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Take precautions when storing wood pellets

February 16, 2019

WOOD pellets seem harmless enough but if they are not stored correctly – they could kill you.

If that sounds far-fetched, consider these real life stories (names not published), which actually happened and give a wider cause for thought when it comes to storage and use of solid fuel:-

A pregnant woman, aged 28, died in Switzerland in February 2011. Her husband was a caretaker and she helped him out, entering a pellet storeroom which led to her death.

An Irish man, aged 38, died when he entered a 7-tonne wood pellet storage room for his boiler. It happened in November 2010 and both his wife and a friend, who tried in vain to help him, were later treated in hospital.

Lastly, a German engineer died in Jan 2010 when he opened the bunker door of a pellet store, which supplied 700 homes. There were about 155 tonnes of pellets there. A second man managed to escape and call for help, but he needed medical treatment.

Why did these people die, or suffer serious harm? What can be serious about walking into a storage room for pellets? Most importantly, what was the common denominator in all the deaths and injuries?  Some nine verified deaths, in total across Europe, since 2002.

The answer: carbon monoxide.

Carbon monoxide (CO) is an invisible, odourless gas, which causes serious harm or death by preventing oxygen from circulating around a body. It’s a toxic gas and one of the many gases produced as a result of a fire. That’s why swept chimneys are so important – a clean chimney provides a safe passage route of CO from an indoor fire to the outside atmosphere.

So what happened with these wood pellets? And what ARE wood pellets? Pellets are a biofuel used in combustible heating and usually constructed from wood shavings, milled and dried sawdust which have been compressed together.

Wood pellet boilers are often used as an alternative to oil or gas boilers. They have also been replacing coal-fired boilers in schools. The pellets are usually stored in sealed tanks/hoppers or store rooms with a screw feeder connected to a boiler. Because it is an intense atmosphere, oxygen levels decrease and CO levels from the pellets rise, due to auto-oxidation of fat acids in the wood.

Even little amounts of wood pellets in a small, unventilated space can be deadly. Other factors include younger pellets producing more CO; and the wood type, such as pine, often used for pellets has more fat acids increasing auto-oxidation.

Take these safety precautions if you do use wood pellets – only allow an approved installer to set up the store room; Check that the store has correct ventilation. NEVER enter a pellet sealed store area or hopper containing toxic gas – only fully trained and equipped professionals should do so; sealed storage areas for wood pellets must be ventilated and gas levels regularly checked by professionals. For further advice, contact the manufacturer, or the Health & Safety Executive.

To get more info about indoor fire safety and advice about carbon monoxide safety, please contact your local member of the Guild of Master Chimney Sweeps. Find your local sweep in this directory: click here.

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