The south Cumbrian council says it is phasing out 55-litre boxes, which are used for paper, card and glass, and will supply 44-litre containers when households request replacements for damaged or broken boxes.
The local authority has said the switch to lighter bins is designed to limit the risk of back injuries to its kerbside teams who operate an alternate weekly collection.
South Lakeland DC expanded collections in 2018, revising its rounds, introducing new vehicles, and supplying new bags to 53,000 properties. Households that recycled glass, cans and paper could then add plastic and cardboard to the kerbside service.
Managers looked at a Health and Safety Executive (HSE) study from 2006, which considered manual handling in domestic recycling schemes where households are provided with boxes to put out recyclable materials, before making the switch.
The HSE research found that operating kerbside box collection schemes, which require the bin collectors to lift and carry a box and sometimes sort its contents at the vehicle, has "potentially increased the risk of manual handling injuries".
The report recommends that, where boxes are used, councils should reduce the capacity to at most 40 litres to provide a method of weigh control.
Councillor Dyan Jones, portfolio holder for the environment, said: "The latest council performance figures for October showed that the council was performing well against its recycling targets and the phased introduction of 44-litre blue recycling boxes will not affect that performance."