Some of those taking part in a trial scheme for Hong Kong's planned pay-as-you-throw system are having difficulties, the government conceded on Thursday, as it was warned of "chaos" if the citywide plan goes ahead as scheduled in August.

Fourteen premises, including restaurants and care homes, have joined the trial, with the implementation date for everyone else in the city pushed back to August 1.

In Legco, Environment Secretary Tse Chin-wan said some of the cleaners and managers involved in the trial have complained of increased workloads and higher operating costs.

Tse said officials will soon carry out a survey of participants to gather more feedback on how they are finding the scheme, which requires rubbish to be disposed of in designated bags.

"We have already heard the views and concerns about the charging scheme. As a responsible government, as a people-oriented government, we need to understand the impact on different quarters of the community, as well as different problems that may arise in the scheme," he said.

During a debate, a number of lawmakers expressed reservations about the scheme, including the DAB's Starry Lee who warned there could be a lot of chaos and complaints from businesses if there is a citywide implementation from August.

Lee added that recent discussions on the scheme have led to increased awareness regarding waste separation and recycling, and the government could consider whether these things should be made mandatory.

Another councillor, Gary Zhang, said the administration may want to make adjustments to the scheme, but they should not forget why it is planned, or give up on the national policy of sustainable development.