Four of Hong Kong’s 15 restaurant chains told diners they could not use their own takeaway containers, the consumer watchdog found, as it asked catering companies to contribute to the government’s waste reduction target .

Consumer Council staff posing as customers made 45 visits to 15 popular restaurant chains during weekday lunchtimes in August and September, the watchdog said on Friday.

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

Staff visited three branches of each chain, and those that 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 community relations committee, said only 30 percent of staff whose applications were rejected were satisfied with how the interaction was handled.

“Staff at one restaurant stated that they do not accept self-brought containers in a slightly impatient tone and did not explain when the perpetrators asked why,” he said, referring to Cafe de Coral.