Asda distribution workers are at risk of injury due to the higher pick-rate targets introduced by voice-pick technology, according to a report commissioned by the GMB union.

The study, carried out by ergonomics consultancy JRP Ergonomics, was completed more than a year ago. Since then, Asda and union bosses have been trying to agree on what action needs to be taken.

The Grocer has now seen a leaked copy of the report, which was compiled after a study carried out at Asda's Wigan depot. It was commissioned following union concerns that the introduction of voice-pick technology would cause injuries due to strain from increased pick targets.

It was not the 1,200 case/eight-hour shift pick-rate set by Asda - equivalent to 150 cases per hour - per se that was contributing to the risk, said the report. It was the fact that picking only took place over six hours and fifty minutes of each shift, meaning workers' average pick rates were effectively 176 cases per hour.

The observed picking activities at Wigan therefore appeared to pose a "significant risk for the majority of healthy workers", claimed researchers.

The report, which the GMB warned could have far-reaching consequences for the distribution sector, also called for changes to warehouse practices. It suggested introducing job rotation every two hours, picking of only one pallet at a time, rather than two, and the reduction of maximum pallet height from 1,700mm to 1,500mm.

In tandem with discussions between Asda and the GMB, the Health and Safety Executive is working on new safety guidelines for distribution workers. It is understood the HSE may refer to the JRP report before publishing its own findings on pick rates and working conditions in 2009.

Meanwhile, negotiations betwen the GMB and Asda to resolve 600 grievances over contract changes, which were due to end last month, have been extended into the New Year. The disputes arose last August when Asda changed 18,000 store workers' contracts to offer a higher hourly wage, but scrapped rights to double-time and time-and-a-half pay, and days off in lieu of bank holidays.