That's the view of a Deakin University academic who believes the State Government's four-week plastic bag 10-cent levy trial is increasing stress levels.

Managing and marketing lecturer Don Swanson said dealing with disgruntled customers reluctant to pay the bag levy combined with the physical demand of packing reusable bags posed health and safety issues for checkout staff.

"I think the trial is important and as an environmentalist I am keen to see the reduction of plastic bags, but we have to consider the human resource as well as the natural resource," Mr Swanson said.

"Back problems are very real and the possibility of stress increasing needs to be addressed because we need to be easing stress at work at every possible opportunity."

The State Government and retail industry trial began last week and will continue until September 14.

The trial's aim is to investigate the impact a 10-cent levy has on plastic bag use.

Mr Swanson said he was concerned customers were not made aware of guidelines regarding the size, hygiene standards and method of filling reusable bags which could result in customer "bag rage".