The consumer watchdog found that four in 15 chain restaurants in Hong Kong have told diners they cannot use their own containers for takeaways and called on caterers to contribute to the government’s waste reduction target.

Consumer Council staff posed as customers and made 45 visits to 15 popular chain restaurants during weekday lunch hours in August and September, the watchdog said on Friday.

Workers tried to use the containers they brought for takeaway food, but were successful only 31 times.

Staff visited three branches of each chain, and those who rejected the requests were Cafe de Coral, Saizeriya, Super Super Congee & Noodle and Yoshinoya Hong Kong.

Victor Lam Hoi-cheung, chairman of the council’s publicity and public relations committee, said only 30 percent of staff whose requests were rejected were satisfied with how the interaction was handled.

“The staff at one restaurant stated in a somewhat impatient tone that they did not accept the containers they brought themselves, and did not explain when the experimenters asked why,” he said, referring to Cafe de Coral.