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BT denies fibre broadband lasers can blind your children

BT says there’s no risk that its ultrafast fibre-optic broadband could blind a child who accidentally unplugs their modem.

Recombu Digital reader Christopher Woods asked if there could be a health risk if a child (or foolish adult) unplugged a fibre to the premises (FTTP) broadband cable and looked directly into it.

FTTP can reach speeds of more than a Gigabit, using laser pulses sent via a fibre-optic cable straight into your home, but they can vary from harmless low-power light to potentially dangerous beams.

BT Openreach said the lasers in its domestic FTTP systems (pictured below) are all low-power ‘Class 1’ devices in the lowest-risk category, which cannot harm the eye, and have built-in safety features.

BT Openreach FTTP ONT modem by Mr ATM/Flickr

BT added: “In the event of any user pulling the connector out of the fibre equipment in the home (known as an ONT) and looking closely at the light output end of the connector, then the light that would reach their eye will have traversed the network and will be at an even lower level than the Class 1 level that was sent. There is no chance of this causing eye damage.

“If a user managed to look closely up the light socket in the customer equipment (ONT), they are also safe and cannot come to harm.

“Not only is the light level low, conforming to industry Class 1, but the laser device will automatically shut down which is its programmed behaviour when it is not receiving any signals from the exchange end.

“The Class 1 specification relates to the maximum power that the device can put out under fault conditions and relates to the maximum effect it can have on the eyes and tissue.

Therefore these devices are intrinsically safe, even if major faults develop within the equipment, which is itself unlikely.”

BT has an internal standard – ISIS SFY/CSP/B039 – for all laser equipment from its national backbone networks to domestic lasers.

BT’s FTTP broadband is only available through 15 exchanges across the UK, but other providers such as Hyperoptic are fitting ultrafast FTTP services in several towns and cities around the UK. Obviously, BT’s statement only applies to its own services.

Virgin Media’s fibre broadband is actually an advanced form of fibre-to-the-cabinet (FTTC), which uses fibre-optic cables only as far as a nearby cabinet, and completes the journey using a coaxial cable which can carry very high data rates over short distances.

Image: Mr ATM/Flickr