Is a magnifying glass a fire hazard?

The key to localising photons is in the convex shape of the magnifying lens. This shape collects photons on one side of the lens and draws them to a single point as they enter out the other side. As such, any item with a convex lens can be a fire hazard. For example, a pair of glasses or a binocular lens can also be used but a magnifying glass or magnifying mirror is bigger.

The larger the lens, the easier it is to start a fire and cause significant fire damage.

The steepness of the convex shape also plays a part in achieving the extreme heat needed to achieve combustion.

Magnifying glasses concentrate the sunlight very effectively, refracting the rays and bringing them to a tight focus. But even fragments of glass can have some focusing effect – with potentially disastrous consequences.

The sun’s rays can be magnified by a lens or magnifying mirror and become focused on a nearby object such as curtains, clothing or even wooden or plastic furniture, fixtures or fittings.

This can cause scorching, or charring potentially leading to smoke, smouldering or an actual fire. Fire damage can spread throughout a domestic or commercial property very quickly if the fire is not detected.

In the evening, morning and during the winter, when the sun is lower on the horizon, the shallower angle at which the sun’s rays hit the earth means that it is particularly important to be aware of objects that can cause a fire hazard. These can be magnifying mirrors, and glass ornaments or a magnifying glass, which may be left exposed to direct sunlight.

Most commonly this is because glass objects like magnifying glass and magnifying mirrors are placed on the top of shelves or drawers which are next to a window according to East Sussex Fire and Rescue Service.

While fire caused by everyday objects may seem like one of the more unusual cases, in principle it is the same as focusing the sun’s rays with a magnifying glass and everyday objects can be a fire hazard, that set light to things like curtains in the home.

Keep your windowsills clear to protect your home and its contents from fire damage.

Reflected light triggering fires are not rare and may have disastrous consequences. Every business and home owner should have a smoke alarm fitted on each floor of their property, to detect smoke early so that serious fires can be prevented. It is also advisable to keep doors closed to contain any fire that may catch you unaware.

CPL t/a Rainbow International have attended fires which were started by a magnifying glass. If you raise the alarm quickly, a serious fire can be avoided.

One such fire occurred during one summer, when a lady was in her garden in Bognor Regis in West Sussex, when a glass ornament caught fire in a living room window. Fire fighters said the ornament concentrated the sun’s rays just as a magnifying glass would. The fire spread so quickly, it gutted the property so the occupants had to move out while fire restoration work was done.

If you have a property that is damaged by fire or smoke, call CPL t/a Rainbow International’s 24 hour number. We offer an out of hours service for any emergencies. Our team will inspect and record the damage for your insurers, store, refurbish and restore furniture and fittings, remove any fire hazards and the smell of smoke, cleaning away any trace of fire damage.