Battery powered parking sensor explodes

Background

In May 2012, a worker sustained burns and scratches to his legs and face when a pneumatic jackhammer he was using drilled through a parking sensor buried in a car park bay causing it to explode.

The hole the sensor was inserted into did not incorporate a warning cover to alert anyone who may need to dig in the area of the sensor’s location.

Underground sensors are increasingly used by councils and private car park owners to help with traffic control in car parks. These devices are typically powered by a long-life lithium battery which, if damaged by digging, can explode with some force and potentially cause serious eye and burn injuries.

The sensor units are approximately 9" long by 1.5" diameter and are buried just below the parking bay surface.

Control measures

If a lithium battery is short-circuited there is a risk of explosion. To help avoid underground parking sensors from exploding the following actions should be taken by the owner and/or manager of car parks where these sensors are installed:

• ensure the location of each sensor buried beneath the car parking surface is clearly identified to people undertaking work which may disturb the sensors
• fit each sensor location with a covering disc or plug that is flush with the road surface. The cover should be embossed or otherwise permanently marked with a warning identifying the presence of a parking sensor immediately below

People engaged to undertake work in car parks should also ensure that they provide appropriate information, instruction, training and supervision to employees, contractors or subcontractors working where lithium battery sensors are installed and who may be involved in digging up the car parking surface.

This information, instruction and training should deal with the locations of the sensors, the risks associated with the sensor battery exploding if the sensor case is damaged by jack hammering or other digging activities, and the required safety measures. It should also include information on the purpose of the covers and the importance of ensuring the covers are refitted after any digging activity.