Bar codes help collectors monitor the way people handle their waste

The codes have been introduced to black and green wheelie-bins in parts of the city, to allow the bins to be traced to their owners.

The council has said it will help educate the public and allow it to meet government recycling targets.

Friends of the Earth welcomed the scheme, but some residents raised concerns over "Big Brother".

I like the whole idea of recycling but I'm not sure about bar coding Resident Karen Marsh

On the streets of Creigiau, on the outskirts of the city, the leafy driveways were lined with wheelie bins - some black, some green, but all marked with an identifying bar code.

The code will be read by computers carried by refuse collectors who will measure whether people are creating too much rubbish.

Councils in Wales have been instructed by the Welsh Assembly Government to recycle 40% of waste by 2010.

Green and black bins are used in thousands of Cardiff homes

Councillor Elgan Morgan, Cardiff executive member for the environment, said the bar codes would help teach residents how to use the new two-bin system.

"It is a health and safety management tool which will allow the council to address issues more easily when they arise," he said.

But a council spokesman said the scheme could result in penalties if people put out too much waste.

"If they are putting out too many black bags we can fine them," he said.

"Persistent offending can result in a fixed penalty notice."

The fines could be raised if the Clean Neighbourhood Act, which is not yet law in Wales, is adopted by the Welsh assembly.

'A bit harsh'

Shoppers in Creigiau on Wednesday supported measures to increase recycling, but some said fines were going too far.

Caroline Holly said: "I think it's good, but it sounds a bit like Big Brother, doesn't it?"

Data from the bar codes will monitor damaged or overloaded bins

Karen Marsh did not like the idea of being fined: "That's a bit harsh," she said. "I like the whole idea of recycling but I'm not sure about bar coding".

Sheila Hunt said: "Personally it doesn't worry me, but I think there's a touch of the Big Brother coming in here again".

Friends of the Earth gave it a cautious welcome and said the threat of fines could be useful, but believed people should be given the chance to understand a new system first.

"People will feel they are being policed, before they are being serviced," said Julian Rosser, director of Friends of the Earth Cymru. "It's important that a good roadside scheme be in place first."