are coated or contaminated with vegetable oils, including cleaning rags, dish cloths, towels and aprons
- Warm or damp linen being stored in a warm area
- Exposure to heat sources like hot pipes or tumble dryers
- Lack of ventilation for compressed or folded laundry
- Exposure to direct sunlight
- Detergents that contain oxidising chemicals

Tips for businesses to prevent spontaneous ignition

The fire risk associated with laundry operations can be reduced if businesses follow a few simple precautions to reduce the chance of spontaneous ignition.

Wash soiled items on the right setting

Cold water washes don’t always remove all the oils, fats or detergent from aprons, tea towels and dishrags. Adjust your wash temperatures and detergent for the optimum removal of any oil and fat contamination, and rinse your laundry before drying.

Maintain equipment correctly

Laundry equipment on your premises should be installed, maintained and operated as recommended by the manufacturer. It’s a good idea to regularly check any thermostat controls and clean and check lint filters daily.

Ensure air exhaust pipes are free of obstruction

Lack of ventilation increases the risk of spontaneous ignition, so ensure that tumble dryer air exhaust vents are free of any obstruction or blockage.

Keep soiled laundry away from heat sources

Don’t store soiled laundry near heat sources like tumble dryers or in direct sunlight. It’s also a good idea to wash things as soon as possible.

Line dry high risk items

Foam rubber, waterproof textiles, plastic shower caps, rubber backed items or clothes, mop heads and anything that has been contaminated with vegetable oils should ideally be line dried – because the temperature of a dryer may cause these items to ignite. 

Only tumble dry while someone is on the premises

If possible, it’s best to only tumble dry laundry while someone is present, and will have time to empty the dryer as soon as it’s finished, and cool and store the laundry. Leaving dryers or hot laundry unattended means that if a fire does start, it might be some time before you catch it. 

Let items cool down

Ensure that when you are using a dryer, you don’t skip the cool-down part of its cycle. Once the dryer is finished, it’s best to empty it immediately and spread out the laundry into small piles to allow it to air out and cool. Dry laundry left in a plastic container or cart will retain heat, so metal open mesh baskets are a good alternative.

What if a fire does start?

Where there is a risk of spontaneous ignition, you should make sure you have a fire extinguisher on hand. It’s useful to get specialist advice on the size, number and location of fire extinguishers a business needs, but dry powder fire extinguishers with the appropriate rating should be the minimum.