Extension leads: a hidden fire risk in UK homes

Fire safety experts are urging households to check the rating printed on their extension leads, warning that overloaded leads are becoming one of the most overlooked fire risks in UK homes. The advice follows a series of serious fires that have highlighted the dangers of everyday electrical habits.

Jonny Smith, a fire risk assessment specialist at Crusader Fire, said extension leads are designed for convenience, not for carrying the full load of multiple high-powered appliances at once. "The risk builds gradually, so people often don't realise there's a problem until it's too late," he warned.

The science behind the danger

When an extension lead is overloaded, it can overheat quickly. According to Smith, the heat has nowhere to go, which can cause the insulation to break down, wires to degrade, and in some cases ignite surrounding materials. "What makes this risk particularly concerning is how normal it's become," he said. "Phone chargers, laptops, kettles, air fryers — people plug in multiple items without thinking about the combined load."

The scale of the problem is significant. Electrical Safety First reports that around half of all accidental house fires in the UK are caused by electricity, with misuse of electrical equipment, such as overloading sockets, being a key contributing factor.

Everyday habits that increase risk

According to Smith, several common behaviours can increase the likelihood of overloading an extension lead:

  • High-wattage appliances on one lead: Items like kettles, heaters, and cooking appliances draw a large amount of power individually; combined, they can quickly exceed safe limits.
  • 'Out of sight, out of mind' setups: Leads tucked behind sofas, desks, or kitchen units can overheat without being noticed.
  • Always-on culture: Devices left plugged in continuously increase heat build-up over time.
  • Daisy-chaining: Plugging extension leads into one another significantly raises the risk of overheating and electrical failure.
  • Ageing or low-quality leads: Older extension leads or cheaper models may lack proper surge protection or overload protection.

Many people assume that if a plug fits, it is safe to use, but extension leads have a maximum load, and exceeding it even slightly can lead to serious consequences.

How to check your extension lead

The rating of a standard UK extension lead is typically 13 Amps, which corresponds to a maximum of 3,000 to 3,120 Watts. However, some leads have lower ratings, such as 5A or 10A, and it is important to check before use.

You can usually find the rating on the back or underside of the socket block, on the main 3-pin plug, or on the cable reel itself. Smith advises looking for that number and making sure you don't exceed it.

Practical steps to reduce risk

To reduce the risk of fire, Smith recommends plugging high-powered appliances such as kettles, heaters, and air fryers directly into wall sockets rather than extension leads. He also advises:

  • Avoiding daisy-chaining extension leads.
  • Keeping cables uncoiled and ventilated to allow heat to escape.
  • Inspecting leads regularly for signs of wear or damage.
  • Unplugging devices when they are not in use.

By taking these simple precautions, households can significantly reduce the chance of an overloaded extension lead starting a fire. As Smith puts it, the risk may be hidden, but it is entirely preventable.